临夏盆地晚中新世维氏大唇犀(奇蹄目,犀科)肢骨化石(英文)

大唇犀 (Chilotherium属 )是中国晚中新世三趾马动物群中占统治地位的类型 ,在亚洲的其他地区和南欧也有广泛的分布。然而 ,有关大唇犀头后骨骼的记述相当少。在山西保德和陕西府谷已经发现了丰富的大唇犀化石 ,但到目前为止仅有安氏大唇犀 (Ch .anderssoni)的少量头后骨骼被记述。维氏大唇犀 (Ch .wimani)最早发现于陕西府谷 ,被记述的材料仅包括头骨标本。最近我们在甘肃临夏盆地发现了大量晚中新世的Ch .wimani化石 ,其中不仅有众多的头骨 ,头后骨骼也相当丰富。本文研究的标本采自临夏盆地内众多的晚中新世三趾马动物群化石地点 ,包括和政县的大深沟、南阳山、大山庄、禾托和高家山 ,广河县的后山、兰家山、山庄、寺沟、次滩、沙地沟、阳洼铺子和桥家 ,以及东乡县的双拱北等。在保德的三趾马动物群中 ,大唇犀以Ch .anderssoni和哈氏大唇犀 (Ch .habereri)为代表 ,而在临夏和府谷却是以Ch .wimani为代表。临夏盆地的三趾马动物群中共有 3种无角犀类 ,即Ch .wimani,Acerorhinuscornutus和A .hezhengensis。根据头骨材料的统计 ,Ch .wimani在犀类中占有绝对优势 ,A .hezhengensis和A .cornutus的个体数量很少。与此对应 ,动物群中的无角犀类肢骨明显可以分为 3组 ,其中具中等尺寸的一组占有绝对优势。?     

A NEW DIPNOAN FISH FROM THE MIDDLE DEVONIAN (EIFELIAN) OF SCOTLAND

Abstract:  A new dipnoan fish, Pinnalongus saxoni gen. et sp. nov., is described from a suite of recently discovered specimens from Caithness and East Sutherland, northern Scotland. The stratum where Pinnalongus occurs is within the middle Eifelian of the Middle Devonian. Pinnalongus has a skull roof consisting of a mosaic of small bones at the anterior end, a feature more typically found in Early Devonian dipnoans. The posterior part of the skull roof is more typical of later advanced Middle Devonian dipnoans with the B-bone separating the I-bones. The postcranial body is now considered not to be so important with respect to the classification of dipnoans as originally proposed by Dollo in 1895, who thought there was an evolutionary transformation series. Nevertheless, the postcranial body of Pinnalongus has more in common with later Middle and Late Devonian dipnoans such as Scaumenacia , with a very long second dorsal fin. Based on the skull morphology, Pinnalongus is most closely related to Tarachomylax from the Lower Devonian of Severnaya Zemlya, Russia. Pinnalongus represents the earliest known complete articulated dipnoan with tooth plates.     

The last hadrosaurid dinosaurs of Europe: A new lambeosaurine from the Uppermost Cretaceous of Aren (Huesca, Spain)

A new hadrosaurid dinosaur, Arenysaurus ardevoli gen. et sp. nov., from the Late Maastrichtian of Aren (Huesca, South-central Pyrenees) is described on the basis of a partial, articulated skull, mandibular remains and postcranial elements, including vertebrae, girdle and limb bones. Arenysaurus is characterized by having a very prominent frontal dome; nearly vertical prequadratic (squamosal) and jugal (postorbital) processes, and deltopectoral crest of the humerus oriented anteriorly. Moreover, it possesses a unique combination of characters: short frontal (length/width approximately 0.5); midline ridge of parietal at level of the postorbital-squamosal bar; parietal excluded from the occiput; squamosal low above the cotyloid cavity. A phylogenetical analysis indicates that Arenysaurus is a rather basal member of Lambeosaurinae and the sister-taxon to Amurosaurus and the Corythosaurini-Parasaurolophini clade. The phylogenetic and biogeographical relationships of Arenysaurus and other lambeosaurines suggest a palaeogeographical connection between Asia and Europe during the Late Cretaceous.     

