Turonian-Santonian echinoids from Egypt

Thirty echinoid species (18 regular and 12 irregular) and an undetermined species belonging to 14 genera are studied from the Turonian-Santonian sequence (14 species from Turonian, two species from Turonian-Santonian and 14 species from Coniacian-Santonian) of Abu Roash, Wadi Dakhl and Wadi Abu Qaada, Egypt. Two new species are established: Thylechinus (Thylechinus) sinaiensis n. sp. from the Turonian of Wadi Abu Qaada and Toxaster dakhlensis n. sp. from the Turonian of Wadi Dakhl. Orthopsis ovata (Coquand, 1862), which is known in other parts of the Tethyan region, is reported for the first time from Egypt. The rank of one subspecies is raised to species level: Coenholectypus roachensis (Fourtau, 1914) n. stat. The generic name of three species is changed: Echinobrissus humei Fourtau, 1906 is changed to Petalobrissus humei (Fourtau, 1906) n. comb.; Periaster duncani (Fourtau, 1906) and Periaster roachensis Gauthier, 1900 are transfered to the genus Mecaster Pomel, 1883. The ontogenetic changes of Mecaster turonensis (Fourtau, 1921) are described. The biostratigraphy and paleobiogeography of the fauna are discussed.