How old is the cheetah skull shape? The case of Acinonyx pardinensis (Mammalia,Felidae)

It is generally believed that the skull CCEC-161821 of Acinonyx pardinensis from Saint-Vallier, an Early Pleistocene French locality, is similar to that of the modern cheetah, in contrast to several other Late Pliocene and Early Pleistocene Old World felids with cheetah-like teeth, assigned either to Acinonyx Brookes, 1828, or to Sivapanthera Kretzoi, 1929. Morphological comparisons and morphometric analysis of the fossil and recent material show that the Acinonyx pardinensis from Saint-Vallier, although dentally similar to the modern cheetah, is not cheetah-like in its skull shape. All those Late Pliocene and Early Pleistocene forms can also be included in Acinonyx, implying that the characteristic skull shape of the modern form is probably a recent acquisition.     

陕西府谷发现的晚中新世维氏大唇犀(奇蹄目,犀科)新材料

新材料有丰富的头骨和下颌骨标本,因而对维氏大唇犀有了更加深入的了解。观察结果显示维氏大唇犀在大唇犀属中的地位相当特别,它具有极窄的顶嵴间平面、马鞍形的头骨顶面、发育的眶上结节和较高的枕面,这些特征显示出它是所有已知大唇犀中最原始的一个种。     

Callistoe vincei, a new Proborhyaenidae (Borhyaenoidea, Metatheria, Mammalia) from the Early Eocene of Argentina

Callistoe vincei nov. gen., nov. sp. is a new South American carnivorous marsupial (Proborhyaenidae, Borhyaenoidea) from Salta Province (Argentina). It is preliminarily described and its phylogenetic relationships with other borhyaenoids are analyzed. The holotype is a complete skull with almost complete postcranial skeleton (missing the pelvis and the tail). It is from the Lumbrera Formation (Early Eocene of northwestern Argentina). It represents the most complete proborhyaenid specimen ever discovered and one of the best-preserved borhyaenoid. In the present paper we analyze the major cranial and dental features, the essential elements to compare C. vincei to Arminiheringia auceta, a Casamayoran proborhyaenid of Patagonia. C. vincei is smaller, much more gracile; its skull is narrower; its lower canines are not procumbent; the metacrista of M3 is U-shaped; the postmetacrista of M4 is present and the mandibular symphysis is shorter. This new material allows reconsideration of some dental traits proposed to diagnose the Proborhyaenidae such as the number of incisors and the open-rooted canines.     

Foraging strategies,craniodental traits,and interaction in the bite force of Neotropical frugivorous bats (Phyllostomidae: Stenodermatinae)

1. Bats in the family Phyllostomidae exhibit great diversity in skull size and morphology that reflects the degree of resource division and ecological overlap in the group. In particular, the subfamily Stenodermatinae has high morphological diversification associated with cranial and mandibular traits that are associated with the ability to consume the full range of available fruits (soft and hard).
2. We analyzed craniodental traits and their relationship to the bite force in 343 specimens distributed in seven species of stenodermatine bats with two foraging strategies: nomadic and sedentary frugivory. We evaluated 19 traits related to feeding and bite force in live animals by correcting bite force with body size.
3. We used a generalized linear model (GLM) and post hoc tests to determine possible relationships and differences between cranial traits, species, and sex. We also used Blomberg''s K to measure the phylogenetic signal and phylogenetic generalized least‐squares (PGLS) to ensure the phylogenetic independence of the traits.
4. We found that smaller nomadic species, A. anderseni and A. phaeotis , have a similar bite force to the large species A. planirostris and A. lituratus; furthermore, P. helleri registered a bite force similar to that of the sedentary bat, S. giannae. Our study determined that all the features of the mandible and most of the traits of the skull have a low phylogenetic signal. Through the PGLS, we found that the diet and several cranial features (mandibular toothrow length, dentary length, braincase breadth, mastoid breadth, greatest length of skull, condylo‐incisive length, and condylo‐canine length) determined bite force performance among Stenodermatiane.
5. Our results reinforce that skull size is a determining factor in the bite force, but also emphasize the importance of its relationships with morphology, ecology, and phylogeny of the species, which gives us a better understanding of the evolutionary adaptions of this highly diverse Neotropical bat group.

