In the Early Pleistocene Red Lower Unit of the Sima del Elefante site (Sierra de Atapuerca karst complex, Burgos, Spain), levels TE9–TE13, dental and mandibular remains of an arvicoline are referred to as the new species Arvicola jacobaeus sp. nov. The new species has medium-sized hypselodont molars, with abundant cementum in the re-entrant folds, and thick enamel band with differentiation of the Mimomys-type. The occlusal morphology of M3 is simple. The dental morphology of the new species resembles that of Arvicola sapidus, though smaller. It is more derived, in size and morphology than the Middle Pleistocene species Arvicola mosbachensis. The morphologic affinities among Arvicola jacobaeus, Arvicola terrestris, and A. sapidus suggest a common ancestry. A preliminary phylogenetic analysis corroborates that Mimomys savini is the sister group of the Arvicola clade.

A left first lower molar of Neocometes from the Bukpyeong Formation, South Korea is more similar to Neocometes similis and Neocometes cf. similis from Europe than to Neocometes urientalis from Thailand, and is therefore referred to Neocometes aff. similis. The new discovery of Neocometes is important in that it is the first evidence in Asia to show close faunal affinity to European Neocometes. It is also of paleobiogeographic significance for the subfamily Platacanthomyinae, because it represents the easternmost occurrence of this subfamily in Eurasia, implying there was continuous gene flow between the Neocometes populations of eastern Asia and western Europe. The paleoclimatic interpretation for the Bukpyeong Formation based on the palynomorphs implies that Neocometes had wider climatic tolerances than either of the two extant platacanthomyine genera. The evolutionary stage of Korean Neocometes is comparable to material from European localities correlated with MN 4 and MN 5, which constrains the age of the Bukpyeong Formation to between 18 and 15.2 Mya.

Sexual dimorphism is reviewed and described in adult skulls of Chilotherium wimani from the Linxia Basin. Via the analysis and comparison, several very significant sexually dimorphic features are recognized. Tusks (i2), symphysis and occipital surface are larger in males. Sexual dimorphism in the mandible is significant. The anterior mandibular morphology is more sexually dimorphic than the posterior part. The most clearly dimorphic character is i2 length, and this is consistent with intrasexual competition where males invest large amounts of energy jousting with each other. The molar length, the height and the area of the occipital surface are correlated with body mass, and body mass sexual dimorphism is compared. Society behavior and paleoecology of C. wimani are different from most extinct or extant rhinos. M/F ratio indicates that the mortality of young males is higher than females. According to the suite of dimorphic features of the skull of C. wimani, the tentative sex discriminant functions are set up in order to identify the gender of the skulls.

Tenrecs (Tenrecoidea) and golden moles (Chrysochloroidea) are among the most enigmatic mammals alive today. Molecular data strongly support their inclusion in the morphologically diverse clade Afrotheria, and suggest that the two lineages split near the K-T boundary, but the only undoubted fossil representatives of each superfamily are from early Miocene (∼20 Ma) deposits in East Africa. A recent analysis of partial mandibles and maxillae of Euchrysuchloris, Jawharia, and Widanelfarasia, from the latest Eocene and earliest Oligocene of Egypt, led to the suggestion that the derived “zalambdomorph” molar occlusal pattern (i.e., extreme reduction or loss of upper molar metacones and lower molar talonids) seen in tenrecoids and chrysochloroids evolved independently in the two lineages, and that tenrecoids might be derived from a dilambdomorph group of “insectivoran-grade” placentals that includes forms such as Widanelfarasia. Here I describe the oldest afrosoricid from the Fayum region, ∼37 Ma Dilambdogale gheerbranti gen. et sp. nov., and the youngest, ∼30 Ma Qatranilestes oligucaenus gen. et sp. nov. Dilambdugale is the most generalized of the Fayum afrosoricids, exhibiting relatively broad and well-developed molar talonids and a dilambdomorph arrangement of the buccal crests on the upper molars, whereas Qatranilestes is the most derived in showing relatively extreme reduction of molar talonids. These occurrences are consistent with a scenario in which features of the zalambdomorph occlusal complex were acquired independently and gradually through the later Paleogene. Phylogenetic analysis places Dilambdogale and Widanelfarasia as sister taxa to the exclusion of crown afrosoricids, but derived features that these taxa share with early Miocene Protenrec hint at the possibility that both taxa might be stem tenrecoids. Late Paleocene Todralestes and Afrodon from Morocco are similarly placed as stem afrosoricids, indicating that African adapisoriculids (including Garatherium) might also be relevant to the origin of the tenrecoid and chrysochloroid clades.

