scholarly journals Neogene amphibians and reptiles (Caudata, Anura, Gekotta, Lacertilia, Testudines) from south of Western Siberia, Russia and Northeastern Kazakhstan

2016 ◽  
Author(s):  
Davit Vasilyan ◽  
Vladimir Zazhigin ◽  
Madelaine Böhme
Keyword(s):  
Northern Hemisphere ◽  
Middle Miocene ◽  
Western Siberia ◽  
Bufo Bufo ◽  
Early Miocene ◽  
Early Pleistocene ◽  
Published Data ◽  
Molecular Clocks ◽  
Western Asia ◽  
Global Cooling

Background. Now-a-day territory of Western Siberia has the poorest diversity of amphibians and reptiles within the Palaearctic Realm, influenced by unfavourable climate. Less is known about the origin and emergence of it. Aside from better-explored European Neogene records of amphibians and reptiles, the Neogene herpetofauna of Western Asia is understudied. The few available studies on amphibian and reptile fossil assemblages need critical reviews and new interpretations considering the latest knowledge of the European record. The comparison with European record will provide data on palaeobiogeographic affiliations of the region as well as origin and emergence of the now-a-day fauna of Western Siberia. Beside these, a study providing overview about the earliest occurences of certain amphibian linages, that can be used for the calibration of the molecular clocks, is missing. Methods and Results. The amphibian and reptile fauna from over 40 Western Siberian, Russia and Northeastern Kazakhian localities ranging from Middle Miocene to Early Pleistocene has been studied. In the study the published data has been considered and critically reviewed and newly interpreted. More then 50 amphibian and reptile taxa has been identified belonging to families Hynobiidae, Cryptobranchidae, Salamandridae, Palaeobatrachidae, Bombinatoridae, Pelobatidae, Hylidae, Bufonidae, Ranidae, Gekkonidae, Lacertidae and Emydidae. Palaeobiogeographic analysis for those group has been done. For 12 localities, palaeoprecipitation values have been estimated using the bioclimatic analysis of herpetofaunal assemblage. Conclusions. The Neogene assemblage of Westren Sibera is dominated by groups (Palaeobatrachidae, Bombina, Hyla, Bufo bufo) with European affinities. A small part of assemblage includes Eastern Palaearctic taxa (e.g. Hynobiidae, Tylototriton, Bufotes viridis, R. arvalis). For several taxa (e.g. Mioproteus, Hyla, Bombina) the Western Siberian records of represent the most east Eurasian records of these groups. The most divers faunas are found in the Middle Miocene, whereas the poorest towards Early Pleistocene. This tendency could be referred to the progressive global cooling of the climate in Northern Hemisphere. Our results showed higher-amplitude changes of precipitation development in Western Siberia from Early Miocene to Pliocene, than earlier assumed.

scholarly journals Neogene amphibians and reptiles (Caudata, Anura, Gekotta, Lacertilia, Testudines) from south of Western Siberia, Russia and Northeastern Kazakhstan

2016 ◽  
Author(s):  
Davit Vasilyan ◽  
Vladimir Zazhigin ◽  
Madelaine Böhme
Keyword(s):  
Northern Hemisphere ◽  
Middle Miocene ◽  
Western Siberia ◽  
Bufo Bufo ◽  
Early Miocene ◽  
Early Pleistocene ◽  
Published Data ◽  
Molecular Clocks ◽  
Western Asia ◽  
Global Cooling

Background. Now-a-day territory of Western Siberia has the poorest diversity of amphibians and reptiles within the Palaearctic Realm, influenced by unfavourable climate. Less is known about the origin and emergence of it. Aside from better-explored European Neogene records of amphibians and reptiles, the Neogene herpetofauna of Western Asia is understudied. The few available studies on amphibian and reptile fossil assemblages need critical reviews and new interpretations considering the latest knowledge of the European record. The comparison with European record will provide data on palaeobiogeographic affiliations of the region as well as origin and emergence of the now-a-day fauna of Western Siberia. Beside these, a study providing overview about the earliest occurences of certain amphibian linages, that can be used for the calibration of the molecular clocks, is missing. Methods and Results. The amphibian and reptile fauna from over 40 Western Siberian, Russia and Northeastern Kazakhian localities ranging from Middle Miocene to Early Pleistocene has been studied. In the study the published data has been considered and critically reviewed and newly interpreted. More then 50 amphibian and reptile taxa has been identified belonging to families Hynobiidae, Cryptobranchidae, Salamandridae, Palaeobatrachidae, Bombinatoridae, Pelobatidae, Hylidae, Bufonidae, Ranidae, Gekkonidae, Lacertidae and Emydidae. Palaeobiogeographic analysis for those group has been done. For 12 localities, palaeoprecipitation values have been estimated using the bioclimatic analysis of herpetofaunal assemblage. Conclusions. The Neogene assemblage of Westren Sibera is dominated by groups (Palaeobatrachidae, Bombina, Hyla, Bufo bufo) with European affinities. A small part of assemblage includes Eastern Palaearctic taxa (e.g. Hynobiidae, Tylototriton, Bufotes viridis, R. arvalis). For several taxa (e.g. Mioproteus, Hyla, Bombina) the Western Siberian records of represent the most east Eurasian records of these groups. The most divers faunas are found in the Middle Miocene, whereas the poorest towards Early Pleistocene. This tendency could be referred to the progressive global cooling of the climate in Northern Hemisphere. Our results showed higher-amplitude changes of precipitation development in Western Siberia from Early Miocene to Pliocene, than earlier assumed.

