Sinopaninae and Arfianinae (Hyaenodontida,Mammalia) from the Early Eocene of Europe and Asia; evidence for dispersal in Laurasia around the Paleocene/Eocene boundary and for an unnoticed faunal turnover in Europe

Hyaenodontida are represented in Europe by three subfamilies: Proviverrinae, Arfianinae and Sinopaninae. Here, we review all the specimens of Arfianinae and Sinopaninae known to date in Europe and Asia. A new Galecyon species is erected: Galecyon gallus nov. sp. We discuss the taxonomic position of the two Asian hyaenodontidans Anthracoxyaena palustris and Arfia langebadreae; the genus Anthracoxyaena is synonymized with Arfia. The analysis of the European and Asian arfianines and sinopanines provides new data concerning the dispersals and faunal events that occurred during the Early Eocene in Laurasia. The Arfianinae and Sinopaninae appeared in Europe around the Paleocene/Eocene boundary (reference-level MP7). The sinopanines are widespread in Europe; they are known in Dormaal (Belgium, reference-locality of the level MP7), Rians, Soissons, Pourcy, Try, Le Quesnoy (France), and Abbey Wood (England). The analysis of the paleogeographic distribution of all Oxyaenodonta and Hyaenodontida at and after the MP7 supports the existence of two European provinces: the North Province and Mesogean Province. We show that the Arfianinae and Sinopaninae rapidly disappeared from Europe; they are unknown in Avenay (reference-locality of the level MP8+9) and younger localities. Their disappearance from Europe is synchronous with that of the Oxyaenodonta. These observations support the existence of a faunal turnover, which occurred between the reference-levels MP7 (Dormaal) and MP8+9 (Avenay). The hypothesis of a dispersal from Europe to North America during the Paleocene-Eocene transition for the Arfianinae and Sinopaninae is supported. Moreover, the study of Arfianinae supports a dispersal from Europe to Asia around the P/E boundary, followed by a short period of endemic evolution. However, our study does not support a close relationship between Arfia and the “Arfia-like South Asian Proviverrinae” (Kyawdawia, Indohyaenodon, Paratritemnodon and Yarshea).     

A new ‘tapir’ from Ellesmere Island, Arctic Canada — Implications for northern high latitude palaeobiogeography and tapir palaeobiology

The oldest and northernmost record of the tapir lineage, Thuliadanta mayri gen. et sp. nov. from Ellesmere Island, Arctic Canada (78°50′N) implies that tapiroid evolution was well underway by early Eocene (Wasatchian) time in northern high latitudes, and raises the possibility of a North American origin for the group. Phylogenetic analyses place the new Arctic tapir as the sister group to the later more advanced Desmatotherium, Colodon, and Irdinolophus. A phylogenetically-derived biogeographic reconstruction posed here suggests the tapir lineage may represent a rare instance of counterflow wherein an exotic North American taxon invaded Asia during the early Eocene. Moreover, Thuliadanta seems a plausible ancestor to Desmatotherium from both continents, suggesting that this branch of the tapir lineage may have originated at high latitudes and subsequently dispersed from there to mid-latitudes. Thuliadanta's occurrence on Ellesmere Island indicates that northern high latitudes should also be evaluated as a potential source area for some of the exotic taxa appearing in mid-latitudes during Eocene time. Using today's tapirs, and specifically the mountain tapir, as analogs, Thuliadanta seems a plausible year-round inhabitant in the mild temperate lowland forests of the Eocene High Arctic.     

亚洲始新世啮齿目一新科——争胜鼠科(Zelomyidae)(英文)

继 1 990年王伴月和李春田记述了发现在吉林桦甸中始新世的争胜鼠 (Zelomys)之后 ,近年又在山西垣曲、河南卢氏、江苏溧阳等地的中始新世到晚始新世 (Irdinmanhan lateShara murunianorErgilian)的 5个地点中陆续发现了一些与争胜鼠相近的新材料。经研究后 ,将所有材料归诸于创建的一新科 :争胜鼠科 (Zelomyidaefam .nov .)。它包括了争胜鼠及本文新记述的安氏鼠 (Andersomysgen.nov.)、耗子 (Haozigen .nov .)和苏鼠 (Suomysgen .nov.)共 4属 6种。新科的特征是 :始啮型头骨 -松鼠型下颌 ;门齿釉质层散系 ;颊齿具有发育的次尖和下次脊 ,后期种类上颊齿的外侧齿尖的唇侧发展成平凹到新月形。新科的系统关系不很清楚 ,尽管与始鼠科 (Eomyidae)有某些相似之处 ,但它更可能是独立发展的一个支系。争胜鼠属化石分布较广 ,在我国吉林、江苏和山西的中、晚始新世地层中都有发现 ,它的特征是下颊齿p4 m2宽度逐渐增大 ,p4 m3具下前边尖 ,并与短的下原尖前臂相接。属中除属型种———东方争胜鼠 (Z .orientalisWangetLi)外 ,还建立了一个约翰争胜鼠新种 (Z .joannessp .nov.) ,一约翰争胜鼠相似种 (Z .cf.Z .joannes)。同时认为Z .gracilisWangetLi,1 990是Z .orientalis的同物异名。约翰种与属型种的区别在于个?     

