Notosuchians from Cretaceous continental environments of Gondwana have developed an unexpected array of morphologies comparable to mammals and their extinct relatives. However, this exceptional diversity is unbalanced, with South America holding nearly three times the generic diversity of Africa-Madagascar. With the exception of the triconodonts and of a very specialized group, the Gondwanatheria, in none of these landmasses do mammals dominate, and as a result, the low notosuchian diversity in Africa-Madagascar appears to be an artifact of sampling. Here, we describe a new miniature notosuchian from the Albian-Cenomanian Kem-Kem Beds of Morocco filling this gap. Lavocatchampsa sigogneaurussellae, gen. et sp. nov., exhibits a new type of heterodonty with absence of maxillary and dentary caniniform dentitions and teeth that gradually become massive posteriorly, and possess a sharp elongate median carina flanked by two multicusped cingula. The occlusion pattern is revealed by computed tomography and scanning electron microscopy (SEM) and shows that the main component of jaw closure is vertical, and not horizontal as has been proposed in closely related forms. Phylogenetic analysis recovers the new taxon as part of a basal stock of Gondwanan ziphosuchians with close affinities to Candidodon itapecuruense, Malawisuchus mwakasyungutiensis, and Pakasuchus kapilimai. We revise the diagnosis of Candidodontidae, a clade characterized by a particular heterodont dentition recalling that of triconodont mammals. The recognition of this new clade confirms previous hypotheses of a vicariant vertebrate assemblage present on a continuous South American-African landmass.

Disarticulated remains of palaeobatrachids coming from the early Pleistocene (Gelasian) of Tegelen (The Netherlands) are here described and referred to the new species Palaeobatrachus eurydices. The new species has been included in the first comprehensive phylogenetic analysis considering all known species of the genus Palaeobatrachus and was found to be the sister taxon of the Oligocene/Miocene P. robustus. Palaeobatrachus eurydices P. robustus form a clade with P. langhae, and this latter clade is sister to all other Palaeobatrachus species. Extreme adaptation to permanent life in water is evidenced in P. eurydices by absence of the fossa cubitalis ventralis, and less developed olecranon on the radioulna. The water-rich and warm environment of Tegelen, indicated by other elements of the fauna such as beavers and the terrapin Mauremys, could have acted as a refugium for these water-dwelling anurans, which were thought to have disappeared from western Europe by the Miocene/Pliocene boundary.

A petrosal bone from the French Middle Miocene locality Sansan is described. It belongs to the tragulid species Dorcatherium crassum. Using high-resolution X-ray computed tomography, we scanned this petrosal bone and segmented its embedded bony labyrinth. We compared the morphological data with those of three living Tragulidae: Tragulus javanicus, Hyemoschus aquaticus, and Moschiola meminna. We ran a phylogenetic analysis where fossil and extant pecoran ruminants were included to understand the distribution of characters of the petrosal bone and bony labyrinth within ruminants. We propose a set of new synapomorphies for the Tragulidae among the Ruminantia, including the absence of the basicapsular groove, a knob-shaped mastoid region, a knob anterior to the subarcuate fossa on the petrosal bone, a high number of cochlea turns, the dorsal insertion of the posterior limb of the lateral semicircular canal, the extension of the lateral semicircular canal beyond the plane of the posterior semicircular canal in dorsal view, and a pouch-like endolymphatic sac on the bony labyrinth. The clade constituted by Tragulus and Moschiola is confirmed by new synapomorphies such as a double convexity of the promontorium and a large pouch-like endolymphatic sac that covers the common crus. We demonstrate the potential of characters of the bony labyrinth for the phylogeny of ruminants.

