For more than 160 years, a segment of a jawbone with serrated, inches-long teeth has resided on a shelf at the Academy of Natural Sciences of Drexel University under one name: Bathygnathus borealis.
But like many of the millions of specimens at the Academy, this 270-million-year-old fossil still had a story to impart. And that story was that it was the fossil of a creature that has a little more name recognition.
Researchers from the University of Toronto Mississauga, Carleton University and the Royal Ontario Museum, led by Kirstin Brink, PhD, used the Academy’s fossil specimen to determine that Bathygnathus borealis was not actually a unique species but instead belongs to the genus Dimetrodon, a “mammal-like reptile” that lived 40 million years before the first dinosaurs.
“By scanning the fossil, they were able to zero in on unique features of this specimen that we’ve suspected for a long time,” explained Ted Daeschler, PhD, the Academy’s vice president for collections and one of the guardians of the extensive fossil collection. “The images they were able to develop allowed them to say ‘This is a pelycosaur, specifically Dimetrodon.’”
The Canadian team’s discovery was published in the Nov. 23 issue of the Canadian Journal of Earth Science.
Featured in (albeit crudely) the 1959 movie “Journey to the Center of the Earth” and many children’s toys, Dimetrodon was a four-legged animal that had a spiny “sail” of skin stretching from the back of its neck to its tail area.
One of the animal’s key features, which is on display in the Academy’s fossil, is serrated, inches-long teeth meant for ripping flesh. Dimetrodon is believed to be the first land-based animal to sport these “ziphodont” teeth.
When the fossil was taken to Canada with the researchers last year, it was something of a homecoming. The jaw was initially discovered in Canada on Prince Edward Island in 1845. A farmer named McLeod was digging a new well when the fossil was discovered nine feet down nestled in red sandstone.
