Student scientists name 309-million-year-old frog-like creature after their moms
Chicago: A newly identified amphibian that lived long before the dinosaurs has been named — after two moms named Jean.
The creature, Jeanerpeton mazonensis, meaning “Jean’s crawler from Mazon Creek,” was described by student scientists Allison Sefcovic and Payton Kohlberg, interns in the Women in Science program at Chicago’s Field Museum. As luck would have it, both their mothers are called Jean.
The fossil, published in the Journal of Vertebrate Paleontology, dates to 309 million years ago when present-day Chicago was a swampy river delta teeming with early land-dwellers and giant insects.
It looked like a salamander but was squat and chubby like a frog, and it may push back the origin of traits seen in today’s frogs and salamanders.
The specimen was found years ago by an amateur collector and donated to the Field Museum, where it was lumped into a “waste bin taxon” — Amphibamus grandiceps — a catch-all for poorly understood fossils from the site.”Jeanerpeton is one of those species,” said co-author Dr. Cam So, a postdoctoral researcher at the Field. “Now, we’ve found enough evidence to support it being an anatomically distinct animal.”Mazon Creek is one of the world’s richest Carboniferous fossil beds. Because sediment quickly buried dead animals in the river delta, it preserves soft details normally lost.
“What’s really cool about Mazon Creek is that it preserves all of these unusual details — things like toe pads and body outlines,” Sefcovic said. “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.”
The discovery came from the lab of Arjan Mann, assistant curator of fossil fishes and early tetrapods.”Before working in the Mann Lab, I didn’t know much about paleontology,” Kohlberg said. “It is scary to take on a project when you feel like you don’t know as much as you should. But I learned it is possible to overcome that fear with hard work.”
