Beyond its translucent, white shell, this small Cymatioa cooki stretches the foot it needs to navigate the sand.
The clam was previously only known from fossils.
Only 11 millimetres or so make up the little clam's length.

Cymatioa cooki, the clam's scientific name, had only ever been discovered as a fossil, leading researchers to believe that the species had been extinct for more than 40,000 years. A white, translucent bivalve measuring around 11 millimetres in length was then discovered by marine scientist Jeff Goddard in 2018 while searching tidal pools for sea slugs off the coast of California.

Goddard of the University of California, Santa Barbara, took pictures of the clam instead of disturbing it and then showed one of his colleagues. The Santa Barbara Museum of Natural History's Paul Valentich-Scott, curator of malacology, was pleased because he, too, had never heard of the aquatic creature. Science is what we do because of new findings, according to Valentich-Scott.

In 2019, the couple successfully caught a living specimen and returned it to the museum to compare it to other species that are known from the fossil record. It remarkably resembled a fossil bivalve that was first reported by naturalist George Willett in the 1930s.

Experts are still perplexed as to how the creatures were able to remain undetected for such a long time. According to one theory, C. cooki prefers the more remote region of Baja, California, which is further south. A body of warm water may have brought some clam larvae into Santa Barbara.

Valentich-Scott and Goddard have already found the living clams at least twice and possibly four times. According to University of Chicago palaeontologist David Jablonski, who was not involved in the study, 'it's rare to find something first as a fossil and then living.'