TxVP 46040-9. Thoracic vertebral centrum. The centrum is amphiplatyan, with flat, distinctly heartshaped anterior and posterior surfaces. The heartshaped cross-section of thoracic vertebrae was noted by Quiring and Harlan (1953), and appears to characterize thoracics of many sirenians, but is not uniquely apomorphic to the group. The morphology of this specimen as preserved is completely consistent with referral to Sirenia, but a more refined taxonomic identification is not justifiable. It is from 41JF50 (McFaddin Beach); field notes indicate the specimen was taken from “Holocene marsh deposits approximately 1 m below the beach sands” in May, 1983.