[Proceedings of the 5th Symposium on Mesozoic and Cenozoic Decapod Crustaceans, Krakow, Poland, 2013: A tribute to Pál Mihály Müller / R.H.B. Fraaije, M. Hyžný, J.W.M. Jagt, M. Krobicki & B.W.M. van Bakel (eds.)]: Neozanthopsis americana (Decapoda, Brachyura, Carpilioidea) from the Middle Eocene Cane River Formation of Louisiana, USA, and associated teleost otoliths

A large collection of Neozanthopsis americana (Rathbun, 1928) from the Middle Eocene (Lutetian) Cane River Formation in Louisiana, USA, represents the first opportunity to describe the species in detail. Detailed analysis of associated teleost otoliths and other vertebrate remains documents a palaeoenvironmental setting characterised by a soft-sediment, inner-shelf setting with normal salinity under tropical or subtropical conditions. Anatomical and morphometric analysis of 21 of the better-preserved crabs demonstrates that gender discrimination cannot be made from dorsal carapace characteristics and that the sample represents post-juvenile individuals. Exocuticle and endocuticle are preserved on some specimens and document the presence of erect endocuticular pillars with exocuticle draped over them. Occurrence of some fractured and expanded specimens results from the presence of expandable clays within the matrix.