Temnospondyl finds rank among the most abundant remains throughout the continental Triassic deposits. In the Central European Basin, they are especially numerous, with diversity peaks in the Röt, Erfurt and Stuttgart formations. Currently, a total of 20 genera and 29 species of temnospondyls is recognized in the German Triassic. The Early Triassic temnospondyl assemblages encompass the five genera Trematosaurus, Sclerothorax, Odenwaldia, Meyerosuchus, and Parotosuchus. Trematosaurus is present with the coeval species T. brauni and T. thuringiensis whereas Parotosuchus is known with the three species P. helgolandicus, P. nasutus and the newly erected P. decumanticus n. sp. from the Black Forest from different time slices. Sclerothorax is known from two widely divergent horizons in the early and late Olenekian of Hesse, whereas Odenwaldia and fragmentarily known Meyerosuchus are from localities in the Black Forest and almost coeval horizons dating late Olenekian. In the Middle Triassic the ten temnospondyl genera Plagiosuchus, Plagiosternum, Megalophthalma, Gerrothorax, Trematolestes, Callistomordax, Eocyclotosaurus, Stenotosaurus, Tatrasuchus and Mastodonsaurus (two species) are recognized. Kupferzellia Schoch, 1997 is a junior synonym of Tatrasuchus Maryanska & Shishkin, 1996. The coeval early Anisian Eocyclotosaurus and Stenotosaurus are morphologically similar but distinct in palate features, whereas the other taxa all fall within the late Ladinian interval of the Erfurt Formation. The lost type and only specimen of “Cyclotosaurus” papilio was most consistent with the genus Eocyclotosaurus. The Late Triassic rock sequence has yielded the six valid genera Plagiosaurus, Gerrothorax, hyperokynodon, Metoposaurus, Capitosaurus and Cyclotosaurus, the latter with the five species C. robustus, C. buechneri, C. ebrachensis, C. posthumus and C. hemprichi. In the Rhaetian, reworked remains may only be referred to indeterminate plagiosaurines and capitosauroids.
1. Introduction
In 1824, Jaeger reported finds of giant teeth and an occipital region of a skull from the alum mine at Gaildorf in northern Württemberg. In a follow-up publication, he named and described these specimens for which he coined the names Mastodonsaurus and Salamandroides giganteus, highlighting his belief that the remains stemmed from giant relatives of lissamphibians, in modern parlance (Jaeger 1828). The subsequent discovery of more substantial material from that site soon revealed most aspects of the anatomy of Mastodonsaurus giganteus, as the taxon was eventually called: a massive triangular-shaped skull with a snout penetrated by huge symphyseal tusks, an elongate body with heavy cylindrical vertebral centra and broadened ribs, and surprisingly feeble limbs (Meyer & Plieninger 1844).
In the following decades, more material, especially similar tusks and bone fragments with the characteristic ornament appeared from different geological formations and in various countries (MüNster 1936; Owen 1841; Huxley 1859; Cope 1868). Meyer (1842) coined the name Labyrinthodontes (modified by Owen in 1860 as Labyrinthodontia) for this group, after he had recognized the maize-like plicidentine structure of the tusks in Mastodonsaurus. In his report of Cyclotosaurus robustus from the Schilfsandstein of Stuttgart, Quenstedt (1850) emphasized similarities to extant anurans in the ear structure, contrasting with Meyer's (1842) hypothesis of a reptilian nature of the newly discovered group. Ever since Zittel (1888), the classical taxa from the German Triassic were referred to the Stereospondyli as a subgroup of the more inclusive Temnospondyli (Schoch & Milner 2000). The taxon Labyrinthodontia was successively extended to embrace the majority of early tetrapods (Lydekker 1890; Romer 1947), but with the advent of phylogenetic systematics it became obliterated as obsolete (Milner 1990).
Temnospondyls have received growing attention during the last decades because they form by far the most disparate and speciose clade of early tetrapods (Ruta et al. 2009; Schoch, 2013). They also have a substantial ontogenetic record that is interesting for evolutionary biologists (FrÖBisch et al. 2010) and based on a range of synapomorphies they are considered as the putative stem-group of extant lissamphibians by many authors (summarized by Anderson 2008; but see Marjanovic & Laurin 2013 for an alternative view). The Triassic stereospondyls are further of interest because they evolved various new ecomorphotypes that parallel modern caimans, gharials, and even flatfishes (Warren 2000; Fortuny et al. 2011).
The temnospondyl material from the Central European Basin (Fig. 1) includes many classic genera (Mastodonsaurus, Capitosaurus, Cyclotosaurus, Trematosaurus and Metoposaurus) that are still valid and have been reported from other regions as well (Schoch & Milner 2000; Damiani 2001). In the 20th and early 21st centuries, much additional material has been collected from quarries and on construction sites (Fraas 1889, 1896, 1913; Huene 1922; Swinton 1927; Schmidt 1931; Jaekel 1922; Wepfer 1923a, b; Kuhn 1932, 1939, 1940, 1942; V. Lilienstern 1935; Jux & Pflug 1958; Hagdorn 1980; Wild 1981; Kamphausen 1989; Werneburg 1990, 1993; Schoch & Milner 2004; Schoch, et al. 2007; Schoch, 2011; Witzmann et al. 2016). Distinct taxa were recognized from old samples at Gaildorf (Plagiosuchus: Huene 1922) and Heilbronn (hyperokynodon: Hellrung 1987). New taxa were reported from the Middle Buntsandstein (Sclerothorax: v. Huene 1932, Odenwaldia: Morales & Kamphausen 1984), the Röt Formation (Eocyclotosaurus: Ortlam 1970), the Erfurt Formation (Kupferzellia: Schoch, 1997, Trematolestes: Schoch, 2006, Callistomordax: Schoch, 2008, Megalophthalma: Schoch, et al. 2014) and the Stuttgart Formation (Cyclotosaurus buechneri: Witzmann et al. 2016).
In the last decades, excavations and focused preparation have yielded much material of temnospondyls particularly in southern Germany. Based on many finds that have recently been donated by private collectors to public collections, updates of the stratigraphic and geographic range are possible for many taxa. At the same time, discoveries especially in other European countries (Maryanska & Shishkin 1996; Sulej & Majer 2005; Sulej 2007; Brusatte et al. 2015; Marzola et al. 2017) have highlighted the need to revise some of the historic German taxa.
The objectives of the present study are (1) to provide a synopsis on all temnospondyl specimens from the Triassic of Germany that are currently housed in public collections, (2) give an overview of their stratigraphic and geographic ranges, (3) update the diagnoses in taxa for which new specimens or other evidence has emerged, and (4) update the taxonomy in cases where new evidence is available. This survey intends to provide a platform for the further analysis of tetrapod assemblages and their change through the Triassic.
Institutional abbreviations: SNSB-BSPG, Bayerische Staatssammlung für Paläontologie und Geologie, Munich, Germany. FSD, Fürstenbergische Sammlung, Donaueschingen, Germany. GG, Geologisches Institut Greifswald, Germany. GIF, Geologisches Institut Freiburg im Breisgau, Germany. GIH, Institut für Geowissenschaften, Universität Heidelberg, Germany. GIJ, Geologisches Institut Jena, Germany. GIUK, Geologisches Institut, Universität zu Köln, Cologne, Germany. GIW, Geologisches Institut, Universität Würzburg, Germany. GMG, Geowissenschaftliches Museum Göttingen, Germany. GPIM, Institut für Geowissenschaften, Universität Mainz, Germany. GPIT, Geologisch-Paläontologisches Institut, University of Tübingen, Germany. GPS.MLU, Geologisch-paläontologische Sammlung, Martin-Luther-Universität Halle an der Saale, Germany. HLD, Hessisches Landesmuseum, Darmstadt, Germany. HMH, Heimatmuseum Halberstadt, Germany. KRE, Krupp Collection Essen, Germany. MB, Museum für Naturkunde, Berlin, Germany. MHI, Muschelkalkmuseum Hagdorn Ingelfingen, Germany. MNM, Museum für Naturkunde Magdeburg, Germany. MNVD, Museum für Natur- und Vorgeschichte, Dessau, Germany. MSB, Museum Schloss Bernburg, Germany. Namu, Naturkundemuseum Bielefeld, Germany. NHMUK, The Natural History Museum, London, UK. NMK, Naturhistorisches Museum, Kassel, Germany. NHMS, Naturhistorisches Museum, Schleusingen, Germany. SMNK, Staatliches Museum für Naturkunde, Karlsruhe, Germany. SMNS, Staatliches Museum für Naturkunde, Stuttgart, Germany. STIPB, Steinmann Institute, University of Bonn, Germany. UMO-BSP-BT, Urwelt-Museum Oberfranken, Bayreuth, Germany. UMZC, University of Cambridge Museum of Zoology, Cambridge, UK.
Anatomical abbreviations: a, angular, apv, anterior palatal vacuity, bc, braincase, ch, choana, ec, ectopterygoid, eo, exoccipital, et, eustachian tube, f, frontal, fm, foramen magnum, ipv, interpterygoid vacuity, ju, jugal, la, lacrimal, m, maxilla, n, nasal, na, naris, ot, otic capsule, p, parietal, pf, postfrontal, pin, pineal foramen, pl, palatine, pm, premaxilla, pmf, premaxilla foramen, po, postorbital, pp, postparietal, pq, paraquadrate foramen, prf, prefrontal, ps, parasphenoid, psp, postsplenial, pt, pterygoid, q, quadrate, qj, quadratojugal, sa, surangular, se, sphenethmoid, sq, squamosal, sp, splenial, st, supratemporal, sta, stapes, stw, subtemporal window, ta, tabular, vo, vomer.
3. Systematic Palaeontology
Temnospondyli Zittel, 1888
Eryopiformes Schoch, 2013
Stereospondylomorpha Yates & Warren, 2000
Stereospondyli Zittel, 1888
Capitosauroidea Watson, 1919
Sclerothoracidae Huene, 1932
Sclerothorax Huene, 1932
Type species: Sclerothorax hypselonotus Huene, 1932.
Sclerothorax hypselonotus Huene, 1932
Figs. 2, 3A
Holotype: HLD–V 607 (Fig. 1B). Skull length 17 cm, total length of preserved parts of specimen 48 cm.
Type locality: Sandstone quarry near Queck in the Fulda Valley (r: 35/41.525; h: 56/20.300).
Type horizon: Eichsfeld Sandstein, lower part of Middle Buntsandstein section (Volpriehausen Folge, S4), Olenekian, Early Triassic (Schoch et al. 2007).
Referred material: Five additional specimens were reported from two widely divergent stratigraphic levels in the Middle Buntsandstein of northern Hesse (Schoch et al. 2007).
1) From the type locality. HLD–V 608 and GPIM–N 2045 from the type locality at Queck.
2) Heimarshausen near Naumburg (from top of Hardegsen Sandstein, S 6). NMK–S 117 (palate and anterior axial skeleton). NMK–S 118 (two skulls, 15 and 18 cm).
Stratigraphic range: Lower (S4) to upper part (S6) of Middle Buntsandstein section, spanning a large part of the Olenekian.
Diagnosis: Autapomorphies: (1) Skull very wide with quadrangular outline, anterior third of skull as wide as cheek, with convex lateral projections. (2) Margin of snout heavily ornamented by gross ridges that form high tubercles. (3) Medial skull roofing elements laterally extended, with frontals and parietals being as wide as long and postparietals being two times wider than long. (4) Neural spines differing in height, converging towards a highest point well anterior to the mid-level of the trunk. (5) Interclavicle extensive, longer than the skull and nearly as wide, thereby proportionately larger than in any other temnospondyls that raises well from the lateral face of the scapulocoracoid.
Fig. 2.
Sclerothorax hypselonotus Huene, 1932. A – Skull reconstruction in dorsal view. B – Palate reconstruction in ventral view. C – Two skulls exposed in dorsal view (NMK–S 118). D – Skeletal reconstruction in lateral view (modified from Schoch, et al. 2007).
Fig. 3.
Capitosauroid skulls (dorsal view). A – Sclerothorax hypselonotus Huene, 1932 (SMNS 91340). B – Odenwaldia heidelbergensis Morales & Kamphausen, 1984. C – Parotosuchus helgolandicus (SCHROEDER, 1913). D – Parotosuchus nasutus (Meyer, 1858). Modified from Schoch, (2008a, 2018).
