Abstract. Mole voles (genus
Ellobius s.l.) are
burrowing rodents common in open and mountainous landscapes in
Eastern Europe and Asia. In the Early Pleistocene the group dispersed
from western areas of Eurasia to North Africa marking the expansion
of steppe-like conditions in this region. Two recent genera (earlier
frequently regarded as subgenera) Ellobius Fischer von Waldheim and
Bramus Pomel (=Afganomys Topachevsky, younger synonym) are
recognized. The earliest fossil record of both groups dates back to
the Late Pliocene of Central Asia and North Caucasus. In the Early
Pleistocene, mole voles broadly dispersed throughout western Asia and
eastern Europe as common elements of the mammalian fauna adapted to
open landscapes of the vast steppe belt in the middle latitudes of
Eurasia.
While mole voles of the genus Ellobius
s.str. apparently never migrated outside the Eurasian continent, the
other group, Bramus, could spread through Central Asia, western
Siberia, southern Urals, Azov and Black Sea areas, Near East, and
North Africa. The African fossil record, first described by Pomel
[1895] under the new genus name Bramus, was subsequently studied in
detail by Jaeger [1988] who attributed it to the genus Ellobius and
described several species successive in time. Among these forms, E.
africanus – E. atlanticus – E. barbarus represent a well defined
endemic phyletic lineage that demonstrates clear morphological trend
to higher hypsodonty, dental complexity, and size increase.
Additional ample materials on these forms from several localities in
Morocco and the detailed analysis of co-occurring large and small
mammalian fauna provided a biostratigraphic context for this lineage
apparently spanning the late Early through the late Middle
Pleistocene [Geraads, 1994, 2002]. The morphological evolution of the
African lineage of mole voles in many features mimics the Eurasian
lineages leading to recent Bramus lutescens and B. fuscocapillus. The
Early Pleistocene fossil record of Eastern Europe (Crimea Peninsula
and lower Don River area) illustrates an ancient form of the genus
(Bramus tarchancutensis) [Topachevsky, 1963; Tesakov, 2008].
The earliest European and African forms
(B. tarchancutensis and B. africanus) share an almost identical
plesiomorphic morphology and stage of evolution indicating a possible
conspecificity of these forms. Therefore, the dispersal event of mole
voles to Africa can be biochronologically dated to at least mid Early
Pleistocene. The Early Pleistocene biological success of larger mole
voles in Eastern Europe was apparently associated with the
combination of warm climate and expansion of open steppe-like
landscapes. Similar conditions facilitated the expansion of the group
to the Middle East and North Africa. The subsequent endemic evolution
of mole voles in North Africa in the Early through Middle Pleistocene
[Jaeger, 1988; Geraads, 2002] provides an excellent example of
parallelism in mammals. The considerable climatic cooling in the
region at the Early-Middle Pleistocene transition could have caused
the disappearance of Bramus in Eastern Europe by the late Early
Pleistocene. Likewise, the extinction of the North African Bramus
lineage in the late Middle Pleistocene is believed to be associated
with climate-based environmental fluctuations [Jaeger, 1988] and/or
with a drastic aridification and a possible competition with gerbils.
Abstract. Phylogenetic analysis of the supraspecies relationships was carried out using partial sequences of two nuclear genes in the subfamily Arvicolinae, which is one of the youngest and species-rich groups of myomorph rodents. The analysis with the new data resolved the majority of polytomy nodes in the phylogenetic trees reported for Arvicolinae, suggesting a gradual, rather than a saltatory, mode for their evolution. Mole voles Ellobiusini, steppe voles Lagurini, and gray voles Arvicolini were fount to be a monophyletic group that corresponds to the latest third wave of radiation within the subfamily. Red-back voles Myodini (=Clethrionomini) are a sister clade to this group and correspond to the second radiation wave. The order of divergence remained unresolved for the earliest radiation wave (Ondatrini, Prometheomyini, Dicrostonychini, and Lemmini). The close relationships observed for mole, gray, and steppe voles are unexpected and contradict the conventional views that Ellobiusini are an ancient group and are separate from all other voles on evidence of the extreme simplicity of their rooted molars and the peculiar structure of their skull and postcranial skeleton. It wasassumed that many of these morphological characters indicate adaptation to subterranean life and provide no phylogenetic signal.
Abstract. The Ostantsevaya Cave (Sakhalin island, russian Far east) yielded rich and diverse vertebrate fauna of late glacial through Holocene time. the bone assemblage is dominated by remains of brown bear and hare, reindeer and snow sheep. the fauna for the frst time documented the presence on Sakhalin of several mammal forms including cave lion, steppe ferret, collared lemming, and ground squirrel. the origin of the bone accumulation in the site is mainly due to natural factors, such as predators and fuvial activity, but the early man was also undoubtedly involved in this process. Brown bear was the most important bone-accumulating agent throughout the investigated history of the cave.
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