New fossil anthropoids from the middle Miocene of East Africa and their bearing on the origin of the oreopithecidae

Recent paleontological collections at the middle Miocene locality of Maboko Island in Kenya, dated at 15-16 million years, have yielded numerous new specimens belonging to at least five species of fossil anthropoids. The most common species of ape at the site, a medium-sized primate with a very distinctive dental morphology, clearly represents a previously undescribed taxon. When compared with other Miocene anthropoids from East Africa, it has its closest affinities with the poorly known species Rangwapithecus vancouveringi from the early Miocene locality of Rusinga Island. The species from Maboko Island is described here as belonging to a new genus of fossil anthropoid, to which "Rangwapithecus" vancouveringi is also referred. The new genus has a highly distinctive suite of derived characters of its molars and premolars, which it shares with Oreopithecus bambolii from the late Miocene of Europe. These synapomorphies indicate a close phyletic relationship between the East African species and Oreopithecus and form the basis for the inclusion of these taxa in a single family, the Oreopithecidae Schwalbe, 1915. In many respects, however, the East African forms are more conservative than Oreopithecus, and in a general sense they can be regarded as an intermediate grade between Oreopithecus and the more generalized early Miocene catarrhines, the proconsuloids. There is, therefore, good fossil evidence to indicate that the origins of the Oreopithecidae can be traced back to the early Miocene of Africa.     

The anatomy of Dolichocebus gaimanensis, a stem platyrrhine monkey from Argentina

Dolichocebus is known from the type skull encased in a concretion, numerous isolated teeth, parts of two mandibles, and a talus. The specimens come from the Trelew Member (early Miocene, Colhuehuapian South American Land Mammal Age) of the Sarmiento Formation near the village of Gaiman, Chubut Province, Argentina, dated to about 20Ma. We describe all Dolichocebus fossil material using conventional surface anatomy and micro-CT data from the cranium. The new material and newly imaged internal anatomy of the skull demonstrate that anatomical characters hitherto supposed to support a phyletic link between Dolichocebus and either callitrichines (marmosets, tamarins, and Callimico) or Saimiri (squirrel monkeys) are either indeterminate or absent. To more fully explore the phyletic position of Dolichocebus, we undertook a comprehensive phylogenetic analysis. We examined 268 characters of the cranium and dentition of 16 living platyrrhine genera, some late Oligocene and early Miocene platyrrhines, Tarsius, some Eocene and Oligocene stem anthropoids, and several extant catarrhines. These analyses consistently indicate that Dolichocebus is a stem platyrrhine, as are late Oligocene Branisella and early Miocene Tremacebus, Soriacebus, and Carlocebus. Platyrrhine evolution often is conceived of as a single ancient adaptive radiation. Review of all available phyolgenetic data suggests a more layered evolutionary pattern, with several independent extinct clades filling modern platyrrhine niche space, and modern platyrrhine families and subfamilies appearing over a nine-million-year interval in the Miocene. The outcome of these analyses highlights the pervasiveness of homoplasy in dental and cranial characters. Homoplasy is a real evolutionary phenomenon that is present at all levels of biological analysis, from amino-acid sequences to aspects of adult bony morphology, behavior, and adaptation.     

The Miocene mammal record of the Vallès-Penedès Basin (Catalonia)

The land mammal record of the Vallès-Penedès Basin (Catalonia, NE Spain) ranges from the early Miocene (Ramblian) to the late Miocene (Turolian), that is from about 20 to 7 Ma. Here we present an updated review of the mammal succession focusing on biochronology as well as on environmental and faunal changes. Based on faunal similarities with central Europe, we interpret this basin as a transitional zone between the forested environments of northern regions and the more arid landscapes of the inner Iberian Peninsula. The quality of the Vallès-Penedès record and its chronostratigraphic control is clearly better for the late Aragonian and the Vallesian (between 12.6–9.0 Ma), especially for small mammals. Therefore, we analyze small mammal diversity dynamics during this interval. Contrary to previous analyses, which found an abrupt extinction event coinciding with the early/late Vallesian boundary (the Vallesian Crisis), our results show that this pattern is due to uneven sampling. Instead, taxonomic richness slowly decreased since the late Vallesian as a result of a series of extinctions that mostly affected forest-dwelling taxa.     

Micropithecus clarki, a small ape from the Miocene of Uganda.

