LATE JURASSIC CASSIDULOIDS (ECHINODERMATA, ECHINOIDEA) FROM WEST-CENTRAL ARGENTINA: TAXONOMIC AND PALEOGEOGRAPHIC IMPLICATIONS

Abstract

Cassiduloids are relatively well-represented in the fossil record, especially in Europe and Northern Africa, ever since their first occurrence in the Lower Jurassic. The group shows an increase in diversity and abundance at the end of the Jurassic. In Argentina, cassiduloids are represented from the Middle Jurassic upwards. This paper describes a Tithonian cassiduloid from the Picún Leufú Formation (Neuquén Basin, Argentina) identified as Mepygurus? andinus new comb. according to the poorly developed bourrelets, straight phyllodes that are continuous up to the margin, and a subpentagonal outline. The species was originally described from the Baños del Flaco Formation on the Chilean slope of the Neuquén-Aconcagua Basin. This record extends the stratigraphical range of the genus to at least the Tithonian and provides further evidence to the interpretation of the spatial continuity of shallow-water platforms during the Late Jurassic in the Andean region.