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1.
The fossil hyaenids from Langebaanweg in South Africa are revised taxonomically using both morphological comparisons and measurement data. Ictilherium preforfex is found to be a synonym of Ikelohyaena abronia . Other hyaenid taxa in this fauna are Hyaenictitherium namaquensis, Chasmaporthetes australis and a new taxon similar to Chasmaporthetes australis in the size and shape of the M1, trigonid and other characters, but differing from this taxon in having short P3 relative to P2, a smaller anterior accessory cusp on P4 and M2, present. This taxon has previously been referred to Euryboas sp***, but comparison with Eurasian hyaenids indicates that it shares diagnostic characters with Hyaenictis graeca , type species of the genus Hyaenictis . This genus is poorly known and its content is reviewed. We find that only the new species from Langebaanweg, formally described as Hyaenictis hendeyi sp. nov. , and the Spanish Hyaenictis almerai probably belong in this genus, while other taxa intermittently referred to Hyaenictis belong to other genera. Thus, neither Leecyaena bosei nor Chasmaporthetes silberbergi belong in Hyaenictis .  相似文献   

2.
Samples of the Chinese upper Mioeene hyaenids Thalassictis wongii (Zdansky), Thalassictis hyaenoides (Zdansky) and Palinhyaena reperta Qiu, Huang & Guo are analysed and characterized statistically. The generic and specific designations above are considered correct. Using these samples as a basis, the taxonomic status of similar forms from Eurasia is evaluated. Lycyaena is considered a subgenus of Thalassictis and includes the species T. (L.) dubia (Zdansky), T. (L.) chaeretis (Gaudry), T. (L.) macrostoma (Lydekker), and T. (L.) crusafonti (Kurtén). 'Lycyaena' proava Pilgrim and 'L.' chinjiensis Pilgrim are removed from this subgenus. The type specimen of Palhyaena hipparionum (Gervais) is missing and cannot be determined to genus on the basis of published information. Most other forms are referred to Thalassictis (Thalassictis) , except 'Ictitherium' sivalense Lydekker, which is considered to be closely related to Palinhyaena .  相似文献   

3.
The importance of body mass prediction from several cranial, dental and appendicular variables in living Equini are studied. Relationships between the body mass changes and the ecogeographic picture of Equini evolution are also analysed. The metapodial and phalanx variables, particularly antero-posterior diameters, are better correlated with body mass than cranial variables in living Equini. Large sized species are correlated with cold climates, open habitats and/or soft soils; small ones are correlated with warm climates, more closed habitats and/or hard soils. Pleistocene horses from Europe and Africa follow an evolutionary trend opposite to their North American counterparts, from larger sized species to smaller ones. In South America the pattern of body size is different to those of the other continents. Species of Hippidion reaching large body mass, whereas some species of Equus, E. andium , follow a diminishing trend.  相似文献   

4.
Fossil fruits including nuts and associated husk valves of a new species of Carya (Juglandaceae) are described from the latest Miocene to earliest Pliocene in northeastern Tennessee, eastern United States. The husk valves are elliptic, 1.2–4.5 mm thick, with a convex exterior face and a concave interior face; the nuts are globose to ovoid in shape, smooth and longitudinally ribbed on exterior surface, with a short protruding apex and a slightly 4-angled base; inner ribs, lacunae and primary septa are well-developed, while secondary septa are absent or weakly developed. The combination of these carpological characteristics clearly shows a close resemblance to the genus Carya in Juglandaceae. Detailed comparisons of carpological morphology and anatomy indicate that the present fossil taxon is different from both living and most other fossil species of the genus, and therefore warrants the designation of a new fossil species, Carya tennesseensis Huang et al., sp. nov. Carya tennesseensis displays a carpological similarity to C. ventricosa from the late Oligocene to early Pliocene in Europe, suggesting a potential species exchange of the genus between Europe and southeastern North America during the late Neogene. The new fossil species represents one of the few fruit fossil species of Carya from its modern distribution range in southeastern North America. It provides crucial information for better understanding the rapid diversification of the genus from the late Miocene to early Pliocene, and the origin and establishment of today's Carya biodiversity in this region.  相似文献   