Micropithecus clarki, from Miocene sediments of Napak, Uganda, is the smallest known hominoid primate, living or fossil. In facial morphology it is very similar to extant gibbons. Dentally, it is most similar to the small apes from the Miocene of Kenya, Dendropithecus and Limnopithecus. All of the apes from the early Miocene of East Africa seem to represent a single phyletic group that could be easily derived from the Oligocene apes known from the Fayum of Egypt. Pliopithecus from the Miocene of Europe is more closely allied with the Oligocene radiation than with the later East African radiation.     

系统发育和被子植物“多系-多期-多域”系统——兼答傅德志的评论

历史地回顾了谱系、系统发育、单系、多系概念的由来和发展。详细讨论了单系(monophyly )和多系(polyphyly)在叙述分类群起源和描述分类群内部系统发育线多样性的不同含义。以此为基础,说明在“多系_多2_多域”的八纲系统中“多系”和“单系”是指自然分类群内系统发育线的多样性,不等同于“多源”和“单源”。通过与近年来所发表的被子植物分类系统的比较,认为基于化石、形态、分子和地理分布证据提出的八纲系统所显示的预言性,必将在今后的科学实践中经受检验。     

Diversification and extinction patterns among Neogene perimediterranean mammals

The best mammalian fossil record during the Neogene of Western Europe is that of the rodents, the most successful and diversified mammal order. The study of origination and extinction during the Neogene (24-3 Ma BP) in one of the best-documented areas, Spain and southern France, gives an insight into the dynamics of these communities and indicates the possible nature of the driving forces. Three main periods of time show a high rate of origination: the late Burdigalian (17.5 Ma BP), the early Vallesian (11.5-11 Ma BP) and the early Pliocene (4.2-3.8 Ma BP). Two of these high origination-rate periods are immediately followed by important extinction events during which all cohorts are deeply affected (11.5-11 Ma BP and 4.2-3.8 Ma BP). The most important extinction event seems to occur during the early Vallesian (11.5-11 Ma BP), which probably includes the middle/late Miocene boundary. At the Miocene/Pliocene boundary, and during the early Pliocene, the faunal turnover seems to become faster, inducing a strong decrease of the mean species duration. Whereas the main immigration event, which occurs at 17.5 Ma BP, can be related to other faunal migrations in terms of the closure of the Tethys, as it occurs also in eastern Africa and in southwest Asia, the middle/late Miocene boundary event may have been related to a period of ice growth in the Southern Hemisphere. The extinction event that affects the planktonic foraminifera at 12 Ma BP cannot be chronologically correlated to this southwestern European land-mammal extinction event, because the calibration of the marine fossil record during that time-span has to be precise. Some limited terrestrial faunal exchanges that occur during the Messinian between southwestern Europe and northwestern Africa do not deeply affect the general faunal dynamics. Both allochthonous cohorts of immigrants become rapidly extinct. Several endemic rodent faunas, indicating insular conditions, have been reported from the southern edge of the western European continent from the middle Miocene up to the Pliocene. All show low taxonomic diversity, strong endemism and short survival. Some of them, like those of the Gargano Islands during the late Miocene, underwent peculiar morphological changes and also speciation. The large number of rodent genera coevolving in the Gargano Islands is indicative of the large surface areas of these islands. The general geographic pattern of southwestern Europe during the Neogene may therefore correspond to a large continental province including Spain and southern France with some kind of fast-modifying archipelago on its southern rim.     

A reappraisal of the phylogeny of Mylodontidae (Mammalia,Xenarthra) and the divergence of mylodontine and lestodontine sloths

The phylogeny of mylodontid sloths has recently been the subject of multiple studies. Contrasting hypotheses have been proposed, especially for the relationships among late Miocene–Pleistocene mylodontines and lestodontines. In this paper, a new and detailed phylogenetic analysis is conducted, after adding new characters and taxa previously unexplored from a phylogenetic point of view. New features derived from postcranial skeletal anatomy are added to previous studies based on craniodental evidence. In this way, the current reappraisal represents the first exhaustive phylogenetic study on the Mylodontidae that incorporates features coded for the entire skeleton. When available, multiple specimens of each bony element are observed for each operational taxonomic unit, in order to take into account intraspecific variation. The taxonomic sample of this study considers Mylodontinae at the specific level. However, many other Mylodontidae are considered, and their phylogenetic relationships tested. The taxonomic sample of this study is enriched with new taxa from central and northern South America, with the aim of compensating for the knowledge bias in favour of austral mylodontids, which have historically been more extensively studied than those from tropical latitudes. Special emphasis is given to the phylogenetic relationships of Mylodontinae, and particularly to the mylodontine and lestodontine sloths, that are recovered in the present study as monophyletic clades, and together form a larger monophyletic group. According to the present results, the Mylodontini–Lestodontini split occurred at the middle–late Miocene transition, giving rise to independent adaptive radiations across South and North America.     

