This is a Paleobiology Database Online Systematics Archive including classification, taxonomy, and description of all species-level taxa of Post-Paleozoic asterozoans (Asteroidea and Ophiuroidea). The classification framework is based on the most recent developments in the systematics of the group and some unpublished data. The OSA is linked to a comprehensive list of collections that describe the Post-Paleozoic fossil record of asterozans.

Sea stars and brittle stars are fragile organisms that are rarely preserved in the fossil record, except as isolated ossicles or in levels of exceptional preservation. The systematic archive helps to standardize taxonomic data within highly heterogeneous literature sources. Occurence data of fossil Asteroidea and Ophiuroida are compiled to describe the pattern of Mesozoic diversification of echinoderms and to address the question of preservational, environmental and human induced biases in the fossil record.

Entry of the data began in 2005, in support of ongoing research projects. In its current state, the OSA offers a classification of all genera mentioned in the paleontological literature. Further developments will include a taxonomy of species and addition of collection records.

• L. Villier, M. Kutscher, and C. Mah. Systematics, palaeoecology, and evolutionary significance of Middle Toarcian Asteroidea (Echinodermata) from the 'Seuil du Poitou', Western France. Geobios 37(6):807-825.
• L. Villier and N. Navarro. Biodiversity dynamics and their driving factors during the Cretaceous diversification of Spatangoida (Echinoidea, Echinodermata). Palaeogeography, Palaeoclimatology, Palaeoecology 214(3):265-282.
• L. Villier, D. B. Blake, J. W. Jagt, and M. Kutscher. A preliminary phylogeny of the Pterasteridae (Echinodermata, Asteroidea) and the first fossil record: Late Cretaceous of Germany and Belgium. Paläontologische Zeitschrift 78(2):281-300.
• M. Kutscher and L. Villier. Ophiuroids remains from the Toarcian of Sainte-Verge (Deux-Sèvres, France): palebiological perspective. Geobios 36(2):179-194.
• L. Villier and M. Kutscher. 1999. How dissociated ossicles can further our understanding of the origins of the Neoasteroidea. An example from the Toarcian of Western Europe. In D. Candia Carnevali & F. Bonasoro eds. Echinoderm Research 1998, Balkema, Rotterdam: 417-422.

Loïc Villier
Centre de Sédimentologie-Paléontologie
FRE CNRS 2761
Université de Provence
Bâtiment de Sciences Naturelle
Case 67
Place Victor Hugo
13 331 Marseille cedex 3
tel. +33 (0)4.91.10.65.82
fax. +33 (0)4.91.10.85.23
e-mail. lvillier@up.univ-mrs.fr