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

摘要

Lopha ramicolaBeurlen, 1964, from the Upper Cretaceous of Brazil is illustrated as an example of xenomorphism and bioimmuration 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.