Article

New Late Cretaceous mytilid and tellinoidean bivalves from California

One new subfamily, one new genus, and two new species of Late Cretaceous warm-water, shallow-marine bivalves from California are described and named. The mytilid Xenomytilus fons, gen. et sp. nov., from middle to uppermost Maastrichtian strata in central and southern California, represents the type genus of Xenomytilinae, subfamily nov. This new subfamily is comprised of Lycettia Cox, 1937, and Xenomytilus. Lycettia is an Old World Tethyan bivalve that ranges from the late Early Jurassic (Toarcian) to the Late Cretaceous (Campanian). Xenomytilus is known only from California, but future studies might reveal it to be more widespread. Xenomytilus fons is from Maastrichtian strata in central and southern California and is locally moderately common. It inhabited siliciclastic nearshore, warm waters and most likely had an epifaunal mode of life, with attachment by byssus to hard substrate. Specimens were commonly transported by turbidity currents into deeper waters. The other new species is the tellinoidean Icanotia californica, sp. nov., from the upper Turonian upper part of the Baker Canyon Member and lower part of the Holz Shale Member of the Ladd Formation in the Santa Ana Mountains, Orange County, southern California. It lived in inner shelf waters and was infaunal in silts and very ?ne sands. Icanotia is a relatively rare, warm temperate and Tethyan, Cretaceous (Valanginian to Maastrichtian) bivalve known predominantly from Europe. Rare dispersals of Icanotia into the New World were, most likely, by westward-?owing equatorial currents that coincided with high stands of sea level. Its occurrence in southern California is its only record on the Paci?c slope of North America. New Late Cretaceous Mytilid and Tellinoidean Bivalves from California (PDF Download Available). Available from:  https://www.researchgate.net/publication/267818112_New_Late_Cretaceous_Mytilid_and_Tellinoidean_Bivalves_from_California [accessed May 13, 2016].

Relationships

Items