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1.
记广西田东却林缅甸先炭兽的新材料   总被引:2,自引:0,他引:2  
李茜  陈耿娇 《古脊椎动物学报》2001,39(4):291-296,T001
记述了产自广西田东县却林那读组中一残破的缅甸先炭兽 (Anthracokeryxbirmanicus)头骨。通过对化石的描述 ,对该种特征进行了补充和分析 ,并认为其终生生长的上犬齿可能是用来作为争夺领域和配偶的武器。终生生长的上犬齿的发现 ,证明炭兽类具有性双形。将那读动物群和缅甸邦唐动物群进行对比 ,认为那读组的时代很可能有一部分属于中始新世  相似文献   

2.
缅甸始新世邦唐组一新的石炭兽类偶蹄类动物(英文)   总被引:1,自引:0,他引:1  
描述了缅甸中始新统上部邦唐组发现的一种新的丘齿形石炭兽Myaingtherium kenyapotamoidesgen.et sp.nov.。标本为破碎的上下颌骨。Myaingtherium是一种基干石炭兽类,其大小和基本形态可以与邦唐一种小的石炭兽Anthracokeryx tenuis相对比。然而,Myaingtheri-um因具有更丘型化的齿列而与Anthracotherium和Anthracohyus在牙齿形态上更相似。在丘型齿石炭兽类中,Myaingtherium以臼齿前小尖非常退化为特点。Myaingtherium的一些牙齿特征,如具有退化的臼齿前小尖的丘型齿列和下臼齿上具有一个中间附尖,与Kenyapotaminae(最原始的化石河马)以及非洲中新世类似河马的石炭兽Kulutherium的牙齿特征相似,暗示Myaingtherium在谱系上可能与Kenyapotaminae有关。尽管需要更多的证据来检验Myaingthe-rium的谱系关系,但这个发现强化了邦唐石炭兽类在检验和理解河马-石炭兽支系的谱系关系和早期演化方面的重要性。  相似文献   

3.
本文记述了产自广西南宁盆地中部长岭坡(村)竹排冲岸边的石炭兽一新种:长岭石炭兽(Anthracotherium changlingensis sp. nov.)这是我国目前发现的体型最大的石炭兽。通过对化石的记述和对比,证明我国有Anthracotherium这一属的存在,并确定了南宁盆地邕宁组上段(即上含煤段)的地质时代为晚渐新世。文中还记述了百色盆地发现的两件石炭兽牙齿化石。  相似文献   

4.
Fossil fruits and a vegetative axis assignable to the extant genus Ceratophyllum are described from four North American Tertiary localities. Fossil fruits assignable to the extant species C. muricatum and C. echinatum are reported from the Eocene Green River and Claiborne formations, and the Miocene Esmerelda Formation, respectively. An extinct species, C. furcatispinum, is described from the Paleocene Fort Union Formation and represents the oldest published report of Ceratophyllum in the fossil record. The existence of extant angiosperm species in the Eocene is very unusual and may be attributable in this case to slow evolutionary rates and unusual evolutionary properties associated with hydrophily in the genus Ceratophyllum.  相似文献   

5.
Abstract

The deciduous premolars of early Eocene Equidae from North America, conventionally attributed to ‘Hyracotherium’, are described and compared, based primarily on a sample of >60 specimens from the early Eocene Willwood Formation of the Bighorn Basin, Wyoming. The sample represents six to nine species assigned to multiple genera by some other authors, but in the absence of diagnostic characters of the deciduous dentition, species assignments remain ambiguous for most specimens. Consequently it is not clear which generic names should be applied, and we employ the widespread name ‘Hyracotherium’ (acknowledging that the type species may not be an equid). We observed considerable variation in our sample, but most differences are minor and are largely inconsistent with respect to time or taxa, hindering attempts to characterise deciduous premolar anatomy of particular species. Comparisons were also made to Bridgerian Orohippus and Uintan Epihippus, to other early perissodactyls, and to non-perissodactyls that have been considered close to the origin of Perissodactyla (phenacodontid condylarths and Cambaytherium). Based on these comparisons, we confirm Butler’s observation that the deciduous premolars of equids show increasing molarization and lophodonty through the Eocene. However, our evidence suggests that there was little directed change through most of the Wasatchian until Wa-7.  相似文献   