5.
In the present paper, the distal end of a humerus referable to a Dendrocygninae anseriform bird is reported. The specimen was collected at the Monte Hermoso Formation (early Pliocene) of the Farola Monte Hermoso locality (Buenos Aires Province, Argentina). This record constitutes one of the oldest for the group in South America and elsewhere. The overview of the anseriform record in South America indicates a similar pattern to that of other localities across the world. Paleogene localities are dominated by non-Anatinae taxa, whereas more recent faunas are dominated by anatines. Following this pattern, in South America the Anatinae appears in the fossil record as recently as in the Pleistocene, probably arriving from North America during the Great American Biotic Interchange. Pleistocene and Recent anseriform avifaunas are dominated by Anatinae taxa, and this dominance is probably due to some “key characters” regarding reproductive biology. In fact, the anatines exhibit a high reproductive success probably due to the capability of having two molts per year, and that the parental care of the downy young is only conducted by the female. The combination of characters may have allowed anatines to dominate most aquatic environments, surpassing in diversity more plesiomorphic taxa.  相似文献   

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  1. The Spalacidae is a family of strictly subterranean rodents with a long evolutionary history. It is unclear how ecological changes have influenced the evolutionary history of these mammals, and the phylogenetic relationship of the subfamilies within Spalacidae is controversial.
  2. Through compiling fossil records, reconstructing molecular phylogeny from molecular data, determining the date of divergence, and analysing their geographical evolution based on molecular data and fossil taxa, we explore the origin and evolutionary process of Spalacidae in detail. Diversification within Spalacidae dates to the Late Oligocene, approximately 25 million years ago, based on molecular data.
  3. This family originated in South and East Asia in the Late Oligocene, and then split into four clades. The first clade includes Rhizomyinae, which was highly diversified in South Asia in the Early-to-Middle Miocene. Then Rhizomyinae from Asia migrated to northern Africa in multiple waves through the Afro-Eurasian land bridge. Its range largely contracted in the Late Miocene, notably in Central Asia. The second clade includes the extinct Tachyoryctoidinae, which was confined to East and Central Asia, and survived from the Late Oligocene to the Late Miocene. The third clade includes Spalacinae, which have remained around the Mediterranean region since the Late Oligocene with slight trend of northward expansion. The fourth clade is Myospalacinae. Ancient genera of this subfamily in East Asia dispersed eastward during the Late Miocene and reached northern China and south-east Russia.
  4. The general distribution pattern of Spalacidae has persisted since the Late Miocene. Extinction of Tachyoryctoidinae and clear range contraction of Rhizomyinae in Central and East Asia are likely to have resulted from increased aridification, while the slight northward expansion of Myospalacinae and Spalacinae since the Quaternary was probably a response to a similar northward expansion of suitable vegetation for these animals.
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9.
Material of the Miocene hyaenid Adcrocuta eximia from China is analysed statistically. No heterogeneities were found within this material. Comparisons with material from Samos and Pikermi, Greece, show that no taxonomic differentiation between these three samples is warranted. Adcrocuta eximia latro from the Sivalik deposits is provisionally considered a valid subspecies. The species A. australis from Langebaanweg, South Africa is removed from Adcrocuta to the genus Chasmaporthetes . The phylogenetic position of Adcrocuta has been subject to dispute, and for this reason we present a study of the interrelationships of selected hyaenid taxa using numerical cladistic methods. Two equally parsimonious trees of length 47 and consistency index 0.766 were found. Adcrocuta is placed as a sister-group to the Recent Crocuta crocuta , and not as a separate clade as suggested by other workers. Recent hyaenids form a crown-group which does not extend deep into the cladogram. Hyaena hyaena and H. brunnea are not sister-groups, and we resurrect the genus Parahyaena for the latter species.  相似文献   

10.
Material of the Miocene hyaenid Adcrocuta eximia from China is analysed statistically. No heterogeneities were found within this material. Comparisons with material from Samos and Pikermi, Greece, show that no taxonomic differentiation between these three samples is warranted. Adcrocuta eximia latro from the Sivalik deposits is provisionally considered a valid subspecies. The species A. australis from Langebaanweg, South Africa is removed from Adcrocuta to the genus Chasmaporthetes. The phylogenetic position of Adcrocuta has been subject to dispute, and for this reason we present a study of the interrelationships of selected hyaenid taxa using numerical cladistic methods. Two equally parsimonious trees of length 47 and consistency index 0.766 were found. Adcrocuta is placed as a sister-group to the Recent Crocuta crocuta, and not as a separate clade as suggested by other workers. Recent hyaenids form a crown-group which does not extend deep into the cladogram. Hyaena hyaena and H. brunnea are not sister-groups, and we resurrect the genus Parahyaena for the latter species.  相似文献   