Schowalteria clemensi Fox and Naylor, from the latest Cretaceous lower Scollard Formation, Red Deer Valley, Alberta, is the only known Mesozoic member of the extinct mammalian order Taeniodonta. Schowalteria clemensi was originally classified in the derived family Stylinodontidae, but more recent studies employing computer-assisted phylogenetic and stratocladistic analyses of taeniodont interrelationships contend that S. clemensi is the basal taeniodont, whereas Onychodectes, long considered the basal taeniodont, is instead the sister group of stylinodontids alone. These studies, however, are deeply flawed, marred by selection of problematic outgroups, incorrect scoring of numerous character states and of the stratigraphic age of S. clemensi, omission of all stylinodontid-like characters of S. clemensi, and reliance on major, implausible reversals during early taeniodont history. The more recent of these analyses also examined the relationship of taeniodonts within Eutheria, but this data set includes 54 (61%) erroneous scores for S. clemensi, the only taeniodont in the analysis. Moreover, subsequently published errata introduced new errors into the analyses. Thus, the hypothesis that S. clemensi is the earliest discovered stylinodontid remains unrefuted by these studies: the earliest history of stylinodontids and that of more basal taeniodonts is still to be discovered, among species older than S. clemensi itself.

Eleven species of archaeopterodactyloid pterosaurs have been reported in China, mostly from the Yixian Formation of western Liaoning. The first uncontroversial archaeopterodactyloid from the Jiufotang Formation is described here. A new genus and species, Forfexopterus jeholensis, is erected on the basis of a unique combination of characters and one autapomorphy: the first wing phalanx is shorter than the second, but longer than the third. The sternum of Forfexopterus is nearly complete and provides the first incontrovertible evidence about the position of sternocoracoid articulations in the Archaeopterodactyloidea. A preliminary geometric morphometric analysis of sterna was carried out with data from 17 species of Pterodactylomorpha. The results document the variation in the shape of the sternum, including the length of the cristospine, the shapes of the lateral, posterior, and anterior margins, and the constriction and expansion of the cristospine. These characters can be used to compare sterna in different pterosaur taxa.

Postcranial morphology of Paleogene lipotyphlans (Mammalia: Laurasiatheria) is poorly known relative to dental morphology. When these elements can be referred, they have proven to be a rich source of data for phylogenetic and ecological inferences. In particular, tarsal morphology has challenged hypothesized relationships of several taxa. We refer isolated tarsals from several early and late Uintan (middle Eocene) localities in the San Diego area to three genera of sespedectine erinaceomorph lipotyphlan, Crypholestes, Proterixoides, and Sespedectes, based on patterns of size, morphology, and abundance. Astragali and calcanei are confidently referred to all three genera, whereas naviculars are more tentatively referred to Proterixoides and Sespedectes, and cuboids to Sespedectes. Tarsals of the three genera are morphologically nearly uniform, supporting their hypothesized close relationship. The most significant difference is a relatively longer calcaneal tuber in Proterixoides. The tarsal morphology of Sespedectinae is most consistent with an unspecialized terrestrial locomotor repertoire. Some distinctive features of the sespedectine tarsus, such as ‘S’-shaped ectal facets and a prominent tuber tibialis on the navicular, are potentially indicative of lipotyphlan affinities. However, there is no support for an exclusive relationship to extant erinaceids (or any other lipotyphlan family) or to other Paleogene erinaceomorphs (Macrocranion, Zionodon). Phylogenetic analysis confirms that sespedectines are most likely relatively basal lipotyphlans and that Erinaceomorpha is not a natural group.

The Bridger Formation of the early middle Eocene of Wyoming has been studied for its sedimentology, paleobotany, herpetofauna, and mammalian fauna. Although several taxa have been erected based on its abundant fish material, there has been little work on Bridger Formation fishes other than these initial descriptions. We here describe the fishes of the Farson Cutoff Fishbed, a single Bridger Formation locality in the Bridger Basin. This material is almost entirely disarticulated and has a notably low taxonomic diversity, representing only three taxa: Lepisosteidae, Phareodus, and Astephus. However, a wide variety of elements are three-dimensionally preserved, showing details that are not visible in articulated specimens and providing insight on the internal anatomy of some elements. The longevity and growth rate of the Bridger Formation catfish Astephus were compared with those of the Cypress Hills Formation Astephus. Longevities were found to be similar, but two distinct growth rates were found in the Cypress Hills material, supporting the hypothesis that two Astephus taxa were present in that formation. The Bridger Formation Astephus had a similar growth rate to the smaller Cypress Hills Formation catfish Astephus taxon B, whereas the larger Astephus taxon A had a significantly faster growth rate.We here interpret the low taxonomic diversity of the Bridger Formation assemblage as a paleoenvironmental indication of hypoxic conditions in the depositional environment. The Farson Cutoff Fishbed probably represents poorly oxygenated backwaters that would have been susceptible to becoming isolated and infilled, preserving a low diversity of fishes capable of sustaining hypoxic conditions.