Odenwaldia Morales & Kamphausen, 1984
Type species: Odenwaldia heidelbergensis Morales & Kamphausen, 1984
Odenwaldia heidelbergensis Morales & Kamphausen, 1984
Figs. 3B, 4
Holotype: GPIH SMO 1, a natural mould of the skull, preserving most of the skull roof, the marginal dentition, parts of the braincase, and traces of the palate.
Type locality: Former construction pit, Waldkatzenbach am Katzenbuckel, Odenwald mountain range (Baden-Württemberg, Germany).
Type horizon: Upper Conglomerate Horizon (Oberes Konglomerat), Solling Formation (S6), top of the Middle Buntsandstein section (Simon 1961), late Olenekian, Early Triassic.
Referred specimen: SMF A 300, a natural mould of the anterior palate from Hallwangen near Freudenstadt (Edinger 1937; Schoch 2011).
Diagnosis: Autapomorphies: (1) Median series of skull roof (frontal, parietal) wide combined with small orbits; (2) preorbital region slender, with lacrimal narrower than prefrontal. Homoplasy: anterior palatal fenestra paired.
References: Simon (1961), Kamphausen & Keller (1986), Morales & Kamphausen (1984), Kamphausen (1989), Schoch (2008a, 2011).
Meyerosuchus Ochev, 1966
(Capitosaurus partim Meyer, 1855)
Type species: Meyerosuchus fuerstenberganus (Meyer, 1855)
Meyerosuchus fuerstenberganus (Meyer, 1855)
Fig. 5D, 6B
Synonym: Capitosaurus fuerstenberganus v. Meyer, 1855.
Holotype: FSD-1 (cast: SMNS 469), a natural mould of the anterior palate.
Type locality: Herzogenweiler near Freudenstadt, Black Forest (Baden-Württemberg, Germany) (Meyer 1855).
Type horizon: Above first Violet Horizon (VH 1c), Hardegsen Formation (S6), top of the regional Middle Buntsandstein, late Olenekian, Early Triassic.
Referred specimen: SMNS 51651, upper Middle Buntsandstein (Hardegsen Formation) from Calw (Hafnerweg), northern Black Forest. A left anterior palate, preserving part of the anterior palatal vacuity, transvomerine tooth row, and vomerine fangs.
Diagnosis: Autapomorphy: Cultriform process with anterior broad ridge merging into a sharp crest posteriorly. Homoplastic or plesiomorphic characters: Snout outline narrow, transvomerine tooth count low, choana elongate and oval, but not slit-like.
References: Meyer (1855), Ochev (1966), Kamphausen (1989), Schoch (2011).
Parotosuchidae Schoch & Werneburg, 1998
Parotosuchus Ochev & Shishkin, 1968 (in Kalandadse et al., 1968)
(Capitosaurus Münster, 1836 partim; Parotosaurus Jaekel, 1922; Archotosaurus Paton, 1976)
Type species: Parotosuchus nasutus (Meyer, 1858)
Parotosuchus nasutus (Meyer, 1858)
Figs. 5A–C, 6C
Synonyms: Capitosaurus nasutus Meyer, 1858; Capitosaurus fronto Meyer, 1858; Parotosaurus nasutus (Meyer, 1858) Jaekel, 1922; Mastodonsaurus weigelti Wagner, 1935.
Neotype: MB.Am.448, a nearly complete skull roof (26.1 cm) preserved as natural mould (Schoch 2018).
Type locality: Merkel′s Quarry, at Teichweg near Fuhne creek, SE of Bernburg an der Saale, Saxony-Anhalt, Germany.
Type horizon: Bausandstein, white to grey sandstone unit below Thüringer Chirotheriensandstein, lower Solling Formation, late Olenekian, Early Triassic.
Referred material: From the type locality and horizon. GG 22.163 (tiny skull, 14 cm). GG 22.186 (large palate, ca. 44 cm). GIH BS1 (complete skull, only dorsal side exposed, 30.5 cm, type specimen of Mastodonsaurus weigelti). GIH BS2 (skull, 29 cm), GIH BS3 (palate, 31 cm). GIH BS4 (partial skull, type of Capitosaurus fronto). GPS.MLU 2016.01 (skull with mandibles). GPS.MLU 2016.07 (mandible). GPS.MLU 2016.16 (skull). GPS.MLU 2016.18 (anterior palate). GPS.MLU 2016.23 (left skull portion). GPS.MLU 2016.28 (anterior palate). GPS. MLU 2016.30 (skull fragment). GPS.MLU 2016.31 (skull fragment). GPS.MLU 2016.35 (right clavicle, Fig. 9A). GPS.MLU 2016.36 (good palate, Fig. 8B). GPS.MLU 2016.40 (small skull, 16 cm, Fig. 5A, B). GPS.MLU 2018.01 (skull with good palate and occiput, Fig. 7A–D, 8A). GPS.MLU 2018.02 (large skull). GPS.MLU 2018.03 (large anterior palate). GPS.MLU 2018.04 (posterior skull portion). GPS.MLU 2018.05 (right part of palate and left part of roof). MB.Am.445 (cast, partial skull roof). MB.Am 447 (partial snout). MB.Am 451 (anterior palate). MNVD 11153 (anterior palate). MNVD 11166 (skull). MNVD 11172 (palate). MNVD 11173 (orbital portion of skull). MNVD 18434 (anterior palate). MNVD 18435 (occipital portion). MSB G395 (skull roof, 18.3 cm). MSB G403 (snout), G424 (preorbital region). SMNS 5776 (skull, 25.5 cm). SMNS 5957 (skull, 28 cm). SMNS 12799 (small dentary). SMNS 81697 (cast, left half of skull, 16.8 cm).
Diagnosis: Autapomorphies: (1) quadrate condyles well posterior to occipital ones, (2) supratemporal in adults anteriorly twice as wide as posteriorly, (3) palatine very slender, distance between choana and interpterygoid vacuity much shorter than choana, (4) interpterygoid vacuity twice the length of vomer plus premaxilla.
References: Meyer (1858), Welles & Cosgriff (1965), Schoch (2018).
Fig. 4.
Odenwaldia heidelbergensis Morales & Kamphausen, 1984 (GPIH-SMO1). Modified from Schoch, (2008). A – Anterior palate. B – Braincase and occiput in dorsal view. C – Palate and braincase. D – Reconstruction in dorsal view.
Fig. 5.
Capitosauroid skulls. A – Parotosuchus nasutus (GPS.MLU 2016.01). B – P. nasutus, right part of palate and left part of roof (GPS.MLU 2018.05). C – P. nasutus, palate (GPS.MLU.2018.01). D – Meyerosuchus fuerstenberganus (Meyer, 1855) (FSD, uncatalogued). E – Parotosuchus decumanticus n. sp. (SMNS 91340). F – P. nasutus, cast of holotype (MB.Am 448).
Fig. 6.
Capitosauroid skulls (palate in ventral view). A – Parotosuchus decumanticus n. sp. (SMNS 91340). B – Meyerosuchus fuerstenberganus (Meyer, 1855) (SNM 469). C – Parotosuchus nasutus (Meyer, 1858) (restored from GPS.MLU.2018.01). D – Parotosuchus helgolandicus (Schroeder, 1913) (restored from MB.Am.441).
Parotosuchus helgolandicus (Schroeder, 1913)
Fig. 3C
Holotype: MB.Am.441, an almost complete skull (48 cm).
Type locality: Cliff at isle of Heligoland, Schleswig Holstein, Germany.
Type horizon: Upper Volpriehausen Formation, early Olenekian, Early Triassic.
Diagnosis: Autapomorphies: (1) Orbits tiny with raised margins, (2) tabular horns large and posteriorly tapering, (3) Occipital condyles level with quadrate ones.
References: Schroeder (1913), Schoch & Milner (2000), Lautenschlager et al. (2016), Witzmann & Werneburg (2017).
Parotosuchus decumanticus n. sp.
Fig. 6A
Etymology: After Agri Decumantes, an ancient Roman name for southwestern Germany, referring to the Black Forest and adjacent regions.
Holotype: SMNS 91340, a right-central anterior palate (estimated skull length 25 cm).
Type locality: Road between Aichelberg and Castle Fautsburg, Black Forest, Baden-Württemberg, Germany.
Type horizon: Bausandstein, basal Volpriehausen Formation, early Olenekian, Early Triassic.
Diagnosis: Autapomorphies: (1) Choana elongate and slender, but not slit-like. (2) tooth row posterior to anterior palatal vacuity consisting of loosely set, not strictly transversely aligned teeth. (3) Vomerine tusks well posterior to anterior palatal vacuity.
References: Schoch (2011).
Cyclotosauridae Shishkin, 1964
Stenotosaurinae Kamphausen, 1989
Stenotosaurus Romer, 1947
Type species: Stenotosaurus semiclausus (Swinton, 1927)
Stenotosaurus semiclausus (Swinton, 1927)
Fig. 7B, F
Synonyms: Capitosaurus semiclausus Swinton, 1927; Parotosaurus semiclausus Watson, 1962; Stenotosaurus gracilis Kamphausen, 1983.
Holotype: NHMUK R.5276, palate and NHMUK R.5277, external mould of skull roof.
Type locality: Villingen, southern Black Forest (Baden-Württemberg, Germany).
Type horizon: VH5, Obere Röttone, Upper Buntsandstein, early Anisian, Middle Triassic.
Referred specimen: SMNS 97120 (partial skull) from Untere Röttone of Kronach, Bavaria (Kamphausen 1983)
Diagnosis: Autapomorphies: (1) Jugal excluded from orbit margin by narrow contact between prefrontal and postorbital; (2) ornament consisting of more widely spaced ridges; (3) naris broad oval and only half as long as orbit. Homoplasies: (a) anterior palatal fenestra paired.
References: Swinton (1927), Paton (1974), Kamphausen (1983, 1989).
Heylerosaurinae Shishkin, 1980
Eocyclotosaurus Ortlam, 1970
(heylerosaurus Shishkin, 1980)
Type species: Eocyclotosaurus woschmidti Ortlam, 1970.
Diagnosis: Autapomorphies: (1) Prefrontal and postfrontal in broad contact, excluding frontal from orbit; (2) orbit small (orbit length: skull length=0.7–0.9); anterior palatal vacuity paired, forming elongate oval openings.
Eocyclotosaurus woschmidti Ortlam, 1970
Fig. 7A, D
Holotype: SMNS 51562, complete skull (32 cm).
Type locality: Kössig quarry, Rotfelden, Black Forest (Baden-Württemberg, Germany).
Type horizon: Basissandstein (basal sandstone member), Untere Röttone, Upper Buntsandstein (Röt), early Anisian, Middle Triassic.
Diagnosis: Autapomorphies: (1) prefrontal and postorbital with unclear but faint contact at best; (2) naris very slender.
References: Ortlam (1970), Kamphausen & Morales (1981); Kamphausen (1989); Schoch & Milner (2000).
Comment: Schoch & Milner (2000) referred SMNS 51562 to E. lehmani Heyler, 1969 because of the close similarity of this specimen to the holotype at the MNHM in suture topology and ornamentation. However, provided that the above-listed features of SMNS 51562 hold as autapomorphies, the two finds may represent distinct taxa, also considering that E. lehmani is from a stratigraphically younger horizon (Durand & Hagdorn 2020).
Eocyclotosaurus papilio Wepfer, 1923
Fig. 7E
Holotype: IGF unnumbered, posterior part of skull including orbits. This specimen was lost during World War II.
Type locality: West of Heckfeld, northern Baden-Württemberg, Germany.
Type horizon: Yellow dolomite bed, Terebratelschichten below Glaukonitkalk, Upper Muschelkalk, Early Ladinian, Middle Triassic.
Diagnosis: Autapomorphies: (1) interorbital distance three times the orbit width; (2) large overarching posterolateral wing formed by squamosal and tabular.
References: Wepfer (1923b) described and figured the specimen thoroughly which permits detailed comparisons.
Comment: The preserved portion is more consistent with Eocyclotosaurus than any other taxon in the size and distance of the orbits and the distance between orbit and otic fenestra.
