The antiquity of the Rhine River : stratigraphic coverage of the Dinotheriensande (Eppelsheim Formation) of the Mainz Basin (Germany)

Background: Mammalian fossils from the Eppelsheim Formation (Dinotheriensande) have been a benchmark for Neogene vertebrate palaeontology since 200 years. Worldwide famous sites like Eppelsheim serve as key localities for biochronologic, palaeobiologic, environmental, and mammal community studies. So far the formation is considered to be of early Late Miocene age (~9.5 Ma, Vallesian), representing the oldest sediments of the Rhine River. The stratigraphic unity of the formation and of its fossil content was disputed at times, but persists unresolved. Principal Findings: Here we investigate a new fossil sample from Sprendlingen, composed by over 300 mammalian specimens and silicified wood. The mammals comprise entirely Middle Miocene species, like cervids Dicrocerus elegans, Paradicrocerus elegantulus, and deinotheres Deinotherium bavaricum and D. levius. A stratigraphic evaluation of Miocene Central European deer and deinothere species proof the stratigraphic inhomogenity of the sample, and suggest late Middle Miocene (~12.5 Ma) reworking of early Middle Miocene (~15 Ma) sediments. This results agree with taxonomic and palaeoclimatic analysis of plant fossils from above and within the mammalian assemblage. Based on the new fossil sample and published data three biochronologic levels within the Dinotheriensand fauna can be differentiated, corresponding to early Middle Miocene (late Orleanian to early Astaracian), late Middle Miocene (late Astaracian), and early Late Miocene (Vallesian) ages. Conclusions/Significance: This study documents complex faunal mixing of classical Dinotheriensand fauna, covering at least six million years, during a time of low subsidence in the Mainz Basin and shifts back the origination of the Rhine River by some five million years. Our results have severe implications for biostratigraphy and palaeobiology of the Middle to Late Miocene. They suggest that turnover events may be obliterated and challenge the proposed ‘supersaturated’ biodiversity, caused by Middle Miocene superstites, of Vallesian ecosystems in Central Europe

3D morphology of pharyngeal dentition of the genus Capoeta (Cyprinidae): Implications for taxonomy and phylogeny

Capoeta is a herbivorous cyprinid fish genus, widely distributed in water bodies of Western Asia. Recent species show a distinct biogeographic pattern with endemic distribution in large fluvial drainage basins. As other cyprinids, the species of this genus are characterized by the presence of the pharyngeal bone with pharyngeal teeth. Despite this, the detailed morphology of the pharyngeal teeth, its interspecific and topologic variations, and the importance for taxonomy and phylogeny of the genus Capoeta are still not established. For the first time, a detailed comprehensive study of the pharyngeal dentition of 10 Capoeta species has been provided. The morphologic study of the pharyngeal dentition bases on the 3D microtomography and follows the purpose to evaluate the potential taxonomic and phylogenetic signals of these elements, as well as to study interspecific and topologic variations of the pharyngeal teeth. In this study, we propose a new methodology to categorize the studied pharyngeal teeth in 18 shape classes. The results of this study show that the detailed 3D morphology of the pharyngeal teeth is a useful tool for the identification of isolated teeth at the generic and/or specific level and that in certain cases, the tooth position in the teeth rows can be identified. Additionally, the preliminary analysis shows that the morphology of the pharyngeal teeth provides a potential phylogenetic signal. Both these patterns are very important for the taxonomy of cyprinid fishes and especially can be applied to fossil records

Possible species-flock scenario for the evolution of the cyprinid genus Capoeta (Cypriniformes: Cyprinidae) within late Neogene lake systems of the Armenian Highland

We studied 4 Ma old isolated pharyngeal teeth from lake sediments of Çevirme (Tekman Palaeolake, Erzurum Province). Based on shape characters defined for 3D models of modern species, we found that the Pliocene lake constitutes sympatric occurrence of four Capoeta species (C. cf. umbla, C. cf. baliki, C. cf. sieboldi and C. sp. sevangi/capoeta), whose modern relatives belong to a monophyletic clade inhabiting today three different drainage systems of this region (Euphrates River, Kura River and Black Sea). We interpreted this high local diversity of closely related species in terms of the species-flock model. The Tekman palaeolake was a part of an unrecognized extended late Miocene to Pliocene palaeolake system in the present- day Armenian Highland, which has been disrupted by Pliocene tectonic activities. Surface uplift of the Armenian Highland contributed to the very characteristic biogeographic distribution and endemism of Capoeta in West Asian drainage systems. Thus, we proposed a species-flock scenario for the evolution and dispersal of the cyprinid genus Capoeta in a huge unrecognized palaeolake system in the present-day Armenian Highland

