Three cingulates from the early Miocene Chucal Fauna of northern Chile (ca. 17.0–19 Ma; Santacrucian SALMA) are described. A dasypodid, represented by isolated osteoderms, a partial rostrum, and postcranial bones, resembles Stenotatus patagonicus (Eutatini), but is ca. 20% smaller (similar in size to Prozaedyus) and may represent a new Stenotatus species. Two isolated peltephilid osteoderms are referred to cf. Peltephilus sp. A new glyptodontid, Parapropalaehoplophorus septentrionalis, is represented by a mandible, ca. 25% of the carapace, a femur, and other postcrania. This new species differs from other glyptodontids in its dentition (triangular n1-3 and distobuccally elongaten 2-3), mandible (unexpanded angle, vertical coronoid process), osteoderms (absent/poorly defined peripheral figures, large principal figure positioned along posterior edge), and femur (highly elevated greater trochaner). A second specimen may represent P. septentrionalis or a closely related species. No sloths have yet been collected at Chucal. A preliminary phylogenetic analysis of glyptodontids—the first for the group—suggests that Glyptatelinae and Propalaehoplophorinae are paraphyletic and that Parapropalaehoplophorus is an early diverging glyptodontid, not closely related to other Santacrucian species. The revised faunal list for Chucal, which includes 18 mammals and one frog, is depauperate compared to coeval Patagonian faunas. This fauna probably occupied a relatively open, seasonal habitat. Endemism in the Chucal xenarthrans parallels that in other mammal groups, indicating significant latitudinal provinciality in South America during the early Miocene. Furthermore, the record of a glyptodontid basal to a radiation matches patterns observed in other Chucal groups (e.g., chinchilline rodents, mesotheriine notoungulates).

Tooth development is traced in dentitions from 169 embryonic Lamna nasus (96–670 mm fork length [FL]), and 8 juvenile to adult L. nasus (67–300 cm FL). The teeth of these dentitions vary significantly in the attitudes and shapes of their crowns, and the forms of their roots. At some stages of their ontogeny they bear characters of carcharhiniform and alopiid shark teeth, and they may also bear ornamentation on their crowns. In early embryos, the teeth are conical with funnel-shaped roots and resemble skate dermal thorns, Raja spp. Tooth shape changes abruptly at about 350 mm FL to a late embryonic dentition, with very elongate lower anterior teeth, as in Pseudocarcharias. Adult teeth also exhibit significant morphological variation, and exhibit some characters that occur also in primitive neoselachians, such as Synechodus and Paraorthacodus. The importance of these tooth ontogenetic and morphological variations for the study of fossil shark teeth is presented, and a generic diagnosis is offered for juvenile and adult Lamna teeth.

A revision of the semionotids from the Lower Cretaceous Lagarcito Formation of Argentina leads to the conclusion that only one taxon, Neosemionotus puntanus Bocchino, 1973, is represented, instead of two monospecific genera and one species of Lepidotes as originally thought. Neosemionotus shares with Lepidotes the presence of more than one suborbital arranged in one row and a long posteroventral process of the dentary, features that have previously been thought to be diagnostic of Lepidotes. On the other hand, it shares with Semionotus the presence of conspicuous dorsal ridge scales. However, Neosemionotus is unique in the characteristics of its dorsal and anal fins, which are both flanked only by high and strong paired basal fulcra. These fulcra become gradually higher/deeper posteriorly, reaching approximately the height/depth of the first fin ray. Other probable synapomorphies of Neosemionotus are the presence of a long parietal pit line, a small, approximately triangular interoperculum, the complete absence of fringing fulcra on the dorsal, and anal fins, and the presence of only very few long and slender fringing fulcra on the pelvic and caudal fins. The systematic position of Neosemionotus is still unknown, but the presence of probably primitive features like the high number of extrascapulars, short parietals, the arrangement of suborbitals, and short snout indicate a relatively basal position among semionotids.

