James C. Lamsdell and Paul A. Selden
Department of Geology and Paleontological Institute, University of Kansas, Lawrence, Kansas, USA

At present three spider species have been described from the Crato Formation of Brazil, a single araneomorph (Cretaraneus matinsnetoi) and two mygalomorphs (Cretadiplura ceara and Dinoplura ambulacra), known from a total of five published specimens. Preliminary study of almost a hundred un-described Crato spider specimens reveals two more mygalomorphs, and at least three araneomorph species. The mygalomorphs are probably assignable to Cretadiplura ceara and display details of the coxosternal region that are not observable in the type specimens. The most common araneomorph is probably congeneric (if not conspecific) with Cretaraneus martinsnetoi, however neither this nor the original material displays the characteristics of Cretaraneus and its assignment needs revision. Two large specimens resemble nephilids, while a single small specimen may represent a palpimanid. Further work is required to accurately identify these specimens. Many of the Crato spiders are preserved in an uncompressed, three-dimensional state, and it is hoped that CT-scanning may reveal further details of their morphology preserved within the matrix that will assist in their identification.