Two new tetrapod trace fossil records from the Triassic of Antarctica are described. The first is a giant terminal chamber collected from the lower Fremouw Formation (Lower Triassic) at Wahl Glacier (Beardmore Glacier region, central Transantarctic Mountains). Comparison to South African burrows known to contain the cynodont Thrinaxodon liorhinus, suggests that the Antarctic fossil was created by a tetrapod of similar size. The second set of tetrapod burrow casts was collected from Member ‘A’ of the Lashly Formation (lower Middle Triassic) and, if correctly interpreted, represent the first evidence of tetrapods from the Middle Triassic of Victoria Land. Our findings demonstrate that tetrapods were present in Victoria Land during the Middle Triassic, despite not being recovered as body fossils until the Upper Triassic in that region. Comparison to morphologically similar South African trace fossils suggests that procolophonids might have produced the Antarctic burrows, but this attribution is necessarily speculative because burrow inhabitants have not been found in situ and no morphological feature uniquely ties procolophonids to this type of trace fossil. We propose that underground burrows and dens were important shelters for Antarctic terrestrial vertebrates during the Triassic, despite a relatively moderate climate.

Chlamydoselachus teeth recorded from the Takatika Grit, Chatham Islands, Southwest Pacific, are Danian in age and represent a new species of Chlamydoselachidae and the oldest Cenozoic record in the world, once considered to be Lazarus taxon for the early Paleogene. The new species Chlamydoselachus tatere n. sp. is diagnosed by three prominent upright cusps that display weak ornamentation restricted to the base of the cusp, a cutting edge that reaches the root and lacks intermediate cusplets. The root is broader than long and is labiolingually shortened with a wide transverse notch and poorly differentiated lobes. The variable tooth morphology within these Chatham specimens confirms that the fossil taxon has a slight degree of intraspecific variation laterally within dentition. Posterolaterally, the cusps become more gracile with greater lingual inclination and increasing separation between cusps. Also, the root becomes labiolingually shorter and the transverse notch wider and shallower. The presence of the chlamydoselachians in the shallow marine Takatika Grit indicates that early in its evolutionary history the group may have inhabited shallow neritic environments and their teeth were more robust, possibly a reflection of the sharks predatory lifestyle.

The Early Permian dvinosaur temnospondyl Acroplous vorax Hotton, 1959 is redescribed based on new specimens from the Eskridge Formation of Nebraska, and an unpublished specimen collected from the Speiser Shale of Kansas in 1960, along with reanalysis of previously described Acroplous specimens. The Nebraska Acroplous specimens are part of the oldest Permian (Asselian) nonmarine vertebrate faunal assemblage in the Paleozoic midcontinental sequence of the United States based upon invertebrate biostratigraphy. This study reveals previously unknown anatomical features for Acroplous, requiring a reassessment of the genus and the Eobrachyopidae. Among the new findings for Acroplous are: an anterior dorsal fenestra; prefrontals excluded from the external naris; lacrimal contacting the orbit; denticulated palatine, ectopterygoid and pterygoid; a lack of a postglenoid transverse trough; an unusual interlocking mandibular symphysis, and an elongate rod-like ilium. A cladistic analysis of 87 characters and 12 temnospondyl taxa indicates that the Eobrachyopidae (Acroplous and Isodectes) may be a paraphyletic group, with Isodectes filling a more basal position within the Dvinosauroidea.

Recent studies have shown that the Middle Jurassic is a key time for understanding the origin and early evolution of crown group turtles, but few turtle-bearing localities from this epoch are known. This study adds to our knowledge by providing a detailed description of two poorly characterized specimens (IVPP-V6507 and IVPP-V8805) from the Middle Jurassic of China that previously were both assigned to the poorly known species Chengyuchelys baenoides. This reappraisal allows us to present new observations, images, and taxonomic conclusions about these specimens and others from the same locality (Dashanpu, Zigong Prefecture, Sichuan Province, China). With at least four species, Dashanpu is the most diverse locality from the Middle Jurassic; all other turtle localities from this time have only one species each. We place Chengyuchelys into a cladistic analysis of turtle relationships for the first time. Our analysis places Chengyuchelys as sister to Xinjiangchelys latimarginalis and solidly on the stem of Cryptodira. This result is surprising because Chengyuchelys retains mesoplastra. Nevertheless, derived osteological and scalation characters of this taxon drive its phylogenetic position as a relatively advanced stem cryptodire. This finding, combined with a reappraisal of other Middle Jurassic turtles from Asia, shows that the crown group Testudines had evolved by the Middle Jurassic. Unfortunately, many key specimens from Sichuan Province are still poorly characterized morphologically and stratigraphically. This lack of phylogenetic and temporal resolution hinders our understanding of the origins of extant turtle clades, but also highlights the importance of Jurassic Asian turtles for ultimately resolving these issues.

