Paleogene bats from Africa are rare with only scant records from Tunisia, Egypt, and Tanzania having been described in the past. Four new genera and six new species of microchiropteran bats are described here from the late Eocene (37–34 Ma) of the Fayum Depression in northern Egypt. Included among these new taxa are the first and only African record of a fossil rhinopomatid and the earliest African records of megadermatids, emballonurids, and vespertilionids. Additionally, a new genus and two new species of the Afro-Arabian bat family Philisidae are described. The new Fayum philisids are the oldest representatives of this family, are represented by the largest species thus far recorded for the group, and include one of the largest fossil bats known. Previous biogeographic reconstructions suggest that most Old World bat families had their origin in Laurasia but several modern bat families may have diversified only after their initial dispersal into Africa. Bats and primates may have entered Africa during the same dispersal event early in the Paleogene.

Wuttagoonaspida is a very peculiar group of Arthrodira, hitherto known only in the Early-Middle Devonian deposits of Australia. The new genus and species Yiminaspis shenme described here is known from an incomplete skull roof from the Pragian of Zhaotong (Yunnan, South China). Despite sharing some features with the Petalichthyida (e.g. two pairs of posterior pitlines), it presents many features of the genus Wuttagoonaspis (e.g. long preorbital plates not separated by the pineal plate, pineal plate placed further anteriorly from the orbits). Some thoracic armor material, also from Zhaotong, is referred to this taxon on the basis of the ornamentation. The occurrence of such a basal arthrodire from the Lower Devonian of China, added to the ante-Emsian geographic isolation of the South China block (evidenced by its vertebrate endemism rate), suggests a Chinese origin for the Wuttagoonaspididae, and a migration episode into the northeastern margin of Gondwana dated at the end of the Pragian (E'Em bioevent).

Cretoxyrhina mantelli is a Late Cretaceous lamniform shark that possibly resembled the modern white shark (Carcharodon carcharias) in size, body form, and feeding strategies. Here, a previously identified set of growth increment (= periodic marker) bands in a vertebra from an individual of Cretoxyrhina mantelli (5 m in total length [TL]) is used as a model to quantitatively infer the ontogenetic development and life history strategies of the fossil shark. The results indicate that its length at birth was large, and that the early part of its life history was marked by a comparably rapid growth, which could have helped the neonatal C. mantelli to efficiently exploit prey items while deterring potential predators. The von Bertalanffy growth function (VBGF) experimentally fitted to the data gives the following estimated growth parameters: the length at birth (L₀) of 1.28 m TL, the asymptotic length (L_∞) of 6.91 m TL, and the rate constant with units of reciprocal time (k) of 0.073 yr⁻¹. The large maximum length indicates that individuals may have weighed 3,400 kg. The VBGF parameters also indicate that the longevity of C. mantelli was possibly up to about 38 years. This study shows that many aspects of ontogeny and life history of C. mantelli are similar to those of the modern white shark, and that a single shark fossil may offer a wealth of biological information.

A specimen collected in 2006 from the Smoky Hill Chalk of central Kansas, USA, represents a rare occurrence of a chimaeroid fish from the Niobrara Chalk. The associated material includes associated right and left vomerine plates, and the right palatine plate. Comparison of the Kansas vomerines with the type of “Edaphodon” laqueatus, a right vomerine from Lower Campanian strata of eastern Mississippi, indicates that the remains are conspecific. However, our analysis also shows that these vomerine plates are distinct from Edaphodon, principally because of a massive, hammer-like beak, and overall modification of the oral surfaces into flat crushing plates, rather than oblique shearing surfaces as seen in Edaphodon. In addition, whereas there are three large tritors on an Edaphodon palatine, the Niobrara palatine has four very small tritors, with two inner tritors, a middle tritor, and an outer tritor. Our conclusion is that the original taxonomic designation, Eumylodus laqueatus Leidy, 1873, is valid, and the geographic distribution of the taxon extended from the Mississippi embayment to the central portion of the Western Interior Seaway, U.S.A.

A collection of fossil material from Eocene deposits of Pakistan includes remains belonging to various taxa of actinopterygian fishes. The material comes from predominantly freshwater deposits, as well as a few marine deposits, in the Kuldana Formation in the Kala Chitta Hills, and from the Chorgali Formation near Gali Jaghir, in Attock District of Punjab Province. The Kuldana and Chorgali formations are early to middle Eocene in age. Isolated bones and teeth are identified as belonging to Eotrigonodontidae, Pycnodontiformes, Amiidae, Osteoglossidae, Siluriformes (cf. Bagridae), and Perciformes, as well as unidentified Teleostei. Some of the fossils are skulls of a channiform fish, which is here described as a new genus and species, Anchichanna kuldanensis. The faunal affinities of the Indo-Pakistan area during the Eocene are not clear, with previous studies suggesting it is faunally more similar to other parts of modern Asia, others as it representing a region of endemism, or even as being similar to northern Africa. The fish material reported here indicates a relationship between the Pakistan fauna in the Eocene with that of northern Africa.