Late Silurian trilobites from the Nuratau and Turkestan ranges, Uzbekistan and Tajikistan

Silurian trilobites of Ludlow and P?ídolí age are described from sections in southern Uzbekistan and from adjacent parts of Tajikistan. They belong to 22 species (10 named and 12 under open nomenclature) distributed among 13 genera belonging to the families Proetidae, Tropidocoryphidae, Aulacopleuridae, Scharyiidae, Cheiruridae, Encrinuridae and Odontopleuridae. The following new species are described: Interproetus pentaxus, Paleodechenella turkestanica, P. zaaminicus, Cromus tamchii and Leonaspis nuratensis. The generic associations from the mid Ludlow bear a striking resemblance to coeval ones from Bohemia, and include genera otherwise known only from that region or from adjacent parts of central Europe. The trilobite faunas from the late Ludlow and P?ídolí series are much less diverse and are dominated by genera of the Warburgellinae (Tropidocoryphidae), which include one species common to Vaigatch Island in the Russian Arctic, and Podolia, Ukraine. The closest links of the diverse central Asian mid Ludlow faunas are therefore to central Europe, whilst the sparser younger Ludlow and P?ídolí faunas, such as they are, suggest closer links to Baltica.     

圆尾鱼属(■Cyclurus,Amiidae,Pisces)在中国的首次发现(英文)

记述了弓鳍鱼亚科一新种:Cyclurus orientalis(东方圆尾鱼),标本采集于中国湖南省湘乡市下湾铺早始新世至中始新世下湾铺组。化石因具有以下特征而被归入弓鳍鱼亚科(Ami-inae):尾前椎为双椎型;除第一尾椎和第一尾下骨外,其余尾椎和尾下骨均一对一愈合;无膜质尾骨;背鳍长。因其第一冠状骨上的牙齿顶端圆钝,而被归入Cyclurus属。本新种与Cy-clurus属中其他种的区别在于:背鳍鳍条较少;身体短而高;脊椎和椎体较少。在始新世淡水鱼类的跨太平洋分布达到鼎盛时,由于弓鳍鱼亚科并非仅分布于太平洋两岸的类群,因此不能作为跨太平洋分布的指示类群。弓鳍鱼亚科在北半球的分布范围更广,与某些其他淡水鱼类群例如狗鱼科(Esocidae)和骨舌鱼科(Osteoglossidae)相似,这种现象只能用有别于形成跨太平洋分布的地质背景来解释。     

亚洲古近纪早期的年代学和哺乳动物群更替(英文)

对广东南雄盆地、江西池江盆地、安徽潜山盆地、湖南衡阳盆地和内蒙古二连盆地古新世和早始新世沉积物进行的生物地层学、化学地层学和磁性地层学研究,第一次给亚洲早古近纪地层框架提供了严格的年代限定。亚洲古新世和早始新世地层划分为4个生物年代单位(陆生哺乳动物期),从老到新为上湖期、浓山期、格沙头期和伯姆巴期4个亚洲陆生哺乳动物期。南雄盆地古地磁数据显示上湖期的底界约位于C29r的上2/3位置。南雄盆地的古地磁资料及池江盆地最新的古地磁和同位素结果显示上湖-浓山期界线在C27n的上部和C26r的下部之间,接近C27n-C26r转换界面。这一记录支持将上湖-浓山期的界线与北美陆生哺乳动物期中的Torrejonian-Tiffanian期以及海相记录中丹尼-塞兰特期(Danian-Selandi-an)的界线相对比。二连盆地古地磁和同位素研究表明典型的格沙头动物群延续至C24r,并且可能向下延伸至C25r和C26n。南雄盆地的记录指示浓山组和古城村组可能相当于C26r的上部。这些结果表明亚洲哺乳动物分期中的浓山-格沙头期的界线可能在北美哺乳动物分期的Tiffanian期中。衡阳盆地的古地磁和同位素证据指示,以短暂的碳同位素漂移为标志的古新世-始新世界线出现在栗木坪组和岭茶组之间,位于C24r中,与海相记录中的坦尼特-伊普里斯期(Thanetian-Ypresian)界线一致。伯姆巴期岭茶动物群的时代似乎与北美Wa-satchian-0带的动物群可以比较。上湖期和浓山期动物群主要由亚洲特有的动物组成。发生在上湖期和浓山期界线处的动物群更替,与北美Torrejonian-Tiffanian期界线以及丹尼-塞兰特期界线一致。在相隔很远的生态系统上的这种巧合,可能反映出各自独立的对气候变化的生态和/或进化上的响应。格沙头动物群的地方性色彩更弱,有与北美Clarkforkian期动物群共有的属一级分类单元。伯姆巴动物群是全球性的。现生哺乳动物各目在格沙头-伯姆巴期界线处突然出现,与北美和欧洲的记录一致,显示动物群的更替与古新世-始新世界线处短暂出现的全球变暖事件(又称古新世-始新世高温事件)有关。     