†Siamamia naga, gen. et sp. nov, is described on the basis of three partly articulated skulls and a collection of isolated ossifications from a continental Early Cretaceous Formation of northeastern Thailand. The new taxon is a †sinamiid halecomorph as demonstrated by the median parietal and other cranial characters. †Sinamiidae is hitherto known by two genera occurring in Early Cretaceous freshwater deposits in China. Although a complete revision of all species within the family is necessary, the Thai material shows characters justifying a new genus. It is the first †sinamiid found outside eastern Asia (South and North Chinese blocks, plus small Central Asian terranes), thus validating the close paleogeographical affinities between mainland Asia and SE Asia in the Early Cretaceous. A preliminary phylogenetic assessment of the new taxon with the data matrix of Grande and Bemis (1998) with the addition of data for †Siamamia and †Tomognathus provides a strict consensus tree similar to the phylogenetic hypothesis of Halecomorphi proposed by these authors, except the basal-most amiids which show a lower resolution in our hypothesis. The †Sinamiidae appear as a monophyletic clade, but the four taxa included in the analysis form a polytomy.

The described actinopterygian—from the Middle Triassic of Canton Graubünden, Switzerland—is a small fish with bones and scales covered with a thick layer of ganoine and with a cranium characterized by large nasal bones sutured medially, an orbital region with an uncommon, large postero-dorsal infraorbital 4 5, possibly one small accessory suborbital bone, and an enlarged preopercle with an expanded antero-ventral region that almost contacts the lateral margin of the skull roof throughout the dorsal limb. The new fish shares with halecomorphs the presence of a supramaxillary bone, and a new halecomorph synapomorphy—the presence of a well-developed dorsal supramaxillary process of the maxilla bearing a posterior notch or articulatory surface for contact with the supramaxilla. The interopercle is small and far away from the posterior part of the lower jaw unlike the condition in halecomorphs and teleosts. †Prosantichthys buergini new genus and new species is proposed as a Halecomorphi incertae sedis, probably close to parasemionotids, but not yet assignable to any of the known halecomorph subgroups.

Significant new material of the Early Carboniferous stem tetrapod Ossinodus pueri has been found in the Ducabrook Formation, Queensland, Australia. An articulated partial skull (including skull roof and palate) as well as isolated jugal, surangular, postsplenial, intercentra, and haemal arch elements are described for the first time. New features of the cranial material include a preopercular bone, and an entirely enclosed quadratojugal sensory canal. This canal exits from the accessory paraquadrate foramen on the inner face of the quadratojugal, suggesting that the foramen was not an opening for nerves or blood vessels to enter the skull. It is argued that enclosed sensory canals may be present but undetected in other early tetrapods. A new reconstruction of the skull and the first full body reconstruction of O. pueri show a tetrapod that appears to be quite different from the whatcheeriids, Whatcheeria and Pederpes. Two phylogenetic analyses, one in which the taxon has an intertemporal, and one in which that bone is absent, place Ossinodus differently. In the first, Ossinodus remains in the Whatcheeriidae, while in the second (in which the intertemporal is absent) it is stemward of the Whatcheeriidae, adding credence to previous suggestions that the Whatcheeriidae may be a grade rather than a clade.

A new genus and species of basal mosasauroid reptile from the Cenomanian (Upper Cretaceous) of Slovenia, previously referred to as the “Trieste aigialosaur,” is described. The new taxon is known from only a single specimen including a well-preserved postcranial skeleton and parts of the skull (i.e., left quadrate, left surangular-prearticular complex, and left angular and splenial). Morphological characters of the quadrate and postcranial skeleton distinguish this new taxon from other basal mosasauroids such as Aigialosaurus dalmaticus, Aigialosaurus (=Opetiosaurus) bucchichi and Carsosaurus marchesettii. Cladistic parsimony analysis of a taxon character matrix composed of 135 characters and 31 terminal taxa resulted in the recovery of 12 equally parsimonious cladograms of 351 steps (CI = 0.48, HI = 0.52, and RI = 0.73). From these cladograms we present a phylogenetic hypothesis on the interrelationships of mosasauroids. Species assigned to Aigialosaurus form the basalmost mosasauroid clade. The new genus described here is reconstructed with Carsosaurus marchesettii in a clade that is the sistergroup to the following clade: (Haasiasaurus ((Halisaurinae, (Tethysaurus nopcsai (Yaguarasaurus columbianus, Russellosaurus coheni)) (Russellosaurina)))); the “Dallas aigialosaur,” Dallasaurus turneri, is found to be the basal-most mosasaurine. Arguments supporting the importance of pelvic evolution to the aquatic adaptations of mosasaurs are given along with a discussion of recent hypotheses of limb evolution in mosasauroids.