Adaptive biological trends in the European upper palaeolithic: the case of the Sunghir remains

Sunghir is one of the most important Upper Palaeolithic sites in the world because of its most Northern location, the extraordinary richness of the artifacts, and the state of human bone preservation. The skeletal finds give evidence for the study both of adult and subadult body builds in the group. For the reconstruction of patterns of postcranial morphology, total measurements of bones and X-ray observations have been used. We have determined the basic structural traits typical for Sunghirians: small corticalisation of adult postcranial skeletons; large volume of the bone marrow cavity relative to the general size; quick tempo of attainment in early ontogenesis of large adult size combined with late synostoses ensuring prolonged linear growth; macroskelia combined with extreme andromorphy in the shoulder belt structure; capacious chest. The above traits can be interpreted in terms of adaptation to such formative factors as low temperature stress, deficit of atmospheric oxygen, high protein nutrition, and mechanical loads.     

The African species Megantereon whitei from the Early Pleistocene of Monte Argentario (South Tuscany,Central Italy)

A partial skull and articulated postcranial elements of Megantereon whitei have been recorded during the 1950s from a karst deposit in the Monte Argentario area (Grosseto). These fossils recently became available for study. The bones are quite well preserved, included in a hard reddish matrix with calcareous clasts. The fossil is part of a faunal assemblage referred to the Late Villafranchian (Early Pleistocene). M. whitei from Monte Argentario is characterised by elongated upper canines, stronger than those of the Upper Valdarno (Tuscany) specimens and similar to the Pirro Nord (Apulia) fossil. The manus is robust, the first phalanges are quite long in comparison to the metacarpals. The Early Pleistocene European M. whitei represents an African element that took part in the faunal dispersal from Africa to Europe that occurred at the Plio-Pleistocene transition.     

A nearly complete skeleton of an early juvenile diplodocid (Dinosauria: Sauropoda) from the Lower Morrison Formation (Late Jurassic) of north central Wyoming and its implications for early ontogeny and pneumaticity in sauropods

A nearly complete skeleton of a juvenile sauropod from the Lower Morrison Formation (Late Jurassic, Kimmeridgian) of the Howe Ranch in Bighorn County, Wyoming is described. The specimen consists of articulated mid-cervical to mid-caudal vertebrae and most appendicular bones, but cranial and mandibular elements are missing. The shoulder height is approximately 67 cm, and the total body length is estimated to be less than 200 cm. Besides the body size, the following morphological features indicate that this specimen is an early juvenile; (1) unfused centra and neural arches in presacral, sacral and first to ninth caudal vertebrae, (2) unfused coracoid and scapula, (3) open coracoid foramen, and (4) relatively smooth articular surfaces on the limb, wrist, and ankle bones. A large scapula, short neck and tail and elongate forelimb bones relative to overall body size demonstrate relative growth. A thin-section of the mid-shaft of a femur shows a lack of annual growth lines, indicating an early juvenile individual possibly younger than a few years old. Pneumatic structures in the vertebral column of the specimen SMA 0009 show that pneumatisation of the postcranial skeleton had already started in this individual, giving new insights in the early ontogenetic development of vertebral pneumaticity in sauropods.

The specimen exhibits a number of diplodocid features (e.g., very elongate slender scapular blade with a gradually dorsoventrally expanded distal end, a total of nine dorsal vertebrae, presence of the posterior centroparapophyseal lamina in the posterior dorsal vertebrae). Although a few diplodocid taxa, Diplodocus, cf. Apatosaurus, and cf. Barosaurus, are known from several fossil sites near the Howe Ranch, identification of this specimen, even at a generic level, is difficult due to a large degree of ontogenetic variation.     

