Musculus somaliensis lived during the late Jurassic, possibly throughout the Ethiopian Faunal Province, which consisted of Ethiopia, Somalia, Jordan, Yemen, Kenya, Madagascar, Saudi Arabia, and Tunisia according to Kiessling.

[1] Fossils of M. somaliensis are known from the Upper Jurassic of Somalia (Callovian/Oxfordian in Jirba Range, Biyo Dader Tug,[2] Bihendula[3]), Ethiopia (Callovian in Mt.

Guresu, Marda Pass;[4] Late Oxfordian in Antalo Limestone north of Mekele[1]) and Tunisia (Late Callovian/Oxfordian in Ghomrassen; Middle Callovian/Late Callovian in Ksar Ben Soltane, Krechem el Miit; Callovian/Early Oxfordian in Foum Tataouine Post Optique; Callovian/Oxfordian in Bir Remtha, Faljet Jdar/Ed-Dghaghra[5]).

[6] The fossil locations cited were tropical shallow seas,[1] where this mussel lived as a stationary epifaunal suspension feeder.

A rounded carina runs from the umbo to the postero-ventral corner of the shell, forming an angle of c. 45° with the dorsal margin, ventrally followed by a shallow sulcus.