Triplomystus applegatei, sp. nov., is described as a new clupeomorph fish belonging to the order Ellimmichthyiformes, based on a single specimen collected from the Early Cretaceous (Albian) limestones of El Espinal quarry, near Ocozocuautla de Espinosa, Chiapas, southeastern Mexico. T. applegatei is differentiated from the other two species of the genus on the basis of body proportions and meristic data, as well as a peculiar development of a complex shape and articulation between the last scutes in the posterodorsal series. This species extends the geographical and geological domain of this genus from the Cenomanian Eastern Tethys Sea to Albian western Tethys Sea.

Georgenthalia clavinasica, a new genus and species of amphibamid dissorophoid temnospondyl, is represented by a small, complete, postmetamorphic skull from the Lower Permian Bromacker locality, Germany. It is only the third non-amniote of an assemblage of 12 terrestrial tetrapod taxa known from this locality. It is characterized by a broadly rounded skull with large orbits, a short postorbital length, and a unique keyhole-shaped external naris superficially resembling that of trematopid dissorophoids. New features that help to discriminate between amphibamid species are highlighted. Phylogenetically informative characters present in G. clavinasica include: anterolateral flaring of the lateral margin of frontals; narrow interorbital width; ventral orbital process of the prefrontal contacts palatine; palatine exposed on lateral surface of ventral rim of orbit; large otic notches closely approach the orbits; absence of a supratympanic flange of otic notch; long supratympanic process of squamosal with flange-like process that underlaps the midcentral portion of supratemporal. Several features support a highly terrestrial habitus of G. clavinasica, which is consistent with the interpretation of the fossiliferous beds of the Bromacker quarry as representing an upland terrestrial environment in which limnic conditions were characterized by ephemeral lakes and ponds.

A new clade, Olsoniformes, is named for Dissorophidae and Trematopidae (dissorophoids exclusive of Amphibamidae), and new phylogenetic definitions for Amphibamidae, Trematopidae, and Dissorophidae are presented. The small neotenic Micromelerpetontidae, and presumably also the neotenic and larval Branchiosauridae, fall within the newly defined clade Amphibamidae in the current study, and future work should focus on clarifying the nature of this relationship.

Newly prepared material of Keichousaurus hui demonstrates that the nasals are very reduced and do not contribute to the margins of external nares, the quadrate lacks a posterior condylar process, the premaxilla and anterior dentary teeth are enlarged and procumbent, the maxilla has a pair of ‘canines,’ the vomers are co-ossified, the suborbital fenestrae are very reduced or lost, a distinct coronoid process is present, and both the mandibular symphysis and retroarticular process are elongated. The presence of an ectopterygoid could not be confirmed. The shape of the prefrontal, length of the quadrate ramus of the squamosal, and length of the quadrate and quadratojugal all indicate that the skull profile of Keichousaurus is much lower than previously thought. A new reconstruction attributes a distinctly eusauropterygian gestalt to the skull. A phylogenetic analysis, although equivocal, suggests that Keichousaurus is more appropriately considered a basal nothosauroid rather than a pachypleurosauroid, and that the Eusauropterygia is paraphyletic.

A new aigialosaur is described from the lower Turonian (Upper Cretaceous) of Nuevo León State, Mexico, on the basis of the posterior half of an articulated skeleton. It is differentiated from other aigialosaurs by a unique combination of characters, including an absent ultimate rib preceded by six short ones, a single pygal vertebra, and an especially large tibia. The scales are uniform, smooth, rhomboidal, and arrayed in oblique rows, as in other aigialosaurs where they are known. Abdominal contents include 15 carbonate pebbles. Many of the features of the posterior presacral ribs and anterior caudal vertebrae are widespread in Anguimorpha, but the extreme elongation of the neural spines of the caudal vertebrae appears to unite described aigialosaurs, including the new species, with Mosasauridae. The new species provides further evidence that aigialosaurs may have had a more primitive pes than previously thought, whereas the pes in a number of dolichosaurs shows the loss of one phalanx in pedal digit V. The presence of this new species, the oldest aigialosaur described from North America, on a different continent from previously known aigialosaurs and in rocks representing the outer shelf suggests an underappreciated ability of primitive mosasauroids to move about in the open sea.