For more than 100 years, most pterosaur workers have accepted the traditional reconstruction of the pteroid, articulated in the fovea of the preaxial carpal and directed medially along the anterior margin of a small propatagium in order to control it. A few workers have rejected the traditional reconstruction and advocated an alternative reconstruction with the pteroid directed anteriorly and controlling a large propatagium extending laterally past the wrist. Articulated specimens of a wide range of pterosaurs preserve a sesamoid associated with the tendon of M. flexorcarpi ulnaris in the fovea of the preaxial carpal. No specimen preserves the pteroid articulated in the fovea, and because the sesamoid articulated there, the pteroid could not. Therefore, both the traditional and alternative reconstructions, which are based on the assumption that the pteroid articulated in the fovea, are falsified. The preaxial carpal acted as a strut to increase the leverage of M. flexor carpi ulnaris for wrist extension. The pteroid articulated with the side of the carpal, was directed medially toward the shoulder, and could be extended and depressed to control the propatagium.

Spinosaurid theropod dinosaurs appear to represent convergent morphological evolution toward a crocodylian-like cranial morphology, previously linked to the possibility that spinosaurs adopted a similar, partially piscivorous, trophic niche. Further conclusions are hindered by a lack of quantitative evidence, and an incomplete understanding of the functional significance of key crocodylian cranial characters. A comparative biomechanical analysis of function in the snout of the spinosaurid theropod Baryonyx walkeri has been performed, comparing B. walkeri with a generalised large theropod dinosaur and two extant crocodylians (Alligator, Gavialis) that represent different endpoints of extant crocodylian morphological diversity. The aims of the analysis were (a) to determine which group is the closest functional analogue to B. walkeri, and (b) investigate the mechanical influence on cranial function of the antorbital fenestra and the secondary palate; morphological characters that appear to be of importance in both crocodyliform and spinosaur functional morphology. Results demonstrate that the closest structural and biomechanical analogue to B. walkeri is the extant gharial, rather than the alligator or conventional theropods. The secondary palate confers strength to the alligator skull in torsion, but provides resistance to bending in gharials and B. walkeri. Loss of the antorbital fenestra strengthens narrow or tubular theropod and gharial snouts, but has limited influence on the broader-snouted alligator morphotypes. Consequently, with their large antorbital fenestrae and lack of secondary palate, most theropod skulls were surprisingly suboptimally constructed to resist feeding-related bite loads. The mechanical impetus for archosaur palatal development and fenestral closure appears more complex than previously thought.

The systematics and taxonomy of the large allosauroid Carcharodontosaurus are reviewed and a new species of this theropod is described from the Late Cretaceous (Cenomanian) Echkar Formation of Niger, which is roughly coeval with Cenomanian beds elsewhere in northern Africa. The type species, C. saharicus, was based originally on a pair of isolated teeth from Algeria, to which was referred a partial skull and skeleton from Egypt. All of this material was either lost or destroyed more than 50 years ago. Thus, a neotype is designated for C. saharicus, a well-preserved cranium from the Kem Kem beds in Morocco. Newly discovered material from Niger is distinct from that of C. saharicus, justifying the erection of a distinct southern species. C. iguidensis, n. sp. is represented by cranial (maxilla, braincase, dentary, lacrimal, teeth) and postcranial (vertebrae) remains and grew to the same large body size as C. saharicus. The skull displays several autapomorphies, including a laterally reduced external antorbital fossa, a maxillary anteromedial process that is broadly arched toward the midline, a prominent horizontal crest on the medial aspect of the maxilla, and a deeply invaginated fossa on the laterosphenoid. Unlike C. saharicus the ventral rim of the external antorbital fossa does not protrude laterally, the anteromedial process does not demarcate a deep ventral fossa, and the frontal-lacrimal suture is not elevated. The new material provides evidence of differentiation among Cenomanian-age faunas from the Sahara and supports a close relationship between Carcharodontosaurus, Giganotosaurus, and Acrocanthosaurus.

