Conocardium is an extinct genus of Rostroconchian mollusk. Its shell-mouth grew to be across. It fed on tiny plants and animals in the water. Fossils have been found all over the world from Ordovician to Permian formations.Conocardium at Fossilworks.org
Species The following species have been described:
C. acadianum C. aliforme (type) C. altum C. aquisgranense C. armatum C. cresswelli C. decussatum C. denticulatum C. elongatum C. eximum C. ferox C. formosum C. frater C. fusiforme C. gogoensis C. gympiense C. hainense C. immatura C. incarceratum C. inceptum C. inflatum C. konincki C. longipennis C. lyelli C. nexile C. oehlerti C. philipsii C. plinthinatus C. prunum C. pseudobellum C. regulare C. renardi C. retusum C. richmondense C. securiforme C. sowerbyi C. spinalatum C. tripartitum C. truncata C. truncatum C. uralicum C. ventriculosum C. villmarense
References
Further reading Dinosaurs to Dodos: An Encyclopedia of Extinct Animals by Don Lessem and Jan Sovak Parker, Steve. Dinosaurus: the complete guide to dinosaurs. Firefly Books Inc, 2003. Pg. 40