The first protorosaur from the Middle Triassic of China, Dinocephalosaurus orientalis Li is known from two specimens: the holotype (an isolated skull in association with the first three cervical vertebrae), and a referred specimen (an almost complete, associated and partially articulated specimen lacking the tail). This material is here described in detail. A complete and amended diagnosis is given for the genus and its only known species. Among protorosaurs, Dinocephalosaurus is the taxon exhibiting the greatest degree of skeletal paedomorphosis, indicating fully aquatic habits.

A new eusuchian skull from the Maastrichtian locality of Oarda de Jos in the southwestern Transylvanian Basin of Romania represents the best-preserved known specimen of Allodaposuchus precedens Nopcsa, 1928. This new fossil allows us to clearly characterize the skull morphology of A. precedens and to reject the idea, as recently suggested, that the taxon could be considered a nomen dubium. Parsimony analysis confirms earlier phylogenetic hypotheses based on the fragmentary holotype from the Maastrichtian of Valioara in Haţeg Basin (Romania), as well as on putative conspecific remains from approximately coeval localities in Spain and France: A. precedens is a non-crocodylian eusuchian. However, some relevant morphological traits differ from what was previously reported for this taxon: the external naris is large and anterodorsally directed; the lateral profile of the skull is not festooned in dorsal view; the suborbital fenestrae reach the eighth alveolus; the postorbital bar is not massive and inset from the jugal margin; the skull table is approximately planar or medially concave and does not markedly overhang the supratemporal fenestrae; the exoccipitals are not significantly involved in the basioccipital tubera. Because the condition of most of these characters was unknown in the holotype, the morphology of the taxon was previously evaluated on non-Romanian remains only. The morphological discrepancies between Romanian and western European fossils could suggest the presence of different taxa, possibly of infra-generic rank. Allodaposuchus and presumably Hylaeochampsa are the only eusuchians showing a laterally open cranioquadrate passage.

The “ethmoid complex” is an enigmatic element of the anterior portion of the braincase first described in Tyrannosaurus rex in 1912, which has since been recognized in many non-avian theropods. Because the “ethmoid complex” is a landmark for the reconstruction of the olfactory apparatus of non-avian theropods, we clarify the homology of this structure among archosaurs. The “ethmoid complex” consists of a trough-shaped element that is attached to an anteriorly-located median septum capped by a dorsal plate. Based on anatomical comparisons with the olfactory region of extant birds and crocodylians, the components of the “ethmoid complex” are shown to have cartilaginous or osteological homologues among extant archosaurs: the trough is homologous to the anterior portion of the planum supraseptale of crocodylians and embryonic birds, whereas the median septum and overlying dorsal plate are homologous to the avian mesethmoid and to the nasal septum and tectum nasi of crocodylians. Based on the location and ossification of olfactory region structures in non-avian theropods, the most appropriate terms for elements of the “ethmoid complex” are the sphenethmoid for the trough and the mesethmoid for the median septum and dorsal plate. The olfactory bulbs of nonavian theropods were housed within the sphenethmoid, which restricted the maximum size of the olfactory bulbs to a size smaller than the cerebral hemispheres.

Historically, the scarcity of non-adult Triceratops fossils collected from Upper Cretaceous sediments of North America limited our understanding and promoted controversy with regard to the morphology, and presence or absence of cranial epi-ossifications in this widely known horned dinosaur. The recent discovery of several exceptionally well preserved juvenile and subadult Triceratops skulls and numerous juvenile, subadult, and adult cranial elements, from the Hell Creek Formation of eastern Montana, confirms the ontogeny and morphology of epi-ossifications in this study. We propose to standardize the terminology for these four cranial epi-ossifications: epinasal, epijugal, epiparietal, and episquamosal. We describe the ontogeny and timing of the fusion of each of these epi-ossifications and the rostral from a cranial growth series. Although the timing is variable, the epinasal fuses first, followed by the rostal, the epijugals, the episquamosals, and lastly by the epiparietals. Co-ossification of the epinasal, rostral and epijugals unites several of the anterior (rostral-nasal-premaxillae) and lateral (jugal-quadratojugal) skull elements. In combination with forward directed postorbital horns and a massive fan-shaped frill, cranial epi-ossifications may have enhanced visual display and species communication in Triceratops.