The first in situ turtle egg clutch reported from China comes from the Lower Cretaceous (Albian) Liangtoutang Formation in the Tiantai Basin, Zhejiang Province. This clutch originally contained a minimum of 27 eggs, but four eggs separated from the clutch during excavation. The spherical eggs vary from 34 to 52 mm in diameter. The eggshell is 0.7–1.0 mm thick and has straight, narrow shell units with parallel margins and a height-to-width ratio of 2.5–3:1. Two eggs from this clutch previously were used to establish the new oogenus and oospecies Tiantaioolithus jiangi Fang et al., 2003, within the oofamily Testudoolithidae Fang et al., 2003. Based on our examination of all available eggs from this clutch, we propose the following: (1) Testudoolithidae Fang et al., 2003, is a junior homonym for Testudoolithidae Hirsch, 1996; (2) Tiantaioolithus Fang et al., 2003, is a junior subjective synonym of Testudoolithus Hirsch, 1996; and (3) the eggs pertain to a distinct oospecies, namely Testudoolithus jiangi (new combination). A previously unreported, isolated egg from the Upper Cretaceous (stage unknown) Chichengshan Formation in the Tiantai Basin is also referred to Testudoolithus jiangi based on its similar size, shell thickness, and shell unit height-to-width ratio; this specimen thus extends the fossil record of this oospecies into the Late Cretaceous. Taphonomic assessment of the egg block suggests that the egg clutch was buried in the substrate in a manner similar to modern turtles. The large, spherical eggs and large number of eggs in the clutch indicate the eggs were laid by a turtle taxon of large body size. The thick eggshell and sparse pores penetrating the shell indicate adaptation for a relatively arid, terrestrial environment.

A rare partial postcranium and isolated humeri of Nothosaurus from the Lower Muschelkalk of Winterswijk, The Netherlands are described. The partial skeleton consists of a vertebral column with ribs, pectoral girdleelements, and incomplete forelimbs. Because current species-level taxonomy of Nothosaurus is based only on features of the skull, we examined the postcranial morphology in detail in order to assign the skeleton to a valid species. We focused on the humerus because this bone generally shows a complex morphology in Lower Muschelkalk Nothosaurus. Three different humerus morphotypes were recognized in the Winterswijk material, which were also seen among humeri from other Lower and lowermost Middle Muschelkalk localities such as Rüdersdorf and Oberdorla (both in Germany), and Gogolin (Poland). Morphotype I is characterized by a slender appearance with a bulky proximal end. The preaxial and postaxial edges of the shaft are very distinct, and the distal end is fan-shaped. Morphotype II is rather small and gracile with the distal end being only slightly fan-shaped. Morphotype III is rather large with an especially massive proximal end, and the distal end is thick and shovel-like. Ontogenetic variation could also be recognized within the morphotypes. Onesmall humerus from Oberdorla belongs to a juvenile and cannot be assigned to a specific morphotype. Type II humeri belong to the N. winterswijkensis-N. marchicus clade. Type III may represent a sexual morph of type II humeri and typeI a new species of Nothosaurus, or both may pertain to the nothosaurian Germanosaurus and/or the eosauropterygian Cymatosaurus.