A partial ornithomimid skeleton, ROM 1790, from the lower Dinosaur Park Formation (upper Campanian) of Alberta was previously referred to Struthiomimus altus, but lacks diagnostic characters of that species. It is here described as the holotype of a new species, Rativates evadens, gen. et sp. nov., diagnosed by the form of the maxilla-jugal contact, the reduction of the mid-caudal neural spines, the convex fusion of the left and right ischial shafts, the straight-edged distal end of the third metatarsal, and possibly the relatively enlarged medial condyle of the tibia. A histological section of the femur confirms that the type specimen is not a juvenile, despite its relatively small size (approximately 50% the size of large individuals of Struthiomimus altus). Phylogenetic analysis recovers Rativates as a member of a derived ornithomimid clade that includes Ornithomimus, Struthiomimus, and the Asian taxa Anserimimus and Qiupalong. Fusion of the proximal tarsals to the tibia in some ornithomimid specimens was observed to be more complete than previously recognized, increasing the suite of features that these non-avian dinosaurs share homoplastically with birds.

New material from the Upper Devonian (Frasnian) Nordstrand Point Formation of Ellesmere Island, Nunavut, Canada, represents the largest known species of antiarch and the first described from the Nordstrand Point Formation. Bothriolepis rex, sp. nov., is additionally remarkable for the thickness and compactness of its dermal skeletal plates. The new species is diagnosed by a preorbital recess with a horizontal rostral margin; the presence of a wide unornamented border surrounding the infraorbital sensory line; central sensory lines that meet the margin of the nuchal close to the lateral corners; a supraotic thickening that does not extend caudal to a transverse crista of the nuchal; and a tall lateral lamina of the anterior dorsolateral. The thick and compact armor of Bothriolepis rex, sp. nov., recalls that of the co-occurring Perscheia pulla and gives occasion to a physical and ecological review of dermal skeletal mass and density in large-bodied, bottom-dwelling organisms in nonmarine ecosystems during the Late Devonian.

Two specimens originally referred by Louis Dollo to Goniopholis simus from the Lower Cretaceous of Bernissart, Belgium, are described. They consist of fully articulated skeletons, one missing the skull and mandible. Comparison of these specimens with recently revised specimens from the Wealden of England allows confirmation that the Belgian specimens are referable to the goniopholidid Anteophthalmosuchus hooleyi. The Belgian specimens are the most completely known representatives not only of this species but also of any Goniopholididae. Study of the postcranial skeletons from Bernissart reveals that the appendicular skeleton closely resembles that of derived neosuchians. The dorsal and ventral shields present a morphology directly comparable to other goniopholidids and pholidosaurids. Such observations stress the necessity to gather an osteological database of postcranial elements to test relationships of the various neosuchian lineages. Goniopholididae were relatively diverse during the Early Cretaceous of Europe, and depending on taxonomic opinion, three to five genera are recognized: Anteophthalmosuchus, Goniopholis, Hulkepholis, and possibly Vectisuchus and Nannosuchus.

Sabinosuchus coahuilensis, n. gen. et sp., is a marine crocodyliform from the Upper Cretaceous Sauz Creek Member or lower part of the Cuevas Creek Member of the Escondido Formation (Maastrichtian) near Sabinas in Coahuila, Mexico. The type specimen exhibits two synapomorphies of family Dyrosauridae: dentary alveolus 7 is reduced in size compared with the eighth, and the mandibular symphysis is nearly as wide as it is high for most of its length. Sabinosuchus coahuilensis is distinguished from all other known members of Dyrosauridae on the basis of three autapomorphic traits: the posterior section of the mandible is distinctly broad and flat, the mandibular rami are considerably longer than the symphysis, and the posterior mandibular alveoli are uniquely arranged. Sabinosuchus coahuilensis joins Hyposaurus rogersii as the second known North American dyrosaurid. Although the two were contemporaneous, they differed notably in rostrum length and shape; S. coahuilensis has a relatively shorter rostrum with a much wider and flatter posterior mandibular symphysis. Phylogenetic analyses and biostratigraphy suggest that S. coahuilensis occupies a basal position in Dyrosauridae.

