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1.
While it is recognized that the overall configuration of the vertebral column, as well as the size and shape of individual vertebrae, differ within and between primate taxa, relatively little is known about the degree to which vertebral morphology reflects a phylogenetic signal or the degree to which vertebral elements can be used in accurate taxonomic classification. Isolated vertebrae are occasionally found in fossil assemblages, and proper taxonomic identification is necessary to make inferences about the animal's biology and place it in a broader phylogenetic and evolutionary context. Recently, three large primate cervical vertebrae (C3, C5, and C6) from Pirro Nord, Italy (early Pleistocene, late Villafranchian) were attributed to the genus Theropithecus based on size comparisons with extant cercopithecoid primates (Rook et al., 2004, J. Hum. Evol. 47, 267-277). These fossils were suggested to indicate an early dispersal of this genus out of Africa around 1.6-1.3 Ma possibly co-incident with early Pleistocene dispersals of Homo. Because of the potential importance of these fossils for interpreting Theropithecus evolution and the relatively few morphological data on primate cervical vertebral morphology, we examined the size and shape of cervical vertebrae in a large sample of extant cercopithecoid taxa (n=106). Specifically, we evaluated whether subfamily and genus level assignments can be made on the basis of isolated cervical elements. Discriminant analyses reveal that scaled shape variables are good discriminators of taxonomic affinity at the subfamily level but are poor discriminators at the genus level. Least-squares regressions show that raw linear dimensions of cervical vertebral morphology are good predictors of body mass in the extant sample. Our regression results produce a likely body mass estimate of 22-38 kg for the Pirro Nord cervical vertebrae. Based on these regression estimates, the poor ability to discriminate cervical vertebrae at the genus level, and paleoenvironmental reconstructions of Pirro Nord, it is unlikely that the Pirro Nord fossils can be confidently attributed to the genus Theropithecus. These findings have important implications for recent interpretations of the nature of Theropithecus dispersal out of Africa.  相似文献   

2.
《Comptes Rendus Palevol》2008,7(8):601-606
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.  相似文献   

3.
Theropithecus and 'Out of Africa' dispersal in the Plio-Pleistocene   总被引:1,自引:0,他引:1  
Theropithecus oswaldi was one of the most widely distributed Plio-Pleistocene primates, found in southern, East, and North Africa, as well as in Spain, India, and possibly Italy. Such a large geographic range for a single primate species is highly unusual. Here, the nature and timing of its dispersal is examined using the Stepping Out cellular automata model. A hypothetical dispersal of T. darti is also modelled to assess whether the late Pliocene might have been a more favorable period for Afro-Eurasian dispersal than the early Pleistocene. Stepping Out draws on climatic and biome reconstruction to provide the paleovegetative and climatic background necessary for the simulations, and model parameters for T. oswaldi and T. darti were set a priori on the basis of their fossil records and paleobiologies. The simulations indicate that T. darti could have readily left Africa in the Pliocene, and that it swiftly reaches Asia. A European T. darti colonization was less certain and less rapid. The simulated T. oswaldi dispersal out of Africa was slower, but nonetheless T. oswaldi arrived at Mirzapur within the time period indicated by the fossil record. Using the a priori parameters, T. oswaldi did not arrive at the European sites of Cueva Victoria and Pirro Nord. It cannot be discounted, therefore, that some of the European fossils are a result of an earlier T. darti dispersal. The simulations also showed that in order for Theropithecus to reach Europe, it needed to be tolerant of a relatively wide range of habitats. In addition, our finding that Asian colonization was more rapid and more probable parallels the information from the hominin fossil record, in which the fossils from Asia predate those from Europe by several hundred thousand years.  相似文献   

4.
The site of Pirro Nord (also known as Cava Pirro or Cava Dell’Erba) is known in literature since the 1970's of the last century as a palaeontological site, of which the mammalian fossil association constitutes a reference (local) fauna for the European latest Villafranchian. This fossil association is also known for the occurrence of some African elements. During the 2005, a lithic industry has been found in three karst fissures, together with the typical elements of the Pirro Nord vertebrate assemblage. The biochronological assessment based on the vertebrate assemblage attributes it to a time interval bracketed between 1.3 Ma and 1.7 Ma. Thus the site of Pirro Nord represents the oldest human occupation of Europe so far known. The lithic assemblage, attributable to the Mode 1, is constituted by three cores and seven flakes, and is made only on flint. Lithic artefacts have been found in stratigraphic context during the preliminary surveys of the three fissures, that they will be the object of systematic excavations in the years to come.  相似文献   

