Selected regular echinoids (Echinoidea) from the upper Campanian–Maastrichtian along the western borders of the Northern Oman Mountains, with description of a new species

Thirteen species of regular echinoid, in ten genera, are recorded from the upper Campanian–Maastrichtian Qahlah and Simsima formations of two sections located along the western borders of the Northern Oman Mountains. Twelve of these are from the Simsima Formation in the Jebel El Rawdah section, four from the Qahlah and Simsima formations in the Jebel Huwayyah section. One new species, Hattopsis muradi, is described from the Jebel El Rawdah section. The status of the genus Pseudorthopsis is confirmed; differences between it and Orthopsis are discussed and Orthopsis sanfilippoi is transferred to Pseudorthopsis, here being recorded for the first time from the Arabian Gulf region. Revision of three species referred to Hattopsis and nine species ascribed to Protechinus (=Noetlingia, Noetlingaster) has elucidated the relationship between these two genera and affirmed the distinctiveness of Hattopsis. Hattopsis sphericus and Echinotiara perebaskinei are recorded for the first time from Jebel Huwayyah. All species identified are compared with other related taxa, and their stratigraphical ranges, affinities, palaeobiogeography and palaeoecology discussed.