On the Sinai Peninsula, a thick pile of terrestrial to shallow-marine sediments accumulated during the Jurassic period. The sea floor at that time was colonized chiefly by brachiopods and bivalves. Among the latter, trigoniids were a comparatively rare but diverse faunal element, represented by very small to small individuals. They belong to 14 species and nine genera. One of these species is new to science, but five genera with species occurring also elsewhere in Jurassic seas were recognized as new, all of them characterized by a very small to small size.

The Jurassic trigoniid bivalves of Gebel Maghara, northern Sinai, Egypt are described and figured. They belong to 14 species, nine genera, and two families. The identified taxa occur in rocks ranging in age from the Toarcian (Lower Jurassic) to the lower Kimmeridgian (Upper Jurassic). Five genera and one species are new: Magharitrigonia asymmetrica new genus new species; Cotswoldella aff. C. hemisphaerica (Lycett, 1853); Cornbrashella pullus (J. de C. Sowerby, 1826); Parorthotrigonia lepidomorpha (Abdallah and Fahmy, 1969); and Retetrigonia imbricata (J. de C. Sowerby, 1826). Five species, Trigonia reticulata Agassiz, 1840, T. cf. T. castor d'Orbigny, 1849, Promyophorella tuberculata (Agassiz, 1840), Orthotrigonia exortiva (Kitchin, 1903), and O. gracilis (Kitchin, 1903) are recorded from the Jurassic rocks of Gebel Maghara for the first time.