Tatrasuchinae Maryanska & Shishkin, 1996
Tatrasuchus Maryanska & Shishkin, 1996
(Kupferzellia Schoch, 1997)
Type species: Tatrasuchus kulczyckii Maryanska & Shishkin, 1996.
Diagnosis: Autapomorphies: (1) broad-parabolic skull with postorbital portion 0.4 times the preorbital one; (2) long axis of naris oblique at 45° to sagittal axis; (3) tabular and squamosal in contact but not firmly sutured.
Tatrasuchus wildi (Schoch, 1997)
Figs. 8A, 9
Synonym: Kupferzellia wildi Schoch, 1997.
Holotype: SMNS 54670, a skull with open midline suture and both hemimandibles (27 cm).
Type locality: Exposure during road construction in spring 1977, SE of Kupferzell-Bauersbach (Baden-Württemberg, Germany).
Type horizon: Top of Untere Graue Mergel, yellow marlstones K4, Erfurt Formation, Ladinian (Schoch et al. 2022).
Referred material: The species is known from at least seven localities and nine horizons in Baden-Württemberg and Thuringia. The specimens fall in a size range of 16–37 cm skull length.
1. Gaildorf, G2, Estherienschichten. SMNS 55908: imprint of partial skull roof, preserving a good portion of the snout (erroneously referred to Plagiosuchus by Huene 1922).
2. Kupferzell, K3, green siltstones. SMNS 80876 (parasphenoid). SMNS 80959 (postorbital). SMNS 80963 (pterygoid). SMNS 81070 (symphysis). SMNS 81561 (dentary). SMNS 80960 (tabular).
3. Kupferzell, K4, yellow marlstones. SMNS 54671–54674 (four partial skulls).
4. Vellberg, E5, brown siltstones. MHI-Ku 1993/1 (skull, 27.4 cm), MHI-Ku 1993/3 (skull with mandible, 21.6 cm), MHI-Ku 1993/6 (skull, 37 cm), and MHI-Ku 1993/4 (interclavicle, Schoch 2015, fig. 9.7d). SMNS 91708 (skull, disarticulated, ca. 25 cm). SMNS 97107 (skull, 24.8 cm). SMNS 97108 (partially disarticulated skull, approx. 25 cm).
5. Vellberg, E6, grey mudstones. MHI-Ku 1993/2 (half small skull, 16.5 cm). SMNS 91088 (clavicle). SMNS 91094 (clavicle). SMNS 91096 (clavicle). SMNS 91276 (pterygoid). SMNS 91277 (mandible). SMNS 91278 (tabular). SMNS 91612 (disarticulated skull). SMNS 91694 (interclavicle). SMNS SMNS 91704 (two condyles). SMNS 91705 (skull bones). 91805 (mandible). SMNS 91817 (12 skull bones). SMNS 91818 (skull bones). SMNS 91843 (dentary). SMNS 91853 (eight skull bones). SMNS 91914 (postglenoid region). SMNS 91980 (postglenoid region). SMNS 97107 (skull, 24.8 cm).
6. Wolpertshausen, top of Untere Graue Mergel. MHI (isolated skull bones), Hagdorn et al. (2015).
7. Michelbach an der Bilz, Leitenäcker excavation, Sandige Pflanzenschiefer. MHI and SMNS material (cranial bones).
8. Michelbach an der Bilz, Wilhelmsglück quarry, Lingula-Dolomite. MHI (impression of partial skull, ca. 25 cm).
9. Arnstadt-Nord, road construction site, Thuringia. NHMS-WT 3314 (symphysis).
Diagnosis: Autapomorphies (in contrast to T. kulczyckii): (1) nasal and alary process of maxilla broad; (2) vomer and choana short and wide; (3) pterygoid and basal plate of parasphenoid with marked ornament; (4) interclavicle with wide triangular ornamented area and without anterior “spoon”.
Cyclotosaurinae Shishkin, 1964
Capitosaurus Münster, 1836
Type species: Capitosaurus arenaceus Münster, 1836
Capitosaurus arenaceus Münster, 1836
Fig. 8B
Holotype: UMO-BSP-BT 14, a partial skull with preorbital and orbital regions and palate (ca. 25 cm).
Type locality: Benk (Weißdorf), Bavaria, Germany.
Type horizon: Benk Sandstone, Benk Formation (Grabfeld Formation), earliest Carnian, Upper Triassic.
Diagnosis: Autapomorphies: (1) Skull margin kinked with gently tapering anterior portion. (2) Interorbital distance greater than two times the orbit width. Plesiomorphic features: cultriform process lacks a ventral crest (contrasting Cyclotosaurus, see discussion in Schoch, 2008b).
Comment: As suggested by Jaekel (1922), the genus Capitosaurus is here restricted to the type species, and for reasons outlined in Schoch (2008a), all stratigraphically younger relatives are referred to Cyclotosaurus Fraas, 1889. The reasons of Welles & Cosgriff (1965) and Damiani (2001) to consider C. arenaceus undiagnostic have been discussed by Schoch (2008b). Based on the here listed autapomorphies, UMO-BSP-BT 14 is here considered diagnostic and the taxon as vaild.
References: Münster (1836), Broili (1915), Jaekel (1922), Kamphausen (1990), Damiani (2001), Schoch (2008a).
Fig. 7.
Cyclotosaurid skulls in dorsal view. A – Eocyclotosaurus woschmidti Ortlam, 1970 (SMNS 51516). B – Stenotosaurus semiclausus (Swinton, 1927) (NHMUK R5277). C – S. semiclausus (SMNS 97120). D–F: reconstructions. D – Eocyclotosaurus woschmidti. E – E. papilio Wepfer, 1923. F – S. semiclausus.
Fig. 8.
Cyclotosaurid skulls in dorsal view. A – Tatrasuchus wildi (Schoch,, 1997). B – Capitosaurus arenaceus Münster, 1836. C – Cyclotosaurus robustus (Meyer, 1844). D – C. buechneri Witzmann et al., 2016. E – C. ebrachensis Kuhn, 1932. F – C. mordax Fraas, 1913, holotype. G – C. posthumus Fraas, 1913. H – C. hemprichi Kuhn, 1942.
Fig. 9.
Tatrasuchus wildi (Schoch,, 1997). A – Skull roof of holotype (SMNS 54670). B – Palate (SMNS 97107). C – Skull and mandible (MHI Ku 1993/3). D – Interclavicle (MHI Ku 1993/4).
Cyclotosaurus Fraas, 1889
Type species: Cyclotosaurus robustus (Meyer & Plieninger, 1844).
Diagnosis: Autapomorphies: (1) broad-parabolic skull with postorbital portion 0.3–0.34 times the preorbital one; (2) choana broad oval or circular; (3) anterior palatal vacuity heart-shaped. A more variable feature is that the tip of the premaxilla may be perforated by symphyseal tusks (shared with Mastodonsaurus).
Cyclotosaurus robustus (Meyer & Plieninger, 1844)
Fig. 8C, 10A, B
Holotype: GPIT PV 30086, a partial skull roof and complete palate on two blocks (61 cm skull length).
Type locality: Feuerbacher Heide (former Kochenhof quarry, Killesberg), Stuttgart, Baden-Württemberg, Germany.
Type horizon: Massive light brown to greenish-grey sandstone, Schilfsandstein facies, Stuttgart Formation, late Carnian (Tuvalian), Late Triassic.
Referred material:
1. Feuerbacher Heide (Schilfsandstein, Stuttgart Formation). GPIT-PV 44620–44849 (numerous bone fragments of the dermal shoulder girdle and skull). SMNS 833 (right palatine and choana, originally referred to Mastodonsaurus keuperinus by Fraas 1889). SMNS 4139 (right part of skull, ca. 60 cm). SMNS 4935 (partial skull roof, ca. 42 cm, figured by Meyer & Plieninger 1844, pl. IX, fig. 1). SMNS 4937 (tip of snout, type specimen of M. keuperinus). SMNS 5775 (best-preserved skull, 50 cm). SMNS 7414 (posterolateral margin of skull). SMNS 91417 (interclavicle). SMNS 91484 (partial interclavicle). SMNS 91492 (partial interclavicle).
2. Stuttgart-Bopser (Schilfsandstein). SMNS 97116 (partial interclavicle).
3. Stuttgart, Steinbruch near Waldorfschule (Schilfsandstein). SMNS 91493 (interclavicle).
4. Wendelsheim (Schilfsandstein). GPIT uncatalogued: Posterolateral portion of skull roof, ventral view.
Diagnosis: Autapomorphies: (1) Postorbital skull table foreshortened, (2) choana with irregular oval outline.
References: Meyer & Plieninger (1844), Quenstedt (1850), Fraas (1889), Sulej & Majer (2005), Schoch (2008a).
Cyclotosaurus buechneri Witzmann et al., 2016
Fig. 8D
Holotype: Namu ES/k 36053, nearly complete skull in dorsal view (29.5 cm).
Type locality: Bielefeld, district Sieker, North Rhine-Westphalia, Germany.
Type horizon: Stuttgart Formation, late Carnian (Tuvalian), Late Triassic.
Diagnosis: Autapomorphies: (1) orbits medially placed with short interorbital distance; (2) region lateral to orbitae only slightly wider than width of orbitae; (3) postorbital skull region slender; (4) preorbital projection of jugal shorter than half the length of snout.
References: Witzmann et al. (2016).
Cyclotosaurus ebrachensis Kuhn, 1932
Fig. 8E, 10E
Holotype: SNSB-BSPG 1931 X1, a complete skull prepared from both sides (35 cm).
Type locality: Former sandstone quarry at Ebrach, Upper Franconia, Bavaria, Germany.
Type horizon: Sandstone bed 5, lower part of Blasensandstein, Hassberge Formation (Middle Keuper, Norian), Late Triassic (Kuhn 1932).
Diagnosis: Autapomorphies: (1) Dermal ornament fine, (2) skull slender (skull width at mid-orbit level: skull length=0.62).
Cyclotosaurus posthumus Fraas, 1913
Fig. 8H, 10D
Synonym: Cyclotosaurus mordax Fraas, 1913.
Holotype: SMNS 12988, a large portion of a skull (51.5 cm).
Type locality: White (Burrer's) quarry near Pfaffenhofen, Stromberg region, Baden-Württemberg, Germany.
Type horizon: Basal, massive light grey to white sandstone unit within Middle Stubensandstein, Löwenstein Formation (Middle Keuper, Norian), Late Triassic (Stoll 1929; Berckhemer 1938).
Referred material: The two main samples include the historic material from Pfaffenhofen (Fraas 1913), and new material collected in the 1980s at Magstadt.
1. Type locality (Pfaffenhofen im Stromberg). SMNS 12195 (interclavicle). SMNS 13014 (anterior part of skull, ca. 49 cm total length, holotype of C. mordax Fraas, 1913). SMNS 18417 (partial interclavicle). SMNS 59769 (partial jaw with teeth). SMNS 91543 (left quadratojugal).
2. Magstadt, sand pit (Middle Stubensandstein). SMNS 50006 (interclavicle). SMNS 50009 (preorbital region, skull ca. 62 cm). SMNS 50059 (left preorbital skull, ca. 60 cm). SMNS 50063 (partial skull, ca. 50 cm). SMNS 51102 (partial skull, 35 cm). SMNS 51426 (partial large skull, ca. 56 cm). SMNS 51436 (interclavicle fragment).
Diagnosis: Autapomorphies: (1) interorbital distance wider (IOW:SL=0.22), (2) naris 70–90% of orbit, (3) ornament coarse (i.e., larger polygons); (4) choana circular. The premaxilla may or may not have openings for symphyseal tusks, but in a more posterior position than in Mastodonsaurus.
Comment: The species C. mordax Fraas, 1913 is based on a single partial skull from the type locality of C. posthumus Fraas, 1913. Although distinct in a few features, the sample from Magstadt revealed that the two skulls form end points of a continuum, which will be described in full in a later study.
Cyclotosaurus hemprichi Kuhn, 1942
Fig. 8H
Synonyms: hemprichisaurus keuperinus Kuhn, 1939; hercynisaurus carinidens Kuhn, 1939; Metoposaurus ultimus Kuhn, 1939.
