Formal description of Valentinaspis profundus gen. et sp. nov., a placoderm fish and zone fossil from the Emsian of Belarus and Estonia

A new late Emsian (Devonian) phlyctaenioideid arthrodire species, Valentinaspis profundus gen. et sp. nov., is described from Belarus and Estonia. This taxon, under the name Kartalaspis belarusica in various spellings, has been reported in literature since the 1980s, but until now had not been formally described or figured (and was known as a nomen nudum). This is unfortunate as various authors have used the species as a zone fossil for the Rēzekne Regional Stage of the Baltic area. This species was also used as a zonal index for the Vitebsk deposits in the territory of Belarus. The late palaeontologist Elga Mark-Kurik was in the process of preparing a manuscript to formally describe the species but died before much progress had been made. The specimens were recovered from two boreholes and consist mostly of disarticulated dermal plates. However, some plates are articulated to one another, and two cranial shields have also been recovered. This has allowed the species to be formally described and compared with similar forms from similar-aged deposits in Spitsbergen (Svalbard).