11.
A juvenile mandible with complete deciduous dentition from the Middle Miocene locality Jianshan near Shilee (Xinan County, Honan Prov., China) belonging toPercrocuta hobeiensis Chen Guanfang & Wu Wenyu is described. The lower deciduous carnassial, which is by far the most informative element of the juvenile dentition, is distinguished from the D4 of all other hyaenas by fundamental differences and exhibits principal similarities to that of the felids. Although these resemblances are very likely a result of parallel evolution, they can be taken as evidence of a considerable phylogentic distance betweenPercrocuta on one side and the Recent hyaenas with their forerunners on the other side. Judging from the special features of the deciduous carnassial and the high degree of hyaenid adaptation already attained in the Middle Miocene,Percrocuta probably derived from the neighbourhood of the Upper Oligocene and Lower Miocene generaStenoplesictis, Palaeoprionodon andProailurus, which in their turn take up a phylogenetically transitional position between felids and viverrids.  相似文献   

12.
Stephania Loureiro is a large genus within Menispermaceae, with approximately 60 extant species naturally distributed in tropical to subtropical areas in Asia and Africa, and a few in Oceania. This genus possesses highly characteristic endocarps that facilitate identification of extant and fossil specimens. Here, we report some well-preserved fossil fruits of Stephania from North America and East Asia. The specimens indicate the endocarps were bony or woody with an obovate to obovate-rotund outline and a horseshoe-shaped locule. The endocarp length varies from 4.7 to 8.3 mm, and width from 3.7 to 7.0 mm. The endocarp has a clear foramen in the central area and is surrounded by a keel with ribs running along the dorsal surface. Only one lateral crest develops on each side of the endocarp. Two new species are recognized: Stephania wilfii Han & Manchester sp. nov. from the Paleocene to Eocene of Wyoming (USA), and Stephania jacquesii Han & Manchester sp. nov. disjunct between the late Eocene of Oregon (USA) and the late Oligocene of Guangxi Province (China). In addition, on the basis of more detailed morphological comparative analyses, we transfer the fossils formerly treated as Diploclisia auriformis (Hollick) Manchester from the early Eocene of London Clay, and the middle Eocene of Alaska and Oregon to Stephania auriformis (Hollick) Han & Manchester comb. nov. These fossil materials indicate a broader biogeographic distribution for the ancestors of extant Stephania lineages. This finding enhances our knowledge of the taxonomic and morphological diversity of Stephania and provides new evidence concerning its phytogeographic history.  相似文献   

13.
The HGL-50 locality, situated on the Glib Zegdou outlier in the Gour Lazib of Algeria (Hammada du Dra), is famous for having yielded several dental remains of primates dating from the late Early to the early Middle Eocene. These primates include Algeripithecus minutus, Azibius trerki and a new species of cf. Azibius (not described yet). Algeripithecus was widely acknowledged to be one of the oldest known anthropoids from Africa. However, very recent discoveries strongly suggest that Algeripithecus is closely related to Azibius and that both taxa are phylogenetically remote from the clade Anthropoidea. Algeripithecus and Azibius make up the family Azibiidae and appear as stem strepsirhines. Here we describe and analyse two ankle bones (tali) found in HGL-50. UM/HGL50-466 is a small left talus, which is appropriate in size to belong to A. trerki, while UM/HGL50-467 is a right talus, which is significantly larger and appropriate in size to belong to the new large species of cf. Azibius. Both tali exhibit a suite of features that resemble conditions primarily found in extinct and extant strepsirhine and adapiform primates; conditions that are consistent with the strepsirhine-like dentition characterizing azibiids. Functionally, these two tali indicate that Azibius species were engaged in a form of active arboreal quadrupedalism with some ability to climb and leap. Azibiids were rather small-bodied primates, approximating the size of some modern dwarf lemurs (Cheirogaleidae) and sportive lemurs (Lepilemuridae) from Madagascar. Given their small body-size and their talar morphology, living cheirogaleid lemurs, which are agile arboreal quadrupeds (with climbing, springing and branch running activities), might appear as good analogues for azibiids in terms of locomotor behaviour.  相似文献   

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An abundant fossil record of the snake clade Scolecophidia exists in Europe; however, the minute snake is noticeably absent in reports about the North American Paleogene and Neogene. Presented here are four localities from Florida, USA, that contain scolecophidian remains older than the Pleistocene: Thomas Farm (late Early Miocene, Hemingfordian Land Mammal Age, LMA), Live Oak (Oligocene-Miocene transition, latest Arikareean LMA), White Springs 3B (late Arikareean LMA), and Brooksville 2 (Late Oligocene, middle Arikareean LMA). These remains extend their known existence by about 26 m.y. and are now the oldest reported scolecophidian remains in North America. Molecular evidence on extant scolecophidians concludes that these tiny snakes have a Gondwanan origin. Interestingly, the oldest record of a scolecophidian is from Europe (Belgium) and dates back to the middle Paleocene (MP 1–5). The earliest African record of the snake clade comes from the Paleocene-Eocene boundary in Morocco. The clade is apparently absent from Europe and Middle East deposits dating from the latest Eocene through to the latest Oligocene (MP 19–30) and to the Early Miocene (MN 4). A portion of this time is known as the booid ‘Dark Period’ which represents an apparent response to global aridization and cooling. Scolecophidians appear to re-emerge into the southern Eurasian record in the Early Miocene (MN 4) and become widely dispersed throughout Europe and Middle East. The fossil record of these minute snakes is largely absent in southern Asia and South America. It is possible that the current lack of a decent fossil scolecophidian record outside of Europe and Middle East is due mainly to a bias in the methodology to recover fossils; wet sieving sediments through < 1.0 mm mesh is needed to recover the minuscule vertebrae.  相似文献   

