Quaternary time scales for the Pontocaspian domain: interbasinal connectivity and faunal evolution

The Pontocaspian (Black Sea - Caspian Sea) region has a very dynamic history of basin development and biotic evolution. The region is the remnant of a once vast Paratethys Sea. It contains some of the best Eurasian geological records of tectonic, climatic and paleoenvironmental change. The Pliocene-Quaternary co-evolution of the Black Sea-Caspian Sea is dominated by major changes in water (lake and sea) levels resulting in a pulsating system of connected and isolated basins. Understanding the history of the region, including the drivers of lake level and faunal evolution, is hampered by indistinct stratigraphic nomenclature and contradicting time constraints for regional sedimentary successions. In this paper we review and update the late Pliocene to Quaternary stratigraphic framework of the Pontocaspian domain, focusing on the Black Sea Basin, Caspian Basin, Marmara Sea and the terrestrial environments surrounding these large, mostly endorheic lake-sea systems

Early Pleistocene enamel proteome from Dmanisi resolves Stephanorhinus phylogeny

The sequencing of ancient DNA has enabled the reconstruction of speciation, migration and admixture events for extinct taxa. However, the irreversible post-mortem degradation2 of ancient DNA has so far limited its recovery—outside permafrost areas—to specimens that are not older than approximately 0.5 million years (Myr). By contrast, tandem mass spectrometry has enabled the sequencing of approximately 1.5-Myr-old collagen type I, and suggested the presence of protein residues in fossils of the Cretaceous period—although with limited phylogenetic use. In the absence of molecular evidence, the speciation of several extinct species of the Early and Middle Pleistocene epoch remains contentious. Here we address the phylogenetic relationships of the Eurasian Rhinocerotidae of the Pleistocene epoch, using the proteome of dental enamel from a Stephanorhinus tooth that is approximately 1.77-Myr old, recovered from the archaeological site of Dmanisi (South Caucasus, Georgia). Molecular phylogenetic analyses place this Stephanorhinus as a sister group to the clade formed by the woolly rhinoceros (Coelodonta antiquitatis) and Merck’s rhinoceros (Stephanorhinus kirchbergensis). We show that Coelodonta evolved from an early Stephanorhinus lineage, and that this latter genus includes at least two distinct evolutionary lines. The genus Stephanorhinus is therefore currently paraphyletic, and its systematic revision is needed. We demonstrate that sequencing the proteome of Early Pleistocene dental enamel overcomes the limitations of phylogenetic inference based on ancient collagen or DNA. Our approach also provides additional information about the sex and taxonomic assignment of other specimens from Dmanisi. Our findings reveal that proteomic investigation of ancient dental enamel—which is the hardest tissue in vertebrates, and is highly abundant in the fossil record—can push the reconstruction of molecular evolution further back into the Early Pleistocene epoch, beyond the currently known limits of ancient DNA preservation

Synopsis of the terrestrial vertebrate faunas from the Middle Kura Basin (Eastern Georgia and Western Azerbaijan, South Caucasus)

This paper summarizes knowledge on the Neogene–Quaternary terrestrial fossil record from the Middle Kura Basin accumulated over a century and aims to its integration into the current research. This fossil evidence is essential in understanding the evolution of the Eurasian biome, since this territory is located at the border of Eastern Mediterranean and Central Asian regions. The general biostratigraphic framework suggests existence of two major intervals of the terrestrial fossil record in the area, spanning ca. 10–7 Ma and ca. 3–1 Ma, and points to an important hiatus between the late Miocene and late Pliocene. General aspects of the paleogeographic history and fossil record suggest that the biogeographic role of the Middle Kura Basin has been changing over geological time from a refugium (Khersonian) to a full-fledged part of the Greco-Iranian province (Meotian–Pontian). The dynamic environmental changes during the Quaternary do not depict this territory as a refugium in its general sense. The greatest value of this fossil record is the potential to understand a detailed history of terrestrial life during demise of late Miocene Hominoidea in Eurasia and early Homo dispersal out of Africa. Late Miocene record of the Middle Kura Basin captures the latest stage of the Eastern Paratethys regression, and among other fossils counts the latest and the easternmost occurence of dryopithecine, Udabnopithecus garedziensis, while the almost uninterrupted fossil record of the late Pliocene–Early Pleistocene covers the time interval of the early human occupation of Caucasus and Eurasia

