Middle Pleistocene fauna and palaeoenvironment in the south of Eastern Europe: A case study of the Medzhybizh 1 locality (MIS 11, Ukraine)

The Middle Pleistocene was a period of dynamic changes in Europe. During MIS 11, a number of modern mammal taxa appeared and environmental conditions remained warm and favourable for a relatively long time. The Medzhybizh 1 locality of Ukraine dated to this very period comprises alluvial deposits with rich animal remains, which allow not only to reconstruct the fauna composition, but also to highlight the environmental conditions that dominated at this locality. A revision of the fauna of Medzhybizh 1 locality based on remains of all vertebrate groups revealed a taxonomically diverse fish community (16 species of 11 genera) dominated by cyprinids common for lacustrine or riverine assemblages. Amphibians are represented by 11 species, while the number of reptile and bird remains are less significant. Mammals are the most represented group at the locality, including small mammals (30 species), carnivorans (2 species), and ungulates (5 taxa), the latter dominated by C. elaphus. The taxonomic composition of terrestrial groups indicates temperate climate with boreal-type forests and meadows similar to cold steppe, as well as low wet areas and riparian habitats inhabited by amphibians, reptiles, insectivores, beavers, and various voles. The fish assemblage indicates a partially overgrown but well-aerated water body (lake or slow-flowing river) with sandy-silty bottom. Lithic artefacts found at the Medzhybizh 1 locality contribute to a better understanding of relationships between ancient hominins and faunas during the Middle Pleistocene of Eastern Europe.Archaeological field works at Medzhybizh were supported by the NASU state research projects 0105U001383 (2005–2009), 0109U008921 (2010–2014) and partly funded by the State Fund of Fundamental Research of Ukraine grant 0118U001457 (F77/50–2018). This research was also supported by the grant 0201/2048/18 ‘Life and death of extinct rhino (Stephanorhinus sp.) from Western Poland: a multi-proxy palaeoenvironmental approach’ financed from the funds of the National Science Centre, Poland. JvdM received support from the Spanish Ministerio de Ciencia, Inovación y Universidades (current grant numbers PGC2018-093925-B-C31 and PGC2018-095489-B-I00).Peer reviewe

Ochotonides (Mammalia, Lagomorpha) du Pliocène inférieur du sud de l'Ukraine

L\u27objectif de cet article est d\u27élargir la connaissance, jusqu\u27alors faible, des ochotonides du Pliocène inférieur (Ruscinien, MN 14) du sud de l\u27Ukraine. Le nouveau matériel abondant d\u27Ochotona antiqua Argyropulo &amp; Pidoplichko, 1939 de Novopetrovka (localité type) et de Frunzovka-1 est analysé en détail et comparé avec le matériel type. Les résultats proposent une nouvelle description du taxon ainsi qu\u27une évaluation de sa variation intra-spécifique, en prenant en compte les formes sortant de cette variabilité et/ou aberrantes qui lui sont proches. Pseudobellatona relicta Topachevsky, Nesin &amp; Topachevsky, 1993, dont la seule occurrence est la localité type de Krasnopol, est redécrite et considérée comme un taxon incertae sedis dans le clade des Ochotonidae. Les spécificités des taxons du Pliocène inférieur des séries sédimentaires du Kuchurganien sont discutées dans le contexte de la phylogénie et de la systématique des ochotonides d\u27Eurasie.The aim of this paper is to enlarge knowledge about poorly known ochotonids from the Early Pliocene (Ruscinian, MN 14) from southern Ukraine. The abundant new material of Ochotona antiqua Argyropulo &amp; Pidoplichko, 1939 from Novopetrovka (type locality) and Frunzovka-1 is analyzed in detail and compared with the type material. The results are expressed in a redescription of the taxon and evaluation of its intraspecific variation, including the outlying and/or aberrant forms closely related to it. Pseudobellatona relicta Topachevsky, Nesin &amp; Topachevsky, 1993 confined to the type locality Krasnopol is redescribed and considered herein as a taxon incertae sedis within the Ochotonidae clade. Specificities of the Early Pliocene taxa from the Kuchurganian sedimentary series are discussed in the context of phylogeny and systematics of Eurasian ochotonids.</p