Holotype: HMH, a complete large skull with mandible (62.5 cm), probably destroyed in World War II. The mandible was figured by Kuhn (1939), the skull by Kuhn (1942).
Type locality: Former Baerecke-Limpricht quarry, Halberstadt, Saxony-Anhalt, Germany.
Type horizon: Grey to brown mudstones of the Knollenmergel facies, upper Arnstadt Formation (Middle Keuper, late Norian), Late Triassic (Kuhn 1942).
Referred material: MB.Am.570, 572, 573, 577 (remains of skull). MB.Am.1547 (left mandibular ramus) (type material of hercynosaurus carinidens Kuhn, 1938).
Diagnosis: Autapomorphies: (1) Quadratojugal wide and lateral margin of skull tapering, (2) naris elongate oval and slightly longer than orbit, (3) orbit small and round, less than 10% skull length.
Mastodonsauridae Jaekel, 1909
Mastodonsaurus Jaeger, 1828
(Salamandroides Jaeger, 1828)
Type species: Mastodonsaurus giganteus (Jaeger, 1828).
Diagnosis: Autapomorphies: (1) Premaxilla with large openings for symphyseal tusks, set anteromedial to naris; (2) orbits large (0.2 times skull length); (3) jugal slender lateral to orbit; (4) lateral line sulci shallow but very wide; (5) parietal elongated anterior to pineal foramen; (6) epipterygoid massive with six distinct processes.
Mastodonsaurus giganteus (Jaeger, 1828)
Figs. 11B, D, 12
Synonyms: Mastodonsaurus jaegeri Holl, 1829; Xestorrhytias perrini Meyer, 1855 partim; Mastodonsaurus acuminatus Fraas, 1889.
Holotype: GPIT Am 678, large occiput with exoccipital condyles and posterior portion of parasphenoid, estimated skull length about 61 cm (Moser & Schoch 2007: fig. 9). The large tusk described by Jaeger (1828) and and whose rounded tip the genus name was based is listed below.
Type locality: Alum mine at Parkschule, Gaildorf, Baden-Württemberg, Germany.
Type horizon: “Vitriolschiefer” or “Alaunschiefer”, a coaly mudstone rich in pyrite and galenite, Top of Estherienschichten, few cm below base of Hauptsandstein (Meyer & Plieninger 1844; Kurr 1852; Quenstedt 1880; Hagdorn 1988; Weber 1992).
Comment: “Vitriolschiefer” is not to be confused with the mudstone unit referred to as Vitriolschiefer at the base of the Lower Keuper.
Referred material:
1. Type locality (Gaildorf). SMNS 4698 (complete skull with mandibles, 62 cm). SMNS 4706 (complete skull with mandibles, 68 cm, and anterior part of vertebral column, 9 intercentra). SMNS 4938 (tip of snout, ca. 65 cm skull length). SMNS 55911 (large tusk, original of Jaeger 1828, pl. 4, fig. 4). SMNS 54679 (complete skull with mandibles, 60 cm; this specimen was erroneously reported by Moser & Schoch (2007) as measuring 74 cm). A large snout (about 107 cm skull length, described in Meyer & Plieninger 1844 is lost (Schoch 1999).
2. Kupferzell, K3 (Untere Graue Mergel, green layer K3 of Schoch et al. 2022). SMNS 54675 (complete skull, 60.5 cm). SMNS 54678 (complete skull, 54.5 cm). SMNS 80704 (complete skull, 55 cm). SMNS 80889 (complete skull, 59 cm). SMNS 80890 (postorbital part of skull, 45.5 cm). SMNS 80905 (disarticulated skull, about 45 cm). SMNS 80945 (disarticulated skull, 60 cm). SMNS 81075 (disarticulated skull, 48 cm). SMNS 81310 (giant specimen, including complete mandible of 110 cm, 88.5 cm skull length, with few remnants of the palate and a total of 28 presacral and 6 caudal vertebrae). SMNS 81368 (posterior part of palate). SMNS 84030 (posterior margin of skull, estimated length 65 cm). Symphyses of larval specimens (SMNS 97035: 12 mm skull length, SMNS 97036, 25 mm skull length).
3. Kupferzell, K4 (Untere Graue Mergel, brown layer K4 of Schoch et al. 2022). SMNS 54676 (complete skull, 56 cm). SMNS 54677 (complete skull, 51 cm, with mandible). SMNS 80249 (posterior rim of skull, SL 65 cm). SMNS 80878 (near-complete skull, about 65 cm, with parts of mandible. SMNS 80887 (snout fragment, 54 cm). SMNS 80913 (fragmentary skull, 65 cm total length, with 28 presacral vertebrae). SMNS 83293 (fragmentary skull, 60 cm). SMNS 83312 (fragmentary skull, 45 cm). SMNS 54676 (complete skull, 56 cm). SMNS 97038–97042 (skull fragments, with skulls of approximately 68, 50, 47, 50, and 57 cm skull length).
4. Markgröningen (Fraas 1889, p. 5: “10 m above Hauptsandstein” = Untere Graue Mergel). SMNS 4974. Skull without cheek regions (71.3 cm skull length).
5. Vellberg, E5 (Untere Graue Mergel, brown layer). MHI 1991-22 (complete skull, 50.5 cm). MHI 1992-20 (complete skull, 59.5 cm). MHI 1992-41 (complete skull, 42 cm). MHI Ku-UC53le1 (skull, 53 cm). MHI Ku-UC53le2 (skull, 34.6 cm). SMNS 81966, (complete skull, 51 cm, with mandible).
6. Vellberg, E6 (Untere Graue Mergel, grey layer). MHI 1992-1 (complete large skull, 72 cm, with mandible detached). MHI 1992-31 (complete juvenile skull, 30 cm). MHI 1992-42 (complete juvenile skull, 28.6 cm). SMNS 97043 (complete skull, 39 cm). MHI Ku-UC54le1 (mandible, 24.1 cm). MHI Ku-UC54le2 (mandible, 20 cm). MHI Ku-UC54le3 (mandible, 35 cm). MHI Ku-UC1 (mandible, skull length 37 cm). MHI Ku-UC2 (mandible, skull length 120 cm). MHI Ku-UC2 (mandible, skull length 100.8 cm). SMNS 92128 (complete skull, 60 cm length). SMNS 97037 (posterior portion of skull, 15 cm length).
7. Vellberg, E7 (Anoplophora Dolomite, E7). MHI 1794-3 (complete skull, 62 cm). MHI 1991-1 (complete skull in 3D with mandible, 54.2 cm). MHI 1991-4 (two partial skulls, 32 and 34 cm). MHI 1991-5 (snout, estimated 66.6 cm skull length). MHI 1991-6 (partial skull, 53.9 cm). MHI 1991-7 (snout, estimated 35 cm skull length). MHI 1991-8 (mandible, estimated 58.3 cm skull length). MHI 1991-11 (complete skull, 38 cm). MHI Ku-UC54le (mandible, 52.7 cm). MHI Ku-UC54le1 (skull, 54.4 cm). MHI Ku-UC (skull, 54 cm).
8. Arnstadt, Thuringia (Oberes Dunkles Band, layer 42, dark coaly siltstone of Werneburg in Hagdorn et al. 2015). NHMS-WT 3323–3368 (partial skull and mandible, estimated 101 cm skull length; Werneburg & Witter 2005).
9. Bedheim, Jahn quarry, Thuringia (Lettenkohlenhauptsandstein; Rühle von Lilienstern 1935; Hagdorn et al. 2015). MB.Am 950 (palate, ca. 55–60 cm).
10. Molsdorf, Thuringia (skull remains in dolomites of Lower Keuper, Schmidt 1931).
Diagnosis: Autapomorphies: (1) Orbits with pointed anterior end and narrow interorbital distance (IOW:SL=0.095); (2) medial premaxillar teeth enlarged; (3) tusks in palate and especially in the symphysis greatly enlarged; (4) postorbital larger than supratemporal; (5) squamosal wide to give broadened cheek; (6) interclavicle with elongate anterior process; (7) intercentra of the trunk dorsally closed in juveniles and adults.
References: Meyer & Plieninger (1844), Huene (1922), Fraas (1889), Schmidt (1931), Rühle von Lilienstern (1935), Schoch (1999, 2002a, b).
Fig. 10.
Cyclotosaurus Fraas, 1889. A – Cyclotosaurus robustus (Meyer, 1844) (SMNS 5775). B – C. robustus, holotype (GPIT PV 30086). C – C. posthumus (SMNS 12988). D – C. mordax, holotype (SMNS 13014). E – C. ebrachensis (SNSB-BSPG 1931 X1).
Fig. 11.
Mastodonsaurid skulls. A – Mastodonsaurus cappelensis Wepfer, 1923, dorsal view. B – M. giganteus (Jaeger, 1828), dorsal view. C – M. cappelensis Wepfer, 1923, ventral view. D – M. giganteus (Jaeger, 1828), ventral view. Modified from Schoch, et al. (2023). Bones highlighted in colour emphasize differences between the two species.
Fig. 12.
Mastodonsaurid skulls. A – Mastodonsaurus cappelensis Wepfer, 1923, dorsal view (SMNS 14845f). B – M. cappelensis, ventral view (RE 551.761.100 A 0040). C – M. giganteus (Jaeger, 1828), dorsal view (SMNS 54677). D – M. giganteus, skeleton mount in oblique anterior view. (Museum am Löwentor, permanent exhibition).
Mastodonsaurus cappelensis Wepfer, 1923
Fig. 11A, C
Synonyms: Mastodonsaurus kappelensis Pfannenstiel, 1932; Cyclotosaurus mechernichensis Jux & Pflug, 1958; heptasaurus cappelensis Kamphausen & Ortlam, 1993; Parotosuchus mechernichensis Sander & Gee, 1998.
Lectotype: STIPB-R-390, partial palate and skull roof including the diagnostic orbit region, both mandible halves from different perspectives and a clavicle (Schoch et al. 2023).
Type locality: Former Reiser quarry at Elsenau, a chapel 800 m west of Kappel and south of the road to Obereschach, Villingen-Schwenningen community, Black Forest, SW Germany. Wepfer (1923) reported that the entire material derived from the same bedding plane covered a continuous area of 30 square metres.
Type horizon: Top of 30 cm thick brownish sandstone in the lower part of Lower Röttone above VH5 (Kamphausen & Ortlam 1993), Upper Buntsandstein, lower Anisian (Middle Triassic).
Stratigraphic range: Lower Röttone, Upper Buntsandstein, lower Anisian (Aegean: Middle Triassic).
Referred material: M. cappelensis is known from five different localities, all within the Röt Formation.
1. From the type locality: GPIT.Am 686 (preorbital skull portion), GPIT.Am 687 (palate); KCE RE 551.761.100 A 0040 (partial palate), KCE RE 551.761.100 A 0041 (skull roof); MB.Am 1548 (partial palate, skull roof, mandible, and postcranial bones); NHMUK R 15882–15888 (disarticulated postcranial and mandible remains), SMNK-FS-1–15 (disarticulated skulls, mandibles and postcranial remains), listed in detail by Schoch, et al. (2023); these are the remains of the former Wepfer collection at Freiburg, GIF, which was largely destroyed in World War II); SMNS 14845 (partial mandible, femur, ilium).
2. Freudenstadt (Baden-Württemberg): GPIT.Am 686 (anterior palate, described by Kamphausen & Ortlam 1993).
3. Sandstone quarry, Detzeln (Baden-Württemberg): SMNS 91406–91410 (isolated neural arches, intercentra, humerus, interclavicle and part of a postorbital skull table).
4. Ore mine “Virginia“, Mechernich, Eifel region (Rheinland-Pfalz): GIUK uncatalogued (posterior skull table, skull approx. 45 cm, and second smaller specimen, Jux & Pflug 1958; Sander & Gee, 1998).