Finely-bedded lacustrine deposits of the Aptian (Lower Cretaceous) Xiagou Formation exposed in the Changma Basin of Gansu Province, northwestern China, have yielded numerous fossil vertebrate remains, including approximately 100 avian specimens. Though the majority of these birds appear referable to the ornithuromorph Gansus yumenensis, a number of enantiornithine fossils have also been recovered. Here we report on a specimen consisting of a complete, three-dimensionally preserved sternum, furcula, and sternal ribs that represents a second ornithuromorph taxon from the Xiagou Formation at Changma. The fossil exhibits morphologies that distinguish it from all previously-known Xiagou birds and demonstrate that it represents a derived non-ornithurine member of Ornithuromorpha. Though it is morphologically distinct from the equivalent elements of all other described ornithuromorphs, the material is too incomplete to justify the erection of a new taxon. Nonetheless, it increases the taxonomic diversity of the Xiagou avifauna, thereby expanding our knowledge of Early Cretaceous avian diversity and evolution.

Feeding traces for carnivorous theropod dinosaurs are typically rare but can provide important evidence of prey choice and mode of feeding. Here we report a humerus of the hadrosaurine Saurolophus which was heavily damaged from feeding attributed to the giant tyrannosaurine Tarbosaurus. The bone shows multiple bites made in three distinctive styles termed “punctures”, “drag marks” and “bite-and-drag marks”. The distribution of these bites suggest that the animal was actively selecting which biting style to use based on which part of the bone was being engaged. The lack of damage to the rest of the otherwise complete and articulated hadrosaur strongly implies that this was a scavenging event, the first reported for a tyrannosaurid, and not feeding at a kill site.

Premaxillary tooth count tends to be stable amongst toothed dinosaurs, and most theropods have four teeth in each premaxilla. Only one case of bilaterally asymmetric variation is known in theropod premaxillary dentition, and there is no record of ontogenetic or individual variation in premaxillary tooth count. Based on these observations, a tyrannosaurid left premaxilla with three teeth (TMP 2007.20.124) is an interesting deviation and represents an unusual individual of Daspletosaurus sp. with a developmental abnormality. The lower number of teeth is coupled with relatively larger alveoli, each of which is capable of hosting a larger than normal tooth. This indicates that tooth size and dental count vary inversely, and instances of reduction in tooth count may arise from selection for increased tooth size. On the other hand, the conservative number of premaxillary teeth in most theropods implies strong developmental constraints and a functional trade-off between the dimensions of the premaxillary alveolar margin and the size of the teeth. In light of recent advances in the study of tooth morphogenesis, tooth count is a function of two parameters: dimensions of an odontogenic field for a tooth series, and dimensions of tooth positions. A probable developmental cause for the low tooth count of TMP 2007.20.124 is that the dimensions of the alveoli expanded by approximately a third during tooth morphogenesis. Numerical traits such as tooth count are difficult to treat in a phylogenetic analysis. When formulating a phylogenetic character, a potential alternative to simply counting is to rely on the morphological signature for developmental parameters that control the number of the element in question.

Two fossil tadpoles collected in the Deseadan levels (Oligocene) at the Scarritt Pocket locality of central Patagonia are studied herein. These specimens, which show different degrees of skeletal development, have been assigned to the neobatrachian Calyptocephalella canqueli based on the morphology of the frontoparietals and the presence of adult specimens of this fossil species at the same locality. The concurrent analysis of three developmental stages (Gosner Stages 35/36 and 38/39, and adult) has provided significant data about the ontogeny of this species, including the change of the pattern of exostosis of the frontoparietals, from a pitted to a tuberculated pattern, and the corroboration of the inclusion of two neural arches in the formation of the urostyle. This evidence will shed light on developmental mechanisms that might be involved in the evolution of the genus Callyptocephalella.