5.
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7.
A new species of the fish genus Ilyodon is described from San Juan Tacámbaro river, Michoacán, México 19 degrees 10' 42" N, 101 degrees 20' 45" W. We used 129 specimens representing I. whitei, 60 of I. furcidens and 84 of the new species for our analyses. These included samples of both sexes. The new species is distinguished from I. whitei and I. furcidens by its strongly convex cephalic profile, the size and disposition of the pores of the lateral line of the preorbital, the thinner caudal peduncle, its strongly bifid tooth and the form and size of neural prezygapophyses of caudal vertebrae.  相似文献   

8.
In this paper we describe a new species of Hypolagus coming from an early Pliocene karstic deposit near Caló den Rafelino (Manacor, Mallorca). It represents the westernmost European record for the genus. The faunal assemblage of this deposit represents an early phase of the second insular faunal episode of Mallorca, related with the Messinian regressive episode (latest Miocene). Although the postcranial are relatively robust, the size of all these elements is included in the range of continental leporids. It is unknown if they display significant allometric changes, as occurred in other insular leporids. p3 is small and displays a markedly trapezoidal outline and a deep hypoflexid (between 54 and 56% of the total tooth width). The presence of Hypolagus in the Neogene of the Balearic Islands is in agreement with the faunal scenario for the European continent during the late Miocene and the Pliocene, where this genus is abundant and widely distributed.  相似文献   

9.
The Middle Stone Age (MSA) sediments of Porc-Epic Cave near Dire Dawa, Ethiopia, have produced a large assemblage of archaeofaunal remains dating to the later periods of the Late Pleistocene. As one of the few MSA faunal assemblages from East Africa subject to detailed analysis, it provides rare insight into the foraging behavior of the early modern humans in this region. The MSA fauna include taxa that were not historically present in the area, with the occurrence of reduncines and alcelaphines indicating widespread grasslands and proximity to a perennial source of water. The faunal analysis examined several lines of evidence, including breakage patterns, surface modification, and skeletal-element representation. By incorporating comparisons with multiple actualistic data sets, the analysis of the assemblage demonstrates that, while the influence of carnivores and other biotic agents was evident, the faunal remains were accumulated primarily by hominid activity. The skeletal-element representation at Porc-Epic includes an abundance of high utility bones, in contrast to the predominance of "head-and-foot" elements documented at other MSA and Middle Paleolithic (MP) sites. The MSA occupants of Porc-Epic effectively exploited a wide range of prey with more emphasis on small- and medium-sized mammals.  相似文献   

10.
The Kibish faunal remains are useful for reconstructing the habitat of the earliest documented Homo sapiens and for understanding the community within which early modern humans existed. A diverse assemblage of large mammals, including many species of bovids, suids, and equids, has been recovered from the Kibish Formation. There are no extinct large mammals represented in the fossil assemblage, and the overall taxonomic composition of the fossil fauna is similar to the modern-day wildlife community living near the Omo River. The fossil faunal assemblage shows a paucity of arboreal primates, and carnivore species are rare. However, the faunal sample includes possible Cephalophus (duiker) remains and Hylochoerus meinertzhageni (giant forest hog), taxa that are extremely rare in the African fossil record, and both indicate more closed habitats. Comparative analyses of the Kibish faunal remains using the ecological-diversity approach document close associations with edaphic grassland and woodland vegetation types. These vegetation forms are similar to current habitats surrounding the Omo River.  相似文献   

11.
The one modern member of the genus Theropithecus, T. gelada (Primates, Cercopithecidae), inhabits grassland and is highly terrestrial. It is often supposed that Theropithecus oswaldi, one of the most common primates of the Plio-Pleistocene of East and southern Africa, was also a highly terrestrial open habitat species. Ecomorphic analysis was used to assess the locomotor strategy and habitat preference of T. oswaldi, and it was found that this species was unlikely to have had a locomotor strategy and habitat preference identical to that of T. gelada, with T. oswaldi possibly using arboreal substrates in a manner similar to some modern baboon groups. Thus, it appears that there has been considerable ecological diversity in the genus Theropithecus over the course of its evolution, mirroring the diversity evident in the hominin fossil record.  相似文献   

12.
A sample of 117 fossil cercopithecids has been collected from the Middle Pleistocene site of Asbole, Afar Region, Ethiopia. A minimum of five species is present. There are two species of Cercopithecini, here recognized as cf. Chlorocebus aff. aethiops, and cf. Chlorocebus cf. patas. There are also two species of Papionini: Papio hamadryas ssp. indet. and Theropithecus oswaldi leakeyi. Finally, there is a single species of colobine present, Colobus sp. indet. The assemblage is chronologically constrained and is derived from sediments dated to approximately 600 ka. Within this sample Colobus sp. is by far the most common species present, outnumbering the other four species combined. The cercopithecid assemblage is most consistent with a woodland habitat, corroborating an earlier interpretation based on the non-primate fauna. Taxonomic, biogeographic, and evolutionary implications of the assemblage are also discussed.  相似文献   