5. Gambach near Gemünden (Bavaria; Trusheim 1937). GIW uncatalogued (mandible, 85 cm, skull length ca. 70 cm).
Diagnosis: Autapomorphies (in contrast to M. giganteus): (1) Orbits elongate oval, narrower to give wider interorbital distance; (2) snout wider and medial premaxillar teeth smaller; (3) ilium with more robust dorsal end; (4) interclavicle with broad posterior process having radially arranged outgrowths. Plesiomorphies (in contrast to M. giganteus): (5) postorbital skull table: supratemporal larger, postorbital smaller; (6) frontal substantially shorter, giving the nasal more typical capitosauroid proportion; (7) palatal and especially symphyseal tusks substantially smaller, and accordingly dorsal premaxillar openings for symphyseal tusks smaller; (8) palatal ramus of pterygoid more slender; (9) atlas with wide gap between condylar facets and medially separate dorsal spines; (10) intercentra of the trunk dorsally not closed in adults and less massive than in M. giganteus.
References: Wepfer (1923a), Pfannenstiel (1932), Jux & Pflug (1958), jux (1966), Kamphausen & Ortlam (1993), Schoch (1999), Schoch et al. (2023).
Trematosauroidea Säve-Söderbergh, 1935
Trematosaurus Burmeister, 1849
(Trematosaurus Braun, 1842, nomen nudum)
Type species: Trematosaurus brauni Burmeister, 1849
Trematosaurus brauni Burmeister, 1849
Fig. 13A, B
Synonyms: Labyrinthodon ocella Meyer, 1855; Trematosaurus fuchsi Seidlitz, 1917.
Syntypes: Specimens of currently unknown whereabouts. Former Bischoff collection as mentioned and partly figured by Meyer (1858: pls. 27–28).
Type locality: Merkel's Quarry, at Teichweg near Fuhne creek, SE of Bernburg an der Saale, Saxony Anhalt, Germany.
Type horizon: Bausandstein, white to grey sandstone unit below Thüringer Chirotheriensandstein, lower Solling Formation, late Olenekian.
Referred material: The hypodigm includes a total of 75 skulls, four mandibles, and ten postcranial remains. GG 22.159 (posterior portion of skull, ∼24 cm), GG 22.159 (skull,21.9 cm), GG 22.162 (partial skull,∼31.2 cm), GG 22.164 (steinkern of skull,19.6 cm), GG 22.165 (posterior skull portion, 19 cm), GG 22.166 (two-thirds of skull,16.9 cm), GG 22.187 (skull roof,19 cm), GG 22.188 (complete palate,21.6 cm), GIHBS5 (complete skull, natural mould, 25 cm), GIH-BS6 (partial steinkern, 21.3 cm), GIH-BS7 (palate, 10.9 cm), GIH-BS8 (partial skull roof, 23.5 cm). GIJ 1 (skull, 16.2 cm), GIJ 2 (partial skull, ca. 32.1 cm), GIJ 3 (skull, 34 cm). GMG uncatalogued 1: posterior two-thirds of of skull (ca. 20 cm); 2: posterior skull portion (ca. 13 cm); posterior skull portion (ca. 16 cm); two-thirds of skull (ca. 28 cm). GPS.MLU 2016.02 (steinkern of skull, 18.2 cm), 2016.03 (cheek portion, ca. 16 cm), 2016.04 (skull roof, 18.3 cm), 2016.05 (complete skull, 25.7 cm), 2016.06 (skull, ca. 22 cm), 2016.11 (palate, 14 cm), 2016.20 (excellent skull roof with ornament, ca. 25.5 cm), 2016.33 (clavicle), 2016.37 (partial interclavicle), 2019.01 (skull roof, 15.6 cm): 2019.02 (skull roof, 40 cm), 2019.03 (palate, 13.2 cm), 2019.04 (palate, 37 cm), 2019.05 (skull), 2019.06 (posterior palate with stapes, ca. 19 cm), 2019.07 (mandible), 2019.08 (interclavicle). MB.Am.585 (snout fragment), MB.Am.596 (steinkern of skull, ca. 23 cm), MB.Am.600 (partial skull, 16 cm), MB.Am.602 (skull fragment, ca. 20.3 cm), MB.Am.603 (palate fragment), MB.Am.614 (palate, 18.3 cm), MB.Am.616 (steinkern of skull, 18.5 cm), MB.Am.936 (skull roof in internal view, 19.6 cm), MB.Am.938 (posterior part of palate, ca. 17.2 cm), MB.Am.959 (palate, 24.7 cm). MNM 2661 (palate 18.1 cm), 4852 (complete palate, 14 cm), 6587 (palate 19.6 cm), 6588 (skull roof with medial portion lacking with parasphenoid exposed in dorsal view), 13304 (posterior palate, 21 cm). MNVD 11154 (complete palate, 15.4 cm), 11156 (two-thirds of a skull roof, 18.5 cm), 11164 (fragment of preorbital region, ca. 26 cm), 11165 (steinkern of a skull, 16.5 cm), 11167 (skull margin and mandible in lateral view, 41 cm), and five interclavicles (G 367, G 368, G 383, G 427, G 428). MSB G 366 (medial part of skull, 23 cm), G 370 (palate, 19.7 cm), G 366 (skull roof, 18.5 cm), G 407 (mandible in labial view, 14 cm), G 423 (skull roof, 21.5 cm), G 366 (posterior skull fragment), G 447 (medial part of skull, 21 cm). NHMS VT 21 (posterior half of palate, ca. 27.5 cm). NMS WS 4484 (good palate, described by Drevermann 1920; 14.6 cm). SMNS 4484a (quite complete skull, internal view of roof, 14.5 cm). SMNS 4484b (posterior skull portion, ca. 14 cm), SMNS 4484c (fragmentary skull, ca. 25 cm), SMNS 4485 (dentary with teeth), SMNS 4526 (palate, ca. 19 cm), SMNS 6207a (skull, 17.9 cm), SMNS 6207b (excellent mould of cheek, ca. 22 cm), SMNS 6207c (mandible), SMNS 59412 (posterior half of skull, ca. 18 cm), SMNS 59423 (right half of skull, 23 cm), and two interclavicles (SMNS 4486, 7958). UMZC T.126 (Watson 1951).
Diagnosis: A trematosaurid growing to 41 cm skull length. Autapomorphies: (1) temporal sulcus of lateral line with two portions, (2) occipital sulcus continuous, (3) preorbital region slightly shorter than half skull length (0.43–0.49), 4) interorbital distance wide (interorbital distance/skull length: 0.15–0.2). Derived characters shared with other trematosauroids: (5) quadratojugal with posterolateral projection, (6) parasphenoid with sharp ventral keel.
References: Braun (1842), Burmeister (1849), Meyer (1858), Jaekel (1903), Drevermann (1914, 1920), Huene (1921), Schoch (2019).
Trematosaurus thuringiensis Werneburg, 1993
Fig. 13C
Holotype: MB.Am.943, skull roof and palate, block and counterblock. Werneburg (1993: figs. 1–2).
Type locality: Vacha, southwestern Thuringia, Germany.
Type horizon: Middle Buntsandstein, late Olenekian.
Diagnosis: Autapomorphies (with respect to type species): (1) Interorbital distance narrower, (2) orbits larger and more rounded, (3) postorbital skull slightly shorter.
Comment: Two other finds from Thuringia were attributed to Trematosaurus but were lost in the course of World War II (Werneburg 1993).
Trematolestes Schoch, 2006
Type species: Trematolestes hagdorni Schoch,, 2006.
Trematolestes hagdorni Schoch, 2006
Figs. 13D, 14
Holotype: SMNS 81790, a nearly complete, juvenile skeleton (Schoch 2006, figs. 1, 2). Skull length: 11.8 cm.
Type locality: Exposed section above bus stop at Albert-Schwegler-Straße, Michelbach an der Bilz, Baden-Württemberg, Germany.
Type horizon: Top of Sandige Pflanzenschiefer (Hagdorn 1980), upper part of Lower Keuper section (Erfurt Formation); Middle Triassic (Ladinian: Longobardian).
Referred material: A total of 44 specimens are referred to T. hagdorni.
1. Michelbach an der Bilz (type locality, Sandige Pflanzenschiefer): SMNS 81791 (posterior skull, 9.5 cm). SMNS 81793 (partial tail skeleton). SMNS 91582 (postcranium with partial skull, 7 cm). SMNS 97025 (skull and trunk skeleton, 16 cm). SMNS 97026 (partial skull, 8 cm). SMNS 97027 (disarticulated skull and anterior trunk, 7.4 cm).
2. Gaildorf (Estherienschichten): SMNS 90053 (three vertebrae; Huene 1922: Fig. 30; Meyer & Plieninger 1844: Pl. 7, fig. 5).
3. Kupferzell (Untere Graue Mergel): SMNS 80968: (posterior skull table). SMNS 83788 (small exoccipital). SMNS 83787 (large exoccipital). SMNS 81794 (anterior fragment of mandible). SMNS 81795 (squamosal of small adult specimen). SMNS 81797 (small interclavicle). SMNS 81798 (small symphysis). SMNS 84120–84127 (intercentra). SMNS 90054 (large pterygoid). SMNS 90049 (three larval skull elements).
4. Rielingshausen (Sandige Pflanzenschiefer): SMNS 90022: juvenile skull (9.8 cm).
5. Ummenhofen (Untere Graue Mergel): SMNS 81964 (symphysis).
6. Vellberg (Untere Graue Mergel): MHI 1715 (skull, ca. 22 cm). MHI Ku 1994-1 (large skull and mandible, 28 cm). MHI 2048 (complete tiny skull, 6 cm). SMNS 81963 (large ilium). SMNS 84809 (small interclavicle). SMNS 90043 (elements of tiny larval skull, right ilium and femur). SMNS 90572 (large interclavicle, approx. 28 cm skull). SMNS 91089 (left and right clavicle approx. skull 27 cm). SMNS 91090 (large supratemporal (approx. 250 mm skull length). SMNS 91546 (posterior skull and postcranium, 26 cm). SMNS 97030 (disarticulated postcranium with partial clavicle, interclavicle). SMNS 97031 (partial skull, approx. 10 cm). SMNS 97032 (posterior palate, 22 cm). SMNS 97033 (disarticulated elements of the cheek and skull table (approx. 28 cm). SMNS 97034 (large symphysis).
7. Wolpertshausen (Untere Graue Mergel): SMNS 81796 (small mandible).
8. Zwingelhausen (Sandige Pflanzenschiefer): SMNS 56252 (postorbital skull, 17 cm).
Diagnosis: Autapomorphies: (1) dorsal exposure of lacrimal minute, confined to anterolateral orbit margin, (2) frontal unpaired, preorbital part slightly longer; (3) maxilla shelf wide, giving gently broadened tip of snout; (4) nasal shorter than prefrontal; (5) jugal with long posterior process pushing quadratojugal far back; (6) palatal tusks laterally compressed and keeled; (7) strut-like prearticular wedged in between large Meckelian and adductor fenestrae; (8) interclavicle very slender with straight sagittal margin of ornamented area and lateral wing hardly wider than anterior end (width:length=0.31).
hyperokynodon Plieninger, 1852
Type species: Hyperokynodon keuperinus Plieninger, 1852.
hyperokynodon keuperinus Plieninger, 1852 Fig. 13E, F
Holotype: SMNS 16670, impression of anterior portion of preorbital skull region in palatal view, with paired openings in the anterior palate for the accommodation of symphyseal tusks (aperturae praemaxillares), choanae, premaxilla and anterior maxilla teeth, and the tusks of the vomer and palatine. Skull length approximately 72 cm.
Type locality: Jägerhaus quarry, Wartberg near Heilbronn, Baden-Württemberg, Germany.
Type horizon: Schilfsandstein, Mittlerer Keuper (km2), late Carnian (early Tuvalian), Late Triassic.
Referred specimen: SMNS 55910, a posterior skull preserved as steinkern, from the type locality.
Diagnosis: (1) Lateral margin of snout straight, curving into a posterolaterally broadening posterior to choana; (2) anterior palatal openings more widely separated than choanae; (3) choana three times longer than wide; (4) long countersunk area along vomerine midline; (5) keeled, laterally compressed vomerine and palatine tusks and premaxilla teeth.
Extended Diagnosis: Based on SMNS 55910: (1) Frontal very slender with straight sagittal lateral margins; (2) lateral margin of postorbital skull strongly concave, (3) postorbital, jugal and especially squamosal extremely narrow; (4) margin of skull posterolaterally wider; (5) supratemporal and parietal proportionately longer than in all other trematosaurids; (6) postfrontal proportionately very large and with wide anteromedial portion.