scholarly journals Neogene amphibians and reptiles (Caudata, Anura, Gekkota, Lacertilia, and Testudines) from the south of Western Siberia, Russia, and Northeastern Kazakhstan

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3025 ◽  
Author(s):  
Davit Vasilyan ◽  
Vladimir S. Zazhigin ◽  
Madelaine Böhme
Keyword(s):  
Middle Miocene ◽  
Western Siberia ◽  
Rana Temporaria ◽  
Bufo Bufo ◽  
Climatic Conditions ◽  
Early Pleistocene ◽  
Molecular Clocks ◽  
Fossil Remains ◽  
Western Asia ◽  
Fossil Records

BackgroundThe present-day amphibian and reptile fauna of Western Siberia are the least diverse of the Palaearctic Realm, as a consequence of the unfavourable climatic conditions that predominate in this region. The origin and emergence of these herpetofaunal groups are poorly understood. Aside from the better-explored European Neogene localities yielding amphibian and reptile fossil remains, the Neogene herpetofauna of Western Asia is understudied. The few available data need critical reviews and new interpretations, taking into account the more recent records of the European herpetofauna. The comparison of this previous data with that of European fossil records would provide data on palaeobiogeographic affiliations of the region as well as on the origin and emergence of the present-day fauna of Western Siberia. An overview of the earliest occurrences of certain amphibian lineages is still needed. In addition, studies that address such knowledge gaps can be useful for molecular biologists in their calibration of molecular clocks.Methods and ResultsIn this study, we considered critically reviewed available data from amphibian and reptile fauna from over 40 Western Siberian, Russian and Northeastern Kazakhstan localities, ranging from the Middle Miocene to Early Pleistocene. Herein, we provided new interpretations that arose from our assessment of the previously published and new data. More than 50 amphibians and reptile taxa were identified belonging to families Hynobiidae, Cryptobranchidae, Salamandridae, Palaeobatrachidae, Bombinatoridae, Pelobatidae, Hylidae, Bufonidae, Ranidae, Gekkonidae, Lacertidae, and Emydidae. Palaeobiogeographic analyses were performed for these groups and palaeoprecipitation values were estimated for 12 localities, using the bioclimatic analysis of herpetofaunal assemblages.ConclusionThe Neogene assemblage of Western Siberia was found to be dominated by groups of European affinities, such as Palaeobatrachidae,Bombina, Hyla,Bufo bufo, and a small part of this assemblage included Eastern Palaearctic taxa (e.g.Salamandrella,Tylototriton,Bufotes viridis). For several taxa (e.g.Mioproteus, Hyla, Bombina,Rana temporaria), the Western Siberian occurrences represented their most eastern Eurasian records. The most diverse collection of fossil remains was found in the Middle Miocene. Less diversity has been registered towards the Early Pleistocene, potentially due to the progressive cooling of the climate in the Northern Hemisphere. The results of our study showed higher-amplitude changes of precipitation development in Western Siberia from the Early Miocene to the Pliocene, than previously assumed.