Northern Eurasian rhinocerotines (Mammalia, Perissodactyla) by the Pliocene–Pleistocene transition: phylogeny and historical biogeography

Pliocene and earliest Pleistocene Northern Eurasian rhinocerotines are poorly documented and understudied in comparison to Pleistocene and Miocene ones. However, they represent a key-group of species for understanding the phylogeny and historical biogeography of their Pleistocene relatives. In the present paper, we revise the abundant material from the late Pliocene locality of Kvabebi, Georgia from a systematic, phylogenetic and palaeobiogeographical perspective. The specimens from Kvabebi are documented by two partially preserved skulls, one mandible and several postcranial remains. Morphological and morphometric comparison with the type material assigned to Pliocene and earliest Pleistocene Northern Eurasian Rhinocerotinae reveal that the specimens from Kvabebi have close affinities with the poorly known Dicerorhinus miguelcrusafonti Guérin & Santafé-Llopis, 1978, described from Layna (Spain). The latter species, represented by scanty remains from the Iberian Peninsula, is usually excluded from morphological and morphometrical comparisons and no findings were reported after the 1990s. Pliocene rhinocerotine species have monotonous dental and postcranial morphologies and only a few features allow us to discern the different species. The material from Layna and Kvabebi is somewhat smaller than that of other Pliocene taxa, except for the largest representatives of Stephanorhinus etruscus (Falconer, 1868). Accordingly, the earliest specimens assigned to S. etruscus on morphometric grounds should be revised in the light of the new data here presented. A cladistic analysis performed on 280 characters and 30 species suggests that the emblematic early Pliocene European species, ‘Dihoplus’ megarhinus (de Christol, 1834), is sister taxon to the Layna and Kvabebi rhinoceroses. Accordingly, both species are here assigned to a new genus named Pliorhinus gen. nov. Although distinct, this clade has close affinities with the paraphyletic genus Stephanorhinus, therefore suggesting the co-occurrence of at least two distinct rhinocerotine lineages raised in the late Miocene interval in Northern Eurasia. http://zoobank.org/urn:lsid:zoobank.org:pub:D3A1AB6D-EFE7-4813-AE74-A27D204A18CA

Paleoecology, biochronology, and paleobiogeography of Eurasian Rhinocerotidae during the Early Pleistocene: The contribution of the fossil material from Dmanisi (Georgia, Southern Caucasus)

Rhinocerotidae represents a common element in the Eurasian Pleistocene faunas. Origin, dispersal route, and biochronology of several species are still poorly understood due to gaps in the fossil record, in particular from central Eurasia. A remarkable collection of rhinoceros remains was recovered from the Early Pleistocene site of Dmanisi (Georgia). This collection is unique for the Early Pleistocene Rhinocerotidae records due to its abundance in remains, its age (ca 1.8 Ma) and geographic position (between Eastern and Western Eurasia). Two crania, which display some different morphological traits, are assigned to two different morphotypes and investigated by means of geometric morphometrics using landmarks and semilandmarks. Shapes in lateral and dorsal views of different Rhinocerotini species are compared with the studied crania to infer paleoecological information. The shape in the lateral view reflects ecological niche, in particular feeding type from browsing to grazing, and it also represent taxonomic discrimination. Morphotypes 1 and 2 from Dmanisi fall in two different clusters, corresponding to two different species, notably in lateral view. The results suggest a niche partitioning during the Early Pleistocene of Dmanisi between a browse-dominated and a grass-dominated mixed feeders, or possibly the presence of two ecomorphotypes of the same species. A comprehensive update of the Early Pleistocene occurrences of Eurasian Rhinocerotidae is reported in the discussion on the paleoecology of the extinct Northern Eurasian rhinocerotines