References: Plieninger (1852), Hellrung (1987), Schoch et al. (2002), Schoch (2024).
Callistomordax Schoch, 2008
Type species: Callistomordax kugleri Schoch,, 2008
Callistomordax kugleri Schoch, 2008
Figs. 15A, B, G, 16A, B
Holotype: SMNS 82035, a nearly complete skeleton (skull length 13.7 cm).
Type locality: Schumann limestone quarry, Vellberg, Baden-Württemberg, Germany.
Type horizon: E6, top of Untere Graue Mergel, Erfurt Formation, late Ladinian, Middle Triassic (Schoch & Seegis 2016).
Referred material: From type locality: MHI-Ku 1995/2 (nearly complete postcranial skeleton including one humerus and both hind limbs). MHI-Ku 1995/3 (small postcranial skeleton with pectoral girdle). MHI-Ku 1995/15 (large postcranial skeleton). MHI-Ku 1995/6 (small skull, 9.5 cm). MHI-Ku 1995/1 (slightly disarticulated skull with good snout region, 16 cm). MHI-Ku 1995/3 (small postcranium). SMNS 55385 (isolated, complete skull, 14.8 cm). SMNS 90516 (anterior two-thirds of skeleton with complete skull in dorsal view, 15.3 cm). SMNS 90519 (humerus). SMNS 90520 (partial skeleton and crushed skull, 14.5 cm). SMNS 90700 (skeleton, 12.5 cm skull length). SMNS 91225 (skull, 16.5 cm). SMNS 91355 (juvenile skull, 4 cm). SMNS 91775 (interclavicle). SMNS 91812 (disarticulated postcranium). SMNS 91829 (three skull bones). SMNS 91989 (clavicle). SMNS 92010 (supratemporal). SMNS 94809 (interclavicle). SMNS 97100 (skull, 16 cm). SMNS 97117 (skeleton). SMNS 97118 (skull, 12.5 cm). SMNS 97119 (small skull, 7.7 cm). SMNS 97121 (skull, 15 cm). SMNS 97122 (posterior palate, ca. 11 cm).
Diagnosis: Autapomorphies: (1) frontal unpaired, with single medial anterior tip and blunt posterior end; (2) pterygoid distinct by very broad and flat quadrate ramus combined with a particularly slender and narrow palatine ramus; (3) subtemporal windows nearly round and wider than the basicranial region; (4) anterior palate very short, with vomers and palatines dominated by huge fangs the sockets of which occupy most of the bone surfaces, and minute, obliquely orientated choanae; (5) palatal and symphyseal fangs laterally compressed and keeled; (6) intercentra forming open crescents with high flanks with pointed upper ends and a massive, anteroposteriorly elongated ventral portion that has a quadrangular outline; (7) shaft of cleithrum curved in semilunar fashion.
Fig. 13.
Trematosaurid specimens. A – Trematosaurus brauni BURMEISTER, 1849, palate (MSB G 366). B – T. brauni, skull roof (SMNS 4484a). C – T. thuringiensis, palate (MB.Am.943). D – Trematolestes hagdorni, holotype (SMNS 81790). E, F – hyperokynodon keuperinus Plieninger, 1852, holotype (SMNS 16670).
Fig. 14.
A, B – Trematolestes hagdorni Schoch, 2006. A: Adult skull in dorsal view. B: Adult skull in ventral view. C – Trematosaurus brauni Burmeister, 1849, adult skull in dorsal view (modified from Schoch, 2019). D – Trematolestes hagdorni, adult skull in dorsal view (modified from Schoch & Mujal 2021). E – hyperokynodon keuperinus, restoration of skull in dorsal view (Schoch, 2024).
Fig. 15.
Trematosauroid skulls. A, B – Skull roof of Callistomordax kugleri Schoch,, 2008 (A: SMNS 82035, B: MHI KU 1995/1). C–F – Metoposaurus diagnosticus (Meyer, 1842). C: Small skull from Helfenstein (SMNS 56633). D: Large skull from Stuttgart, Feuerbacher Heide (SMNS 4943). E: Skull from Fichtenberg (SMNS 80573). F: Partial skeleton from Hanweiler near Winnenden (SMNS 5143). G – Skeleton of Callistomordax kugleri (SMNS 82035).
Metoposauridae Watson, 1919
Metoposaurus Lydekker, 1890
Type species: Metoposaurusdiagnosticus(Meyer, 1842).
Metoposaurus diagnosticus (Meyer, 1842)
Fig. 15C–F
Synonyms: Metopias diagnosticus Meyer, 1842; Metoposaurus stuttgartiensis Fraas, 1889; Metoposaurus heimi Kuhn, 1931.
Holotype: SMNS 10825 (right-central portion of a skull, ca. 32.5 cm; Meyer & Plieninger 1844, pl. 10, fig. 1; Sulej 2002, fig. 2).
Type locality: Feuerbacher Heide (former Kochenhof quarry, Killesberg), Stuttgart, Baden-Württemberg, Germany.
Type horizon: Massive light brown to greenish-grey sandstone, Schilfsandstein facies, Stuttgart Formation, late Carnian (Tuvalian), Late Triassic.
Referred material:
1. From the type locality: SMNS 1010 (steinkern of skull), SMNS 1011 (skull roof, ventral view), SMNS 4943 (nearly complete skull with mandible attached, ca. 38 cm), SMNS 59768, two intercentra.
2. Schilfsandstein (Stuttgart Formation): SMNS 5143 (right half of skull and torso from Hanweiler near Winnenden, skull ca. 35 cm). Still unprepared material is housed at the SMNS from a lacustrine mudstone collected at a new locality in Limpurger Berge and a conglomerate horizon at Obernzenn near Ansbach, Bavaria.
3. Lehrbergschichten (Steigerwald Formation): From Stuttgart-Sonnenberg, SMNS 210 (mandible). SMNS 309 (symphysis). SMNS 10505 (intercentrum). SMNS 11423 (interclavicle). SMNS 12713 (three ribs). SMNS 11423, 12714 and 17943, clavicles (the latter is the holotype of M. stuttgartiensis Fraas, 1889). SMNS 56633 (small skull, 17.3 cm; green mudstone bed from above the Lehrbergbank III, found in a vinyard at Söhlbach-Beilstein near Helfenberg; Seegis 1997; Milner & Schoch 2004, fig. 2). SMNS 80754, 80758, 80759, 80762 (jaw fragment and isolated palatal tusks from north of Stuttgart; Seegis 1997).
4. Kieselsandstein (Hassberge Formation): SMNS 80573 (partial imprint of skull roof, approx. 28 cm) in a coarse sandstone block from Fichtenberg, northern Baden-Württemberg (Milner & Schoch 2004, fig. 3).
5. Blasensandstein (Hassberge Formation): BSP 1931 X3, large skull (44 cm) from Ebrach in northern Bavaria, the holotype of M. heimi Kuhn, 1932. This specimen was erroneously reported by Milner & Schoch (2004) as lost.
6. Middle Stubensandstein (Löwenstein Formation): NHMUK 37938 is a skull (ca. 32 cm) lacking the left posterolateral corner and the premaxillae (Milner & Schoch 2004, fig. 4).
Diagnosis: (1) Lacrimal enters orbit margin; (2) interclavicle with very small, pitted area; (3) lateral line sulci shallow.
Comment: Sulej (2002) distinguished two subspecies, M. d. diagnosticus and M. d. krasiejowensis which were accepted by Milner & Schoch (2004).
References: Meyer (1842, 1855), Meyer & Plieninger (1844), Hunt (1993), Seegis (1997), Sulej (2002, 2007), Milner & Schoch (2004).
Brachyopoidea Lydekker, 1885
Plagiosauridae Abel, 1919
Plagiosuchinae Schoch & Milner, 2014
Plagiosuchus Huene, 1922
Type species: Plagiosuchus pustuliferus (Fraas, 1896).
Plagiosuchus pustuliferus (Fraas, 1896)
Figs. 17C, G, 18D, E
Lectotype: SMNS 55909, interclavicle (Fraas 1889: pl. 6, fig. 15).
Type locality: Alum mine at Parkschule, Gaildorf, Baden-Württemberg, Germany.
Type horizon: “Vitriolschiefer” or “Alaunschiefer”, a coaly mudstone rich in pyrite and galenite, Top of Estherienschichten, below base of Hauptsandstein (see above).
Referred material: Articulated specimens were collected at four localities in Württemberg and one in Thuringia, and isolated remains are known from a range of further sites.
1. Gaildorf. SMNS 55909, central portion of interclavicle (type specimen, acquired in 1865), SMNS 13331, pectoral girdle, vertebrae and posterior part of mandible, donated to the SMNS by the University of Göttingen (Huene 1922), SMNS 90573, an isolated occiput.
2. Kupferzell. (Untere Graue Mergel, K3). SMNS 97110 (clavicle and five intercentra). SMNS 97111 (clavicle). SMNS 97112 (12 vertebrae). SMNS 97113 (eight vertebrae).
3. Vellberg. (Untere Graue Mergel, E5, E6). MHI 1988/1 (skeleton without skull). MHI 1988/3 (left mandible). MHI 1804 (axis). MHI 1988/4 (clavicle and interclavicle). MHI 1988/7 (large interclavicle). MHI 1988/8 (small partial skeleton). MHI 2189 (disarticulated skeleton without skull). SMNS 57921 (skull and first two vertebrae, Damiani et al. 2009). SMNS 57921 (postcranium). SMNS 97106 (skeleton without skull).
4. Ummenhofen, Schneider quarry (green mudstone at top of Untere Graue Mergel). SMNS 84794 (articulated postcranium, Schoch 2015: fig. 9.11).
5. Kochertal bridge at Ilshofen (black coaly bed of Untere Graue Mergel). SMNS 84793 (postcranium).
6. Wolpertshausen (Untere Graue Mergel). MHI material (Hagdorn et al. 2015).
7. Michelbach an der Bilz (Sandige Pflanzenschiefer). MHI 1046 (several vertebral columns) (Hagdorn et al. 2015).
8. Arnstadt-Nord, road construction site, Thuringia. NHMS-WT 650 (large postcranium).
9. Molsdorf, road construction site, Thuringia. NHMS-WT 2848–57 (clavicles, vertebrae).
Stratigraphic range: Top of Estherienschichten to Anoplophora Dolomite, Erfurt Formation, Ladinian, Middle Triassic.
Diagnosis: Autapomorphies: (1) Extremely short, transversely aligned tooth row, restricted to anterior oral margin. (2) Prefrontal, postfrontal and postorbital absent. (3) Supratemporal reduced to narrow transverse strut. (4) Pineal foramen relatively large. (5) Subtemporal fenestra anteriorly expanded to extend over 4/5 the skull length. (6) Orbit and jugal greatly expanded anterioposteriorly. (7) Cleithrum very large, with anteriorly convex dorsal head.
References: Huene (1922), Werneburg & Witter (2005), Damiani et al. (2009), Witzmann & Soler-Gijón 2010), Schoch & Witzmann (2011).
Fig. 16.
Trematosauroid skulls. A, B – Callistomordax kugleri Schoch,, 2008 (A: skull roof, B: palate). C, D – Metoposaurus diagnosticus (Meyer, 1842) (C: skull roof, D: palate).
Fig. 17.
Plagiosaurid skulls (modified from Schoch & Milner 2014). A, F – Gerrothorax pulcherrimus (Fraas, 1913). B, G – Plagiosternum granulosum (Fraas, 1889), dorsal view. C, H – Plagiosuchus pustuliferus (Fraas, 1896). D, I – Megalophthalma ockerti (Fraas, 1889). E – Plagiosauruus depressus Jaekel, 1914. A–D, dorsal views. E–H, ventral views. Modified from Schoch & Milner (2014) and Witzmann & Schoch (2024).
Fig. 18.
Plagiosaurid material. A – Gerrothorax pulcherrimus, skull in dorsal view (SMNS 84786). B – G. pulcherrimus, skeleton in dorsal view (SMNS 83866). C – Skull of Plagiosternum granulosum, skull in dorsal view (SMNS 56614). D – Plagiosuchus pustuliferus, skull in dorsal view (SMNS 57921). E – P. pustuliferus, partial skeleton in dorsal view (SMNS 84794).