A new species of the basal tylosaurine mosasaur Taniwhasaurus, is described from materials collected from upper Santonian-lower Campanian marine clastics outcropping near Mikasa City, Island of Hokkaido, Japan. The type species, Taniwhasaurus oweni Hector, 1874, was originally described from a partial frontal and right and left dentaries collected from the middle Campanian, Conway Siltstone Formation at Haumuri Bluff, New Zealand. Taniwhasaurus n. sp. shares the diagnostic features of the generic type (i.e., prefrontal forms portion of naris precluding frontal-maxillary contact), but is differentially diagnosed at the specific level by features of the teeth (number of flutes), the postorbitofrontal morphology, the contact and degree of overlap of the premaxilla and frontal, and the morphology of the jugal. Recent recharacterization and rediagnosis of Lakumasaurus antarcticus Novas et al., 2002, as Taniwhasaurus antarcticus, establishes the existence of a third species of the genus, and broadens the paleogeographic and stratigraphic distribution of these animals in Upper Cretaceous circum-Pacific basins. These three species range temporally from the upper Santonian-lower Campanian to upper Campanian, and geographically, from the northern to the southern hemisphere. Endemism of the previously recognized species of Taniwhasaurus is contradicted by recognition of the first Japanese Taniwhasaurus.

Aspects of the cranial and postcranial anatomy are presented for a new specimen of the Upper Cretaceous Gondwanan snake, Dinilysia patagonica Woodward, 1901, collected near Paso Cordoba, Rio Negro Province, Argentina, during the field season of 2001. The specimen preserves important features of the dentary and postdentary bones (inparticular the coronoid and compound bone), the quadrate, and the ventral surface of the basicranium, as well as the axis, atlas, and anteriormost cervical vertebrae. The third and fourth cervicals are preserved with unfused and articulating intercentra on large, ovate, concave hypapophyses (typical of dolichosaurs, mosasaurs, adriosaurs, etc.), while the inter-centrum of the fifth appears to be fused to a long, narrow hypapophysis (this latter condition is typical of modern snakes). These new data influence the construction of primary homology statements used in cladistic analyses of squamate phylogeny generally and ophidian phylogeny specifically. Comparison of the cranial anatomy of Dinilysia to that available for the recently described Argentine Gondwanan snake, Najash rionegrina Apesteguía and Zaher, 2006, indicates important similarities in the two species to the exclusion of scolecophidian snakes.

A partial but largely articulated skeleton of a ‘rauisuchian’ archosaur from Late Upper Triassic strata of the Durham sub-basin, Deep River basin, Newark Supergroup, North Carolina, represents a new species of Postosuchus Chatterjee, 1985. It represents the first record of this taxon from eastern North America. The well preserved specimen includes cranial bones, a largely articulated right manus, right and left pedes, pubes, axis, several postaxial cervical, dorsal, and caudal vertebrae, chevron bones, osteoderms, interclavicle, clavicles, cervical ribs, a sacral rib, and a complete set of gastralia. The skeletal elements are described and compared to those of other ‘rauisuchians’. An apparant autapomorphy of Postosuchus alisonae includes a well developed flange on the proximal portion of metacarpal II fitting into strongly proximally grooved metacarpal I. The new specimen includes many bones previously unknown for Postosuchus and it allows a more complete differentiation of Postosuchus from other ‘rauisuchian’ genera. Diagnostic features of this genus include an axis with two ventral keels; postaxial cervical centra with strongly developed single ventral keels that are anteriorly and/or posteriorly extended into hypapophyses; short ribs on the anterior cervical vertebrae; heart-shaped cervical neural ‘spine tables’; a subrectangular, relatively short coracoid; and proportionately short manus with dorsoventrally compressed, reduced, blunt unguals on manual digits III and IV. Morphological comparisons indicate a close relationship between Postosuchus and Batrachotomus and possibly also Tikisuchus.

New material of the fossil crocodyliform taxon Mahajangasuchus insignis from the Upper Cretaceous Maevarano Formation is described. The holotype lacked cranial remains but the new material includes an almost complete skull as well as at least two additional partial skulls. These new specimens add important information and allow us to diagnose Mahajangasuchus insignis as a derived mesoeucrocodylian crocodyliform distinguished by the following combination of characters (autapomorphies indicated with an asterisk): broad platyrostral snout; laterally compressed and serrated teeth; dorsally arched mandible; prominent caudofemoralis flange on femur; surangular with prominent lateral expansion anterior to glenoid fossa; supraocciptial excludes the parietal from occipital margin; massive choanal septum*; anterior margins of choanal septum contact ventral lamina of pterygoid, enclosing internal choanae*; strongly arched jugal with depression below orbit*; three prominent ridges running longitudinally on dorsal surface of snout*; fused nasals.* The new specimen offers new information to explore the phylogenetic relationships of Mahajangasuchus insignis and bears important information for understanding the evolutionary history of the crocodyliform palate and the adaptive significance of the modern eusuchian-style palate. The phylogenetic analysis conducted results in the discovery of monophyly of the traditional Peirosauridae and a derived position for Mahajangasuchus and Stolokrosuchus as successive sister taxa to Neosuchia. Inclusion or exclusion of Trematochampsa taqueti, a fragmentary taxon from Africa, greatly affects the phylogenetic relations of Mahajangasuchus.