Pachyosteosclerosis suggests archaic Homo frequently collected sessile littoral foods

Fossil skeletons of Homo erectus and related specimens typically had heavy cranial and postcranial bones, and it has been hypothesised that these represent adaptations, or are responses, to various physical activities such as endurance running, heavy exertion, and/or aggressive behavior. According to the comparative biological data, however, skeletons that show a combination of disproportionally large diameters, extremely compact bone cortex, and very narrow medullary canals are associated with aquatic or semi-aquatic tetrapods that wade, and/or dive for sessile foods such as hard-shelled invertebrates in shallow waters. These so-called pachyosteosclerotic bones are less supple and more brittle than non-pachyosteosclerotic bones, and marine biologists agree that they function as hydrostatic ballast for buoyancy control. This paper discusses the possibility that heavy skeletons in archaic Homo might be associated with part-time collection of sessile foods in shallow waters.     

Hindlimb adaptations in Ourayia and Chipetaia, relatively large-bodied omomyine primates from the Middle Eocene of Utah

North American omomyids represent a tremendous Eocene radiation of primates exhibiting a wide range of body sizes and dietary patterns. Despite this adaptive diversity, relatively little is known of the postcranial specializations of the group. Here we describe hindlimb and foot bones of Ourayia uintensis and Chipetaia lamporea that were recovered from the Uinta B member (early Uintan Land Mammal Age), Uinta Formation, Utah. These specimens provide insights into the evolution of postcranial adaptations across different body sizes and dietary guilds within the Eocene primate radiation. Body mass estimates based on talar measurements indicate that Ourayia uintensis and Chipetaia lamporea weighed about 1,500-2,000 g and 500-700 g, respectively. Skeletal elements recovered for Ourayia include the talus, navicular, entocuneiform, first metatarsal, and proximal tibia; bones of Chipetaia include the talus, navicular, entocuneiform, and proximal femur. Both genera had opposable grasping big toes, as indicated by the saddle-shaped joint between the entocuneiform and first metatarsal. Both taxa were arboreal leapers, as indicated by a consistent assemblage of characters in all represented bones, most notably the somewhat elongated naviculars, the high and distinct trochlear crests of the talus, the posteriorly oriented tibial plateau (Ourayia), and the cylindrical head of the femur (Chipetaia). The closest resemblances to Ourayia and Chipetaia are found among the Bridger omomyines, Omomys and Hemiacodon. The results of our comparisons suggest that the later, larger, more herbivorous omomyines from Utah retained a skeletal structure characteristic of earlier, smaller North American omomyids.     

Postcranial morphology and growth of the pachypleurosaur Anarosaurus heterodontus (Sauropterygia) from the Lower Muschelkalk of Winterswijk, The Netherlands

Sauropterygia from the Muschelkalk are only found in lag deposits known as bone beds, and most of the material consists of isolated bones. Alpha taxonomy of Sauropterygia from the Germanic Basin which include Pachypleurosauria is thus based mainly on skull morphology of a few specimens. Articulated or associated postcranial material of pachypleurosaurs, associated with diagnostic skull material, is very rare in the Germanic Basin and currently occurs in larger numbers only in the Lower Muschelkalk of Winterswijk (Gelderland Province, The Netherlands), which continuously produces new material. For the first time, the morphology of several partially articulated skeletons of the pachypleurosaur Anarosaurus heterodontus is described and compared. Some of those specimens have skull material attached; others were identified as pachypleurosaurs on the basis of their long bone histology. The current study revealed that postcranial bones of A.?heterodontus feature a diverse morphology reflecting differences during ontogeny. Thus, A.?heterodontus specimens could be assigned to size classes (I?CIII). However, on the basis of morphology, histology, and maximal known size of isolated skulls and humeri, none of these specimens represent fully grown individuals. Growth mark counts of midshaft-femur samples, morphologically assigned to size class?III, document that this size class was reached within the first year of life. Size class?III continued into the second year of life, and then afterwards skeletal maturity was reached. Thus, a juvenile A.?heterodontus grew very fast, which is also indicated by its bone tissue type, composed of a high number of radial vascular canals and a fast-deposited bone matrix. The assignment of isolated bones from Lower to Middle Muschelkalk localities to A.?heterodontus is now possible with an extensive amended diagnosis of this taxon. This largely contributes to the understanding of taxonomical diversity and distribution. Morphological comparison of the postcranial skeleton of A.?heterodontus with that of the two other valid pachypleurosaurs from the Germanic Basin, Anarosaurus pumilio and Dactylosaurus, supports their close phylogenetic relationship. Furthermore, the skeleton of A.?heterodontus has no morphological or histological aquatic adaptation such as pachyostosis or pachyosteosclerosis and thus represents the least degree of aquatic adaptation within Pachypleurosauria.     