Plagiosterninae Jaekel, 1914
Plagiosternum Fraas, 1896
Type species: Plagiosternum granulosum (Fraas, 1889).
Plagiosternum granulosum (Fraas, 1889)
Figs. 17B, F, 18C
Lectotype: SMNS 11824, left clavicle (Fraas 1889: pl. 6, fig. 1).
Type locality: Heldenmühle quarry, Crailsheim, Baden-Württemberg, Germany.
Type horizon: Grenzbonebed, basal Erfurt Formation, late Ladinian, Middle Triassic.
Referred material: Mostly disarticulated bones and skull fragments were collected at several localities in Baden-Württemberg, Bavaria and Thuringia.
1. Type locality at Heldenmühle (Grenzbonebed). SMNS 8675 (interclavicle), SMNS 8733 (interclavicle), SMNS 11827 (surangular), SMNS 13168 (skull roof, figured by Fraas 1913 and Huene 1922), SMNS 13169 (skull roof fragment), SMNS 13170 (clavicle), SMNS 84000 (right hemimandible), SMNS 84804 (nasal).
2. Rüblingen (Grenzbonebed): SMNS 81364 (clavicle), SMNS 81365 (clavicle),
3. Ummenhofen (Grenzbonebed). SMNS 56614 (complete skull, figured by Warren 1995).
4. Rothenburg ob der Tauber (Grenzbonebed). SMNS 90602 (left part of skull).
5. Mundelsheim, Epple quarry (Fränkische Grenzschichten, Upper Muschelkalk). SMNS 82002 (right half of skull).
6. Vellberg, Schumann quarry (Untere Graue Mergel, E4). MHI 1805 (right clavicle), SMNS 90698 (left hemimandible, interclavicle and clavicle), SMNS 90720 (right hemimandible),
7. Arnstadt-Nord, road construction site, Thuringia (sandstones and green mudstones, below Melchendorfer Dolomit). NHMS-WT 2835–48 (skull bones). NHMS-WT 2997 (juvenile clavicle).
8. Neudietendorf near Gotha, Thuringia (“Ockerdolomit”). MB. Am 686 (anterior middle part of skull; Schmidt 1931) and several NHMS specimens.
Stratigraphic range: Fränkische Grenzschichten to Untere Graue Mergel, Meissner and Erfurt formations, late Ladinian, Middle Triassic.
Diagnosis: Autapomorphies: (1) Postfrontal absent. (2) Quadratojugal with elongate posterolateral projection, giving the skull a boomerang shape. (3) Supraquadrate ramus of quadratojugal directed posteriorly. (4) Adult ornament consisting of polygonal ridges, juvenile ornament with parallel, curved long ridges.
References: Fraas (1889, 1896), Schmidt (1931), Warren (1995), Schoch & Milner (2014).
Megalophthalma Schoch, Milner & Witzmann, 2014
Type species: Megalophthalma ockerti Schoch, Milner & Witzmann, 2014.
Megalophthalma ockerti Schoch, Milner & Witzmann, 2014
Fig. 17D, H
Holotype: MHI 2047, partial skull.
Type locality: Schumann quarry, Vellberg, Baden-Württemberg, Germany.
Type horizon: Hauptsandstein, Erfurt Formation, late Ladinian, Middle Triassic.
Diagnosis: Autapomorphies: (1) orbits medially extended to give very thin interorbital region (only half the width compared to Plagiosternum granulosum) and cheek; (2) posterior skull table abbreviated (only two-thirds the length compared to P. granulosum), with splint-like supratemporals, postparietals and parietals; (3) supraorbital lateral line sulcus absent on frontal, with blind ending on parietal, and continued at the anterior margin of the postorbital; (4) occiput sloping posteriorly, with subtympanic fossa exposed in ventral view; (5) cultriform process and basicranial suture extremely narrow; (6) mandibular, palatine-ectopterygoid and maxillary teeth very long with crowns markedly curved inwards.
References: Schoch et al. (2014).
Plagiosaurinae Shishkin, 1986
Plagiosaurus Jaekel, 1914
Type species: Plagiosaurus depressus Jaekel, 1914.
Plagiosaurus depressus Jaekel, 1914
Lectotype: MB.Am.637, posterolateral portion of skull.
Type locality: Baerecke-Limprecht clay quarry, Halberstadt, Saxony-Anhalt, Germany.
Type horizon: Top of Arnstadt Formation (Knollenmergel), Middle Keuper, Norian, Late Triassic.
Referred material: From the type locality and horizon. MB.Am.619, interclavicle (original to Jaekel 1914: fig. 28). MB.Am.620 (trunk vertebral centrum. MB.Am.621, 10 trunk vertebral centra and one neural arch). MB.Am.622 (proximal fragment of a right rib). MB.Am.623 (23 fragments of ribs, one proximal rib fragment being the original to Nilsson, 1937: fig. 13). MB.Am.624-627 (undetermined bone fragments). MB.Am.628 (12 bone fragments and teeth). MB.Am.629-630 (two clavicles). MB.Am.631 (clavicle with articulated cleithrum, original to Nilsson 1939: figs 1, 2, pl. 1). MB.Am.632 (right humerus, original to Nilsson, 1939: fig. 3, pl. 2). MB.Am.633 and 634 (three poorly preserved fragments of neural arches). MB.Am.635: four fragments of neural arches. MB.Am.636: left clavicle (original to Jaekel, 1914: fig. 29). MB.Am.637 (posterolateral skull fragment, lectotype, original to Jaekel, 1914: fig. 26; Nilsson, 1937: fig. 13, pl. V; Hellrung, 2003: figs 35, 36). MB.Am.638 (three mandibular fragments from three individuals, the largest one is original to Jaekel, 1914: fig. 27). MB.Am.678 (interclavicle).
Diagnosis: Autapomorphies: (1) Postorbital in broad contact with parietal. (2) Tabular much abbreviated. (3) Postfrontal absent, so that parietal participates in the orbital margin. (4) Presacral neural spines with broad longitudinal dorsal groove that slopes in a posteroventral direction between the postzygapophyes (Witzmann & Schoch 2024).
References: Jaekel (1914), Nilsson (1937), Hellrung (2003), Witzmann & Schoch (2024).
Fig. 19.
Stratigraphy of the German Lower and basal Middle Triassic with ranges of all valid temnospondyl taxa mapped.
Gerrothorax Nilsson, 1934
Type species: Gerrothorax pulcherrimus (Fraas, 1913)
Gerrothorax pulcherrimus (Fraas, 1913)
Figs. 17A, E, 18A, B
Synonyms: Plagiosternum pulcherrimum Fraas, 1913; Plagiosaurus pulcherrimus Huene, 1922; Gerrothorax franconicus Kuhn, 1932; Plagiosuchus pustuloglomeratus Huene, 1922; Plagiosaurus striatopustulatus Huene, 1922; Gerrothorax rhaeticus Nilsson, 1934.
Lectotype: SMNS 12592, skull (12 cm), figured by Schoch & Witzmann (2012).
Type locality: White (Burrer's) quarry, Pfaffenhofen im Stromberg, Baden-Württemberg, Germany.
Type horizon: Werkstein (white-grey sandstone), Middle Stubensandstein, Löwenstein Formation, Middle Keuper, Norian, Late Triassic.
Referred material:
1. Type locality and horizon. SMNS 12038 (anterior trunk). SMNS 13416 (interclavicle). Erfurt Formation. Kupferzell. SMNS 81518, 81520–81522, 81528 (isolated parasphenoids). SMNS 83616 (skull, ca. 4.8 mm). SMNS 83625 (skull, ca. 4.8 cm). SMNS 83628 (skull, ca. 5.7 cm skull). SMNS 83634 (skull, ca. 4.5 cm). SMNS 83866 (articulated skeleton). SMNS 83070 (fragmentary skull and mandible). SMNS 83867 (postorbital skull bones). SMNS 83868 (skull bones). SMNS 83869 (fragmentary skull). SMNS 84786 (disarticulated skeleton, skull 8 cm). SMNS 84787 (articulated skeleton, skull incomplete). SMNS 84788 (incomplete skeleton, skull 8.6 cm). SMNS 84789 (fragmentary skeleton). SMNS 84791 (hemimandibles). Vellberg. MHI 1989/1 (disarticulated skeleton without skull). SMNS 91284 (articulated postcranium with parts of mandible). SMNS 91354 (partial skull and mandible). Schwäbisch Hall-Steinbach (Albertibank). MHI 1348/1 (right part of skull). Arnstadt, road construction site (sandstones and green mudstones, below Melchendorfer Dolomit). NHMS-WT 2804 (two interclavicles).
2. Grabfeld Formation (Acrodus-Bank). Kaubenheim (Neustadt an der Aisch), Bavaria. SMNS 97109 (dermal bone fragment) (Moreno et al. 2024).
3. Stuttgart Formation (Schilfsandstein). Feuerbacher Heide, Stuttgart, Baden-Württemberg: SMNS 17032 (interclavicle and cleithrum).
4. Steigerwald Formation (Lehrbergschichten). Sonnenberg, Stuttgart. SMNS 11424 (interclavicle fragments, holotype of Plagiosaurus striatopustulatus Huene, 1922), SMNS 55345–55350 (vertebrae). Blasensandstein of Ebrach (Kuhn 1932: pl. 5, Fig. 4; BSM lost in 1944).
5. Exter Formation. Esslingen. SMNS 84180 (osteoderm).
6. Arnstadt-Nord, road construction site, Thuringia. (Few specimens, NHMS).
7. Molsdorf, road construction site, Thuringia. (Few specimens, NHMS).
Diagnosis: Autapomorphies: (1) Skull three times wider than long. (2) Skull dorsoventrally flat, with skull table and palate paralleling one another. (3) Ilium low, with expanded and rugose dorsal end. (4) Ischium and pubis forming large and flat compound bone. (5) Carapace of numerous osteoderms and closed ventral armour of plate-like gastralia, with both types of elements densely ornamented with pustules.
References: Fraas (1913), Nilsson (1934, 1937), Hellrung (2003), Jenkins et al. (2008), Schoch, & Witzmann (2012), Witzmann & Soler-Gijón (2010), Witzmann & Schoch (2013), Witzmann et al. (2012), Sanchez & Schoch (2013).
3. Discussion
3.1. Patterns of relative diversity
The German Triassic is rich in temnospondyl finds that represent a total of 20 genera and 29 species (Figs. 19, 20). They comprise the longest-ranging major tetrapod group in the period and are present in many horizons from the Induan to the Rhaetian stage. The German occurrences of temnospondyls are characterized by a dominance of capitosauroids in various habitats especially in the Olenekian and Anisian, whereas from the Ladinian to the Norian they were less diverse but persisted as abundant apex predators in freshwater environments. Plagiosaurids appear in the basin in the early Ladinian and peaked in diversity in the late Ladinian, with four highly distinct taxa in the Erfurt Formation; with the plagiosaurines they survived up to the Rhaetian. Trematosauroids are the least diverse clade in the basin. The slender-snouted trematosaurids are present with one genus each in the late Olenekian, late Ladinian and late Carnian; each of these taxa appears to have been locally more restricted than other, coeval temnospondyls, especially the widespread capitosauroids. Metoposau-rids are also much less dominant in the Central European Basin (CEB) than in other regions (North America, India) but were locally abundant as apex predators in playa lakes (Gaildorf Horizon, Lehrbergschichten). Interestingly, their size appears to correlate with the size of the lakes or their properties, as indicated by new finds from the Schilfsandstein of Limpurger Berge and the Lehrbergeschichten of several localities in northern Württemberg.
All three clades – capitosauroids, trematosauroids and plagiosaurids – appear to have dwelled streams originally, which must have formed their primary pathways of migration. However, in each clade, lake dwellers evolved (or immigrated) over time: Mastodonsaurus and Tatrasuchus in the Middle Triassic, plagiosaurids in the late Ladinian and Metoposaurus in the Carnian. Plagiosaurids are present in the Anisian and possibly the late Olenekian of cis-Ural Russia (Shishkin et al. 2000, 2023) and probably immigrated in the time when the Muschelkalk Sea covered the basin.