A gavialoid crocodylian from the Maastrichtian of the Oulad Abdoun phosphatic Basin (Morocco) is described, representing the oldest known crocodylian from Africa. The specimen consists of a skull that exhibits several features not found in other gavialoids, and a new genus and species is erected, Ocepesuchus eoafricanus. A phylogenetic analysis has been conducted including 201 characters and 71 taxa, where Ocepesuchus eoafricanus appears as the most basal African gavialoid, and the South American gavialoids are paraphyletic. This paraphyly has strong biogeographic implications, and the previous hypothesis of South American and Asian assemblages derived from African gavialoids should be reviewed. The historical biogeography of Gavialoidea is probably more complex than previously supposed. The phosphatic deposits of Morocco provide a unique opportunity to study the vertebrate faunal turnover across the Cretaceous-Tertiary (KT) boundary. The crocodyliforms are very scarce in the Maastrichtian marine basins of Africa which are dominated by mosasaurid squamates. The latter became extinct by the KT boundary, while crocodyliforms survived and diversified in the Paleocene. Mosasaurids and crocodyliforms both lived in probably comparable marine environments during the Maastrichtian. The selectivity of the KT boundary extinctions remains to be explained; since freshwater environments are known for having been less affected by the KT crisis than marine ones, a freshwater lifestyle of the juveniles, like in extant marine crocodiles and unlike the fully marine mosasaurs, could explain this difference with regard to survivorship.

Sexual size dimorphism (SSD) is prevalent among extant vertebrates and presumably was as common among fossil archosaurs. Here, we test the hypothesis that femur shape is a reliable indicator of sex among archosaurs using linear and geometric morphometric analyses on a large sample of sexed Alligator mississippiensis femora. Linear regression of femoral dimensions onto femur length in alligators shows that male femora are the largest and stoutest in midshaft and articular dimensions, whereas females show more variation in their midshaft dimensions. Using thin-plate splines analyses, regression of partial warps onto alligator femur length revealed that with increasing size the midshaft expands whereas shaft torsion diminishes, that femur shape differs according to sex, and that females show the maximum amount of shape variation at a size 72% that of the largest males. However, sexual dimorphism accounts for only 3% of the total femur shape variation in the sample. Differences in reproductive physiology (e.g, shelling eggs in females) may account for some of the fine morphological differences between males and females. However, size and individual variation appear to effect femur shape the most. These results have significant implications for inferring fossil archosaur sex from femoral dimensions and shape.

A new dromaeosaurid dinosaur—Velociraptor osmolskae n. sp.—is described on the basis of associated paired maxillae and a left lacrimal discovered in Campanian (Upper Cretaceous) deposits at Bayan Mandahu (Inner Mongolia, P. R. China). The maxilla of this new taxon is characterized by its long rostral plate and its enlarged, teardrop-shaped promaxillary fenestra, which is as large as the maxillary fenestra. The teeth are robust and the serrations are weakly developed on their distal carinae. This new taxon appears more closely related to Velociraptor mongoliensis, from the Campanian Djadokhta Formation in Mongolia, than to other dromaeosaurids described to date. The identification of the Bayan Mandahu Velociraptor as a distinct species is in keeping with the taxonomic distinction of the entire dinosaur fauna of this locality. Minor regional differences among Djadokhta-like localities in regards to their dinosaur faunas may reflect either some kind of geographic isolation, or small differences in their age or in their paleoenvironment.

