Acta Palaeontologica Polonica

Placoderms from the Lower Devonian “placoderm sandstone” of the Holy Cross Mountains, Poland with biostratigraphical and palaeobiogeographical implications

Piotr Szrek and Vincent Dupret

Acta Palaeontologica Polonica 62 (4), 2017: 789-800 doi:

The siliciclastic sequence of the Lower Devonian of the southern part of the Holy Cross Mountains in Poland is renown for abundant vertebrate fossils, including ostracoderm, sarcopterygian, acanthodian, chondrichthyan, and placoderm remains. Study of the vertebrate assemblage from the “placoderm sandstone” from Podłazie Hill in the Holy Cross Mountains reveals that the remains belong to Kujdanowiaspis sp. among other unspecified actinolepids and brachythoracids. The Polish actinolepid material is characterised by sizes bigger than those of the Podolian specimens; this may be related to geographic variation. Owing to the proximity between Podolia and Holy Cross Mountains we suggest that Kujdanowiaspis sp. from the Holy Cross Mountains may be a refugee of some species of Kujdanowiaspis from the Lochkovian–Pragian of Podolia and/or from Spain. Some anterolateral plates provisionally assigned to Arthrodira indet. probably represent a new genus due to the high overlapping surface for median dorsal and anteroventrolateral plates.

Key words: Placodermi, Arthrodira, Actinolepidoidei, palaeobiogeography, Devonian, Poland, Holy Cross Mountains.

Piotr Szrek [], Polish Geological Institute-National Research Institute, ul. Rakowiecka 4, 00-975 Warszawa, Poland. Vincent Dupret [], Department of Applied Mathematics, Research School of Physics and Engineering, The Australian National University, Acton 2601 (Canberra) ACT, Australia.

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