Population structure of the freshwater flatworm Crenobia alpina (Dana): old lineages and low gene flow

Aim  The freshwater flatworm Crenobia alpina lives almost exclusively in headwaters of mountainous areas and is supposed to be a glacial relict. We examined genetic diversity within and between populations of C. alpina in order to determine the taxonomic status of purported subspecies and to understand large-scale biogeographical patterns of glacial relicts.
Location  Central Europe.
Methods  We analysed mitochondrial DNA sequences and polymorphic allozyme loci of C. alpina populations across its range in central Europe. Sequences were compared using parsimony, minimum evolution and maximum likelihood. Allozymes were analysed using traditional as well as Bayesian estimates of F statistics.
Results  We found considerable divergence between haplotypes. For each of the two lineages occurring throughout central Europe, allozymes showed considerable differentiation between populations and a strong isolation by distance effect. Hence populations are effectively isolated even across rather small spatial scales.
Main conclusions  There is strong evidence that C. alpina is a complex of distinct lineages or cryptic species that date back to the late Miocene. The separation of lineages may be associated with the formation of deep valleys at the end of the Messinian Crisis.     

亚洲土著类群硅藻鼠科的演化

硅藻鼠科是仅分布于亚洲的啮齿类类群,头骨具豪猪型咬肌结构,下颌则为松鼠型。该类群代表了一个从梳趾鼠类分化出的区域性支系,虽与豪猪次目相近,但并不是它的成员。最早的硅藻鼠化石记录发现于Baluchistan渐新世陆相地层中,稍晚的记录发现于南业晚渐新世。印度次大陆连续的地层为该科的演化历史提供了主要的化石依据。早中新世晚期至中中新世,硅藻科化石也发现了泰国、中国以及日本。其后的硅藻鼠种类少且鲜有化石记录。晚中新世早期在巴基斯坦有一个种,中国南部晚中新世也可能有一个种。尽管在最早的化石地点发现的标本较多,但其后的时段内除泰国李盆地外化石并不丰富,这指示了其特殊的生活习性或其生活区域化石保存的偏差。已知的化石记录并没有指示出该类群的多样性,也可能是缺少石化作用的结果。硅藻鼠类在水系外围区域延续生存与最近在老挝中部多岩石地带发现的现生Laonastes也是一个硅藻鼠的假设相一致。     

A reassessment of the taxonomic and phylogenetic affinities of the fossil catarrhines from fort Ternan,Kenya

This paper presents a reassessment of the taxonomic and phylogenetic affinities of the fossil catarrhine primates from the important middle Miocene site of Fort Ternan in Kenya. Although the sample of specimens is rather small, the material can be attributed to at least five different species, identified here asKenyapithecus wickeri, Proconsul sp., a large species of oreopithecid,Simiolus sp., and a small species of catarrhine of indeterminate status.Kenyapithecus wickeri probably represents a conservative sister-taxon of the extant large hominoids. It is more derived than“Sivapithecus” africanus from Maboko Island, from which it can be distinguished at the generic level. A small species of catarrhine from Fort Ternan can be attributed toSimiolus. It is probably a different species fromSimiolus enjiessi from the early Miocene of East Africa, but additional material is needed to confirm its taxonomic distinctiveness. The occurrence of at least five species of catarrhine primates at Fort Ternan confirms that species diversity levels were as high during the middle Miocene as they had been during the early Miocene. However, the overall taxonomic and ecological composition of the middle Miocene catarrhine community was quite different, evidently due to a significant change in the local ecological setting. Taxonomic differences between the catarrhine faunas at Fort Ternan and Maboko Island can probably be explained as a consequence of a chronological separation between the two sites, and, to a lesser degree, to paleoecological differences.     

A review of Semigenetta (Viverridae,Carnivora) from the Miocene of Eurasia based on material from the hominid locality of Hammerschmiede (Germany)

The present article offers a detailed review of the taxonomy, distribution and palaeoecology of the genus Semigenetta. The study is based on new craniodental and postcranial remains of the genus from the early late Miocene (Tortonian) locality of Hammerschmiede (Bavaria, Germany). Most of the new specimens are attributed to the medium-sized species Semigenetta sansaniensis, whereas one lower carnassial is assigned to the large-sized Semigenetta grandis, making Hammerschmiede 4 the first known locality with two species of the genus. The variability of the material of S. sansaniensis from Europe allows us to revise the taxonomic weight of some previously used characters, and to identify the smaller-sized late Miocene form Semigenetta ripolli as a junior synonym of the former. Such an evolutionary transition of S. sansaniensis towards smaller forms is explained by niche partitioning with larger carnivorans of similar ecology, such as the herein reported S. grandis. Additionally, the species Semigenetta huaiheensis is here considered as a junior synonym of Semigenetta elegans.     

