Gastropod

AN ENIGMATIC DENTAL PLATE REVEALS A UNKNOWN EAGLE RAY, THE FIRST FOR THE CARIBBEAN AND THE ATLANTIC OF THE AMERICAS

For nearly ten years, a set of mysterious dental plates sat quietly in a small Venezuelan collection, collected by artisanal fishers off the coast of Chichiriviche. No one knew exactly what they belonged to, only that they came from an eagle ray, a group of winged, shell-crushing rays with pavement-like teeth. Now, an international team of researchers has re-examined those plates and made a surprising discovery: likely belong to the genus Aetomylaeus, a group of eagle rays never before documented in the Caribbean Sea or the entire Western Atlantic Ocean.

Using detailed comparisons with museum specimens and fossil records from the Pacific and Eastern Atlantic, the researchers analyzed the shape, arrangement, and proportions of the teeth. The results clearly set the Venezuelan specimen apart from Caribbean eagle rays like Aetobatus narinari (the spotted eagle ray) and local Myliobatis species. Instead, its closest match was with Aetomylaeus bovinus from the Eastern Atlantic and even fossil Aetomylaeus from Chile. This opens three fascinating possibilities: an unknown relict population that survived the closure of the Central American Seaway millions of years ago; a long-distance vagrant from Africa; or, less likely, a hybrid between two known Caribbean genera.

Regardless of which hypothesis proves correct, this finding rewrites a small but important chapter of marine biogeography. Most Aetomylaeus species are already classified as threatened or Data Deficient, and this first modern record in the Caribbean underscores just how little we know about the region's hidden biodiversity. The authors caution that tooth plates alone cannot give a definitive species identification, genetic material would be needed for that—but the evidence is strong enough to call for urgent, expanded surveys of Venezuela's overlooked elasmobranch fauna. In a world where even charismatic rays can go unnoticed for a decade in a museum drawer, this study is a quiet but powerful reminder: sometimes, the most extraordinary discoveries are found not in the open ocean, but in collections waiting for a second look.