Sex assessment on the basis of long bone circumference

Discriminant functions have long been used to classify individuals into groups according to the dimensions of their bones. Although lengths, widths, and diameters have been extensively used, the circumferences have not been adequately validated. In this work, the importance that the circumferences of long bones can have in assigning the sex of ancient human remains is demonstrated. The functions produced by using just one circumference achieved accuracies higher than 80%, and circumference at the radial tuberosity of the radius is able to classify 92.8% of skeletons from the Late Roman site of Mas Rimbau/Mas Mallol (Spain). When functions are produced by using more than one circumference, they can achieve the uppermost classification attained in this sample. The functions also showed that the arm circumference functions are more useful than those of the leg, probably because male individuals of the population had greater mechanical stress than did females. The classification percentages, as well as other statistical values for the functions, demonstrated the great ability of long bone circumferences in helping to classify the sex of individuals of other sites of the Mediterranean area besides the ones examined in this study.     

The ontogeny of Holocene and Late Pleistocene human postcranial strength

While a wide variety of studies have focused on population variation in adult cross‐sectional properties, relatively little is known about population variation in postcranial robusticity in immature individuals. Furthermore, the age at which the population differences readily detected in adults manifest during growth is also unknown. This research addresses these gaps in our current understanding through the analysis of immature humeral and femoral long bone strength. Cross‐sectional geometry was used to compare the developmental trajectories of diaphyseal strength in Late Pleistocene Neandertal and modern human subadults to a sample of immature humans from seven geographically diverse Holocene populations. Population differences in size‐standardized cross‐sectional properties appear to be systemic and develop very early in ontogeny in the Holocene sample. In many cases, these differences are present before one year of age. In general, the Late Pleistocene fossil samples fit within the range of recent human variation in long bone strength. Population differences detected here are likely related to a combination of factors including activity patterns, genetic propensities, and nutritional status. These results highlight the complex mosaic of processes that result in adult postcranial robusticity, and suggest that further exploration of the developmental interplay between intrinsic and extrinsic influences on skeletal robusticity will likely enhance our understanding of adult postcranial morphology. Am J Phys Anthropol 2010. © 2009 Wiley‐Liss, Inc.     

Nacholapithecus skeleton from the Middle Miocene of Kenya

An almost entire skeleton of a male individual of Nacholapithecus kerioi (KNM-BG 35250) was discovered from Middle Miocene (approximately 15 Ma) sediments at Nachola, northern Kenya. N. kerioi exhibits a shared derived subnasal morphology with living apes. In many postcranial features, such as articular shape, as well as the number of the lumbar vertebrae, N. kerioi resembles Proconsul heseloni and/or P. nyanzae, and lacks suspensory specializations characteristic of living apes. Similarly, N. kerioi shares some postcranial characters with Kenyapithecus spp. However, despite the resemblance, N. kerioi and Proconsul spp. are quite different in their body proportions and some joint morphologies. N. kerioi has proportionally large forelimb bones and long pedal digits compared to its hindlimb bones and lumbar vertebrae. Its distinctive body proportions suggest that N. kerioi was more derived for forelimb dominated arboreal activities than P. nyanzae and P. heseloni. On the other hand, it exhibits a mixture of derived and primitive cranio-dental and postcranial features relative to the contemporaneous Kenyapithecus and Early MioceneMorotopithecus. While the phylogenetic position of N. kerioi is unsettled, it seems necessary to posit parallel evolution of cranio-dental and/or postcranial features in fossil and living apes.     