Middle Miocene recovery of Caribbean reef corals: New data from the Tamana Formation, Trinidad

2001 ◽  
Vol 75 (3) ◽  
pp. 513-526 ◽  
Author(s):  
Kenneth G. Johnson
Keyword(s):  
Middle Miocene ◽  
New Records ◽  
Early Miocene ◽  
Early Pleistocene ◽  
Reef Corals ◽  
Rigorous Description ◽  
Caribbean Coral Reef ◽  
The Caribbean ◽  
Stratigraphic Ranges ◽  
Biotic Change

Caribbean coral reef communities were restructured by episodes of accelerated biotic change during the late Oligocene/early Miocene and the late Pliocene/early Pleistocene. However, rigorous description of the effects of rapid biotic change is problematic because preservation and exposure of coral-bearing deposits is not consistent in all stratigraphic intervals. In the Caribbean, early and middle Miocene exposures are more rare than late Miocene and Pliocene exposures. One exception is the late early to early middle Miocene Tamana Formation of Trinidad, and old and new collections from this unit were studied to determine the timing of recovery after the Oligocene/Miocene transition. A total of 41 species of zooxanthellate corals were recovered from the unit, including 21 new records. Within these assemblages, species first occurrences outnumber species last occurrences by a factor of four (31 first occurrences and eight last occurrences). The extension of the stratigraphic ranges of species previously first recorded in Pliocene sediments has reduced an apparent Pliocene pulse of origination, indicating that the Pliocene/Pleistocene transition was largely a result of accelerated extinction against a background of near-constant origination. The fact that few species last occur in the Tamana fauna indicates that the Oligocene/Miocene transition was complete by the end of the early Miocene.

scholarly journals Body-size structure of Central Iberian mammal fauna reveals semidesertic conditions during the middle Miocene Global Cooling Event

PLoS ONE ◽  
2017 ◽  
Vol 12 (10) ◽  
pp. e0186762 ◽  
Author(s):  
Iris Menéndez ◽  
Ana R. Gómez Cano ◽  
Blanca A. García Yelo ◽  
Laura Domingo ◽  
M. Soledad Domingo ◽  
...  
Keyword(s):  
Body Size ◽  
Middle Miocene ◽  
Size Structure ◽  
Mammal Fauna ◽  
Global Cooling

Foraminifera Biostratigraphy of Two Wells in Niger Delta

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Dairo VA
Keyword(s):  
Niger Delta ◽  
Middle Miocene ◽  
Early Miocene ◽  
Orbulina Universa ◽  
Exploratory Wells ◽  
Stratigraphic Range

Biostratigraphic studies of foraminifera were carried out on two exploratory wells drilled in the Eastern Niger Delta to establish the age, biozonation and paleoenvironment of the foraminifera present in the strata penetrated by the wells. A total of 80 ditch cutting samples retrieved at 60ft intervals from AX-1 and AX-2 Wells at the depth of 3,600ft to 6,000ft and 4,200ft to 6500ft. respectively were subjected to micropaleontological analysis which involves picking and identification of the foraminifera present. The resulting data were loaded into the Stratabug software and interpreted. The foraminifera recovered and identified from the two wells are made up of both benthic and planktic species. The marker species, whose stratigraphic range are well established were used to describe the biozonation and these includes Heterostegina sp, Catapsydrax stainforthi, Chiloguembelina victoriana, Orbulina universa/suturalis, Praeorbulina sicana,Buliminella subfusiformis, Nonion centrosulcatum, Catapsydrax dissimilis, Globigerinoides bisphericus and Globigerinoides sicanus. Four biozones of foraminifera made up of N8, N7-N8, N6-N7 and N5-N6 were recognised based on the zonation scheme of Grandstein; with their stratigraphic age ranging from early Miocene to middle Miocene. Furthermore, the environment of deposition prevailing in the Formations penetrated by the two wells are predominantly middle neritic with similarity in their ages as observed from the correlation of the biozones from the two wells

scholarly journals Petrography of the Siwalik sandstones, Amlekhganj-Suparitar area, central Nepal Himalaya

2003 ◽  
Vol 28 ◽  
Author(s):  
Naresh Kazi Tamrakar ◽  
Shuichiro Yokota ◽  
Suresh Das Shrestha
Keyword(s):  
Middle Miocene ◽  
Foreland Basin ◽  
Early Pleistocene ◽  
Nepal Himalaya ◽  
Central Nepal ◽  
Present Study Area ◽  
Mean Grain Size ◽  
Siwalik Group ◽  
Variation Trends ◽  
The Himalaya

