Acta Palaeontologica Polonica

On a new galeropygid genus (Echinoidea) from the Jurassic (Upper Lias) of Morocco

Wanda Jesionek-Szymańska

Acta Palaeontologica Polonica 23 (2), 1978: 187-193

Considered as holectypoid (Gnathostomata) Pygaster microstoma Lambert, 1933 from the Toarcian of Morocco is actually the most primitive galeropygid (Atelostomata) for which the new genus Eogaleropygus is proposed. Incipient "irregular" position of the periproct and very shallow anal groove are in sharp contrast with much more advanced evolutionary changes such as small size and unnotched peristome (external manifestations of the loss of dental apparatus and gills) as well as dense and unordered tuberculation. The morphology of Eogaleropygus suggests that galeropygids became atelostomate probably long before they became bilateral.

This is an open-access article distributed under the terms of the Creative Commons Attribution License (for details please see, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.