This tiny clam, only 11 milimimeters in length, named Cymatioa cooki, was believed to be extinct for 40,000 years, but was recently found living on the coast of Santa Barbara, California, only about 3 of them have been found. In 1937, the molluscan fauna from local Pleistocene deposit described nearly 300 species, with the description of two clams, Rochefortia reyana and Bornia cooki (now Cymatioa cooki). Since then, Cymatioia cooki was believe to be extinct, until now.
Cymatioa cooki is a rare species, and while other related species have been shown to be commensal with other invertebrates, researchers have been unable to determine any specific commensal relationships for it.
Photo: Robin Gwen Agarwal
Reference: Valentich-Scott & Goddard (2022) A fossil species found living off southern California, with notes on the genus Cymatioa (Mollusca, Bivalvia, Galeommatoidea). ZooKeys
Photo description: The clam has a long foot, the shell is ovaloid, pale and translucent. The clam is in sand with small algaes nearby.