A fossil egg clutch from the Pleistocene of Lord Howe Island, Australia that we assign to Testudoolithus lordhowensis, oosp. nov. belongs to the stem turtle Meiolania platyceps. This ootaxon is diagnosed by the following unique combination of characters: large spherical eggs (53.9 mm diameter), 800-µm-thick eggshell, and barrel-shaped shell units with height-to-width ratio of 1.2:1. Thin sections and scanning electron microscopy demonstrate that these eggs are composed of radiating acicular aragonite crystals. This mineral composition first evolved either before the split between Meiolaniformes and crown Testudines or prior to Proterochersis robusta, the earliest known stem turtle. A calculated gas conductance of 170.27 mg H₂O day^-1 Torr^-1 for Meiolania platyceps eggs compares closely with that of two extant tortoise eggs. This value and the presence of at least two superimposing egg layers within the clutch indicate that Meiolania platyceps deposited its eggs inside an excavated hole nest. This nesting strategy likely evolved no later than the Early to Middle Jurassic.

The postcranial anatomy of giant titanosaurians remains poorly known because of a combination of preservational and collection biases. Dreadnoughtus schrani, a recently described, large titanosaur from the Campanian—Maastrichtian Cerro Fortaleza Formation of Santa Cruz Province, Argentina, offers the first opportunity for detailed study of appendicular anatomy of a truly giant titanosaurian. The entire appendicular skeleton is represented except the manus and portions of the pes. Comparisons with related titanosauriforms reveal that the holotype skeleton (MPM-PV 1156) exhibits three appendicular autapomorphies: (1) a cranioventrally-caudodorsally oriented ridge across the medial surface of the cranial end of the scapular blade; (2) a distinct concavity on the caudomedial surface of the proximal radius; and (3) the distal end of the radius is subrectangular with subequal craniocaudal and mediolateral dimensions. Appendicular synapomorphies shared between Dreadnoughtus and other titanosauriforms encompass a wide range of body sizes, from the giant Argentinosaurus to the dwarf Magyarosaurus. Among described titanosauriforms, only a single feature occurs exclusively among the appendicular skeletons of the largest taxa: an accessory ventrolateral process is present on the preacetabular lobe of the ilium in Dreadnoughtus, Alamosaurus, and Giraffatitan. This process appears to have arisen in response to greater stress applied by hind limb adductor musculature in these giant terrestrial vertebrates. Continued investigation of titanosaurian anatomy, myology, and biomechanics is needed to gain greater understanding of the functional nature of widegauge posture.

A new ginglymodian fish, Khoratichthys gibbus, gen. et sp. nov., is described based on the impression of a single articulated fish preserved on a sandstone slab from the Late Jurassic—Early Cretaceous Phu Kradung Formation, northeastern Thailand. Khoratichthys gibbus is characterized by a distinct humpbacked body with elongate posterior spines on the dorsal ridge scales; the cheek is completely covered by bone; it has few infraorbitals, the elongate anterior-most one shows a tiny contact with the orbit, and six suborbitals arranged in one row; the opercule is rectancular in shape; the preopercule is narrow and regularly curved; and the interopercule large. A cladistic analysis including the type species of 25 ginglymodian genera indicates that Khoratichthys is the basal-most Lepisosteiformes, in an unresolved position with Neosemionotus and Lophionotus. This taxon provides a new evidence of the high diversity of ginglymodian fishes in the Phu Kradung Formation. A high taxic diversity of ginglymodians in Middle Jurassic—Early Cretaceous of southern Asian (excluding India) freshwater environments is observed, indicating that this clade occupied a major position in freshwater fish assemblages.