Eocene Lagomorpha (Mammalia) of Asia: 2. Strenulagus and Gobiolagus (Strenulagidae)

Two species of early lagomorph, Strenulagus solaris sp. nov. (Monogolia, Khaychin-Ula 2 and 3 localities, Middle Eocene) and Gobiolagus hekkeri (Kyrgyzstan, Andarak 2 locality, terminal Lower Eocene), are described. A revision of Romanolagus hekkeri Shevyreva from the Andarak 2 locality has shown that it belongs to the genus Gobiolagus; consequently, the monotypic genus Romanolagus Shevyreva, 1995 is a junior synonym of Gobiolagus Burke, 1941. The diagnoses and species compositions of the genera Strenulagus and Gobiolagus are revised. Zaissanolagus gromovi Erbajeva from the Lower Oligocene of eastern Kazakhstan is shown to be the latest representative of the genus Gobiolagus and the family Strenulagidae.     

硅藻鼠科(哺乳纲,啮齿目)与亚洲中始新世啮齿类的双脊齿(英文)

亚洲特有的啮齿类硅藻鼠科自渐新世以来分布于东亚和南亚。现生硅藻鼠类的分布只限于老挝的喀斯特地区。就目前所知,这些具有豪猪型头骨-松鼠型下颌的啮齿类的颊齿都是不同程度的横向双脊齿。时代最早的硅藻鼠类产于巴基斯坦渐新世地层中,其颊齿的双脊齿构造上仍保留齿尖残迹,基本符合双脊齿型牙齿结构。至渐新世末期,硅藻鼠科的牙齿出现分化。中新世及以后硅藻鼠类的化石记录相对较少。分子生物学证据将硅藻鼠类归入Ctenohystrica,这种归属也从始新世梳趾鼠类的臼齿形态上得到一定的支持。除此之外,有关硅藻鼠类的起源问题几乎一无所知。亚洲中始新世的Hydentomys臼齿表现出轻微的双脊型,然而其他方面却与硅藻鼠类不同。另一个具双脊齿的啮齿类Dolosimus(新属)产于江苏中始新世,其具有更为发育的双脊齿,特别是臼齿型下牙。新属的不完整记录及其形态不能解决如下问题:它是否与后来出现的像硅藻鼠类和跃兔类这些具有明显双脊齿型颊齿的啮齿类有亲缘关系,或者只是这种形态发育中没有留下后继者的早期试验品。     

Fossil reptiles from the Spanish Muschelkalk (mont‐ral and alcover,province Tarragona)

The marine tetrapods from the late Ladinian Spanish Muschelkalk deposits located between the towns of Mont‐ral and Alcover (province Tarragona) are reviewed. The fauna comprises an undetermined thalattosaur, a small cyamodontoid placodont probably referrable to Psephoderma, a possible pachypleurosaur with (if any) affinities to the Serpianosaurus‐Neusticosaurus clade, lariosaur specimens currently referred to Lariosaurus balsami, an incomplete specimen of Lariosaurus calcagnii, an endemic nothosaur (Nothosaurus cymatosauroides), and a possible pistosaur. Collectively, the faunal mix comprises endemic taxa as well as elements with affinities to the fauna of the Alpine and/or Germanic Triassic. The fauna suggests faunal interchange through the Burgundy Gate linking the southern branch of the developing Neotethys to the Germanic Basin.     