A new alligatoroid from the Eocene of Vietnam highlights an extinct Asian clade independent from extant Alligator sinensis

During systematic paleontological surveys in the Na Duong Basin in North Vietnam between 2009 and 2012, well-preserved fossilized cranial and postcranial remains belonging to at least 29 individuals of a middle to late Eocene (late Bartonian to Priabonian age (39–35 Ma)) alligatoroid were collected. Comparative anatomical study of the material warrants the diagnosis of a new taxon, Orientalosuchus naduongensis gen. et sp. nov. The combined presence of an enlarged fifth maxillary tooth, prominent preorbital ridges, a large supraoccipital exposure on the skull table, a palatine-pterygoid suture anterior to the posterior end of the suborbital fenestra, and a pterygoid forming a neck surrounding the choana is unique to this species. Unlike previous phylogenies, our parsimony analysis recovers a monophyletic Late Cretaceous to Paleogene East to Southeastern Asian alligatoroid group, here named Orientalosuchina. The group includes Orientalosuchus naduongensis, Krabisuchus siamogallicus, Eoalligator chunyii, Jiangxisuchus nankangensis and Protoalligator huiningensis, all of them sharing a medial shifted quadrate foramen aerum. The recognition of this clade indicates at least two separate dispersal events from North America to Asia: one during the Late Cretaceous by Orientalosuchina and one by the ancestor of Alligator sinensis during the Paleogene or Neogene, the timing of which is poorly constrained

A new testudinoid turtle from the middle to late Eocene of Vietnam

Testudinoidea is a major clade of turtles that has colonized different ecological environments across the globe throughout the Tertiary. Aquatic testudinoids have a particularly rich fossil record in the Tertiary of the northern hemisphere, but little is known about the evolutionary history of the group, as the phylogenetic relationships of most fossils have not been established with confidence, in part due to high levels of homoplasy and polymorphism.Methods: We here focus on describing a sample of 30 testudinoid shells, belonging to a single population that was collected from lake sediments from the middle to late Eocene (35–39 Ma) Na Duong Formation in Vietnam. The phylogenetic placement of this new material is investigated by integrating it and 11 other species of putative geoemydids from the Eocene and Oligocene to a recently published matrix of geoemydid turtles, that embraces the use of polymorphic characters, and then running a total-evidence analysis.Results: The new material is highly polymorphic, but can be inferred with confidence to be a new taxon, Banhxeochelys trani gen. et sp. nov. It shares morphological similarities with other southeastern Asian testudinoids, Isometremys lacuna and Guangdongemys pingi, but is placed phylogenetically at the base of Pan-Testuguria when fossils are included in the analysis, or as a stem geoemydid when other fossils are deactivated from the matrix. The vast majority of other putative fossil geoemydids are placed at the base of Pan-Testuguria as well.Discussion: The phylogenetic placement of fossil testudinoids used in the analysis is discussed individually and each species compared to Banhxeochelys trani gen. et sp. nov. The high levels of polymorphism observed in the new taxon is discussed in terms of ontogenetic and random variability. This is the first time that a large sample of fossil testudinoids has its morphological variation described in detail

Habitat tracking, range dynamics and palaeoclimatic significance of Eurasian giant salamanders (Cryptobranchidae) - indications for elevated Central Asian humidity during Cenozoic global warm periods

