Newfound fossil species of lamprey were flesh eaters

The modern kin of these dinosaur contemporaries can consume either blood or flesh

An artist's rendition of a Yanliaomyzon ingensdentes.

Yanliaomyzon ingensdentes, shown in this artist’s rendition, is one of two newly discovered species of flesh-eating lamprey found in 160-million-year-old rocks.

Heming Zhang

Found in roughly 160-million-year-old rocks in North China, the Yanliao Biota is a diverse array of beautifully preserved fossils, including dinosaurs, pterosaurs and even early mammals. But it isn’t all fur and feathers. Paleontologists have now unearthed fossils of two surprisingly large ancient lamprey species, swimming menaces that latched onto and bored holes into their unsuspecting neighbors.

Modern parasitic lampreys’ funnel-shaped, toothy mouths tend to be adapted to consume blood or flesh. Based on the arrangement of teeth and other feeding apparatuses in the fossils, the newly discovered species probably weren’t bloodsuckers — they were flesh eaters, the team reports October 31 in Nature Communications.

The fossils are the oldest lamprey specimens to clearly indicate a preference in feeding mode, say paleontologist Feixang Wu of the Chinese Academy of Sciences in Beijing and colleagues. In fact, the tooth arrangement of both ancient species strongly resembles that of a modern species of Southern Hemisphere flesh-eating lamprey.

Yanliaomyzon occisor — “occisor” is Latin for “killer” — was the bigger of the two, about 64 centimeters long, the length of a small dog. The species name for its smaller cousin, Y. ingensdentes, comes from the Latin for “large teeth.” Modern adult lampreys range in length from about 15 to 120 centimeters.

An artists rendition of Yanliaomyzon ingensdentes on the left and Yanliaomyzon occisor on the right in black and white.
These reconstructions depict the mouth and part of the body of two newly discovered lamprey species that lived 160 million years ago: Yanliaomyzon ingensdentes (left) and Y. occisor (right).Heming Zhang

Lampreys, a lineage of jawless vertebrates, have been around for 360 million years. But they rarely fossilize well, leaving large gaps in their evolutionary record and uncertainty about their ecology and when their feeding styles evolved.

The earliest lampreys weren’t such fierce predators: They were only a few centimeters long and lacked the powerful teeth of later species. They also didn’t have modern lampreys’ distinct life cycle, which consists of a larval filter-feeding stage, a juvenile parasitic stage and an adult spawning stage.

The newfound fossils suggest that by this time in the Jurassic Period, lampreys had become fierce predators, acquiring larger body sizes and complex feeding structures.

Carolyn Gramling is the earth & climate writer. She has bachelor’s degrees in geology and European history and a Ph.D. in marine geochemistry from MIT and the Woods Hole Oceanographic Institution.

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