陕西蓝田晚中新世灞河组鼠科化石

详细描述了陕西蓝田晚中新世灞河组发现的两种鼠科化石 :中华原裔鼠Progonomyssinensissp .nov .和Muridaegen .etsp .indet.。新种的特征是 :个体通常比ProgonomyscathalaiSchaub ,1 938大 ;下臼齿的唇侧齿带和附属尖很弱 ;三分之二的m1具有一很小的中间前边尖(tma) ;M1的t1和t3偶见后刺 ,在个别的m1中有一短的中间脊 ;臼齿的尺寸落入P .woelferi的变异范围 ,但t6～t9间的连接没有该种那样常见 ,而t1 2较为明显。新种产于灞河组下部层位 ,其牙齿的大小和形态特征介于ProgonomyscathalaiSchaub ,1 938与P .woelferiBachmayeretWilson ,1 970之间。据此可证实 ,把灞河组下部层位的时代置于晚中新世早期 ,相当欧洲瓦里士期晚期或MN1 0的时代比较恰当。新种的重要意义不仅在于它具有狭义Progonomys属的特征 ,而且是我国现知鼠科动物最古老的一种。未定种产于灞河组较上部层位 ,牙齿形态与Progonomyssinensis的相似 ,很可能与其有较接近的亲缘关系。     

Enters the shrew,some considerations on the Miocene palaeobiogeography of Iberian insectivores

The fossil record of the Iberian insectivores forms a subset of those found in central Europe. Comparison of the late early to early late Miocene record of the two areas shows that, particularly during the late Early Miocene, central European taxa have transient occurrences in Spain. Most taxa appear earlier and survive longer in central Europe. A notable exception is the gymnure Galerix, which extirpates earlier in central Europe, except for a transient occurrence in Germany just prior to its extinction. The main period of insectivore migrations is the late middle Miocene, although some of the taxa that enter remain restricted to the coastal areas. Overall, the pattern of distribution in time and space is best explained by the preference of insectivores for humid environments, as were found during the early Miocene and re-appeared at the end of the middle Miocene.     

Inferring habitat and feeding behaviour of early Miocene notoungulates from Patagonia

Cassini, G.H., Mendoza, M., Vizcaíno, S.F. & Bargo, M.S. 2011: Inferring habitat and feeding behaviour of early Miocene notoungulates from Patagonia. Lethaia, Vol. 44, pp. 153–165. Notoungulates, native fossil mammals of South America, have been usually studied from a taxonomic point of view, whereas their palaeobiology has been largely neglected. For example, morpho‐functional or eco‐morphological approaches have not been rigorously applied to the masticatory apparatus to propose hypothesis on dietary habits. In this study, we generate inferences about habitat and feeding preferences in five Santacrucian genera of notoungulates of the orders Typotheria and Toxodontia using novel computer techniques of knowledge discovery. The Santacrucian (Santa Cruz Formation, late‐early Miocene) fauna is particularly appropriate for this kind of studies due to its taxonomic richness, diversity, amount of specimens recorded and the quality of preservation. Over 100 extant species of ungulates, distributed among 13 families of artiodactyls and perissodactyls, were used as reference samples to reveal the relationships between craniodental morphology and ecological patterns. The results suggest that all Santacrucian notoungulates present morphologies characteristic of open habitats’ extant ungulates. Although the Toxodontia exhibits the same morphological pattern of living mixed‐feeders and grazers, the Typotheria shows exaggerated traits of specialized grazer ungulates. □Craniodental morphology, ecomorphology, fossil ungulates, knowledge discovery, South America.     

Dabbling ducks (Aves: Anatidae) from the Middle Miocene of Mongolia

A new genus and two new species of ducks (Aves: Anatidae) from the Middle Miocene Sharga locality are described. Mioquerquedula minutissima gen. et sp. nov. is a very small duck. Anas velox Milne-Edwards, 1868 from the Middle Miocene of France is transferred to the genus Mioquerquedula. Aix praeclara sp. nov. described here is the oldest record of the modern genus Aix. A revision of the previously described small duck Anas soporata Kurochkin, 1976 shows that only the specimens from the Sharga locality should be referred to this species. The status of other small ducks from the Neogene of Europe and North America is discussed. The diversity of herbivorous and diving ducks in the Sharga locality indicates that Miocene Shargyn Govi Lake was rich in food resources.     