Environmental fluctuations are a driving force in vertebrate evolution,but cryptobranchids (giant salamanders) show little morphologic changesince the Jurassic. Here we analyze their fossil distribution in theCenozoic of Eurasia and show that morphologic stasis is also maintainedby stable environments, making giant salamanders an ideal proxy-groupfor environmental and palaeoclimatic studies. The climate space ofrecent and fossil cryptobranchids is best characterized by high humiditywith mean annual precipitation values over 900 mm. The recordedpatchiness of their fossil record can be explained by habitat trackingand/or range expansion from higher altitudes into lowland settingsduring humid periods with increased basinal relief. In Central Asiacryptobranchids are recorded from five intervals, four of them areglobal warm periods: Paleocene-Eocene Thermal Maximum, Late Oligocenewarming, Miocene Climate Optimum, and Mio-Pliocene transition. Thisdistribution suggests that during global warmth the Asian cold highpressure zone during winter months may be weak or absent, thus moistwesterly winds penetrate far into the continent. The presence ofcryptobranchids also indicates that the aridification across theEocene-Oligocene boundary as reported from Mongolia and northwesternChina, does not occur in the Zaysan Basin, probably due to increasedupslope precipitation in the rising Altai Mountains

Tragulidae and pecoran ruminants from the latest Middle Miocene (Sarmatian, late Astaracian) of Austria.

One of the richest and most complete European terrestrial vertebrate faunas of late Middle Miocene age (12.2¿12.0 Ma; Gross et al., in press) was found near Gratkorn, at the northeastern realm of the Styrian Basin (Austria). It is one of the rare localities from the Sarmatian sensu stricto (late Serravallian) in the Central Paratethys area with a vertebrate fauna, both high in quality as well as rich in quantity. So far, 62 taxa are recorded, including Euprox furcatus, Micromeryx flourensianus and Dorcatherium naui. This is one of the rare records of Dorcatherium naui older than Vallesian and the oldest finding of the species from the Paratethys realm so far. Up to now, Dorcatherium naui of pre-Vallesian ages have only been described from Przeworno (Poland; Glazek et al., 1971), and Abocador de Can Mata (Spain; Alba et al., 2011), which are of latest Middle Miocene age like Gratkorn. Therefore the latter does not only represent one of the oldest records of Dorcatherium naui but also supports the wide distribution of the taxon already at the latest Middle Miocene. In contrast to the site of Abocador de Can Mata, where Dorcatherium naui is an infrequent element (Alba et al., 2011), the species is abundant at the locality of Gratkorn. Apart from this the larger mammal fauna of Abocadar de Can Mata and Gratkorn is quite similar, except of proboscidean and bovid taxa. While in Abocador de Can Mata Gomphotherium, Deinotherium and bovids are present (Alba et al., 2009), in Gratkorn only Deinotherium giganteum was found until now. Bovids were found in contemporaneous sediments in the eastern Styrian Basin (Gross et al., in press), though. With the material of Gratkorn previous ideas on ecological adaptations in Dorcatherium (Rössner, 2004) are supported and the understanding of the ecological niche of the ¿forest-dweller¿ Dorcatherium is specified. Besides new ideas on dispersal, evolution and ecology of Dorcatherium the locality of Gratkorn also enables an in-depth evaluation of its species separation. The specimens from Gratkorn demonstrate, in comparison with other Material from the Paratethys area, a clear distinction between Dorcatherium crassum and Dorcatherium naui and underline the taxonomic separation of both species as accepted by several authors (e.g. Alba et al., 2011). REFERENCES Alba, D.M. et al. (2009). Middle Miocene vertebrate localities from Abocador de Can Mata (els Hostalets de Pierola, Vallès Penedès Basin, Catalonia, Spain): An update after the 2006-2008 field campaigns. Paleolusitana, 1, 59¿73. Alba, D.M. et al. (2011). Middle Miocene tragulid remains from Abocador de Can Mata: the earliest record of Dorcatherium naui from Western Europe. Geobios, 44, 135-150. Glazek, J. et al. (1971). Miocene vertebrate faunas from Przeworno (Lower Silesia) and their geological setting. Acta Geologica Polonica, 21(3), 473-516. Gross, M. et al. (in press). Gratkorn ¿ A benchmark locality for the continental Sarmatian s. str. of the Central Paratethys. International Journal of Earth Sciences, doi: 10.1007/s00531-010-0615-1. Rössner, G.E. (2004). Community structure and regional patterns in late Early to Middle Miocene Ruminantia of Central Europe. Courier Forschungs-Institut Senckenberg, 249: 91-100.Peer Reviewe