A new lambeosaurine hadrosaurid, Velafrons coahuilensis, is described as the first lambeosaurine from the Cerro del Pueblo Formation of Coahuila, Mexico, and the first lambeosaurine genus to be named from North America in more than 70 years. Although the holotype specimen is a juvenile individual—as evidenced by its incomplete crest development and relative size compared to other North American lambeosaurines—ontogeny independent autapomorphies have been identified including quadrate with narrow quadratojugal notch and a postorbital with well developed, dorsally positioned squamosal process. Additionally, this taxon is unique in that the prefrontal is not dorsally deflected and anteroposteriorly expanded as in other lambeosaurine taxa of its size, but rather retains the frontal-prefrontal “clamp” present in smaller individuals of other taxa. Phylogenetic analysis places Velafrons in a polytomy with numerous other fan-crested lambeosaurines. The crest structure of Velafrons more closely resembles that of Corythosaurus and Hypacrosaurus because it possesses an anteriorly projecting nasal process over the dorsal premaxilla process. Biogeographically, Velafrons is one of three distinct hadrosaurids known from approximately 73.5 Ma—two lambeosaurines and one hadrosaurine—all restricted to the southern region of the Western Interior Basin of North America.

The teeth of six dinosaur taxa (Carcharodontosauridae indet., Dromaeosauridae indet., Troodontidae indet., Brachiosauridae indet., Iguanodontoidea indet., and Nodosauridae indet.) are identified and described from the early Cenomanian of the Charentes region, western France. The composition and paleoecology of this coastal, insular fauna is discussed. The Charentes dinosaur assemblage shares affinities with Asiamerican and Gondwanan faunas. This clarifies and highlights the role of the European islands in the paleobiogeography of Cretaceous dinosaurs.

The centrosaurine ceratopsid genus Styracosaurus is known from multiple specimens and a multigeneric bone bed in the upper 30 m of the Late Cretaceous Dinosaur Park Formation of southern Alberta, and a single specimen (S. ovatus) from approximately time equivalent sediments of the Two Medicine Formation of Montana. Key cranial elements (nasals and postorbitals) of Styracosaurus appear to undergo similar ontogenetic changes as documented in Centrosaurus. Although all adult-sized centrosaurines except Centrosaurus apertus are known to possess spike-like parietal ornamentation at the P3 position on the parietal, only Styracosaurus has the P4 ornamentation expressed as a well-developed spike. Styracosaurus shows intraspecific variation in the shape of the more anteriorly placed P5–P7 ornamentation that are either the typical unmodified crest-shaped epoccipitals of other centrosaurines or are developed as short spikes. S ovatus from Montana is retained as a valid species based on the autapomorphic convergence of the P3 spikes toward the midline.

Molecular estimates for the divergence of Chrysochloridae (golden moles) and Tenrecoidea (tenrecs) date back to near the K-T boundary, but at present the oldest undoubted fossil members of these clades are early Miocene in age (∼20 Ma). The only Paleogene African genus that has been proposed as a possible stem tenrecoid is late Eocene (∼34 Ma) Widanelfarasia from Egypt, heretofore known only from the lower dentition. Here we employ high-resolution computed tomography to reveal the morphology of the maxillary post-canine dentition of Widanelfarasia, and describe fragmentary dental and mandibular remains of early Oligocene Jawharia (gen. nov.) and Eochrysochloris (gen. nov.). The upper molar dentition of Widanelfarasia provides evidence for an intermediate morphological stage between moderate dilambdodonty and incipient zalambdodonty. Phylogenetic analysis employing the morphological character matrix of Asher and Hofreiter (2006) places Widanelfarasia within crown Tenrecoidea, but an alternative placement of that genus as a stem tenrecoid could not be statistically rejected. Additional support for the latter hypothesis, and for the hypothesis of convergent evolution of zalambdodonty within Afrosoricida, is provided by Eochrysochloris gen. nov., which shares apomorphic premolar features with Miocene Prochrysochloris and extant chrysochlorids, but retains a well-developed talonid basin on its lower molars. Jawharia gen. nov. is interpreted as an advanced stem tenrecoid that provides additional support for the hypothesis that tenrecoid zalambdodonty evolved from moderate dilambdodonty. Some of the apomorphic morphological features shared by Widanelfarasia and early Miocene Protenrec are also seen in Todralestes, from the oldest (late Paleocene) placental mammal-bearing locality in Africa. As such Todralestes may be a stem or crown afrosoricid, and, if so, the oldest known Afro-Arabian member of Afrotheria.

