Basal Archosauriformes had a wide geographic distribution through the Lower to Middle Triassic. Osmolskina czatkowiensis gen. et sp. nov. from EarlyOlenekian karst deposits at Czatkowice, west of Cracow, provides the first record from Poland. The reconstructed skull and attributed postcranial elements show a morphology closely resembling that of the Early Anisian African genus Euparkeria Broom, 1913, while differing at generic level. Both genera display the same mosaic of plesiomorphic and apomorphic character states, but share no unique apomorphic character state. They might thus be combined in the family Euparkeriidae Huene, 1920, but could also constitute two plesions of the same grade lying just below the Archosauria + Proterochampsidae node. Currently, Euparkeriidae remains monotypic because no other genus can be assigned to it with confidence. Until this problem is resolved, the term “euparkeriid” essentially denotes a grade of Lower to Middle Triassic non−archosaurian archosauriforms that are more derived than proterosuchid grade taxa, but lack the specializations of either erythrosuchids or proterochampsids. They were probably Pangaean in their distribution.

Magdalena Borsuk−Białynicka[borsuk.b@twarda.pan.pl], Instytut Paleobiologii Polskiej Akademii Nauk, ul. Twarda 51/55, PL−00−818 Warszawa, Poland; Susan E. Evans [ucgasue@ucl.ac.uk], Department of Anatomy and Developmental Biology, University College, Gower Street, London, WC1E 6BT, England.