Late survival of dryopithecine hominoids in Southern Caucasus

Dryopithecine hominoids attained an extraordinary diversity during the late middle and early late Miocene (Vallesian) in Europe, including the genera Dryopithecus, Hispanopithecus, Pierolapithecus, Anoiapithecus and Rudapithecus (Agustí et al., 2001a; Alba, 2012). However, after 9.7 Ma, they were decimated and ultimately became extinct in the frame of the so-called Vallesian Crisis (Agustí and Moya-Sol a, 1990; Agustí et al., 2013 ). The Vallesian Crisis, between 9.7 and 8.9 Ma (Garces et al., 1996; Agustí et al., 1997 ), has been explained on the basis of increasing seasonality and spread of deciduous forest (Agustí et al., 2003) and involved the extinction of several of the most common middle Miocene mammalian elements, such as rhinoceroses (Lartetotherium sansaniense, “Dicerorhinus” steinheimensis), suids (Conohyus, Listriodon, Parachleuastochoerus), cervids (Amphiprox, Hispanomeryx), bovids (Protragocerus, Miotragocerus) and carnivores (the barbourofelid Sansanosmilus and the amphicyonids Amphicyon major and Pseudarctos bavaricus). Among the small mammals, the Vallesian Crisis affected several dormice (Eomuscardinus, Myoglis, Bransatoglis, among others), hamsters (Megacricetodon, Eumyarion), flyingsquirrels (Albanensia, Miopetaurista) and beavers (Euroxenomys). The last dryopithecine hominoid (Hispanopithecus laietanus) in Europe is recorded at the late Vallesian site of La Tarumba 1 (Valles- Penedes Basin). This site is placed in a reverse chron identi fied as C4Ar.2r (Garces et al., 1996; Agustí et al., 2001a ), therefore ranging between 9.43 and 9.65 Ma. This is also the case of the Hispanopithecus bearing site of Can Llobateres 2 (Agustí et al., 1996). In Western Europe, only the endemic genus Oreopithecus managed to survive in the Tusco-Sardinian Island, until its connection with the continent at 6.7 Ma (Rook et al., 1999; Alba et al., 2001; Rook et al., 2011; Rook, 2016).Fil: Agustí, J.. Universitat Rovira i Virgili. Institut Català de Paleoecologia Humana i Evolució Social; EspañaFil: Oms, O.. Universitat Autònoma de Barcelona; EspañaFil: Piñero García, Pedro. Universitat Rovira i Virgili. Institut Català de Paleoecologia Humana i Evolució Social; España. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Chochisvili, G.. Georgian National Museum; GeorgiaFil: Bukhsianidze, M.. Georgian National Museum; GeorgiaFil: Lordkipanidze, D.. Georgian National Museum; Georgi

Zoogeographic significance of Dmanisi large mammal assemblage

We undertake a comparative mammalian zoogeographic analysis with the aim of revealing the extent to which the Dmanisi Early Pleistocene large mammal assemblage resembles, at the genus level, African, Arabian, and Eurasian localities of similar age. The inclusion of Old World Pliocene and Pleistocene mammalian faunas provides us with insights into the provincial origins of specific mammalian taxa and permits us to assess the relative affiliation of the Dmanisi mammalian faunas to other faunas in the Old World. Our analysis also allows us to consider hypotheses about the timing and direction of zoogeographic connections between western Eurasia and Africa during the Early Pleistocene. We utilize multiple zoogeographic analytical tools as a cross-comparison of Dmanisi with 42 other Eurasian and African mammalian-bearing localities between 2.7 and 0.7 Ma. Overall, we find that Dmanisi compares most closely with a subgroup of Greek, Italian, and Spanish localities that are slightly younger than Dmanisi itself. This could suggest a progressive dispersal from East to West of the large mammal communities during the late Early Pleistocene and the first occurrence at Dmanisi, and then later in Western Europe, of some taxa such as Stephanorhinus ex gr. etruscus-hundsheimensis, Equus altidens, Bison georgicus, Soergelia minor, Megantereon whitei, Canis borjgali, Canis (Xenocyon) lycaonoides. Dmanisi's habitats included drier areas, probably of open wooded savannah and grassland and by mountainous to semiarid rocky terrain. There is evidence that Dmanisi records short intervals of increased aridity in the middle part of the succession contemporaneous with the occurrence of Homo