     

A small,narrow-beaked albatross from the Pliocene of New Zealand demonstrates a higher past diversity in the feeding ecology of the Diomedeidae

We describe a nearly complete, three-dimensionally preserved skull of a new albatross species from the late Pliocene (3.0–3.4 million years ago) Tangahoe Formation of New Zealand. Aldiomedes angustirostris, n. gen. et sp. has only about 90% of the length of the skull of the smallest extant albatross and is the geologically youngest record of a small-sized albatross known to date. The new species is characterized by a mediolaterally compressed beak, which is not found in any living albatross. The small size and some cranial features of A. angustirostris indicate that, in spite of its comparatively young geological age, the new species was not part of crown group Diomedeidae. We hypothesize that A. angustirostris was more piscivorous than extant albatrosses, which predominantly feed on squid. The reasons for the extinction of smaller-sized albatrosses are elusive but may be related to changes in seabird fauna during the Pliocene epoch, which witnessed the radiation of various non-procellariiform seabird groups.     

山西榆社—有角大唇犀

本文记述了产自山西榆社大唇犀属的一个新种——有角大唇犀Ch.(Acerorhinus)cornutum sp.nov. 过去,对大唇犀是否有角虽然也有过种种推测,但缺乏可靠依据,榆社的材料鼻部前端的构造,显示了角的存在。因此,Acerorhinus是大唇犀属三个亚属(Heissig,1975)中,唯一有角的一个亚属。文中还就大唇犀头骨吻部主要肌肉进行了复原,对其功能和生态进行了初步的讨论。     

New observations on the Late Miocene–Early Pliocene Lutrinae (Mustelidae: Carnivora,Mammalia) from the Middle Awash,Afar Rift,Ethiopia

New observations on the Late Miocene and Earliest Pliocene mustelids from the Middle Awash of Ethiopia are presented. The Middle Awash study area samples the last six million years of African vertebrate evolutionary history. Its Latest Miocene (Asa Koma Member of the Adu-Asa Formation, 5.54–5.77 Ma) and Earliest Pliocene (Kuseralee and Gawto Members of the Sagantole Formation, 5.2 and 4.85 Ma, respectively) deposits sample a number of large and small carnivore taxa among which mustelids are numerically abundant. Among the known Late Miocene and Early Pliocene mustelid genera, the Middle Awash Late Miocene documents the earliest Mellivora in eastern Africa and its likely first appearance in Africa, a new species of Plesiogulo, and a species of Vishnuonyx. The latter possibly represents the last appearance of this genus in Africa. Torolutra ougandensis is known from both the Late Miocene and Early Pliocene deposits of the Middle Awash. The genus Sivaonyx is represented by at least two species: S. ekecaman and S. aff. S. soriae. Most of the lutrine genera documented in the Middle Awash Late Miocene/Early Pliocene are also documented in contemporaneous sites of eastern Africa. The new observations presented here show that mustelids were more diverse in the Middle Awash Late Miocene and Early Pliocene than previously documented.     

The Skull of Stephanomys and a Review of Malpaisomys Relationships (Rodentia: Muridae): Taxonomic Incongruence in Murids

The cranial morphology of the extinct murid genus Stephanomys, previously known only by dental remains, is described here on the basis of partial skulls of three species of Pliocene age. Important cranial characters of the genus are a robust rostrum, a high zygoma, a wide zygomatic arch, a narrow interorbit, a large orbit, and an optic foramen in the backward position. In addition to some dental characters, Stephanomys shares most of these cranial traits with the extinct Malpaisomys from the Canary Islands. Some of these traits may be linked to the development of large eyes and life in a rocky environment. The peculiar dental pattern of Stephanomys (stephanodonty) is also present in some recent murids (Oenomys and Thamnomys) having a different skull morphology. A comparison with nine other extant genera of murids verified the relationship among Malpaisomys, Stephanomys, and Acomys, supporting our previous conclusion. Phenetic and cladistic analyses of 17 cranial and 23 dental characters show that skull morphology is phylogenetically informative but highly convergent and incongruent with other partial evidence based on dental and biochemical characters. The combined analyses of skull and teeth illustrate a case of mosaic evolution in murids.     

