Meet Stenokranio boldi! Albuquerque-based researcher on international team discovering new amphibian species

The world is one of discovery.

An Albuquerque-based research associate is part of an international team that discovered a new species of carnivorous amphibian living nearly 300 million years ago.

Meet Stenokranio boldi.

Stenokranio boldi — named for the Greek “stenos” and “kranio,” meaning “narrow-skulled” — was discovered in rocks in Rhineland-Palatinate, in southwestern Germany, that date back to the Carboniferous period.

Scientists believe Stenokranio grew to nearly five feet long and weighed more than 150 pounds. Alongside early forerunners of mammals, Stenokranio was one of the largest known predators of its time.

Larry Rinehart, New Mexico Museum of Natural History & Science research associate, working with researchers from Urweltmuseum GEOSKOP in Thallichtenberg, Germany, Naturhistorisches Museum Schloss Bertholdsburg in Schleusingen, Germany, and other international partners published a paper in the Journal of Paleontology identifying the newly discovered amphibian.

Rinehart traveled to Germany for many years to work with his German associates on the discovery.

“I worked in Germany for a total of about a year, though it was spread out over a handful of years,” Rinehart said. “When I was working with the museum on their digs, we had the opportunity to meet German archaeologists that would help us. When I retired in 2013, I was presented the opportunity to work in Germany. It was a no-brainer.”

Rinehart said the group of researchers knew immediately that the fossils were that of an amphibian.

Meet Stenokranio boldi, a new amphibian species

“You can tell by the features of the skeleton,” Rinehart said. “The texture of the bone on the skull indicates that it’s an amphibian. The shape and layout of the skull bones along with the rest of the skeleton indicate it’s amphibian.”

Rinehart said the Stenokranio boldi is closely related to a species in New Mexico called the Eryops.

He said discovering new species adds to our understanding of how animals evolved from less derived forms into more complex forms and how they change with their environment.

“The takeaway is that amphibians 300 million years ago weren’t the small species we see today,” he said. “They were several feet long and had a crocodilelike lifestyle. And they were the top predators in their environment.”

As an amphibian, this species was able to live and hunt in water and on land.

Long before the emergence of crocodiles, Stenokranio lived as a lurking predator in and on the edge of tropical waters.

In terms of body shape and lifestyle, the animal occupied the ecological niche of the later crocodiles, preying on fish and other small animals.

Stenokranio had three pairs of large, backward-curved fangs and hundreds of tiny teeth on its palate, which were used to hold on to slippery prey.

Amphibians like Stenokranio were one of the dominant groups of animals alive nearly 300 million years ago, during what’s now known as the boundary between the Permian and Pennsylvanian periods, during the Paleozoic Era.

“Not only does this discovery increase our understanding of life before the dinosaurs, but it also demonstrates the value of international collaboration in paleontology,” said Anthony Fiorillo, New Mexico Museum of Natural History & Science executive director. “We’re proud to see our museum listed alongside prominent organizations from all over the world on discoveries like this one.”