DEVONIAN BIVALVE Grammysioidea (Hall)
This Devonian clam-like bivalve occurs rarely on the IVFP reef, usually as less complete casts than this speciman. Grammysioidea ("Grammysia-like") clams had thinner shells than its more robust cousin Grammysia, and usually appear as flattened, pancake-like impressions in the mudstone.

IVFP #07112004 D. Tuttle collection