Plastomenidae is a speciose clade of soft-shelled turtles (Trionychidae) known from Campanian to Eocene deposits throughout western North America. We here describe two large skulls from the Upper Cretaceous (Maastrichtian) Hell Creek Formation of Carter County, Montana, that document the adult morphology of the plastomenid Gilmoremys lancensis. Whereas juveniles of this species, as previously documented by five subadult skulls, have narrow skulls, a narrow processus trochlearis oticum, a deep and narrow median palatal groove, low accessory ridges, and a secondary palate fully formed by the maxilla, skeletally mature individuals have notably broad skulls, a broad processus trochlearis oticum, a shallow but broad median palatal groove, high accessory ridges, and a substantial contribution of the vomer to the secondary palate. An expanded phylogenetic analysis reveals that the Campanian Aspideretoides foveatus and the Paleocene Aspideretoides superstes, nov. comb., are situated within Plastomenidae as sister to all previously identified plastomenid turtles, despite their general resemblance to trionychine soft-shelled turtles. The name Aspideretoides should therefore not be used as a taxonomic wastebasket for fossil trionychids with unclear phylogenetic relationships.

The extinct clupeomorph genus Armigatus has been included in a number of phylogenetic analyses, with disagreement about its placement and relationships among the fishes of the extinct clupeomorph order Ellimmichthyiformes. There are currently four species known, all from the Late Cretaceous Tethys Sea. Here we describe a fifth species of Armigatus from Campanian deposits of Dalmatia and present a phylogenetic analysis of the genus. The new species is found to be sister group to A. oligodentatus from Morocco, and the two together form the sister group to the species from Lebanon, A. namourensis plus A. brevissimus (A. alticorpus was excluded because of lack of data). The genus Armigatus is found to be monophyletic, as are the included members of its sister group, Diplomystus, and the analysis supports the grouping of these two genera in the family Armigatidae. The relationships among the species of Armigatus indicate that these fishes arose in the eastern part of the central Tethys, then from there reached more northern (Dalmatian) and western (Morocco) areas.

The frog genus Odontophrynus comprises 10 species arranged in three species groups that inhabit southeastern South America. In Argentina, it is represented by the O. americanus and O. occidentalis species groups and, despite being a fairly common taxon of the extant herpetofauna, it has no known fossil record. Here we report on the first fossil record of the genus, based on an almost complete right ilium from the lower levels of the Buenos Aires Formation (OIS 11, Bonaerian age, middle Pleistocene) in the Bonaerian Pampas of Argentina. The taxonomic allocation is derived from a thorough survey of anuran ilia and is grounded in a set of distinct ilial characters that, in combination, do not occur in any other anuran. These include: ilium not fused to ischium; well-developed dorsal acetabular expansion; broad preacetabular zone with a shallow preacetabular fossa; straight ilial shaft lacking dorsal ridge; and spike-like dorsal prominence bearing a distinct dorsal protuberance. Additionally, after comparing with a large sample of specimens representing most species of Odontophrynus, we propose two main characters (high spike-like dorsal prominence, absence of a lateral knob on the dorsal prominence) that allow referral to Odontophrynus aff. O. americanus or O. cordobae.

A new litoptern Cramaucheniinae species, Pternoconius bondi, sp. nov., from Colhuehuapian levels of the Sarmiento Formation in Bajada del Diablo (Chubut, Argentina) is described herein. The specimen belongs to an adult animal and preserves the anterior portion of the skull with the maxillary region, some fragments of nasal bones, a small portion of the left zygomatic process, and most of the upper dentition (i.e., left P2–M3, right C, and right P1–M3). It is compared with the Deseadan species ?Coniopternium primitivum Cifelli and Soria 1983 and Pternoconius polymorphoides Cifelli and Soria 1983, and also with the Colhuehuapian species Cramauchenia normalis Ameghino and Theosodon lydekkeri Ameghino. Although the hypocone and precingulum development, the paracone and metacone heights, and the connection between paraconule and protocone are singular features, the main characters that diagnose this new species are lack of a mesostyle pillar, soft labial bending of the ectoloph, absence of the metaconule in molars, and the smaller size with respect to other species of the genus. Comparative study leads us to recognize this specimen as a new species that increases the diversity of the Macraucheniidae in the early Miocene of Patagonia.