13.
贵州兴义中三叠世 Nothosaurus一新种   总被引:12,自引:4,他引:8  
记述了贵州兴义法郎组竹竿坡段幻龙一新种———Nothosaurusyoungisp .nov .。新种以眶后弓窄 ,上颌骨和眶后骨在轭骨之后相连 ,外翼骨形成明显的腹向凸缘 ,下颌具清晰的冠状突 ,和夹板骨前端进入下颌缝合部等特征区别于幻龙的其他种。支序分析的结果表明N .youngi的原始性仅次于N .juvenilis。新种N .youngi具有Nothosaurus中的一些原始特征 ,短的下颌缝合部 ,短的上颌齿列和窄的眶后弓 ,新种在法郎组竹杆坡段的发现支持含化石地层为中三叠世拉丁期的结论。  相似文献   

14.
Two isolated trunk vertebrae from the ?uppermost Albian–lower Cenomanian Kem Kem beds of Morocco are described and assigned to Lapparentophis, an early snake genus known from coeval deposits in Algeria. The Moroccan specimens represent a new species, Lapparentophis ragei, which can be distinguished from the type and only known species, Lapparentophis defrennei, by its smaller size, its more elongate vertebrae, the presence of parazygosphenal foramina, and paradiapophyses extending anteroventrally closer to the cotyle. The discovery of Lapparentophis in the Kem Kem beds adds to the relatively diverse snake assemblage previously reported from this formation and extends the geographical range of the genus. The distribution of Lapparentophis and lapparentophiid-grade (?lapparentophiid) snakes is discussed. This poorly known family of terrestrial snakes seems to be restricted to the latest Albian–early Cenomanian of North Africa, with the exception of Pouitella from the early–middle Cenomanian of France. As for many other vertebrate taxa of this period, this distribution is consistent with a dispersal event from Africa to the western part of the European archipelago.  相似文献   

15.
An account is given of the morphology and taxonomy of the African genus Ornithoglossum Salisb. The genus belongs to the Liliaceae–Wurmbeoideae, a phytochemi–cally distinct taxon sometimes treated as a separate family, the Colchicaceae. Ornithoglossum belongs to the tribe Iphigenieae, which is here amended to include the former tribe Glorioseae. Within the genus Ornithoglossum 8 species are here recognized, 3 of which are new, viz. O. parviflorum B. Nord., O. vulgare B. Nord. and O. gracile B. Nord. Two varieties of O. parviflorum are recognized. O. zeyheri (Baker) B. Nord. is a new combination. The chromosome number 2n = 24 is recorded for four species. The genus is believed to have originated in formerly arid regions of tropical Africa. Because of a climatic change, an increase in humidity, a south– and southwestward migration took place, followed by speciation in response to factors in the new environment. Sympatric speciation may have been promoted by the development of differences in flowering times and by specialization to different pollinators. The evolution of the nectary region of the tepals is particularly illuminating, and taxonomically useful. The proposed taxonomy is further supported by ultrastructural features of the seeds and pollen grains.  相似文献   

16.
Two associated incomplete thyreophoran dorsal vertebrae from the Callovian Marnes de Dives Formation of the Vaches Noires cliffs, on the Normandy coast, are referred to an indeterminate stegosaur that appears to be different from Lexovisaurus, previously reported from the Callovian of western France. These vertebrae are the first evidence of thyreophorans from the Vaches Noires and complement the dinosaur assemblage from this locality, which hitherto consisted of several theropod taxa and an indeterminate sauropod. The dinosaur record from the Vaches Noires is heavily dominated by theropods and this imbalance is difficult to explain. A possible explanation may be that the dinosaur sample from the Vaches Noires is too small to be statistically significant and representative of the original faunal assemblage from which it is derived.  相似文献   

17.

Background and Aims

Salvia is the largest genus in Lamiaceae and it has recently been found to be non-monophyletic. Molecular data on Old World Salvia are largely lacking. In this study, we present data concerning Salvia in Africa. The focus is on the colonization of the continent, character evolution and the switch of pollination systems in the genus.

Methods

Maximum likelihood and Bayesian inference were used for phylogenetic reconstruction. Analyses were based on two nuclear markers [internal transcribed spacer (ITS) and external transcribed spacer (ETS)] and one plastid marker (rpl32-trnL). Sequence data were generated for 41 of the 62 African taxa (66 %). Mesquite was used to reconstruct ancestral character states for distribution, life form, calyx shape, stamen type and pollination syndrome.