Middle Miocene to early Pleistocene sedimentary sequence deposited in the foreland basin of the Himalaya is represented by the Siwalik Group. In the present study area the Siwalik Group extends in a NW-SE direction and well-exposed. Forty­four sandstone samples were studied for texture, fabric and composition in order to assess their petrographic properties and variation trends of these properties in stratigraphic levels. Sandstones were classified into sublitharenite, subarkose, lithic arenite, arkosic arenite and feldspathic graywacke and further thirteen sub-clans. Mean grain size (M) and Trask sorting coefficient (So) increase up-section. Recalculated quartz, matrix, modified maturity index (MMI), total cement (Ct), cement versus matrix index (CMI) and ratio of strong cement over total cement ((Cfc/Cs)/Ct) also increase, whilst packing proximity (PP), packing density (PD) and consolidation factor (Pcc) decrease up-section showing distinct trends, and therefore, these properties are promising in recognizing the older sandstones from the younger ones.

scholarly journals A mid-miocene age for the Slanci formation near Belgrade (Serbia), based on a record of the primitive antelope Eotragus cf. Clavatus from Visnjica

2007 ◽  
pp. 53-59
Author(s):  
der van ◽  
Slobodan Knezevic ◽  
Ivan Stefanovic
Keyword(s):  
Middle Miocene ◽  
Lacustrine Sediments ◽  
Early Miocene

In a borhole at Veliko Selo near Belgrade in the Miocene lacustrine sediments Slanci, which are locally known as the Slanacka Serija, a mammal tooth was found. The age of these deposits is under discussion. The fossil is here described and attributed with a query to the primitive antelope Eotragus clavatus (GERVAIS, 1850), which is suggestive of a Early Serravallian ("upper Badenian") or Early Middle Miocene age for these deposits, whereas an Aquitalian or Eggenburgian ("Egerian" or "Eggenburgian") (Early Miocene) age can be ruled out.

scholarly journals The distribution of <i>Triebelina raripila</i> and <i>Carinocythereis carinata</i> (Ostracoda) from the Middle Miocene of the Central Paratethys and their palaeogeographic implications

1998 ◽  
Vol 17 (2) ◽  
pp. 125-130 ◽  
Author(s):  
J. Szczechura
Keyword(s):  
Shallow Water ◽  
Late Miocene ◽  
Middle Miocene ◽  
Early Miocene ◽  
Central Paratethys ◽  
Eastern Paratethys ◽  
Main Species ◽  
Late Middle Miocene ◽  
The Mediterranean

Abstract. Late Middle Miocene (Upper Badenian) strata of the Fore-Carpathian Depression of Poland yield a shallow-water ostracod fauna which contains the species Triebelina raripila (G. W. Müller, 1894) and Carinocythereis carinata (Roemer, 1838). The palaeobiogeographic distribution of the two main species suggests, that in the late Middle Miocene, Central Paratethys was still connected to the Mediterranean, although still separated from the Eastern Paratethys and from southeastern Eurasia. The continuous occurrence of Triebelina raripila and Carinocythereis carinata in the Mediterranean basins, from the Early Miocene to Recent, indicates that marine conditions existed throughout, thereby allowing them to survive the Late Miocene salinity crisis.

scholarly journals The largest early-diverging angiosperm family is mostly pollinated by ovipositing insects and so are most surviving lineages of early angiosperms

2018 ◽  
Vol 285 (1870) ◽  
pp. 20172365 ◽  
Author(s):  
Shi-Xiao Luo ◽  
Lian-Jie Zhang ◽  
Shuai Yuan ◽  
Zhong-Hui Ma ◽  
Dian-Xiang Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Food Reward ◽  
Early Miocene ◽  
Molecular Clocks ◽  
Plant Interactions ◽  
Insect Pollination ◽  
Basal Angiosperms ◽  
Gall Midges ◽  
Beetle Pollination ◽  
Direct Observations

Insect pollination in basal angiosperms is assumed to mostly involve ‘generalized' insects looking for food, but direct observations of ANITA grade (283 species) pollinators are sparse. We present new data for numerous Schisandraceae, the largest ANITA family, from fieldwork, nocturnal filming, electron microscopy, barcoding and molecular clocks to infer pollinator/plant interactions over multiple years at sites throughout China to test the extent of pollinator specificity. Schisandraceae are pollinated by nocturnal gall midges that lay eggs in the flowers and whose larvae then feed on floral exudates. At least three Schisandraceae have shifted to beetle pollination. Pollination by a single midge species predominates, but one species was pollinated by different species at three locations and one by two at the same location. Based on molecular clocks, gall midges and Schisandraceae may have interacted since at least the Early Miocene. Combining these findings with a review of all published ANITA pollination data shows that ovipositing flies are the most common pollinators of living representatives of the ANITA grade. Compared to food reward-based pollination, oviposition-based systems are less wasteful of plant gametes because (i) none are eaten and (ii) female insects with herbivorous larvae reliably visit conspecific flowers.

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