17.
Abstract: The fossil record of the Canidae in North‐western Africa begins near the Miocene–Pliocene boundary with a form close to Nyctereutes, a genus best known in the late Pliocene of Ahl al Oughlam. This site yields two other canids. Vulpes hassani sp. nov. is a small fox, probably ancestral to the modern V. rueppelli, recorded from the Middle Pleistocene onwards. Lupulella paralius sp. nov. is a primitive jackal that probably belongs to the clade of modern African jackals. In the middle Pleistocene, the most common canid is Lupulella mohibi sp. nov., remarkable by its Nyctereutes‐like dentition and primitive skull‐features. These are all endemic forms, but V. vulpes and C. aureus, of northern origin, appear in the course of the middle Pleistocene. Lycaon has a sparse record in the middle and late Pleistocene.  相似文献   

18.
由于地理位置上处于北美和旧大陆西部之间,中国晚中新世的三趾马提供了重要的生物地层与生物地理信息。这些信息反映出晚中新世时期北美和欧亚大陆之间的动物群交流,同时也与当时的古环境变迁相关联。依据面部和牙齿形态以及肢骨比例,将中国的三趾马与欧亚大陆及北美的其他种类进行了对比。中国的三趾马可识别出两个分类类群,其中一个非系统发育意义上的类群包括 Hipparion dermatorhinum,H. weihoense,H. fossatum,H. hippidio-dus 和 H. coelophyes,这一类群与旧大陆西部的三趾马在形态上高度相似; 另一个为本土类群,包括 H. ptychodus,H. platyodus,H. tylodus,H. sefvei 和 H. plocodus,它们与其他地区的种类并无相似之处。前一个类群是中国北方草原型动物群中的典型分子,对欧亚大陆化石地点的生物地层对比相当重要; 后一类群与北美的三趾马( "Cormohipparion"属) 在面部形态上具有相似性,这些本土的三趾马是中国北方森林型动物群的分子。  相似文献   

19.
The following ten new species of the ant genus Temnothorax are described and illustrated: T. anaphalantus (California, Baja California), T. arboreus (California), T. caguatan (Oregon, California, Baja California), T. morongo (California, Baja California), T. myrmiciformis (California, Baja California), T. nuwuvi (Nevada), T. paiute (California, Nevada), T. pseudandrei (Arizona, California), T. quasimodo (California) and T. wardi (California). A key to workers of the twenty-two Temnothorax species known or expected to occur in California is provided.  相似文献   

20.
Aim To document the distribution of two closely related macrophyte species, the fossil Nitellopsis (Tectochara) merianii (A. Braun ex Unger) Grambast & Soulié‐Märsche and Nitellopsis obtusa (Desvaux) J. Groves, the single living species of genus Nitellopsis and to draw the relationships between first finds of N. merianii in North Africa and previously known records. Location South part of the High Atlas Range, Aït Kandoula basin, Morocco. Methods New finds of fossil charophyte gyrogonites were determined and illustrated. Using a large bibliographic database of both fossil and extant charophytes, we depict the biogeographical distribution N. merianii and N. obtusa and summarize the ecological requirements of N. obtusa as a modern analogue. Results The Aït Kandoula deposits, dated by magnetostratigraphy and vertebrate fossils to Upper Miocene, provided the first fossil populations of N. merianii in Africa. The distribution patterns of the Tertiary N. merianii and the living N. obtusa superimpose on a large area that extends from Spain to East Asia and characterize them as typically Eurasian taxa indicative for permanent, relatively cold and deep freshwater lakes. During the Quaternary, similar palaeolakes in the Sahara were colonized by N. obtusa. Main conclusions The presence of the Eurasian species N. merianii in North Africa is the result of dispersal by migratory waterbirds and attests to N–S migration occurring during the Upper Miocene (10–5 Myr ago). Gyrogonites imported from Southern Europe could germinate and fulfil their life cycle so as to form a new seed bank of gyrogonites because they had been deposited in a suitable environment consisting of a freshwater mountain lake.  相似文献   

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