Dugongs, marine mammals closely related to manatees, spend much of their time grazing on seagrass in the Arabian Gulf. As they feed, they carve trails into the sediment, reshaping the seafloor and stirring up nutrients that help sustain ecosystems. New fossil evidence from Qatar shows that ancient sea cows played the same role more than 20 millions years ago.
The fossils were discovered at Al Mashrabiya, a bonebed in southwestern Qatar often described as the world’s richest sea cow deposit. Although geologists first uncovered the site in the 1970s during mining and petroleum surveys, the remains were not initially recognized as belonging to sea cows.
In a recent study, researchers recovered more than 300 fossil specimens representing at least six individuals of ancient dugong relatives from 172 locations across Al Mashrabiya. The exposed rock layers at the site date back approximately 23 to 21.6 million years. Notably, the fossils were found less than 10 miles from a modern bay that supports thriving seagrass meadows and dugong populations today.
Today’s dugongs have stout bodies and downward-facing snouts lined with sensitive bristles that help them detect food, giving them a general resemblance to manatees. Their tails, however, set them apart: manatees have rounded, paddle-shaped tails, while dugongs possess dolphin-like tails with flukes.
Analysis of bone shape and genetic data revealed that the Al Mashrabiya fossils belong to a previously unknown species, the Salwasiren qatarensis. The name honors the nearby Bay of Salwa, the sirenian group of sea cows, and Qatar itself. These extinct animals likely resembled a smaller version of the modern dugong, but with a straighter snout and smaller tusks. Its presence suggests that the region once supported extensive seagrass beds and that a diverse array of sea cow species evolved in the Arabian Gulf over tens of millions of years.
The fossils provide strong evidence that abundant seagrass meadows existed in the region more than 20 million years ago, during a period of high marine biodiversity. By feeding and disturbing the sediment, sea cows would have helped maintain the health of these underwater ecosystems.
Researchers also note that Salwasiren qatarensis may not have been the only species occupying this ecological space. Sea cow fossils are often found clustered together, making it possible that the Al Mashrabiya bonebed could yield additional species of ancient dugong relatives.
Fossil records show that sea cows’ ancestors have fed on aquatic plants for nearly 50 million years. Despite this long evolutionary history, modern dugongs in the Gulf now face mounting threats. They are sometimes accidentally caught in fishing gear, while coastal developments degrade the water where they feed. Rising temperatures and increasing salinity further stress the seagrass meadows that dugongs depend on for survival.
To preserve the findings and make them widely accessible, the research team digitally scanned several fossil sites along with the skull, vertebrae, tooth, and other skeletal elements of the newly described species. The resulting 3D models are available for public viewing through the Smithsonian Voyager platform.
