Dispatch: a fossil collected in Illinois in 1965 is pulled out of a "waste bin taxon" and gets a new name honoring two researchers' moms.

Dispatch, we have a museum specimen with a brand-new name tag. A fossil collected in 1965 from Pit 11 at Mazon Creek in Illinois, catalogued as FMNH PR 558, has been reclassified as a new genus and species, Jeanerpeton mazonensis, Earth.com reports. The specimen holds an almost complete skeleton, missing only the tail. It had been treated as an unusual amphibamiform related to Amphibamus grandiceps. Amphibamiforms were small extinct four-limbed vertebrates, important for understanding the early history of modern amphibians. Cam So, a co-author and postdoctoral researcher at the Field Museum of Natural History, described the old classification as a "waste bin taxon," a catch-all label for fossils whose differences haven't been carefully sorted. The fresh look found a narrower snout, sharply pointed single-cusped teeth where Amphibamus had two-cusped ones, and 22 vertebrae in front of the hip region, compared with 20 in the specimen used for comparison. The fossil even preserves an eye impression with the lens and 10 small bones around it. "In the fossil of Jeanerpeton, we can see some of the scales on its back and tiny 'belly ribs' called gastralia. You can even see the eye impressions! It's so cool to see," said co-lead author Allison Sefcovic, a 2025 Women in Science intern at the Field Museum. The name Jeanerpeton honors the mothers of Sefcovic and fellow co-lead author Payton Kohlberg. The species name refers to Mazon Creek, where the rocks are about 309 to 307 million years old. "With this publication, we officially pull Jeanerpeton out of this waste bin taxon," So said. The authors argue at least four forms distinct from Amphibamus grandiceps may be present at the site. The fossil can't say what the animal ate or how it lived. It can say that a label on a museum drawer is only as good as the last person who looked closely. Over.