New specimens, including the first record of lower dental plates, of the extinct myliobatid Myliubatis wurnoensis were recovered from the Maastrichtian (Late Cretaceous) of the Iullemmeden Basin, Mali, and are the oldest record of the taxon. We evaluated the phylogenetic position of this taxon with reference to other myliobatids (extinct and extant) using osteology and dentition. Our results indicate that Myliobatinae and Myliobatis are each paraphyletic, and that Aetobatus and Rhinoptera are monophyletic. We also found that taxa known only from the Cretaceous, Brachyrhizodus and Igdabatis, are highly nested within Myliobatidae. The phylogenetic position of these taxa unambiguously extends the origin of Myliobatidae and most of its representative taxa into the Mesozoic.

Throughout their history, species had to face environmental variations spatially and temporally. How both levels of variation interact will be of key importance in conditioning their response to major perturbations. We addressed this question by focusing on a period in Earth's history marked by dramatic environmental and faunal changes, the Late Devonian Frasnian/Famennian boundary. From a paleogeographic point of view, this period is characterized by a cosmopolitanism of the faunas across a large ocean, the Prototethys. We considered the biotic reaction at a seldom considered scale, namely within a single subgenus of conodont, Palmatulepis (Manticolepis). Patterns of spatial and temporal differentiation were quantified using morphometrics of its platform element. The recognized cosmopolitanism of the faunas was confirmed at this scale of variation since temporal records gathered in distant areas around the Prototethys, including the seldom documented regions located nowadays in South-East Asia, displayed similar morphological trends in response to the major F/F crisis. Beyond this overall cosmopolitanism, subtle geographic structure was evidenced but was not stable through time. Geographic differentiation was maximal shortly before the F/F crisis, suggesting that despite high sea-level, tectonics leaded to complex submarine landscapes promoting differentiation. In contrast any geographic structure was swamped out after the crisis, possibly due to a global recolonization from few favorable patches.

Evidence of brachiopod shell infestation by tube dwelling parasitic-commensal organisms is very rare in the fossil record. The oldest record of this kind of biotic interaction is known as Eodiorygma acrotretophilla from the Early Cambrian phosphatic acrotretoid Linnarsonia. The youngest evidence of parasitic infestation was documented in the Early Cretaceous rhynchonellide Peregrinella multicarinata. Two other records of vermiform tubes inside brachiopod shells come from the Devonian. These are Diorygma atrypophilia, infesting Givetian atrypide shells, and Burrinjuckia spiriferidophilia, found in some Emsian spiriferides. Here we describe the fifth record of this kind of infestation for which a name Haplorygma dorsalis ichnogen. et ichnosp. nov. is proposed. The tubular infestation structure was revealed in two silicified dorsal valves of spirolophous brachiopods found in the Mississippian Muhua Formation of the Southern China. The affinity of the tube-dwelling organism is rather enigmatic, but its annelid relationship and kleptoparasitic nature seems highly probable. In addition, the phoronid affinity of Diorygma is here questioned.

Retained colour pattern on the shells of Plectodonta sp. from the earliest Devonian of Podolia (Ukraine) is the first finding for strophomenide brachiopods and the oldest among articulate brachiopods. The colour pattern in Plectodonta sp. is composed of small, round, brownish spots scattered rather irregularly on the ventral valve only. This may suggest that the described pattern probably performed a protective function through disruptive camouflage against visual systems of potential predators. The occurrence of the colour pattern in Plectodonta sp. exclusively on the ventral valve strongly suggests that these brachiopods lived with the patterned (and convex) ventral valve upwards and the patternless concave dorsal valve facing to the underlying substrate. It thus contradicts a general assumption that concavo-convex brachiopods lived with their convex valves resting on the sediment.

