100-Million-Year-Old Hagfish Complete with Slime Kit Discovered

By Mindy Weisberger, Senior Writer | January 21, 2019 03:39pm ET

Scientists recently discovered a rare and important hagfish fossil that includes traces of preserved slime dating to 100 million years ago.

Eyeless, jawless hagfish — still around today — are bizarre, eel-like, carrion-eating fishes that lick the flesh off dead animals using their spiky tongue-like structures. But their most well-known feature is the sticky slime that they expel for protection.

And now, scientists know that hagfish slime is robust enough to leave traces in the fossil record, finding remarkable evidence in a fossilized hagfish skeleton excavated in Lebanon. This new discovery is also prompting researchers to redefine the hagfish's relationship to other ancient fish and to all animals with backbones. [Photos: The Freakiest Looking Fish]

Hagfish fossils are scarce, and this specimen — an "unequivocal fossil hagfish" — is exceptionally detailed with lots of soft tissue preserved, scientists reported in a study published online today (Jan. 21) in the journal Proceedings of the National Academy of Sciences (PNAS).

The fossil dates to the late Cretaceous period (145.5 million to 65 million years ago), and measures 12 inches (31 centimeters) in length. Researchers dubbed it Tethymyxine tapirostrum: Tethymyxine comes from "Tethys" (referencing the Tethys Sea) and the Latinized Greek word "myxnios," which means "slimy fish." Tapirostrom translates as "snout of a tapir," and refers to the fish's elongated nose, the study authors wrote.

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