6.
Previously undescribed notharctine primate fossils are reported from the early Eocene San Jose Formation, San Juan Basin, New Mexico, and the early Eocene Wasatch Formation, southern Wyoming. These collections include the most complete specimens yet discovered of the poorly known species Copelemur tutus and Copelemur praetutus; the first upper dentitions of Cantius angulatus and Cantius frugivorus from the type area of these taxa; and fossils attributable to two new notharctine species, Copelemur australotutus and Smilodectes gingerichi. These new fossils reveal that current ideas concerning notharctine phylogeny are incorrect. Two major, monophyletic clades are apparent within the subfamily: the tribe Copelemurini, consisting of the genera Copelemur and Smilodectes, and the tribe Notharctini, comprising the genera Cantius, Pelycodus, and Notharctus. Analysis of the paleobiogeographic distribution of the Copelemurini indicates that this clade was limited to more southerly regions of western North America during early Eocene time. Northward migration of more tropical habitats during the late Wasatchian and early Bridgerian in western North America, associated with an overall climatic warming trend through the early and middle Eocene, appears to have allowed several mammalian taxa, including Smilodectes, to extend their ranges northward during this time interval. Such taxa thus possess diachronous distributions and have been partly responsible for the long-standing confusion regarding the biostratigraphic correlation of early Eocene faunas from New Mexico with those from Wyoming. Based on several taxa which are also known from the Wasatchian of Wyoming, the age of the San Jose Formation appears to be middle Wasatchian.  相似文献   

7.
We describe new skeletal elements of Vastanavis from the early Eocene Cambay Shale Formation of western India, including a small coracoid that represents an unnamed new species, and comment on the relationships between this avian taxon and the recently described Avolatavis from the early Eocene Green River Formation in North America. Like the previously described ones, the new Vastanavis bones resemble those of the late Eocene Quercypsittidae, thus strengthening psittaciform affinities of the Indian taxon. Vastanavis differs from Avolatavis in the presence of a crista medianoplantaris on the tarsometatarsus and in claw morphology, but a fossil from the early Eocene London Clay, which was previously assigned to Vastanavidae, closely resembles Avolatavis in these features and all other osteological aspects. We show that most branches in a recent phylogeny of stem group Psittaciformes collapse after modification of a single erroneous character scoring for Vastanavis. We further describe a morphologically distinctive distal humerus of a small bird resembling the stem group nyctibiid Paraprefica, which was discovered in the most recent excavation in Vastan Lignite Mine.  相似文献   

8.
Joel  Cracraft 《Ibis》1971,113(2):229-233
A new fossil genus and species, Onychopteryx simpsoni, is described for a proximal end of a tarsometatarsus from the lower Eocene (Casamayor Formation) of Argentina. Onychopteryx is considered most closely related to the Opisthocomidae but is sufficiently distinct to be placed in its own family, the Onychopterygidae. Onychopteryx indicates that the Opisthocomiformes had differentiated by the early Eocene and were present in South America at that time.  相似文献   

9.
《Palaeoworld》2022,31(1):131-139
The Dawenkou Basin is a Cenozoic terrestrial fault basin in Shandong Province, East China, containing abundant mineral resources, especially gypsum. Recently a borehole was drilled in this basin unearthing the upper and middle members of the Dawenkou Formation. From the upper member, well-preserved ostracodes were discovered, which are entirely non-marine taxa including species of Eucypris, Caspiolla, Candona and Candoniella. Based on the new material, a new species Candona dawenkouensis n. sp. was erected. The ostracode assemblage biostratigraphically indicates an age of middle Eocene to Oligocene of the upper member of the Dawenkou Formation and the strata bearing mineral resources (mainly gypsum) of the middle member of the Dawenkou Formation is likely early Eocene.  相似文献   