Upper Jurassic marginal marine strata of the Lusitanian Basin (central Portugal) yield a rich benthic macro fauna from which three bivalve target taxa, i.e., Arcomytilus, Isognomon, and Eomiodon, were chosen for morphometric studies, because of their abundance both in space and time and their variability in shell shape. The shells have been analysed with regard to outline shape (Fourier shape analysis), dimensions, ornamentation (Arcumytilus) and ligament arrangement (Isognomon). Additionally, data on co-occurring fauna and palaeotemperatures calculated from δ¹⁸O values have been recorded. The results of the morphometric analyses have been interpreted with regard to phytogeny and palaeoecology. In all target taxa, a distinct, rapid size increase at around the Early/Late Kimmeridgian boundary is evident. Potential causes for this process are discussed, and an increase in food availability is regarded the most likely scenario. In Isognomon rugosus, a distinct change in resilifer arrangement co-occurs with size increase, resulting in the evolution of an endemic species in the Lusitanian Basin, for which the name Isognomon lusitanicus is re-established. Like in several extant Mytilidae, morphological species characterisation in Arcomytilus turns out unsatisfactory, due to high intra-specific variability. However, Arcomytilus morrisii is still regarded as a valid species that evolved in the Lusitanian Basin. Despite high shape variability, Eomiodon securiformis is also considered to be a clearly distinguished species. For all target taxa morphologic variability is discussed with regard to environment, and variation between populations is delineated. The data suggest a weak correlation of facies and shell shape in Arcomytilus, while Isognomon lusitanicus seems to develop local varieties in different subbasins. Finally, the great morphologic plasticity of bivalves from rather distinct systematic entities is shown to result from different causes, thus demonstrating that careful studies of the involved species are a prerequisite to draw correct palaeoecological conclusions.

The trace fossil Spongeliomorpha iberica locally occurs in the Tortonian (Upper Miocene) marine strata of the Fortuna basin in southeastern Spain, and its excellent preservation state allows a reliable reconstruction of its main morphologic features. The burrow systems are branched (but not anastomosing), and they include numerous, short, blind tunnels. The burrow walls are strongly ornamented with bioglyphs displaying a rhomboidal pattern, consisting mostly of individual “Y”-shaped scratches. Smaller, secondary bioglyphs consist of sets of less incised transverse scratches. These features allow us to assign the ichnospecies to a decapod crustacean, most likely an alpheid or thalassinidean shrimp. The burrow apparently served as a refuge for the inhabitant, which fed upon microorganisms growing on the walls of the burrow by means of scraping the interior surfaces with the maxillipeds or other mouth parts. It is also likely that the shrimp used the multiple blind tunnels to store organic material (probably plant detritus) to be used for later consumption. The crustaceans colonized mud firmgrounds, which were formed by erosion during a rapid sea-level fall. Thus, the burrows occur in direct association with erosional regressive surfaces and therefore are good stratigraphic indicators of abrupt paleoenvironmental change.

Open antra, a special form of external brood pouches in Ordovician ostracodes suitable for both egg and brood care, are enabled by the associated pore system. Special kinds of radial pores connected with the adventral sculptures are described for the first time. Relationships exist between antral development and lifestyle in that open antra occur in nektobenthic taxa, while closed antra (false brood pouches) are connected with a benthic lifestyle. Taxa, particularly those with open antra, which are morphologically very similar in being non-lobate or non-sulcate, can be distinguished by the construction of the respective antra and the associated pore systems, as exemplified by Levisulculus, Swantina, and Ampletochitina.

“Miacid” carnivorans comprise one of the modern mammal groups appearing around the Palaeocene-Eocene Thermal Maximum (PETM) in the Northern Hemisphere. Here we describe a new very small “miacid” carnivoran from the earliest Eocene of Dormaal, Belgium, that shares a particular dental morphology with the species “Miacis” winkleri and “Miacis” rosei from the early Eocene of North America. The three species present very gracile and sharp teeth, and are hereby placed in the new genus Gracilocyon. Comparative dental analysis of Gracilocyon with other early “miacids” contributes to better resolve the polarity of dental characters and indicates that this genus is one of the most primitive members of the family. Diversity of early modern carnivorans is greater than previously considered and early “miacids” seem to have dispersed into North America from two different geographic origins.

The Varswater Formation of Langebaanweg at the west coast of South Africa is one of the few fossil sites in Africa dating from the early Pliocene (approx. 5 Mya) (Hendey 1981) and excels in being especially rich in well preserved, though generally isolated, bird remains. Rich (1980: 166) regarded this site as richest pre-Pleistocene bird bone accumulation in the world with at least 60 bird species representing among them penguins, tubenoses, parrots and mousebirds. Studies on seabirds, ibises and other taxa (Olson 1985a, b, 1994) indicated that the Pliocene avifauna is even more diverse than initially thought. Passerines are represented by at least nine species (Rich 1980), but no attempts have been made so far to identify these specimens below the subordinal level. The screening of previously unsorted and unidentified material excavated during the 1960s and 1970s at “E” Quarry, Langebaanweg, yielded several hundred remains of passerines. This sample included five fragmentary humeri that show the characteristics of swallows and martins (Hirundinidae), which are described herein.