Trilobite and brachiopod fossils have been found in Gregory's Cave. Marcellus fossils include specimens of the large clam-like brachiopod Spinocyrtia. The earliest unequivocal brachiopod fossils appeared in the early Cambrian Period. Rhynchonella is an extinct genus of brachiopod found in Silurian to Eocene strata worldwide. During Paleozoic brachiopod (richtofenida) and stromatoporoidea reefs were erected. Fish and crustaceans seem to find brachiopod flesh distasteful. Fish and crustaceans seem to find brachiopod flesh distasteful and seldom attack them. The sparse fossils found in this sequence include the brachiopod "Terebratulina" and the echinoid "Conulus". Exceptional brachiopod specimens from this time still retain traces of their shell colorations. Novocrania anomala is a species of brachiopod found offshore in the eastern Atlantic Ocean. Discinidae is a family in the brachiopod superfamily Discinoidea. "Copsychus stricklandii" Motley & Dillwyn (1855) as well as the brachiopod genus "Stricklandia". It attached directly to hard surfaces, such as brachiopod shells. The smallest living brachiopod, "Gwynia", is only about long, and lives in between gravel. Brachiopod fossils are sometimes found in it.