10.
The first Sinopa species, S. jilinia sp. nov., from outside of North America is described. It comes from the Huadian Formation, locality Gonglangtou, Jilin Province, north‐east China. The new species represents the northernmost and one of the latest and most complete Asian Prototomus‐like hyaenodontidans known. It also represents one of the youngest specimens of Sinopa, because the age of the Huadian Formation is correlated to the later Uintan and only one doubtful citation of North American Sinopa younger than the early Uintan exists. S. jilinia sp. nov. is characterized by having m3 clearly smaller than m1, very strong and extended labial molar cingulids, backward leaning protoconids in all molars and its m3 cristid obliquum joining the postvallid very labially. With S. jilina, Sinopa is the first hyaenodontidan genus known to be present on two continents during the time interval between the earliest Eocene (c. 55.0 Ma) and latest middle Eocene (40 Ma). Its occurrence in the Huadian Formation supports the idea of a faunal exchange between North America and Asia in the early middle Eocene, a hypothesis formerly based mainly on the presence of the omomyid primate Asiomomys in the Huadian Formation, on a small radiation of East Asian trogosine tillodonts and on a couple of perissodactyl genera shared between the middle Eocene of North America and the Irdinmanhan of East Asia. As with the new Sinopa species, these Asian taxa had their closest relatives in North America.  相似文献   

11.
山西垣曲先炭兽类一新种   总被引:4,自引:2,他引:2  
本文主要报道1983年9月,在山西省垣曲县寨里发现的一件较完整的先炭兽类老年个体上颌骨.带有颇为完整的左、右齿列. I~1-P~2 各齿前、后均有较长的齿隙. P~1、P~2、P~3 前的齿隙颌骨上,保留有乳前臼齿的齿槽.这块标本在大小及形态特征上,与目前所知先炭兽属 Anthracokeryx 中任何种都有相当大的差异.它代表了该属中的一个新种.  相似文献   

12.
A new fossiliferous locality is discovered from the upper Eocene Aydim Formation, in Dhofar, Southern Sultanate of Oman. A left ulna of Arsinoitherium is described, and cranial and postcranial specimens found in close proximity are referred to the same taxon. The locality is promising for the recovery of additional fossil specimens. Moreover, the presence of Arsinoitherium in Oman is of biogeographic significance; as the Red Sea did not exist during the late Eocene, these large-bodied animals were able to freely travel between what is now the Arabian Peninsula and continental Africa.  相似文献   

13.
Abstract: Among the new dental remains from the late Early Eocene of Chambi (Kasserine area, Tunisia) is a large‐sized upper molar of a new bat species, Witwatia sigei nov. sp. (Chiroptera, Vespertilionoidea, Philisidae), described herein. The locality of Chambi has revealed evidence for an early appearance of two modern microchiropteran superfamilies in Africa: Dizzya exsultans, a Philisidae, which is considered to be an archaic Vespertilionoidea, and an indeterminate Rhinolophoidea. In addition to D. exsultans, the new species, W. sigei, is the second representative of the Philisidae in this locality. W. sigei extends back to the late Early Eocene the occurrence of the genus Witwatia, which was previously only reported from the early Late Eocene of the Fayum (BQ‐2, Egypt). By analogy with the largest extant microbats, the large size of Witwatia suggests a tendency to the opportunistic diet of this taxon, thereby contrasting with the strict insectivory characterizing primitive bats found in other continents in the same epoch.  相似文献   

14.
A lower jaw of the mesonychian Hapalodectes is reported from Nongshanian sediments (Upper Doumu Formation; middle Paleocene) of the Qianshan Basin (Anhui Province, China). The fragmentary mandible is only the third specimen of Hapalodectidae discovered in Paleocene deposits, and the first in south east China; it is moreover the oldest, the two other specimens having been found in Gashatan (late Paleocene) localities. The premolars and molars of the new fossil are morphologically similar to Hapalodectes dux (late Paleocene of Mongolia), which has been considered to be the most primitive hapalodectid, but their relative proportions recall H. paleocenus and the Eocene Hapalodectes species. As a result, the fossil described herein appears to be different from the other previously described species of Hapalodectes in being morphologically intermediate between H. dux and the other Hapalodectes species, notably the Bumbanian Hapalodectes hetangensis and H. huanghaiensis from China; it is thus identified as a new species, Hapalodectes lopatini (possibly a male individual). Its discovery is important because it sheds light on the initial radiation of hapalodectids. The presence of one primitive hapalodectid in Mongolia previously suggested the Mongolian Plateau as the centre of origination of this carnivorous family, but the discovery of H. lopatini in older sediments from south‐east China challenges this hypothesis. In the earliest Eocene, Hapalodectes dispersed from Asia to North America; this event being part of the ‘East of Eden’ dispersals. This event resulted in the geographical separation of two distinct Hapalodectes groups, in North America and south‐eastern China respectively.  相似文献   