Phylogenetic relationships and biogeographical patterns in Circum-Mediterranean subfamily Leuciscinae (Teleostei, Cyprinidae) inferred from both mitochondrial and nuclear data

<p>Abstract</p> <p>Background</p> <p>Leuciscinae is a subfamily belonging to the Cyprinidae fish family that is widely distributed in Circum-Mediterranean region. Many efforts have been carried out to deciphering the evolutionary history of this group. Thus, different biogeographical scenarios have tried to explain the colonization of Europe and Mediterranean area by cyprinids, such as the "north dispersal" or the "Lago Mare dispersal" models. Most recently, Pleistocene glaciations influenced the distribution of leuciscins, especially in North and Central Europe. Weighing up these biogeographical scenarios, this paper constitutes not only the first attempt at deciphering the mitochondrial and nuclear relationships of Mediterranean leuciscins but also a test of biogeographical hypotheses that could have determined the current distribution of Circum-Mediterranean leuciscins.</p> <p>Results</p> <p>A total of 4439 characters (mitochondrial + nuclear) from 321 individuals of 176 leuciscine species rendered a well-supported phylogeny, showing fourteen main lineages. Analyses of independent mitochondrial and nuclear markers supported the same main lineages, but basal relationships were not concordant. Moreover, some incongruence was found among independent mitochondrial and nuclear phylogenies. The monophyly of some poorly known genera such as <it>Pseudophoxinus </it>and <it>Petroleuciscus </it>was rejected. Representatives of both genera belong to different evolutionary lineages. Timing of cladogenetic events among the main leuciscine lineages was gained using mitochondrial and all genes data set.</p> <p>Conclusions</p> <p>Adaptations to a predatory lifestyle or miniaturization have superimposed the morphology of some species. These species have been separated into different genera, which are not supported by a phylogenetic framework. Such is the case of the genera <it>Pseudophoxinus </it>and <it>Petroleuciscus</it>, which real taxonomy is not well known. The diversification of leuciscine lineages has been determined by intense vicariant events following the paleoclimatological and hydrogeological history of Mediterranean region. We propose different colonization models of Mediterranean region during the early Oligocene. Later vicariance events promoted Leuciscinae diversification during Oligocene and Miocene periods. Our data corroborate the presence of leuciscins in North Africa before the Messinian salinity crisis. Indeed, Messinian period appears as a stage of gradually Leuciscinae diversification. The rise of humidity at the beginning of the Pliocene promoted the colonization and posterior isolation of newly established freshwater populations. Finally, Pleistocene glaciations determined the current European distribution of some leuciscine species.</p

Early Miocene gastropod and ectothermic vertebrate remains from the Lesvos Petrified Forest (Greece)

The Lesvos Petrified Forest (western Lesvos, Greece) has long been famous for its plant fossils. Recently, one proboscidean (from the Gavathas locality) and seven micromammalian species (from the Lapsarna locality) were described; these were the first animals to be found in the Early Miocene subtropical forest. For the first time, a fauna of gastropods and ectothermic vertebrates from the Lapsarna locality is now available. This fauna derives from lacustrine sediments under the pyroclastic material that contains the petrified plants. Based on fragmented mollusc remains, isolated fish pharyngeal teeth and utricular otoliths (lapilli), fragmented amphibian vertebrae and a tooth-bearing element, and reptile fragmented dentaries, teeth, osteoderms and vertebrae, the presence of eight freshwater and three terrestrial gastropod species, three freshwater cyprinid species, and two amphibian and five reptile taxa has been confirmed. Stratigraphical and radiometric data suggest an age older than 18.4 ± 0.5 Ma (latest Early Miocene), in good agreement with the faunal composition. This paper is the first report of the concurrent presence of three cyprinid fish species in a Greek Early Miocene locality, as well as the first documentation of an Early Miocene proteid amphibian in southeastern Europe. The present findings represent one of the best- documented Early Miocene gastropod and fish faunas in the Aegean/southern Balkans, thus adding to our knowledge of Early Miocene amphibians and reptiles from that region and providing valuable information on the local subtropical ecosystem