DISTRIBUTIONAL PATTERNS AMONG BRACHIOPODS IN THE JURASSIC ETHIOPIAN PROVINCE

The Ethiopian Province ranges geographically from eastern to western north Africa including the Maghreb (most of northwest Africa west of Egypt), Egypt. Ethiopia, Somalia and Kenya, as well as the Cutch (India) and has been recognized from the beginning of the Jurassic until probably the end of the Cretaceous. The brachiopods found within this faunal region have been isolated to such an extent that they have developed morphologies that separate them from their original stock and thus exhibit strong endemism. The same phenomenon can also be observed in Callovian nerineids. Brachiopod genera such as Sphriganaria, Ectyphoria, and Cooperithyris are found in Gebel Engabashi, northern Sinai, but are missing in Hamakhtesh Hagadol (Kurnub Anticline), Negev, southern Israel. Amydroptychus, Schizoria, Cymatorhynchia and Eurysites have been described from the Jordan Valley but are not present in southern Israel. The ubiquitous genus Daghanirhynchia, found throughout the Ethiopian Province, is strangely missing in the Negev strata. It appears that many genera and species from Saudi Arabia and the Cutch, are closely related (e.g. Pycnoria, Schizoria). The reasons for this distributional pattern may be due to varying environments such as shallow to neritic facies, selection pressures of unknown origin, tectono-eustatic cyclical events including a transgressive phase during the Callovian.