Journal of Vertebrate Paleontology 21, 625-627 (2001).
A new Paleorhinus fauna in the early Late Triassic of Poland

Jerzy Dzik
Instytut Paleobiologii PAN, Twarda 51/55, 00-818 Warszawa, Poland. e-mail:

Abstract. A new locality in the middle Keuper marly clays with excellently preserved tetrapod skeletons was discovered at Krasiejów near Opole, southern Poland. It has yielded abundant cranial and postcranial material of metoposaur and capitosauroid labyrinthodonts, phytosaurs, aetosaurs, and undetermined archosaurs. Based on the position of the Krasiejów fossiliferous horizon in the lithostratigraphic column, it seems to be coeval to the Lehrberg beds in Germany, which probably terminate the Carnian sedimentary cycle. The initial part of the cycle in Germany is the Schilfsandstein, a local rock equivalent of which is represented about 80 m below in boreholes drilled in the area. The labyrinthodont Metoposaurus found at Krasiejów is conspecific with, or at least closely related to, M. diagnosticus, occurring in these strata in Germany. The phytosaurs from Krasiejów confirm such age determination. They belong to a species of Paleorhinus, geologically the oldest and anatomically the least derived of phytosaurs. The co-occurrence of Paleorhinus with Metoposaurus indicates that the Krasiejów fauna chronologically belongs to the Late Carnian part of the Paleorhinus biochron. Paleorhinus is represented in the material from Krasiejów by several skulls, more or less fragmentary articulated postcranial skeletons and numerous isolated bones. Individuals of various ontogenetic stages are represented, forming an ontogenetic series. The Krasiejów fossil assemblage is dominated by skeletons of semiaquatic amphibians and reptiles, but less numerous bones of strictly terrestrial reptiles are also represented. Among them there is an aetosaur species. Its isolated scutes are closely similar to those of Stagonolepis. A few archosaurian bones of undetermined affinities (same of relatively large size) have been found at Krasiejów. Among them of special interest seems to be a small second sacral vertebra with a flat anterior surface of the centrum. Unlike sacrals of the associated phytosaurs and aetosaurs, as well as Ornithosuchus, it bears very short and deep ribs. This indicates a rather narrow pelvic girdle, unusually narrow as for early archosaurs. Such sacra are known among the herrerasaurid dinosaurs. The second sacral vertebra of Staurikosaurus and Chindesaurus resemble the Krasiejów specimen especially close in their short ribs with vertically extended bases. Whether this is truly a member of the herrerasaurid lineage remains unknown until more complete material is found. The occurrence of a diverse tetrapod assemblage with Paleorhinus and Metoposaurus in Silesia extends much eastward its known distribution within the Germanic Basin and improves the Late Triassic age correlation in this part of Europe. Early dinosaurs may be represented in the assemblage which makes it of special importance.