Bulletin of the Mizunami Fossil Museum

Bulletin of the Mizunami Fossil Museum No. 49

Early Cretaceous echinoids from the Greater Antilles have not been adequately investigated or described. In great part, this is because they are rare, except locally, and are commonly poorly preserved. Two sites are now identified that have yielded these rare fossils. The Lower Cretaceous Hatillo Formation in the Dominican Republic (central Hispaniola) is on the property of the Pueblo Viejo gold mine. Although these rocks are well-lithified, fossils can be seen on the weathered surfaces of the exposed limestone. These fossils include robust echinoid radioles (= spines) that are globular to elongate and are elliptical in section. More commonly, tests are recognised only in section and of uncertain orientation; at least some of these are regular echinoids, bearing auricles, but it is likely that more than one species is represented. Similar radioles have also been found in Jamaica, in the Benbow Inlier, from limestones of the Devils Racecourse Group; there are no associated tests. The preservation of these spines is undoubtedly a function of their mineralogy and the fact that there are few delicate structures to be destroyed. The radioles are referred to the hemicidarid taxon Pseudocidaris sp. cf. P. clunifera (L. Agassiz); Pseudocidaris clunifera has been recorded previously from Lower Cretaceous (Valanginian–Albian) formations of central Mexico.