A long-standing taxonomic error is corrected by recognizing that the previously enigmatic early Paleocene (Torrejonian) mammal Microclaenodon assurgens (Cope, 1884) from western North America is a subjective junior synonym of Oxyclaenus cuspidatus (Cope, 1884). Carcinodon simplex (Cope, 1884) (= C. filholianus) is suggested as a new combination. Specimens previously incorrectly referred to O. cuspidatus are tentatively referred to the genus Carcinodon as a new species, “C.” olearyi. A phylogenetic analysis that reconstructed the relationships of Oxyclaenus, “Carcinodon,” selected “triisodontids,” selected basal ungulates, and basal mesonychians incorporates 30 taxa and 66 dental characters and results in up to 210 MPTs, each 180 steps long, with a C.I. of 0.51 and a H.I. of 0.49. O. cuspidatus is resolved as the sister species of Andrewsarchus mongoliensis. The Andrewsarchus Oxyclaenus clade is the sister lineage of Mesonychia. Outside of this grouping, “triisodontids” form a polytomy, which is followed by a clade composed of “C.” olearyi n. sp. and “C.” antiquus.

A new skeleton of Pseudotomus eugenei is described and compared to extant large bodied rodents and those fossil manitshines represented by postcranial material (Pseudotomus robustus, Pseudotomus petersoni, and Manitshatanka). The postcranial skeleton of P. eugenei is unspecialized in terms of individual joint function as well as in overall proportions. The forelimb is heavily muscled with a generalized shoulder but with some distinctive features of the elbow and manus. These include an extremely broad distal humerus, long olecranon process, short proximal and middle phalanges and long, uncompressed ungual phalanges. The hind limb of P. eugenei is also generalized, but departs from those of earlier manitshines in the deeper patellar groove and femoral condyles, and in the size reduction of the peripheral metatarsals, suggesting a stronger commitment to terrestrial life. A quantitative analysis of limb proportions indicates that P. eugenei and the other manitshines generally resemble terrestrial rather than arboreal rodents. This is especially evident in the shape of the radial head, and in the shape and relatively greater lengths of the olecranon process, phalanges and metapodials. These features of the forelimb together with the long and uncompressed ungual phalanges of the manus suggest that when P. eugenei diverges from other manitshines, it is in a semi-fossorial direction. Here it is reconstructed as a generalized terrestrial rodent with fossorial tendencies.

A complete skull of Ursus deningeri recovered from the Middle Pleistocene site of the Sima de los Huesos in the Sierra de Atapuerca (Spain) was studied with computed tomography. This technique makes it possible to study new and relevant information in the endocranial structures and avoids any damage to the specimen. The previously undescribed endocranial cavity of U. deningeri is compared with related species such as Ursus spelaeus Rosenmüller 1794 and Ursus arctos Linné 1758. The characters analyzed include the braincase morphology and also quantitative and volumetric measurements, which are only attainable with this technique. In particular, the volume, surface area, and form of the frontal sinuses and brain cavity, the shape of the ethmoid bone, and the basioccipital pneumatization were studied. The resulting analysis supports an ancestor-descendant relationship for the two ursids included in the cave bear phylogenetic lineage (U. deningeri and U. spelaeus). In contrast, U. arctos exhibits a different endocranial morphology, one that seems to be mainly plesiomorphous. Finally, this study has identified several new endocranial characters which are useful in reconstructing ursid phylogeny.

The species Myosorex meini Jammot, 1977 was a nomen nudum because it was named in an unpublished dissertation. The species is here revised using the new material found in the Late Pliocene fissure infillings of Almenara-Casablanca 1 and 4 (province of Castelló, East of Spain) and from the Tollo de Chiclana localities 1B, 3, 10, and 10B in the Guadix Basin (province of Granada, Southeastern Spain). A new diagnosis is given with some differential characters to identify the species within the family. The species definitively belongs to the genus Myosorex. A definitive new allocation for the genus into the subfamily Crocidosoricinae is proposed as an alternative to the classical assignment to the Crocidurinae. This is justified by available data coming from different fields of research, such as genetics, reproductive biology, morphology, and paleontology. Within the Crocidosoricinae, the tribe Myosoricini Kretzoi, 1965 is resurrected, and two other ones, the Crocidosoricini and the Oligosoricini, are redefined. From the paleobiogeographical point of view, the occurrence of the African genus Myosorex constitutes a new striking evidence of the faunal exchange between Eurasia and Africa that took place during the Messinian Salinity Crisis.