Description of a Well Preserved Fetus of the European Eocene Equoid Eurohippus messelensis

The early Middle Eocene locality of Grube Messel, near Darmstadt (Germany), is famous for its complete vertebrate skeletons. The degree of preservation of soft tissues, such as body silhouettes, internal organs and gut contents, is frequently remarkable. The present specimen was analyzed for remnants of the reproductive system. Classic anatomy and osteology and high-resolution micro-x-ray were applied to describe the fetus of the European Eocene equoid Eurohippus messelensis. Scanning electronic microscopy (SEM) was used for determination of soft tissue remnants. The fetus is the earliest and best-preserved fossil specimen of its kind. The postcranial fetal skeleton is almost complete and largely articulated, allowing the conclusion that the pregnant mare was in late gestation. The apparent intrauterine position of the fetus is normal for the phase of pregnancy. Death of mare and fetus were probably not related to problems associated with parturition. Soft tissue interpreted as the uteroplacenta and a broad uterine ligament are preserved due to bacterial activity and allow considerations on the evolutionary development of the structures.     

A diseased Panthera leo spelaea (Goldfuss 1810) lioness from a forest elephant graveyard in the Late Pleistocene (Eemian) interglacial lake at Neumark-Nord,central Germany

A solitary articulated skeleton of a middle-aged and diseased Panthera leo spelaea lioness from the Eemian interglacial has been found amongst numerous articulated skeletons of Palaeoloxodon antiquus forest elephants, in sediments from a small, shallow lake at Neumark-Nord in central Germany, which has Neanderthal settlements along its shoreline. Several pathologies such as a fibula fracture, arthritis in one of the front legs and a lost canine tooth with associated maxillary inflammation and dissolution made the lioness vulnerable to other predators such as hyenas, whose presence is indicated by their bones, coprolites and many scavenging marks on the elephant skeletons and on a femur from a male lion. The scavenging of hyenas and lions at this site is commonly documented by canine bite marks on the joints of elephant bones. Bite and scratch marks on the ventral vertebral columns and pelvises of two P. antiquus forest elephant skeletons suggest that the intestines and inner organs may have been consumed by large predators, as is commonly the case with modern African lions feeding on elephants. The weak and diseased lioness may possibly have been killed during antagonistic battles between hyenas and lions over their larger prey.     

Brief communication: evidence bearing on the status of Homo habilis at Olduvai Gorge

Students of the early hominin career have debated the status of Homo habilis since its discovery in 1960. Today discussion centers on which specimens should be included in the species and what constitutes the holotype. Recent reviews of early Homo suggest that the Olduvai Hominid 8 foot may sample Paranthropus while the OH 7 skull bones, mandible, and hand sample H. habilis. Moreover, some suggest that while H. habilis in Middle Bed I at Olduvai is craniodentally Homo-like, the postcranial skeleton of H. habilis is more like that of Australopithecus. Evidence presented here indicates not only that OH 7 and OH 8 represent H. habilis but also that they come from a single individual. The association of OH 35 with OH 7 and OH 8 is less certain. Morphological, pathological, and taphonomic evidence favors the inclusion of OH 35 in the holotype. However, stratigraphic evidence suggests that OH 35 and OH 8 are not coterminous. With or without OH 35, the holotype of H. habilis ranks as one of the most complete early hominin skeletons and the most complete and functionally informative specimen of early Homo.     

Human foot bones from Klasies River main site, South Africa

The caves at Klasies River contain abundant archaeological evidence relating to human evolution in the late Pleistocene of southern Africa. Along with Middle Stone Age artifacts, animal bones, and other food waste, there are hominin cranial fragments, mandibles with teeth, and a few postcranial remains. Three foot bones can now be added to this inventory. An adult first metatarsal is similar in size and discrete anatomical features to those from Holocene burials in the Cape Province. A complete and well-preserved second metatarsal is especially long and heavy at midshaft in comparison to all Holocene and more recent South African homologues. A large fifth metatarsal is highly distinctive in its morphology. In overall size, these pedal elements resemble specimens from late Pleistocene sites in western Asia, but there are some differences in proportions. The fossils support earlier suggestions concerning a relatively high level of sexual dimorphism in the African Middle Stone Age population. Squatting facets on the two lateral metatarsals appear to indicate a high frequency of kneeling among members of this group. The new postcranial material also underlines the fact that the morphology of particular skeletal elements of some of the 100,000-year-old Klasies River individuals falls outside the range of modern variation.     