15.
Summary Stratigraphic and microfacies investigations carried out on the Oligocene sequence exposed at Gabal Bu Husah, northwest of Marada Oasis, south of the Sirte Basin, Libya, showed that the Oligocene sequence conformably overlies the Late Eocene Thamat Formation and unconformably underlies the Early to Middle Miocene Marada Formation (Qarat Jahannam Member). The lithostratigraphic studies of the Oligocene sequence revealed the presence of two rock units, from base to top: 1- Umm Ad Dahiy Formation (Early Oligocene, Rupelian) and 2- Bu Hashish Formation (Late Oligocene, Chattian). The Oligocene sequence yields a rich foraminiferal assemblage with fifty-one benthonic and large formaminiferal species. The foraminiferal analysis allowed to subdivide the sequence into three local foraminiferal assemblage zones, arranged stratigraphically from base to top: 1)Elphidium minutum zone comprising the Umm Ad Dahiy Formation. 2)Miogypsinoides complanatus/Nonion granosus assemblage zone covering the lower two thirds of the Bu Hashish Formation. 3) Zone with abundantNummulites spp., including the upper part of the Bu Hashish Formation. The paleoenvironmental significance of the recorded species is described and discussed. The microfacies studies led to the recognition of eleven microfacies types. These microfacies indicate that the lower part of the Umm Ad Dahiy Formation was deposited in a shallow warm marine environment, but the conditions changed to fluviomarine in the uppermost part. The Bu Hashish Formation was deposited in a shallow-marine, inner-shelf environment (as indicated by the operculinid limestone) but a probable hiatus in its middle part is indicated by the presence of a nummulitic coquina and gypsum beds formed in a lagoonal environment. After returning to a shallow marine environment at the end of Oligocene the marine sedimentation ended.  相似文献   

16.
Abstract

The ichnospecies Nummipera eocenica occurs in thick-bedded, tabular bioclastic massive sandstone of the upper Eocene San Jacinto Formation in the San Jacinto Fold Belt Basin, Colombia. Nummipera eocenica is a vertical to oblique burrow locally displaying a conical shape. The lining structure of the specimens studied consists of uniformly distributed lepidocyclinids and operculinids, with tests typically dipping towards the burrow wall, and well-compacted lining. The burrow infill is identical to the host rock, a bioclastic sandstone with abundant bivalve fragments. The diagnosis of Nummipera is emended to include as components of burrow lining all representatives of the Subclass Rotaliana characterized by being lenticular to discoidal in shape. In the San Jacinto Formation, Nummipera eocenica is present in the transition between deltaic mouth-bar and carbonate platform deposits.  相似文献   

17.
The genus Osmunda L. contains approximately 10 extant species widely distributed in tropical and temperate regions, with the greatest concentration of species in East and Southeast Asia. Osmunda is characterized by dimorphic or commonly hemidimorphic fronds with dimorphic pinnae. Its geological history has been traced back to the Triassic. Most records of the genus are based on rhizomes and rarely on pinnae bearing sporangia and spores. Here, we describe fossil pinnae, sporangia, and spores of Osmunda lignitum (Giebel) Stur recovered from the middle Eocene of the Changchang Formation in the Changchang Basin, Hainan Island and the Youganwo Formation in the Maoming Basin, Guangdong, South China. The fossils closely resemble the extant Osmunda banksiifolia (C. Presl) Kuhn of the subgenus Plenasium on the basis of their morphological and anatomical structures. The present occurrence of O. lignitum indicates subg. Plenasium flourished and extended from the high latitude regions such as Northeast China to the low latitude areas of South China during the middle Eocene. Large numbers of specimens described here also indicate that Osmunda was the dominant understory fern element beneath mixed evergreen broad-leaf angiosperm and gymnosperm forests living in a warm and humid environment.  相似文献   

