Abstract

Pannonicola and Ischymomys are two extinct genera of the family Cricetidae, and both of them were placed at the base of the evolutionary trunk of the subfamily Arvicolinae. Over the last 100 years, the latter has provided the most important fossils for the biostratigraphy of terrestrial Neogene and Quaternary deposits of the Holarctic. The type material of Pannonicola comprises only one m2 and one m3. The first finds of Ischymomys were initially rare, not figured, and their nomenclatural status was faced with various problems. Some authors finally assumed that Ischymomys was a junior synonym of Pannonicola. In this paper, we use new finds from the territory of Ukraine and previously published data to show that Ischymomys is an independent genus, and that the finds described as Pannonicola should probably be placed in the genus Microtodon.

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Abstract

A new specimen of the fossil puffer fish Archaeotetraodon winterbottomi (Tetraodontidae) is described from the lower Oligocene deposits of the Sheshory locality, Ukraine. The specimen reveals a number of characters, some of which are diagnostic and others which were recognized herein for first time, such as the possession of a relatively narrow neurocranium in the supraorbital region, smooth frontals, eight abdominal and nine caudal vertebrae, and long and slender postcleithrum.

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