Key Results

Salvia in Africa is non-monophyletic. Each of the five major regions in Africa, except Madagascar, was colonized at least twice, and floristic links between North African, south-west Asian and European species are strongly supported. The large radiation in Sub-Saharan Africa (23 species) can be traced back to dispersal from North Africa via East Africa to the Cape Region. Adaptation to bird pollination in southern Africa and Madagascar reflects parallel evolution.

Conclusions

The phenotypic diversity in African Salvia is associated with repeated introductions to the continent. Many important evolutionary processes, such as colonization, adaptation, parallelism and character transformation, are reflected in this comparatively small group. The data presented in this study can help to understand the evolution of Salvia sensu lato and other large genera.  相似文献   

18.
The ultrastructure of the microsporidian parasite Nosema grylli, which parasitizes primarily fat body cells and haemocytes of the cricket Gryllus bimaculatus (Orthoptera, Gryllidae) is described. All observed stages (meront, meront/sporont transitional stage ("second meront"), sporont, sporoblast, and spore) are found in direct contact with the host cell cytoplasm. Nuclei are diplokaryotic during almost all stages of the life cycle, but a brief stage with one nucleus containing an abundance of electron-dense material is observed during a "second merogony." Sporogony is disporous. Mature spores are ovocylindrical in shape and measure 4.5+/-0.16micromx2.2+/-0.07 microm (n=10) on fresh smears and 3.3+/-0.06 micromx1.4+/-0.07 microm (n=10) on ultrathin sections. Spores contain 15-18 coils of an isofilar polar filament arranged in one or two layers. Comparative phylogenetic analysis using rDNA shows N. grylli to be closely related to another orthopteran microsporidian, Nosema locustae, and to Nosema whitei from the confused flour beetle, Tribolium confusum. Antonospora scoticae, a parasite of the communal bee Andrena scotica, is a sister taxon to these three Nosema species. The sequence divergence and morphological traits clearly separate this group of "Nosema" parasites from the "true" Nosema clade containing Nosema bombycis. We therefore propose to change the generic name of N. grylli and its close relative N. locustae to Paranosema n. comb. We leave N. whitei in former status until more data on fine morphology of the species are obtained.  相似文献   

19.
现存狒狒类(Papionin)生活于非洲(如Papio和Theropithoan)、亚洲(如Macaca)和北非(M.sylvanas)。在上新世和更新世,Theropithecus经历了从非洲到亚洲的扩散过程,在印度发现了类似化石。这次在云南中甸金沙江附近发现的下更新世狒狒化石(Papio)证明,如同亚洲猕猴和现代人类祖先一样,非洲狒狒类(Papio和Theropithecus)在同一时期从非洲扩散到亚洲。所不同的是它们没有像猕猴和人类一样生存下来。这次化石的发现对于研究以下生物学问题提供了重要依据1)探讨旧大陆猴类在上新—更新世从非洲到亚洲的扩散过程;2)研究不同旧大陆猴类的进化和环境适应性;3)为现代人类祖先在非洲—亚大陆的扩散研究提供证据;4)由于化石产地包括有人类祖先和其他动物的化石,因此,狒狒在亚洲的生态适应研究将为探讨人类在同一时期的生态适应提供证据。  相似文献   

20.
《L'Anthropologie》2022,126(4):103054
The Kromdraai archaeological site is located in a fossiliferous paleokarst situated in the UNESCO World Heritage Site referred to as the “Cradle of Humankind” in the Gauteng Province of South Africa. Kromdraai is noteworthy because it features among the three southern African early hominin-bearing sites considered to represent distinct temporal periods within the same stratigraphic succession. Kromdraai also yielded a partial skull and dentition (TM 1517) in 1938 that was designated as the holotype of a new genus and species, Paranthropus robustus. Although the hominin fossil assemblage collected from Kromdraai between 1938 and 2014 is rather paltry, morphometric and cladistic analyses of this material suggested that it represented a somewhat less-derived form of P. robustus than the considerably larger assemblage from the nearby site of Swartkrans. However, the geochronological and biotic relationships among the P. robustus-bearing sites in South Africa are not resolved. Since 2014, the previously unknown, albeit densely fossiliferous Unit P produced 51 individually catalogued hominin fossils (36 craniodental and 15 postcranial) that currently represent 13% of the faunal assemblage from this unit with a minimum number of 10 juvenile and 9 adult individuals. P. robustus and early Homo coexisted at the time of the accumulation of Unit P at Kromdraai, with a relative abundance of 89% and 11%, respectively. P. robustus and early Homo are associated with a highly diverse fauna that includes several water-dependent species, and a large variety of bovid and carnivore taxa. Biochronological data from Unit P and an interval of reversed polarity measured in younger deposits above it are interpreted in the context of the regional chronological framework to infer that it represents a deposit that was likely accumulated prior to 2 Ma.  相似文献   

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