Comparison of radiologic and gross examination for detection of cancer in defleshed skeletons

The reliability of visual examination of defleshed bones was assessed for detection of postcranial metastatic disease in individuals known to have had cancer. This was compared with standard clinical radiologic techniques. The skeletons of 128 diagnosed cancer patients from an early 20th century autopsied skeletal collection (Hamann-Todd Collection) were examined. Radiologic examination detected evidence of metastatic disease in 33 individuals, compared to 11 by visual examination of the postcranial skeletons. Four of these cases were detected by both techniques. Blastic lesions were most commonly overlooked on visual examination, because they were localized to trabecular (internal bone) structures. The ilium was the most commonly affected bone, with lytic or blastic lesions detected in 30 of 33 individuals. While the proximal femur was affected in only nine individuals, x-ray of the proximal femur and ilium detected all individuals with postcranial evidence of metastatic disease. Skeletal distribution of metastases provides no clue to the location of origin or histologic subtype of the cancer. Survey of archeological human remains for metastatic cancer requires radiologic examination. Such skeletal surveys should x-ray at least the ilia and femora. © 1995 Wiley-Liss, Inc.     

Monotreme ossification sequences and the riddle of mammalian skeletal development

The developmental differences between marsupials, placentals, and monotremes are thought to be reflected in differing patterns of postcranial development and diversity. However, developmental polarities remain obscured by the rarity of monotreme data. Here, I present the first postcranial ossification sequences of the monotreme echidna and platypus, and compare these with published data from other mammals and amniotes. Strikingly, monotreme stylopodia (humerus, femur) ossify after the more distal zeugopodia (radius/ulna, tibia/fibula), resembling only the European mole among all amniotes assessed. European moles also share extreme humeral adaptations to rotation digging and/or swimming with monotremes, suggesting a causal relationship between adaptation and ossification heterochrony. Late femoral ossification with respect to tibia/fibula in monotremes and moles points toward developmental integration of the serially homologous fore- and hindlimb bones. Monotreme cervical ribs and coracoids ossify later than in most amniotes but are similarly timed as homologous ossifications in therians, where they are lost as independent bones. This loss may have been facilitated by a developmental delay of coracoids and cervical ribs at the base of mammals. The monotreme sequence, although highly derived, resembles placentals more than marsupials. Thus, marsupial postcranial development, and potentially related diversity constraints, may not represent the ancestral mammalian condition.     

The sculpture and morphology of postcranial dermal armor plates and associated bones in gasterosteiforms and syngnathiforms inhabiting Estonian coastal waters

Lees, J., Märss, T., Wilson, M. V. H., Saat, T. and ?pilev, H. 2011. The sculpture and morphology of postcranial dermal armor plates and associated bones in gasterosteiforms and syngnathiforms inhabiting Estonian coastal waters. ―Acta Zoologica (Stockholm) 93 : 422–435. Five fish species inhabiting Estonian coastal waters (Gasterosteus aculeatus L., Pungitius pungitius (L.), and Spinachia spinachia (L.) of the order Gasterosteiformes and Syngnathus typhle L. and Nerophis ophidion (L.) of the order Syngnathiformes) are described on the basis of the sculpture and morphology of their postcranial dermal armor plates, as revealed and illustrated by SEM images. This study shows that the shapes of these superficial skeletal elements vary by species as well as by their position on the body, whereas the sculpture on the bones is taxon specific. The detailed features allow the identification of isolated fossil and subfossil remains and show promise for future systematics studies.