Several teeth with ceratosaurid affinities from the Tacuarembó Formation (Kimmeridgian–Hautevirian) of Uruguay (South America) are reported herein. The most diagnostic specimen is a small rostral crown (probably the first or second left premaxillary crown), the most conspicuous features of which are the presence of several, well-marked longitudinal grooves on the lingual face and the absence of mesial denticles. This combination of characters is only found in the Late Jurassic genus Ceratosaurus Marsh, 1884. The tooth was carefully compared with all potentially similar theropod teeth in order to discard non-ceratosaurid affinities. The occurrence of a South American ceratosaurid in the Tacuarembó Formation was not unexpected, given the temporal range known for the family and the probable Late Jurassic age independently proposed for the lower, fossiliferous member of this unit. Thus, the interpretation of this tooth as belonging to a Ceratosaurus-like ceratosaurid has important biostratigraphic implications, reinforcing the aforementioned hypothesis. Furthermore, it indicates the presence of the ceratosaurid lineage in South America earlier than recognized, the only ceratosaurid previously identified being the Argentinean Genyodectes, of probably Aptian–Albianage. The identification of this Ceratosaurus-like ceratosaurid allows the establishment of new links with several Late Jurassic faunas.

New specimens of the traversodontid cynodont Menadon besairiei from the Middle/Late Triassic ‘Isalo II’ beds of southwestern Madagascar are described. The new specimens include a skull and the first postcranial material described for this taxon. Although the referred skull differs from the holotype of M. besairiei in some regards, these differences are interpreted as intraspecific variation and preservational artifacts. The new material allows clarification of some aspects of the cranial morphology of Menadon, showing that, contrary to previous reports, this taxon had a well-developed internarial bar and four upper incisors. The postcranium of Menadon displays a mixture of advanced features observed in the South American traversodontid Exaeretodon, such as tall caudal neural spines, and primitive features observed in earlier traversodontids like Luangwa, such as heterogeneous rib morphology. A phylogenetic analysis incorporating information from the new specimens supports the placement of Menadon as the sister taxon to the clade Exaeretodon Scalenodontoides.

This paper describes a new tree-kangaroo of the extinct genus Bohra (B. illuminata sp. nov.). Its remains were collected from a diverse middle Pleistocene fauna preserved in caves recently discovered beneath the Nullarbor Plain of south-central Australia. The adult holotype and juvenile paratype are represented by associated cranial and postcranial material. They confirm that two previously known species, B. paulae and B. wilkinsonorum, which were described on the basis of disparate parts of the skeleton, are congeneric. While Bohra is closest in morphology to the extant tree-kangaroo genus Dendrolagus, it shares several similarities with Petrogale (rock-wallabies). This is consistent with recent molecular studies that suggest that tree-kangaroos and rock-wallabies share a common ancestry.

The new dugongine dugongid Nanosiren garciae is the third species of fossil sirenian to be described from the Bone Valley phosphate deposits of Florida. It is found in the Upper Bone Valley Formation and is of latest Hemphillian (early Pliocene) age. Nanosiren sanchezi is described from the late Miocene upper member of the Urumaco Formation, Falcón State, Venezuela. It appears to be directly ancestral to N. garciae, and was preceded in the West Atlantic, Caribbean, and East Pacific region by other, undescribed members of the same generic lineage dating back at least to the early Miocene. The Nanosiren lineage is the most basal clade of the Subfamily Dugonginae after Crenatosiren olseni, and is the sister group to all remaining dugongines. It comprises the smallest known post-Eocene sirenians, with adult body lengths and weights probably around 2 m and 150 kg. Newborn animals may have had body masses little greater than the theoretical limit of 6.8 kg for a viable aquatic endotherm. In addition to a shallow draft, Nanosiren spp. had small conical tusks and strong rostral deflections. These characters possibly indicate that they foraged in shallower water than the larger dugongids with which they were sympatric, such as Metaxytherium (a rib from Urumaco probably referable to this genus is also recorded here). Nanosiren probably fed in nearshore marine waters on small seagrasses such as Halodule and Halophila.

