A new genus and species of regular echinoid from the Late Cretaceous of Gebel El Rowdah, Hatta area, Oman-U.A.E.

Abstract

This paper is the fourth in a continuing series describing Late Cretaceous echinoids from the United Arab Emirates (Ali, 1989, 1990, in press). A single semi-spherical Arbaciidae was discovered while I was preparing my earlier paper on additional echinoids of Gebel El Rowdah. This specimen resembled Codiopsis L. Agassiz (1840), but differs in having the ambulacral and interambulacral tubercles developed throughout the adapical and adoral sides. The ambulacral structure in the new genus is also unique among arbaciids. Therefore, the specimen is here placed in a new genus, having been omitted from previous papers because of the paucity of the material. Recently, during a field trip with students of the Geology Department, U.A.E. University, to the same location visited in December 1990, an additional 18 specimens were collected. These provide the basis for the present description of a new genus.