Mosasaurus beaugei Arambourg, 1952 (Squamata, Mosasauridae) from the Late Cretaceous phosphates of Morocco

Mosasaurus beaugei Arambourg, 1952 was based on isolated teeth from the Maastrichtian phosphatic deposits of Morocco. The recent discovery of new material, including skull and mandibular remains, improves our knowledge of this species. M. beaugei shares the following synapomorphies with the genus Mosasaurus: large teeth bearing two prominent carinae and with asymmetrical labial and lingual surfaces, the labial one being flattened and strongly facetted and the lingual one being convex; premaxillae with a small pointed rostrum and dentary without rostrum; palatal elements closely united; coronoid with very large ventromedial process overlying the prearticular. M. beaugei is characterised by the following autapomorphies: 12-13 maxillary teeth; marginal teeth bearing 3-5 prisms on the labial surface and 8-9 on the lingual one; palatine with posterior border concave and perpendicular to the long axis of the skull; splenial visible laterally on half of the dentary ventral surface; coronoid with anterior wing well developed and bearing two notches. M. beaugei is only known to date in the Maastrichtian phosphates of Morocco.     

First complete skull of an octodontoid (Rodentia, Caviomorpha) from the Early Miocene of South America and its bearing in the early evolution of Octodontoidea

Octodontoidea is the most diverse group of caviomorph rodents. The systematics of most of the fossil representatives has been essentially based upon dental characters. Described here is an almost complete skull with dentition assigned to Prospaniomys Ameghino based upon its dental morphology. The specimen comes from the Sarmiento Formation at Pampa de Gan Gan (central Patagonia, Argentina), assigned to the Colhuehuapian SALMA (early Miocene). The most remarkable features are in the posterior portion of the skull, some of them shared with the modern octodontids and interpreted as specialized by previous authors, which contrast with the generalized dental morphology. These combined features were not previously known in other octodontoids. The comparisons with other fossil and extant members of the superfamily suggest that the characters traditionally used to associate Prospaniomys with the echimyids are very probably plesiomorphies. Prospaniomys would represent an early diverging lineage more closely related to modern octodontids than to echimyids, in which cranial structures evolved more rapidly than dental and mandibular ones.     

The Large Porcupine Hystrix refossa (Rodentia,Hystricidae) from the Early Pleistocene Taurida Locality in Crimea

Doklady Biological Sciences - The remains of large porcupines (an incomplete skull, cranial and mandibular fragments, isolated teeth and postcranial bones) from the Early Pleistocene Taurida cave...     

A new species of Theriosuchus (Atoposauridae, Crocodylomorpha) from the Late Jurassic (Kimmeridgian) of Guimarota, Portugal

A new species of an atoposaurid crocodilian, Theriosuchus guimarotae, is described from the Late Jurassic (Kimmeridgian) of Portugal. Theriosuchus guimarotae can be distinguished from other species of Theriosuchus by a lateral surface of squamosal bevelled ventrally; a rounded, caudally projecting and dorsally sculptured caudolateral corner of the squamosal; a premaxillomaxillary suture aligned caudomedially in dorsal aspect; a minimum space between the supratemporal foramina that comprises one third of the total width of the cranial table; a minimum width of the frontal between the orbits that comprises one third of the maximum width of the skull at the orbits; a dentition that comprises only pseudocaniniform and lanceolate-shaped teeth; the presence of an external mandibular fenestra and all vertebral bodies amphicoelous. Its osteology also sheds light on the diagnosis of Theriosuchus within Atoposauridae. The material additionally includes specimens representative of several ontogenetic stages, each of which is discussed here. With its Late Jurassic age, T. guimarotae represents the oldest well-preserved material of Theriosuchus and reveals further knowledge about the palaeobiogeography of the genus in western Europe.     

