Sciuridae FISCHER, 1817

Tesakov, Alexey S., Titov, Vadim V., Simakova, Alexandra N., Frolov, Pavel D., Syromyatnikova, Elena V., Kurshakov, Sergey V., Volkova, Natalia V., Trikhunkov, Yaroslav I., Sotnikova, Marina V., Kruskop, Sergey V., Zelenkov, Nikita V., Tesakova, Ekaterina M. & Palatov, Dmitry M., 2017, Late Miocene (Early Turolian) Vertebrate Faunas And Associated Biotic Record Of The Northern Caucasus: Geology, Taxonomy, Palaeoenvironment, Biochronology, Fossil Imprint 73 (3 - 4), pp. 383-444 : 412-413

Family Sciuridae FISCHER, 1817

Pl. 11, Figs 19–21

C o m m e n t s. There were very few squirrels in the studied material. All available specimens represent pteromyines. They originated from the Volchaya Balka site. Neopetes cf. hoeckarum shows typical morphology with generally smooth occlusal surface of molars, smooth, oblique and subparallel proto- and metalophs in the upper molars, well developed entoconid and mesostylid in lower molars (Pl. 11, Figs 19–20). This is the first record of this medium size flying squirrel in the Caucasus. In central Europe, this form occurs from Early to Late Miocene and shows a notable morphological stability ( Daxner-Höck 2004b, Daxner-Höck and Höck 2015). M1–2: 1.93 × 2.04; m1: 2.27 × 2.12.

A fragment of heavily worn upper molar (P4 or M1–2) of a large (W> 3.6 mm) sciurid with preserved rugged protocone and part of the central basin and metaloph (Pl. 11, Fig. 21) is tentatively assigned to? Miopetaurista sp. This large flying squirrel was reported from a number of Vallesian and early Turolian sites in Central Europe ( Daxner-Höck 2004b), and in southern Ukraine ( Nesin 2013). In the North Caucasus Miopetaurista was previously listed from a poorly known Early Pleistocene (?Gelasian) site Zhukovskoe ( Derevyanko et al. 2010).

Family Eomyidae DEPÉRET et DOUXAMI, 1902 Pl. 8, Figs 5–9

C o m m e n t s. The first record of eomyids in the Late Miocene of the Caucasus is only the third find of this family in Russia. Previously known records originated from the Early and Late Pliocene levels in the Obukhovka locality in the Sea of Azov area ( Estramomys sp. ; Topachevsky et al. 1988) and the late Early Miocene Tagay fauna from the Baikal area ( Keramidomys sp. and Leptodontomys sp. ; Daxner-Höck et al. 2013). The few records of eomyids from the Late Miocene of the northern Black Sea area date back to Vallesian of Ukraine and Moldova and are reported to include Keramidomys and Leptodontomys sp. from the fauna of Gritsev ( Nesin 2013) and Keramidomys sp. and Eomyops aff. catalunicum (HARTENBERGER, 1967) from Buzhor ( Lungu and Rzebik-Kowalska 2011), plus undetermined eomyids from the late Turolian fauna of Andreevka in Ukraine ( Topachevsky 1971). The Keramidomys sp. from the Caucasus fits the characteristic morphology of the genus (Pl. 8, Figs 5–9) but looks quite simplified (reduction of mesolophids and mesolophs) even in comparison with the late Turolian form from Maramena (de Bruijn 1995). No affinities with Estramomys , e.g., no trends to the formation of the sygmoid ridge pattern in upper molars, are obvious. More material is needed for a clear definition of the systematic position of this form.

Superfamily Dipodoidea FISCHER, 1817 Pl. 11, Figs 1–4

C o m m e n t s. Two forms are represented in the fauna of Gaverdovsky: the zapodid Eozapus intermedius (n = 7) and the sminthid Sicista sp. (n = 1). Eozapus is a common member of European faunas of late Vallesian and Turolian. The Caucasian sample of E. intermedius closely corresponds to the morphology and size of the species (Pl. 11, Fig. 2–4).

This first record of Sicista in Miocene of Europe is remarkable. The earliest true Sicista , S. primus is recorded in Eurasia as early as the Early Miocene of North China ( Kimura 2011). Scanty late Early and Middle Miocene record of Sicista in Asia has recently become known ( Qiu and Li 2016). It thus bridges the gap between the Early Miocene finds and the rich records from Late Miocene (Turolian) of Kazakhstan ( Savinov 1970) and Early Pliocene of North China ( Qiu and Storch 2000). The Caucasian record shows that birch mice were already present in wooded biotopes of the eastern margin of Europe by the early Turolian. The morphology of the single m1 fits a simple dental pattern, but shows an unusually long lingual branch of posterolophid (Pl. 11, Fig. 1).

Large mammals

The previous records of large land mammals remains from the Late Miocene deposits near Maikop are very scarce. The coarse sandy gravels of the upper part of the

Gaverdovsky Fm near the Khanskaya village, downstream from the city of Maikop, yielded remains of Mammut cf. borsoni, Anancus arvernensis cf. turolensis, Deinotherium proavum , cf. Procapreolus ( Titov and Tesakov 2013) . These finds are mostly stored in the National Museum of the Republic of Adygea (Maikop, Russia). The mandible of zygodont mastodon Mammut cf. borsoni (HAYS, 1834) is partially coated with cemented clayey sand ( Alexeeva 1955). The size and morphology of m3 are similar to those of the zygodont mastodons from middle/late Turolian sites of the Sea of Azov and the northern Black Sea region: Obukhovka- Yanovka and Morskaya 2 ( Titov et al. 2006, 2013).

Both size and primitive morphology of the isolated m3 of Anancus arvernensis cf. turolensis GAZIRY, 1997 are similar to Late Miocene Anancus from Dorn-Dürkheim 1 ( Germany, MN 11) and Develi ( Turkey, MN 13) ( Gaziry 1997, Mayda et al. 2014).

The lower molars of deinothere are similar to the teeth of the largest form of the genus, Deinotherium proavum (EICHWALD, 1831) from early – middle Turolian localities Dorn-Dürkheim 1 ( Germany, MN 11) and Obukhovka ( Russia, Lower Don area, MN 12) ( Bajgusheva and Titov 2006, Pickford and Pourabrishami 2013).

Recently an isolated molar of Deinotherim cf. proavum was also found in the shallow marine Khersonian deposits underlying the sandy-ocherous continental sediments ( Tarasenko et al. 2015).

Large mammal remains in the studied localities Gaverdovsky and Volchaya Balka are very rare ( Tab. 8). They are represented by detached teeth and rare postcranial bones of ungulates and carnivorans.