Teeth Enamel Ultrastructural Analysis of Selected Equidae Taxa

This paper presents historical and evolutionary insights into the “tarpan” group of small horses by examining molar tooth enamel ultrastructure. Mathematical methodologies were applied to enhance the analysis. Tooth enamel from species such as Equus gmelini (tarpan), E. latipes, and E. hydruntinus from Pleistocene Ukrainian localities, E. przewalskii from the Chornobyl Exclusion Zone in Ukraine, and E. caballus form sylvaticus (Polish konik) from Roztocze National Park, Poland, underwent scanning microscope examination. Measurements of enamel structures, including prisms (PE) and interprismatic matrix (IPM), were conducted, with the K-index used as their ratio, categorized by enamel type (I, II, III). The findings confirmed that the crystal structures of enamel in these horse groups vary based on genus evolution, diet, and environmental conditions, shaping the enamel’s morphological features. Through analysis, clusters were identified, allowing for potential reconstructions of relationships among study groups. The results revealed distinct differences between species, enabling their classification within an established phenogram. Two primary clusters emerged: one consisting of extinct small horse forms from diverse localities and another grouping modern forms. Notably, the Late Pleistocene European species E. latipes showed close affinities to the latter cluster

Enamel ultrastructure of lower molars of the red squirrel Sciurus vulgaris (Rodentia, Mammalia) from different populations in Ukraine

The second lower molars of the red squirrel Sciurus vulgaris from different regions of Ukraine were examined in order to search for additional features to study the variability and clarify the subspecies status of its individual populations. Generally accepted methods were used to study the enamel ultrastructure. It is established that the tooth enamel of the red squirrel has a layered structure and is represented by different types (radial, HSB and PLEX), which are also characteristic for other rodent species. The arrangement of crystalline prisms of the radial layer in the IPM matrix is the main distinguishing feature of the morphological variability of enamel on main tooth conids. In various regional populations of the species, they act as an indicator of the adaptability of the teeth and their functionality as a single structure. This was reflected in differences in the thickness ratio of the radial layer and HSB, especially between the metaconid and the entoconid. The development of HSB is usually associated with greater functional load. Squirrel populations in the northern part of Ukraine have a relatively thick HSB layer, while those from central and southern parts of the country have a more strongly developed radial layer. According to these features, the Crimean populations are close to those from southern Ukraine and slightly differ from the Altai subspecies Sciurus vulgaris exalbidus, which was introduced into the Crimea in the first half of XX century. It is assumed that the enamel ultrastructure as a morphological character has changed in the process of adaptation of squirrels to a new environment. The distinguishing character of the enamel structure of Altai populations of the Teleut squirrel is that prisms do not fill cells of the radial layer on the hypoconid and protoconid. The tooth enamel ultrastructure of the Eurasian red squirrel cannot be an independent morphological character for their intraspecific differentiation. However, it can be successfully used in combination with other characters (e.g., fur coloration, craniometrical data), as well as the results of special molecular studies

Ancient DNA of narrow-headed vole reveal common features of the Late Pleistocene population dynamics in cold-adapted small mammals.

International audienceThe narrow-headed vole, collared lemming and common vole were the most abundant small mammal species across the Eurasian Late Pleistocene steppe-tundra environment. Previous ancient DNA studies of the collared lemming and common vole have revealed dynamic population histories shaped by climatic fluctuations. To investigate the extent to which species with similar adaptations share common evolutionary histories, we generated a dataset comprised the mitochondrial genomes of 139 ancient and 6 modern narrow-headed voles from several sites across Europe and northwestern Asia covering approximately the last 100 thousand years (kyr). We inferred Bayesian time-aware phylogenies using 11 radiocarbon-dated samples to calibrate the molecular clock. Divergence of the main mtDNA lineages across the three species occurred during marine isotope stages (MIS) 7 and MIS 5, suggesting a common response of species adapted to open habitat during interglacials. We identified several time-structured mtDNA lineages in European narrow-headed vole, suggesting lineage turnover. The timing of some of these turnovers was synchronous across the three species, allowing us to identify the main drivers of the Late Pleistocene dynamics of steppe- and cold-adapted species