Systematics of the southern Patagonian-Fueguian endemic Abrothrix lanosus (Rodentia: Sigmodontinae): Phylogenetic position,karyotypic and morphological data

Abrothrix lanosus (Thomas, 1897) is morphologically redescribed on the basis of new specimens collected in Tierra del Fuego (Argentina). Cranial, mandibular, skeletal, penile, and chromosomal characteristics are described and compared with other species of Abrothrix, especially those of the Patagonian-Fueguian region. Its phylogenetic position within Abrotrichini is explored using DNA sequences of the mitochondrial cytochrome b (cyt b) and the nuclear Interphotoreceptor Retinoid Binding Protein (IRBP) genes. Phylogenetically, cyt b places A. lanosus as sister of A. jelskii, whereas IRBP groups A. lanosus and A. longipilis. The latter topology is most consistent with morphological data and taxonomic history. Several cranial and mandibular characters distinguish A. lanosus from the other species of the genus, including A. longipilis, which is its most similar species. A. lanosus shares with other congeners a 2n=52 karyotype and differs from other species of Abrothrix by at least 10% (p-distances) sequence divergence in cyt b. In conclusion, A. lanosus is a valid species, readily distinguishable from other Abrothrix in the southern Patagonian-Fueguian region. Although many data, including penile and skull morphology, suggest that A. longipilis is its closest living relative, A. jelskii is retained as a viable alternative until additional data are obtained.     

New skull of Schizodelphis sulcatus Gervais, 1861 (Mammalia, Odontoceti, Eurhinodelphinidae) from the Lower Miocene of Pignan (Hérault, France) and its implications for systematics of Eurhinodelphinidae

Schizodelphis sulcatus is the type species of the Eurhinodelphinid genus Schizodelphis and was until now only known from a rather fragmentary specimen, lacking some important parts of the skull (vertex, ear bones and apex of rostrum). The study of a well-preserved skull of S. sulcatus Gervais, discovered in the lower Miocene of Hérault (France), helps to improve the diagnosis of this enigmatic species. Diagnostic features include the low height at the base of the rostrum, the lower position of the paroccipital process compared to the height of the postglenoid process in lateral view, the ventrally deflected postglenoid process and the ovoid-shaped nasals. It also confirms that the type species of Schizodelphis is indeed distinct. For the first time in Schizodelphis, the vertex is preserved and the ear bones are found in anatomic connection with the basicranium. A cladistic analysis of cranial characters of Eurhinodelphinidae, including ear bones, is performed and reveals a close phylogenetic relationship between S. sulcatus and the North American species Schizodelphis barnesi. This analysis also highlights some apomorphies of the genus as the smoothly laterally deflected anterior spine of the bulla in ventral view and the reestablishment of the contact between the falciform process of the squamosal and the lateral lamina of the pterygoid. Conversely, the attribution of Schizodelphis morckhoviensis to the genus Schizodelphis is questioned by this analysis.     

Reassessment of the cranial characters of Glossotherium and Paramylodon (Mammalia: Xenarthra: Mylodontidae)

Nomenclatural confusion has existed within the Mylodontinae for several genera, and has resulted in the supposition that Paramylodon of North America is synonymous with Glossotherium of South America. A taxonomic revision of crania for Glossotherium and Paramylodon upholds their separation as distinct genera and provides a list of diagnostic characters that have been lacking. Assessment was made using principal components analysis for suites of cranial and mandibular measurements, evaluation of ratios and measurement distribution, and by examining qualitative characters. Results show the greatest characterization for the skull comes from differences relating to cranial length versus width, whereas the mandible is predominantly distinguished by qualitative characters of the predental spout. Examination of the Pliocene species Glossotherium chapadmalense from South America shows a combination of characters indicative of each genus, but exhibits more with Glossotherium and is tentatively retained under that genus. The mix of characters indicates that G. chapadmalense is the likely ancestor to Paramylodon, although when and where the transition took place is still unclear. During the evolutionary transition, Paramylodon crania emphasized an increase in length of the palate, whereas those of Glossotherium emphasized an increase in cranial width. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 155 , 885–903.     