Italian Cenozoic crocodilians: taxa, timing and palaeobiogeographic implications

Crocodylian remains are collected in 39 fossil-bearing localities but only in seven localities specimens with reliable taxonomic attributions, at least to genus level have been collected. Three species have been reported from the early Lutetian Purga di Bolca site: Pristichampsus cf. Pristichampsus rollinati, Asiatosuchus sp., Hassiacosuchus sp. (=Allognathosuchus sp.). The three crocodilians discovered at Purga di Bolca have been reported also from Geiseltal and Messel (Middle Eocene, Germany). Bolca at that time was part of a Tethysian archipelago and no mammals have been found there till now. Crocodilians and turtles clearly arrived from the European mainland across a marine water barrier. Among the other fossiliferous localities of Veneto, very interesting is the Monte Zuello site, of late Middle Eocene age, yielding a longirostrine crocodilian, Megadontosuchus arduini, a tomistomine species. Tomistomines are known in contemporaneous sediments of both Europe and Africa, but the European forms Dollosuchus and Kentisuchus seem the closest taxa. Remains of Oligocene age have been collected in Veneto and Liguria, but the fossils discovered in the second region are teeth or fragmented bones. The fossil crocodilians of Monteviale (Veneto), of Early Oligocene age, have been assigned to two species but they have been recently all identified as Diplocynodon ratelii, known from several European sites of Late Eocene, Oligocene and Miocene age. This species arrived in the Monteviale area from the European mainland across a narrow sea. Several crocodilian fossils of Miocene age are very fragmentary or represented by isolated teeth. In the Middle and Late Miocene of Sardinia, a well-established species, Tomistoma calaritanum is present. Remains of Tomistoma of the same age have been reported in some localities in Tuscany, Apulia, Sicily and Malta. In the Mediterranean area, the genus is known from European and African sites (of older age). The colonisation of Europe by this genus is the result of a dispersion from Africa (or less probably from Asia). During Late Miocene Sardinia and Tuscany belong to the same palaeobioprovince characterized by the Oreopithecus-Maremmia fauna. In Tuscany, a crocodilian identified as Crocodylus bambolii is present in the late Miocene site of Monte Bamboli. If the generic attribution of this form is correct, its ancestors must have arrived from Africa. Another fossil assemblage of Late Miocene age characterizes the Apulia-Abruzzi palaeobioprovince (Hoplitomeryx-Microtia fauna) and testifies complete isolation between the two palaeobioprovinces. In this last area, remains of Crocodylus sp. have been collected in coastal sandstones at Scontrone (Abruzzi) and in several fissure fillings of Gargano of slightly younger age. The ancestors of this species arrived from Africa while no African elements are present among the mammalian fauna. The dispersion of the genus Crocodylus in the Italian palaeoislands may have taken place once, with allopatric differentiation of the two populations (Tuscany-Sardinia and Apulia-Abruzzi) or twice with independent colonisation of each area.     

亚洲早古近纪哺乳动物生物年代学与生物地理学的新认识(英文)

近期的研究极大地丰富了亚洲古新世和早始新世哺乳动物群信息,因此有必要对现存亚洲生物年代学和生物地理学框架做出调整。在定量和定性分析的基础上,将生物年代界线与主要的动物群更替事件对应起来,改进了古新世和早始新世亚洲陆相哺乳动物分期年代对比及生物地理学的认识。以往知之甚少的上湖期以原始啮形类和钝脚类为主,其后的浓山期则呈现出亚洲哺乳动物的地方性分异。随着新的基干啮形类以及真正的啮型类的出现,啮形类开始辐射。上湖期-浓山期的界线与北美Torrejonian-Tiffanian界线相当,并且动物群更替很可能是由全球变冷阶段的开始引发的。格沙头期哺乳动物进一步分化,亚洲土著类群急剧减少,以多瘤齿兽类、夜鼩类(nyctitheriids)、克莫土兽类(cimolestids)和食果猴为代表的北美迁入物种开始出现。而在北美,亚洲哺乳动物(包括北柱兽类和原恐角兽类)的第一次入侵发生于Tiffanian-5a期初期,第二次入侵发生于Clarkforkian初期,包含了啮齿类、裂齿类及冠齿兽类。因此格沙头期的开始可与北美Tiffanian-5a的开始相对比。伯姆巴期的开始以偶蹄类、奇蹄类和真灵长类的首次出现为标志,与古新世-始新世界线相当。这些类群在亚洲的出现与它们在北美和欧洲出现于始新世之初的情况类似。与格沙头期初期的动物群扩散不同,伯姆巴期的动物群扩散似乎持续了更长时间,并且也有可能直接发生在亚洲和欧洲之间。     

Rhabdomesid and cystoporid bryozoans from the Permian of Deh-e Mohammad, Shotori Mountains (northeastern Iran)

Seven bryozoan species belonging to the Order Rhabdomesida and Order Cystoporida are described from the Permian deposits exposed near the small town of Deh-e Mohammad, Shotori Mountains (northeastern Iran): Rhabdomeson cf. consimile Bassler, Pamirella nitida Gorjunova, Clausotrypa conferta Bassler, Streblotrypa (Streblotrypa) elegans Sakagami, Streblotrypa (Streblascopora) supernodata nov. sp., Cystodictya sp., and Filiramoporina cf. kretaphilia Fry and Cuffey. The described fauna identifies the age of the Jamal Formation at the locality near Deh-e Mohammad as Lower Permian. It displays palaeobiogeographic connections to the Lower Permian of Pamir (Tajikistan), Indonesia, Thailand and Kansas (North America).