Martin Košt'ák

Sepia from the Miocene of the Central Paratethys: new taxa and notes on late Cenozoic cuttlefish diversity

A new and locally abundant species of Sepia, S. juliebarborarum sp. nov., and single records of S. aff. loerentheyi and S. aff. sanctacrucensis from the upper Badenian of Slovakia and Austria, S. mikuzi sp. nov., S. aff. mikuzi sp. nov. and Sepia sp. from the middle Badenian of Slovenia, document a greater Miocene sepiid diversity in the Central Paratethys than previously recorded. In the present study, Miocene sepiids from the Central Paratethys are systematically revised and, in part, compared to other coeval taxa from elsewhere. Middle Miocene diversity in the Central Paratethys amounts to nine species, inclusive of four taxa retained in open nomenclature. Here we use the morphology of the dorsal shield and septal suture lines as key features for systematic assignment at the species level. Usage of the generic name Sepia for these Miocene sepiids is corroborated by uniquely preserved material of S. vindobonensis from the middle Badenian of Austria. This reveals only minor morphological differences during ontogeny from the Recent type species of Sepia, S. officinalis. The stratigraphical range of sepiids in the Central Paratethys is reinterpreted and shown to be early to late Badenian. Miocene Sepia diversity in the Central Paratethys is greater than previously supposed, which supports normal marine conditions and an open connection with the Mediterranean. http://zoobank.org/urn:lsid:zoobank.org:pub:3B32BA47-EB28-4A75-95FE-6349C08BB5EA.

Formal concept analysis with background knowledge: a case study in paleobiological taxonomy of belemnites

We present a case study in identification of taxa in paleobiological data. Our approach utilizes formal concept analysis and is based on conceiving a taxon as a group of individuals sharing a collection of attributes. In addition to the incidence relation between individuals and their attributes, the method uses expert background knowledge regarding importance of attributes which helps to filter out correctly formed but paleobiologically irrelevant taxa. We present results of experiments carried out with belemnites—a group of extinct cephalopods which seems particularly suitable for such a purpose. We demonstrate that the methods are capable of revealing taxa and relationships among them that are relevant from a paleobiological point of view.

Evidence for fish predation on a coleoid cephalopod from the Lower Jurassic Posidonia Shale of Germany

A specimen of the Early Jurassic actinopterygian fish Pachycormus sp. from the Lower Jurassic Posidonia Shale of Germany has a well preserved filling of the alimentary canal. The region interpreted as the stomach contains numerous hooklets that can be referred to the coleoid cephalopod Phragmoteuthis Mojsisovics, 1882. The presence of arm hooklets clearly demonstrates predation on coleoid cephalopods by actinopterygian fishes.