Keasius WELTON , 2013

Přikryl, Tomáš, 2013, An Annotated List Of The Oligocene Fish Fauna From The Osíčko Locality (Menilitic Fm.; Moravia, The Czech Republic), Acta Musei Nationalis Pragae Series B 69 (3 - 4), pp. 195-203 : 195-196

Genus Keasius WELTON, 2013

Keasius sp.

M a t e r i a l: NM Pc 02878a, b, Pc 02879; collected from the Dynów Mb.

R e m a r k s: The specimens are represented by well preserved distal parts of isolated branchiospines, their halfelliptical bases are preserved only as an imprint on the surface of the sediment. Due to incomplete preservation, the specimens are classified using open nomenclature.

The Oligocene – middle Miocene branchiospines were traditionally classified in the genus Cetorhinus BLAINVILLE, 1816 , in particular as C. parvus LERICHE, 1910 . Welton (2013), however, transferred this species into the new genus Keasius . The specimens were found in many Moravian localities, namely Kelč, Špičky, Litenčice, Nikolčice, Mouchnice, Rožnov pod Radhoštěm, and Nítkovice ( Kalabis and Schultz 1974, Kalabis 1975a, b, Schultz 1982, Gregorová 1988, 2011, 2012, Gregorová and Požár 2003).

Branchiospines are usually found mainly as isolated elements, but articulated specimens are also known (see Hovestadt and Hovestadt-Euler 2012). The recent C. maximus ( GUNNERUS, 1765) is a coastal pelagic and semioceanic filter-feeder of the boreal to warm-temperate waters ( Compagno 2002); the distribution in the water column is usually in the range of 200 to 2000 m, but they have also been sighted in the surface waters and in the oceanic basins at 2000 to 4000 m ( Compagno 2002).

Elasmobranchii gen. et sp. indet.

Text-fig. 2A

M a t e r i a l: NM Pc 02876a, b, Pc 02883a, b, Pc 02884, Pc 02885; collected from the Dynów Mb.

R e m a r k s: The specimens are represented by isolated amphicelous vertebrae. They appear as rounded objects with a small notochordal foramen in the middle region. The maximum size does not exceed 9 mm in diameter. They are distributed in several strata of the Dynów Mb., usually accompanied by ichnofossils and remains of “ Glossanodon ” skeletons. Due to the lack of any other preserved morphological features, more exact determination is not possible. Isolated elasmobranchian vertebra centrae were described only from the Litenčice locality in the Moravian region as Keasius parvus and? Carcharias sp. ( Gregorová 2011).

Figures

Text-fig. 2. A – Elasmobranchii gen. et spec. indet. specimen NM Pc 02876b; B – Scopeloides glarisianus dentary NM Pc 02888 (the white arrows mark the tips of the “fang-like” teeth); C – S. glarisianus disarticulated skeleton NM Pc 02887a; D – Sardinella sardinites scale NM Pc 02886; E – Clupeidae gen. et spec. indet. articulated skeleton without head NM Pc 02889; F – Anenchelum glarisianum body fragment NM Pc 02880a; G – Percoidei gen. et sp. indet. preoperculum (G-1) and its interpretation (G-2) NM Pc 02891. The arrow shows the enlarged spine in the angle between rami verticalis and horizontalis. Abbreviations: cl – cleithrum; op – operculum; pcl – postcleithrum.