Original paper

The sixth abdominal tergites of paguroid anomurans - a newly recognized crustacean macrofossil type

Fraaije, René H.B.; Krzemiski, Wiesław; Van Bakel, Barry W.M.; Krzemiska, Ewa; Jagt, John W.M.

Abstract

Isolated decapod crustacean remains from the Oxfordian (lower Upper Jurassic) of the Polish Uplands around Kraków and from the Kimmeridgian (middle Upper Jurassic) of the Swabian Alb (southern Germany) have been recognized as the operculate sixth abdominal tergites of pylochelid paguroids. This type of crustacean macrofossil has not been described as such from the fossil record previously, but now that its systematic position has been determined, more finds from Mesozoic and Cenozoic strata may be expected. These small-sized and carapace-like structures have a high fossilization potential and may even be of biostratigraphic importance. Here we use a parataxonomy for this kind of material, similar to what has been done in previous studies of isolated or fragmentary remains such as ammonite aptychi, belemnoid arm hooks, holothurian ossicles and phytolitharia. Only by naming these remains can our study of paguroids and our understanding of hermit crab evolution be augmented. One new genus, Pylochelitergites, and four new species, Stagmacaris adielklompmakeri, S. biarcus, P. westerbergensis, and P. gelasinus, are erected.

Keywords

paguroideapylochelidaesixth abdominal tergitesparataxonomynew taxalate jurassicpolandgermany