Three other temnospondyl clades known from the Triassic of other regions, the dvinosaurians, amphibamiform dissorophoids and lissamphibians, have not been found in the German Triassic. However, the presence of a salientian (Czatkobatrachus) in the Czatkowice fissure fills of southwestern Poland (Evans & Borsuk-BiaŁynicka 2009) shows that at least lissamphibians may be expected and may appear in microvertebrate samples. Conceivably, they were abundant in environments with poor fossilization potential or whose deposits have not yet been found.
3.2. Faunal changes across the German Triassic
The oldest temnospondyl remain in the German Triassic is a mandible fragment from the Eck Conglomerate (Lower Buntsandstein, Induan) of Nagold in the Black Forest (Schoch, 2011). This is a dentary with closely set, transversely oval tooth sockets typical of stereospondyls, and most likely stems from a small capitosauroid.
The Volpriehausen Formation (basal Middle Buntsandstein, early Olenekian) has yielded a range of diagnostic temnospondyl finds that fall into two genera, Parotosuchus in the Black Forest and Heligoland and Sclerothorax in northern Hesse. Conversely, the Dethfurt Formation is locally rich in tetrapod tracks (Fichter & Kunz 2015) but has not produced diagnostic temnospondyl finds. Relatives of Parotosuchus were extremely widespread during the Olenekian, ranging from Russia (P. orenburgensis, P. orientalis), Poland (P. ptaszynskii) and Germany (P. decumanticus, P. helgolandiae, P. nasutus) over Utah (still undescribed Parotosuchus sp.) to South Africa (P. haughtoni) (Ochev 1966; Damiani 2001; Lucas & Schoch 2002; Sulej & NiedŹWiedzki 2013). The three Parotosuchus species in Germany occur in different time slices and appear not to be closely related, which suggests they document separate events of immigration rather than intra-basin evolution.
In the Hardegsen Formation, the occurrence of two capitosauroids in almost coeval horizons and in close geographic proximity is somewhat surprising, but considering the very incomplete knowledge of Meyerosuchus it may still turn out that Odenwaldia is either a junior synonym or a local variant. The Black Forest region yielded further, mostly indeterminate capitosauroid finds from the Hauptkonglomerat (Geröllsandstein) some of which suggest large animals up to 80 cm skull length or 3.5 m body size (Schoch, 2011). Their symphyseal morphology indicates that these were not mastodonsaurids, but probably parotosuchids. This agrees with the occurrence of large parotosuchid (P. ptaszynskii) at Wiory in Poland (Sulej & NiedŹwiedzki 2013).
The Solling Formation falls into a lower Olenekian-aged unit and an upper member that has an earliest Anisian age (Bachmann et al. 2021). At Bernburg an der Saale, the massive white channel-fills of the lower unit (Bausandstein), exposed in the basal part of the former quarry, have yielded the rich finds of Parotosuchus nasutus and Trematosaurus brauni (Burmeister 1849; Meyer 1858; Schoch, 2018, 2019).
Temnospondyl remains peak in three formations which represent rather divergent facies and environments: the Röt Formation (early Anisian), Erfurt Formation (late Ladinian) and Stuttgart Formation (late Carnian). These are also the time slices with the highest taxonomic diversity. At closer sight, these occurrences fall within quite different environmental settings. In the Röt Formation, stream and lake habitats locally offered good conditions for aquatic predators in cases of more permanent water cover. However, in contrast to later time slices, these habitats did not permit complex trophic networks to form, but the diversity of temnospondyls only emerges as a basin-wide pattern. Locally, Eocyclotosaurus, Stenotosaurus and Mastodonsaurus appear to have been mutually exclusive. The two morphologically close heylerosaurines were apparently confined to rivers, whereas the larger Mastodonsaurus dominates in a rich (reworked) lake deposit in which a mass accumulation formed after a drought (Wepfer 1923). By the late Ladinian, Mastodonsaurus had become established as a giant apex predator in a wide range of lakes, but is also found in lagoons, shallow marine environments, and channel deposits of large rivers.
The slender-snouted heylerosaurines Eocyclotosaurus woschmidti and Stenotosaurus semiclausus of the Röt Formation had more distant relatives in western Europe and North America: Procyclotosaurus stantonen-sis in southern England, Quasicyclotosaurus campi and Eocyclotosaurus wellesi in Arizona and Eocyclotosaurus appetolatus in New Mexico (Kamphausen1989; Schoch, 2000c; Rinehart et al. 2016). Hence rather than adding to ecological diversity, these occurrences probably mirror regional speciation of taxa that filled similar niches in fluviatile environments across northern Pangaea.
The consistency of Wepfer's (1923) lost Heckfeld specimen with the genus Eocyclotosaurus adds to narrowing the Muschelkalk gap in the temnospondyl record of the CEB. Given this assignment is correct, Eocyclotosaurus would occur in three time slices: the Röt Formation in the Upper Buntsandstein, the Grès-à-Voltzia (Grès-àMeules Member) in an equivalent horizon of the Lower Muschelkalk of Alsace and the Meissner Formation of the Upper Muschelkalk. In contrast, the partial skull of “Mastodonsaurus” silesiacus Kunisch, 1885 from the Lower Muschelkalk (late Anisian) of Sacrau near Gogolin (Poland) is fairly consistent with the genus Tatrasuchus and may well represent a distinct, stratigraphically older regional variant or species, which would also give three distinct occurrences in the late Anisian (T. silesiacus), early Ladinian (T. kulczyckii) and late Ladinian (T. wildi).
The Erfurt Formation, classically known as Lettenkohle or Lettenkeuper, was deposited under estuarine conditions in which a vast delta alternated with lakes, swamps, and lagoons (Nitsch 2015). This formation has yielded the most diverse temnospondyl fauna in Europe: the capitosauroids Mastodonsaurus giganteus and Tatrasuchus wildi, the trematosaurid Trematolestes hagdorni, the metoposaurid relative Callistomordax kugleri and the four plagiosaurids Plagiosternum granulosum, Megalophthalma ockerti, Plagiosuchus pustuliferus and Gerrothorax pulcherrimus. Three decades of collecting by private collectors and focused scientific excavations have yielded a wealth of data on the occurrence of these taxa in a variety of lake, stream, and lagoonal deposits (Schoch, & Seegis 2016; Schoch, et al. 2022). According to these, Mastodonsaurus was the most common apex predator in lakes and streams, occasionally replaced or supplemented by Tatrasuchus. Usually only one plagiosaurid occurred at the same time and place, with either Plagiosuchus or Gerrothorax co-occurring with Mastodonsaurus, whereas Plagiosternum inhabited lagoons in which Nothosaurus was the apex predator, and Megalophthalma was found in a large river channel of the Hauptsandstein. Trematolestes was an able swimmer and occurs in many lacustrine deposits with richer faunas, where it was a medium-sized predator. Conversely, Callistomordax is confined to the lake deposits E5 and E6 at Vellberg, where it formed the most common medium-sized predator. Swimming tracks from the Erfurt Formation of Vellberg have recently been described by Mujal & Schoch (2020) who identified capitosauroids as most likely producers.
The Grabfeld Formation formed under more hostile, arid conditions in which large playa lakes or sabkhas were subject to frequent evaporation (Bachmann et al. 2021). In some mudstone-dominated lacustrine sediments, temnospondyl finds are present but throughout fragmentary and hard to identify. A few metoposaurid fragments, a capitosauroid intercentrum and single bones of Plagiosternum and Gerrothorax form the most distinctive of these. These finds show that temnospondyl diversity was lower than in the Erfurt Formation, but still higher than during the Olenekian and even Anisian (Moreno et al. 2024). The marginal, fluvial Benk Formation yielded the skull of Capitosaurus arenaceus, a probable early relative of Cyclotosaurus.
The locally much richer samples from the Stuttgart Formation document that during the late Carnian the number of habitable environments had again increased, and the tetrapod faunas diversified. Two different temnospondyl-bearing facies have been identified: thick fluvial or deltaic sandstones and conglomerates (Stuttgart, Heilbronn, Sulzbach, Mittelhausen, Ansbach, Bielefeld) and a mudstone-dolomite sequence that formed in local lacustrine environments (Gaildorf Horizon). The channel deposits yielded mass accumulations of temnospondyl skulls at Feuerbacher Heide in Stuttgart from which the historic specimens of Cyclotosaurus and Metoposaurus were derived. In the famous Kochenhof quarry, which existed since the late 16th century, large quantities of material had amassed. Single finds from quarries at Bielefeld and the Tübingen area are from such channel deposits (Witzmann et al. 2016). The apex predator Cyclotosaurus is most common in such stream deposits, whereas Metoposaurus was rarer here but formed the single taxon in the Gaildorf Horizon. Gerrothorax is only known from fragments at Feuerbacher Heide, possibly washed in from lakes in the periphery. The giant trematosaurid hyperokynodon is known only from the Jägerhaus locality of Heilbronn that has not yielded other taxa, and for which an estuarine setting based on tidal features was reported by Gehrmann & Aigner (2006). The Stuttgart Formation marks the last occurrence of a trematosaurid globally (Schoch, 2024). This said, the enigmatic stereospondyl Calamops paludosus from Carnian deposits of Pennsylvania bears some resemblance to trematosaurids, but probably is most closely related to the non-trematosaurid trematosauroids from Russia (Inflectosaurus) and Jordan (Sues & Schoch, 2013).
By the latest Carnian, conditions had changed again to more arid but with locally restricted Fossillagerstätten in the Lehrbergschichten and Kieselsandstein. These preserve large playa lakes that were habitable at least in some phases, when Metoposaurus and Gerrothorax settled (Seegis 1997). In the latest Carnian Hassberge Formation (Kieselsandstein in Württemberg, Blasensandstein in Bavaria), Metoposaurus and Gerrothorax were accompanied by Cyclotosaurus. These coarse-grained sandstones derive from sources in the Bohemian Massif and formed in braided or meandering rivers with narrow channels (BEUTLER et al. 1999). As in the channel facies of the Stuttgart Formation, Cyclotosaurus formed a stream dwelling aquatic predator, but in the late Carnian it was accompanied by phytosaurs (Kuhn 1932).
In the Norian, both diversity and abundance of temnospondyls decreased. However, they still rank among the most frequent finds, accompanied by phytosaurs (Hungerbühler 2002; Kimmig & Arp 2010), turtles (Joyce et al. 2013) and aetosaurs (Schoch, 2007) in some facies or regions. Remains of Cyclotosaurus occur in channel sandstones of all Stubensandstein (Löwenstein Formation) units but are most common in the Middle Stubensandstein, where it co-occurs with Gerrothorax. A single diagnostic skull of Metoposaurus in the Natural History Museum London is labelled as “from Stuttgart” and is embedded in a rock with typical sedimentary features as found at Aixheim (Middle Stubensandstein). In fact, old quarries in the Stuttgart region produced sandstones similar to those from Aixheim (Milner & Schoch 2004), and given that the Krasiejów locality, which is so rich in Metoposaurus, was recently found to have an early Norian age (JEwuŁa et al. 2019), its occurrence in the Arnstadt and Löwenstein formations is not that suprising. The occurrence of Cyclotosaurus hemprichi and Plagiosaurus depressus at Halberstadt is consistent with the pattern of the Stubensandstein localities in that a cyclotosaurid and a plagiosaurine formed the last two abundant temnospondyls in the German Triassic whose remains are also found in the Rhaetian Grenzbonebed.
Acknowledgements
We are indebted to Hans Hagdorn, Edgar Nitsch, Dieter Seegis, Theo Simon, Max Urlichs, Rupert Wild, Ralf Werneburg and Florian Witzmann for providing access to specimens under their care or helping with locality data. Isabell Rosin, Norbert Adorf and Andreas Radecker conducted many excavations through the years and have always made my work enjoyable. Traugott and Ute Haubold, Werner Kugler, Brigitte Rozynek and Frank Ullmann donated valuable specimens and provided many hours of help during field work. In recent time, our dear colleague Eudald Mujal has helped with organizing field work and manifold discussions. We thank Ralf Werneburg and Florian Witzmann for their constructive reviews and Günter Schweigert for his editorial work.