Molecular Relationships of the Extinct Pig-Footed Bandicoot Chaeropus ecaudatus (Marsupialia: Perameloidea) Using 12S rRNA Sequences

The pig-footed bandicoot, Chaeropus ecaudatus, is presumed to be extinct as no specimens have been collected or seen since early this century. Usually classified as a specialized member of the family Peramelidae, there is nevertheless still some doubt as to its taxonomic affinities, because this animal is highly specialized and shows several uniquely derived characters. We report here the first attempt to determine the molecular relationships of this animal using mitochondrial 12S rRNA sequences derived from spirit-preserved museum specimens. Phylogenetic analysis shows that the sequence derived from the Chaeropus sample is clearly that of a bandicoot. Within the bandicoot clade, the pig-footed bandicoot is quite distinct from all other taxa. Divergence-time estimates from the 12S rRNA sequences suggest that Chaeropus diverged from the other bandicoot genera in the late Oligocene or early Miocene and that bandicoots diverged from other Australian families in the late Paleocene–early Eocene.     

El géneroJacquinia L. (Theophrastaceae) en Cuba

The term phyletic diversity is used here to denote the continued co-existence and evolution of separate major phyletic groups which have a similar mode of life (e.g. within the angiosperms). This work attempts to show that an understanding of the factors which determine the degree of phyletic diversity could contribute to understanding the nature and evolution of higher taxonomic categories, such as families. The opposite of phyletic diversity, phyletic uniformity (Fig. 1A—B), should result from unequal evolutionary rates of different groups and repeated adaptive radiations of the most successful groups; the following competition for essential, limiting resources should lead to the extinction of all less rapidly evolving, inferior groups. At least some plant families are shown to have specific adaptive specializations which give them competitive advantages for part of the environmental resources only. This ensures their co-existence and the maintainance of phyletic diversity. The nature of these family specializations is considered briefly. It is shown that physiological adaptations to particular conditions, symbioses which aid in obtaining nutrients and, especially, chemical defence mechanisms could be major components of these specializations and thereby the raison d'être of plant families.     

Dental remains of Equatorius africanus from Kipsaramon, Tugen Hills, Baringo District, Kenya.

Forty-one isolated large hominoid teeth, as well as most of the mandibular and three maxillary teeth associated with a partial skeleton, were recovered from middle Miocene Muruyur sediments near Kipsaramon in the Tugen Hills, Baringo District, Kenya. The isolated teeth were collected as surface finds and the skeleton was excavated in situ at locality BPRP#122 dated between 15.58 Ma and 15.36 Ma. The majority of the teeth recovered at BPRP#122 are referable to a minimum of five individuals of the hominoid Equatorius africanus. Three of the teeth, however, are provisionally assigned to Nyanzapithecus sp. The new hominoids from Kipsaramon add to an increasing inventory of specimens that suggest greater large hominoid taxonomic diversity from the middle Miocene of Kenya than was previously recognized. It is suggested that there are two large-bodied hominoid species present at Mabako, only one of which is assignable to Equatorius.     

Southward Pleistocene migration of Douglas-fir into Mexico: phylogeography, ecological niche modeling, and conservation of 'rear edge' populations

? Poleward Pleistocene plant migration has been an important process structuring modern temperate and boreal plant communities, but the contribution of equatorward migration remains poorly understood. Paleobotanical evidence suggests Miocene or Pleistocene origin for temperate 'sky island' plant taxa in Mexico. These 'rear edge' populations situated in a biodiversity hotspot may be an important reserve of genetic diversity in changing climates. ? We used mtDNA sequences, cpDNA sequences and chloroplast microsatellites to test hypotheses of Miocene vs Pleistocene colonization of temperate Douglas-fir in Mexico, explore geographic patterns of molecular variation in relation to Pleistocene climate history using ecological niche models, and assess the taxonomic and conservation implications. ? We found strong evidence for Pleistocene divergence of Douglas-fir in Mexico (958 thousand yr before present (ka) with the 90% highest posterior density interval ranging from 1.6 million yr before present (Ma) to 491 ka), consistent with the southward Pleistocene migration hypothesis. Genetic diversity was high and strongly partitioned among populations. Spatial patterns of molecular variation and ecological niche models suggest a complex late Pleistocene history involving periods of isolation and expansion along mountain corridors. ? These results highlight the importance of southward Pleistocene migration in establishing modern high-diversity plant communities and provide critical insights into proposals to conserve the unique biodiversity of Mexican Douglas-fir and associated taxa.