The ichnotaxobases previously used to classify avian-like footprints, at the ichnogeneric, ichnospecific, and ichnofamily level, are varied and contrasting. Consequently, an agreement on the most adequate taxobases to use for classifying these vertebrate trace fossils is necessary. The authors follow an ichnotaxonomy treatment independent to the age, locality provenance, and possible tracemaker of the trace fossils. The ichnotaxobases used to classify tracks with avian affinities at ichnogeneric and ichnospecific levels are evaluated and a proposal is made for useful and appropriate ichnotaxonomic criteria, considering those currently in use. Previous criteria used to distinguish avian footprints from non-avian theropod or ornithischian tracks are discussed. These concepts are applied to the avian footprints from the upper part of the Late Triassic-Early Jurassic Santo Domingo Formation from La Rioja province, northwest Argentina, which has yielded a diverse assemblage of trace fossils. The most conspicuous avian footprint is Gruipeda dominguensis isp. nov. The ichnogenus Gruipeda Panin and Avram, 1962 is revised and an emendation of its diagnosis is suggested. Trisauropodiscus Ellenberger, 1972, from South Africa and Antarctichnus Covacevich and Lamperein, 1970 from Antarctica are considered as junior synonyms of Gruipeda. Three other morphotypes of avian footprints are left under open nomenclature: one is assigned as cf. Alaripeda isp., other as bird-like footprints type C, and the third bird-like footprint with elongated drag marks. These specimens could be related to avian origin, but the possibility of a case of convergence with birds is not discarded. The presence of tracks with a wide total divarication produced in ephemeral fluvial systems with shallow ponds and mudflats suggest that it is likely the attainment of a convergent avian-form feet to improve controlled movements.

Detailed description of the Middle Permian Russian caseid Ennatosaurus tecton shows that three autapomorphies distinguish it from other caseids: a broad anterior ramus of the jugal, a large contribution of the frontal to the dorsal orbital margin, and a relatively narrow parasphenoid body. Phylogenetic analysis of Caseidae yields a single most parsimonious tree and its topology posits Ennatosaurus tecton as the sister taxon to the clade of the North American caseids Angelosaurus dolani and Cotylorhynchus romeri. Phylogenetic analysis supports the position of Oromycter dolesorum from the Lower Permian Richards Spur locality as the most basal member of Caseidae. In addition, the genus Casea is resolved as paraphyletic, whereby C. rutena forms the sister taxon to the clade containing E. tecton, C. romeri, and A. dolani. The current topology reveals that the pattern of dental complexity in terms of the number of apical cuspules is homoplasious, cautioning against its use as a unidirectional phylogenetic character.

New remains of Megathericulus patagonicus Ameghino, 1904, the first additional material of this species found since erection of the species, are described. Two individuals from separate localities, the Cerro Guenguel and Arroyo Pedregoso localities in southern Argentina, are represented. The specimens were recovered from the Río Mayo Fm. and are assigned to the middle Miocene Friasian South American Land Mammal Age. Radiometric dating from the Cerro Guenguel locality indicates an age somewhat younger than 11.8 Mya. Megathericulus patagonicus is the earliest certain megatheriine and the new remains provide information on primitive megatheriine features. Among these are that lower molariforms are mesiodistally compressed, as in the palate of the type specimen; ventral margin of dentary is prominently bulged; angular process approximately in same relative position as in most megatheriines, rather than elevated as in Megatherium species; posterolateral opening of the mandibular canal on anterior edge of base of ascending ramus, posterior to m4, and visible in lateral view; ascending ramus begins approximately at level of distal surface of m4, so that m4 was uncovered in lateral view; inclination of base of ramus suggests that anterior margin of coronoid process inclined less steeply than in other megatheriines; symphysis begins posteriorly well anterior to m1; humerus possesses very prominent deltopectoral crest; in the ulna, proximolateral articular facets face nearly laterally, and olecranon process compressed mediolaterally; in the femur, patellar trochlea contiguous distally with medial and lateral articular facets for the tibia; in the astragalus, navicular facet relatively dorsal, with plane of discoid facet intersecting its middle portion; and fibular facet elongated, reaching the ectal facet.

A new assemblage of Cingulata (Xenarthra) from the late Pleistocene of northwestern Venezuela is reported. The fauna includes Dasypus sabanicola, Propraopus sulcatus, and Pampatherium humboldtii, all three of which are reported for the first time from the Venezuelan Pleistocene. Glyptodon clavipes is also reported. A systematic problem with the species of Propraopus is reported, with a suggestion for the probable inclusion of Dasypus bellus, Dasypus (Hyperoambon) kappleri, and Propraopus with its two valid species, P. punctatus and P. sulcatus, in the same genus. Hyperoambon Peters, 1865 would have seniority over Propraopus Ameghino, 1881 and would include four species, the extant D. kappleri, and the extinct D. bellus, P. punctatus, and P. sulcatus. The paleoecological aspects of the Mene de Inciarte Cingulata reflect a complex and heterogenic faunal community dominated mainly by savanna elements with some forest elements that could represent seasonally dry forest.

