Bivalvia - Myalinida - Ambonychiidae
Synonym: Opistholoba Ulrich in Hussey 1926
Full reference: F. B. Meek. 1871. A preliminary list of fossils collected by Dr. Hayden in Colorado, New Mexico, and California, with brief descriptions of a few of the new species. Proceedings of the American Philosophical Society 11:425-431
Parent taxon: Ambonychiidae according to J. Pojeta 1966
Sister taxa: Allonychia, Ambonychia, Ambonychinia, Ambonychiopsis, Amphicoelia, Amphiocoelia, Anomalocoelia, Anomalodonta, Byssopteria, Cleionychia, Congeriomorpha, Elasmodophora, Glyptonychia, Gosseletia, Leconychia, Lophonychia, Maryonychia, Mytilarca, Notonychia, Paramytilarca, Praeanomalodonta, Psilonychia, Pteronychia, Silurinka
Subtaxa: Opisthoptera alternata, Opisthoptera casei, Opisthoptera gouldi, Opisthoptera griffini
Type: Megaptera casei
Ecology: stationary epifaunal suspension feeder