18.
《Palaeoworld》2023,32(3):523-546
The stratigraphic correlation of the Kuma Formation from the south of the Russian Platform and the Crimea-Caucasian region has been a matter of debate for decades. A bed-by-beds study of dinocysts and nannoplankton from the the Kuma Formation made it possible to recognize a sequence of biotic events, important for defining and correlating the biozones. At the Bakhchisarai limestone quarry, six dinoflagellate zones and six nannoplankton zonal units were recognized, assignable to the Middle Eocene Lutetian and Bartonian stages. Our paleoecological analyses of the organic-walled microphytoplankton assemblages and of the palynofacies indicate that the the Kuma Formation deposited in the inner shelf zone, probably of anoxic and eutrophic settings within the Pontic-Transcaucasian magmatic belt. Assemblages of organic-walled microphytoplankton comprise potentially toxic dinoflagellate species of Alexandrium. The Middle Eocene Climatic Optimum event is recorded in the upper part of the the Kuma Formation, presumably indicated by the Dracodinium rhomboideum dinoflagellate zone, which is characterized by an acme of Dracodinium laszczynskii Gedl and the lowest occurrence of nannofossils Reticulofenestra bisecta (Hay, Mohler and Wade) Roth. Two new species are described: Pentadinium rugosum Vasilyeva, n. sp. (dinocyst) and Corannulus tauricum Musatov, n. sp. (nannofossil). The bioevents and biozones established herein are significant for correlations of the Middle Eocene of the Crimean Peninsula and the south of the Russian Platform.  相似文献   

19.
Eight species rank taxa arc described from Eocene sites in the Gobi Desert, Mongolia. Irdinolophus gen. now is erected for Desmalotherium mongoliense Osborn and for Irdinolophus? tuiensis sp. nov. The genus is placed at the stem of the family Depcrctellidae. Intraspecific variation in lekolophus magnus is documented for the first time; Pachylophus is synonymized with leleoloplms; and Deperetella cf.birmanica is recorded far north of its previously known range in Burma. The first known lower teeth of Colodon inceptus support referral ofDesmalotherium Jissum to Colodon. The stratigraphic range of the hyracodontid Ardynia is extended back from the late Eocene to the early middle Eocene. A range of primitive tapiroids and rhinocerotoids arc analysed cladistically to resolve the problematic affinities of the extinct families Dc-peretellidae and Rhodopagidae. The Depcrctellidae are shown to belong to a monophyletic superfamily Tapiroidca, whilst the Rhodopagidae belongs to the Rhinocerotoidea, but is distinct from the Hyracodontidae. Veragromovia, previously synonymized with the tapiroid Helaleles, is resurrected as a valid genus within the Rhodopagidae. Tsagan Khutcl and other sites in the Kholbolchi formation may be older than Irdinmanhan faunas in Asia, equaling with those from the Arshanto Formation of China of probable early Lutetian or latest Ypresian age. The Irdinmanhan Mergen fauna may be slightly older than that from Irdin Manha, because of the primitive aspect of its Lophialetes.  相似文献   

20.
A complete post-incisor upper dentition and a left mandible with P/3-M/3 of the proviverrine hyaenodontid (Creodonta: Mammalia)Paratritemnodon indicus, which was hitherto known by heavily worn P/3-M/3, are described from the uppermost Subathu Formation (Middle Eocene) of the Kalakot-Metka-Mohgala area, Rajauri District, Jammu and Kashmir.P. indicus is most closely related to the North American Early Eocene proviverrine,Tritemnodon; its relationships withProdissopsalis from the Middle Eocene of Europe andPropterodon from the Middle to Late Eocene of China are also close. In the Kalakot Eocene vertebrate community of the Subathu vertebrate bioprovince,P. indicus is the only land dwelling carnivorous mammal against more than 20 species of herbivorous mammals, a majority of which are larger than it. This is viewed as an imbalance in trie community and it reflects an immaturity of the ecosystem supporting the fauna. The scarcity of carnivore remains in the Kalakot mammalian fauna is not an artifact.  相似文献   

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