The fossil suids from the Chiwondo Beds in northern Malawi constitute four separate assemblages that may be used for internal and external biostratigraphic correlation. Pig remains occur in two stratigraphic units. Unit 2 contains Notochoerus jaegeri. The younger stratigraphic unit 3A can be subdivided by the suid fauna into an older zone 3A-1 containing Notochoerus euilus and zone 3A-2 with more advanced forms such as Notochoerus scotti and early Metridiochoerus andrewsi. Unit 3B contains advanced M. andrewsi and M. compactus. Bushpig and warthog remains have also been recovered but their stratigraphic position could not be determined. A method of documenting the structural density of enamel bands on the occlusal surface of suid cheek teeth can be used to correlate the Chiwondo Beds suids with similar species from elsewhere in sub-Saharan Africa and thereby for estimating the age of the two hominins discovered by the Hominid Corridor Research Project.

The late early Miocene Santa Cruz Formation of Patagonian Argentina is remarkable for its well-preserved and diverse mammalian fauna. This study evaluates the feeding preferences of three notoungulates from Santa Cruz (Nesodon imbricatus, Adinotherium ovinum and Protypotherium), typically reconstructed as open habitat grazers. Diets are inferred from enamel microwear features using a low-magnification microscopy technique. Analysis indicates that these notoungulates were primarily feeding on browse, a result that contrasts sharply with previous interpretations based on their hypsodont dentitions. All three notoungulates exhibit a low average number of scratches per taxon, indicative of browsing; high scratch averages are characteristic of grazers. Furthermore, these notoungulates were not primarily feeding on either hard objects (e.g., fruits with seeds) or abrasives (e.g., grasses). Nesodon imbricatus, however, exhibits microwear, suggesting it infrequently fed on hard objects such as bark. The association of tall tooth crowns with browsing diets as demonstrated by the Santa Cruz notoungulates is evidence that hypsodonty does not necessarily indicate open habitat feeding or grazing and that the diets of hypsodont herbivores should be evaluated on a case-by-case basis.

Until now, the pre-Pleistocene record of the bovid tribe Hippotragini was rather poor. Two new taxa are described from the late Miocene of Toros-Menalla in northern Chad, which yielded the earliest known hominid, Sahelanthropus tchadensis. Tchadotragus sudrei n.gen. n.sp. is known by complete skulls and numerous horn-cores. It has typical hippotragine features such as long slender, curved horn-cores, weak cranial flexure, large frontal sinus, and hippotragine-like dentition, and is here taken as a basal member of the tribe, branching before the divergence between Oryx-Praedamalis and Hippotragus s.l. Saheloryx solidus n.gen. n.sp. is less well-known; it differs mainly by the lack of sinus in the frontal and horn-cores, shorter horn-cores, and rounded brain-case, but it shares with Tchadotragus a large number of features that prompt us to classify it also at the base of the hippotragine tree, perhaps as the sister-taxon of Tchadotragus. No other African taxon looks like Saheloryx, and the only one similar to Tchadotragus is from Sahabi, Libya. The abundance of hippotragines sharply distinguishes Toros-Menalla from the East African late Miocene bovid faunas.

Hipparionin material recovered from the middle Miocene El Camarón Formation (late early Barstovian, K-Ar dated 15. 0 ± 0.8 to 16.7 ± 0.71 Ma) of the state of Oaxaca, southeastern Mexico, is formally described. The sample consists of upper and lower cheek teeth, whose sizes and occlusal patterns are closest to those of the North American Cormohipparion quinni from the late Barstovian of the Great Plains. The material is referred to C. aff. C. quinni and constitutes one of the southernmost occurrences of the genus, extending its geographic distribution from the Northern Great Plains to southeastern Mexico during the middle Miocene. The dentally derived species reported here is contem poraneous with C. goorisi from the early Barstovian of Texas and Florida, the oldest and most plesiomorphic known species, thus lending support to the hypothesis that part of the hipparionin differentiation probably took place in southern (tropical) North America. This in turn leads to a reappraisal of where and when the radiation of some middle Miocene hypsodont horses actually occurred.