Partial skeleton of Theropithecus brumpti (Primates, Cercopithecidae) from the Chemeron Formation of the Tugen Hills, Kenya

Here we describe a complete skull and partial skeleton of a large cercopithecoid monkey (KNM-TH 46700) discovered in the Chemeron Formation of the Tugen Hills at BPRP Site #152 (2.63 Ma). Associated with the skeleton was a mandible of an infant cercopithecoid (KNM-TH 48364), also described here. KNM-TH 46700 represents an aged adult female of Theropithecus brumpti, a successful Pliocene papionin taxon better known from the Omo Shungura Formation in Ethiopia and sites east and west of Lake Turkana, Kenya. While the morphology of male T. brumpti is well-documented, including a partial skeleton with both cranial and postcranial material, the female T. brumpti morphotype is not well-known. This skeleton represents some of the first associated evidence of cranial and postcranial female T. brumpti remains. In addition to the complete skull, postcranial material includes elements of the axial skeleton and lower limb. While aspects of the skeleton conform to those of specimens previously assigned to T. brumpti, other features on the femur and tibia appear to differ from those previously described for this species. It is unclear whether these differences represent general variation within the T. brumpti population, variation between the sexes in T. brumpti, or the incorrect assignment of previous isolated hindlimb specimens. In total, the observable morphological features of the hindlimb suggest that KNM-TH 46700 was a terrestrial quadruped similar to modern savannah baboons (Papio). From the available evidence, it is difficult to assess whether or not KNM-TH 46700 frequently engaged in the specialized squatting and shuffling behavior observed in extant geladas (Theropithecus gelada).     

A large pholidosaurid in the Phu Kradung Formation of north‐eastern Thailand

In the early 1980s, the remains of a large crocodilian, consisting of a nearly complete lower jaw, were referred to a distinct species of Sunosuchus, S. thailandicus. The specimen was recovered from a road‐cut near Nong Bua Lamphu, north‐eastern Thailand, in the upper part of the continental Phu Kradung Formation, and then considered Early to Middle Jurassic in age. Since then, this age has been revised and most of the formation is now considered Early Cretaceous, although a Late Jurassic age is possible for its lowermost part. Here, we report for the first time cranial elements associated with mandibular remains assignable to ‘S’. thailandicus. An attribution to Pholidosauridae is proposed on the basis of premaxillary morphology, and the original referral of this taxon to the goniopholidid Sunosuchus is discarded. A new genus name Chalawan now designates the originally described material of S. thailandicus. Nevertheless, the newly described specimen shares a characteristic with both ‘traditional’ Goniopholididae and Pholidosauridae: the presence of a depression located on the lateral wall of the maxilla and jugal. A phylogenetic analysis confirms the inclusion of both Goniopholididae and Pholidosauridae into a common clade, Coelognathosuchia tax. nov. Although the new Thai skull is much fragmented, its original shape is reconstructed and is compared with other pholidosaurid genera, namely Elosuchus, Meridiosaurus, Oceanosuchus, Pholidosaurus, Sarcosuchus and Terminonaris. The presence of the genus Sunosuchus being highly questionable in Thailand, it cannot be used as evidence to link the Chinese and Indochinese blocks. Instead, the recognition of a freshwater pholidosaurid in a continental formation of the Indochinese block suggests that early in their evolutionary history, these crocodilians, already known from Europe, Africa and South America, were more widely distributed along the northern margin of the Tethys than previously recognized.     

New data on Trematosauroid labyrinthodonts of Eastern Europe: 1. Genus <Emphasis Type="Italic">Inflectosaurus</Emphasis> Shishkin, 1960

New materials and previously unpublished data on trematosaurid labyrinthodonts from the Early Triassic Bolshoe Bogdo locality (Astrakhan Region) are described. All cranial trematosaurid specimens from this locality are assigned to the monotypic genus Inflectosaurus based on the postorbital length of the skull roof. The diagnosis of the genus is amended. The intermediate position of Inflectosaurus between Angusaurus and Trematosaurus is marked.