RESUMEN—Se describe una nueva especie de dugongine dugongido como Nanosiren garciae, la cual representa la tercera especie fósil de sirenido descrita de los depósitos de fosfato de Bone Valley en Florida, USA. Proviene de la Formación Upper Bone Valley de edad Hemphillian tardío (Plioceno temprano). Se describe igualmente la especie Nanosiren sanchezi del Miembro superior de la Formación Urumaco, estado Falcón, Venezuela, de edad Mioceno tardío. Esta especie pareciera ser el ancestro directo de N. garciae, que a su vez es precedida por otro miembro del mismo linaje genérico aun no descrito de edad Mioceno temprano y que se distribuye en el Atlántico occidental, el Mar Caribe y en la región oriental del Océano Pacifico. El linaje Nanosiren es el clado más basal de la Subfamilia Dugonginae luego de Crenatosiren olseni y es el grupo hermano del resto de los dugongines. Estos incluyen los sirenios post-Eocénicos de menor tamaño conocido, con longitudes corporales y pesos en adultos que alcanzan alrededor de 2 m y 150 kg respectivamente. Los animales al nacer pudieron tener una masa corporal algo mayor que el límite viable teórico de los 6,8 kg para endotérmicos acuáticos. Adicionalmente a ser de poco calado, Nanosiren spp. poseen pequeños colmillos de forma cónica y rostros fuertemente desviados. Estas caracteristicas probablemente indican que pastan en aguas más someras que los grandes dugongidos con los cuales son simpátricos, como es Metaxytherium (una costilla hallada en Urumaco que se registra en el presente trabajo probablemente se relaciona con este género). Nanosiren probablemente se alimentaba de gramíneas marinas próximas a la costa tales como Halodule y Halophila.

Craniodental remains of fossil bovids from the late Miocene İncesu Formation, from sites near the city of Sivas, Turkey, are described. The bovid remains represent at least five species: Gazella cf. G. capricornis, Prostrepsiceros houtumschindleri syridisi, cf. Protoryx sp., Tethytragus cf. T. koehlerae, and Tragoportax cf. T. amalthea. The Sivas fossil bovid assemblage is fairly typical for the Greco-Iranian-Afghan paleobiological province, and compares well with the classic Turolian sites of Samos, Pikermi, and Maragheh. Biochronological correlations using these fossil bovids suggest the Sivas fossil assemblage is MN11 or early MN12 in age, or somewhere between 9–7 Ma. The presence of Tethytragus at Sivas represents only the second occurrence of this typically mid-Miocene (MN5–8) taxon from the late Miocene. Paleoecological attributes of the Sivas fossil bovids suggest local paleoenvironments at Sivas comprised shrubland to woodland biomes, perhaps devoid of expansive grasslands or dense forests. The presence/absence and relative abundances of bovid taxa within and among different Greek and Anatolian late Miocene fossil sites is compared and contrasted by way of correspondence analysis. Sivas plots among a number of sites all characterized by high proportions of Gazella, Tragoportax, and Protoryx/Pachytragus, and these in turn are readily distinguished from sites in which Palaeoreas/Majoreas, Protragelaphus, Oioceros, and Miotragocerus are more common. It is suggested that Sivas and similar sites (e.g. Sinap, Akkaşdağı) may have sampled drier, more open habitats than those with strongly differing faunal compositions (e.g. Nikiti-1, Çorakyerler).

Stenasodelphis russellae, a new genus and species of extinct dolphin in the odontocete family Pontoporiidae, is based on a partial cranium of Late Miocene age (Tortonian), circa 9 to 10 Ma, from the Little Cove Point Member of the St. Marys Formation, Maryland, USA. Pontoporiidae are amongst the smallest cetaceans, and this dolphin is one of the smallest reported pontoporiids, being probably less than 1.5 m long. It is also the second oldest named pontoporiid in the world. Stenasodelphis russellae shares with late Middle Miocene Brachydelphis mazeasi (eastern South Pacific) and the latest Miocene and Pliocene species of Parapontoporia (North Pacific) left-skew asymmetry of the cranial vertex. Thus, all of the earliest known Pontoporiidae have cranial asymmetry, in contrast to symmetrical crania in the Pliocene pontoporiids, Pontistes rectifrons and Pliopontos littoralis, and the Recent Franciscana, Pontoporia blainvillei. This suggests that cranial asymmetry may be the primitive character state among stem Pontoporiidae. Autapomorphies of Stenasodelphis russellae include small size, thick cranial bones, wide premaxillary sac fossae, a medial projection of each maxilla onto the lateral side of each nasal, and the highest part of the cranial vertex being formed by the nasals rather than the frontals.