Xenomorphism, bioimmuration, and biologic substrates: an example from the Cretaceous of Brazil

Abstract
Lopha ramicola Beurlen, 1964, from the Upper Cretaceous of Brazil is illustrated as an example of xenomorphism and bioimmaturation on an unknown, possibly botanical, substrate not preserved in the fossil record. The shells preserve a sharp negative replica of the biologic substrate on the attached valve and a protruding positive replica, including a geometric pattern of nodes, on the unattached valve.