A new species of shark, which lived shortly after the mass extinction of the dinosaurs, was discovered when palaeontologist Jun Ebersole came across a 100-year-old box of teeth at the Geological Survey in Alabama, USA.
“Having documented hundreds of fossil fish species over the last decade, I found it puzzling that these teeth were from a shark that I didn’t recognise,” says Ebersole, Director of Collections, McWane Science Center, Birmingham, AL, who quickly realised the teeth belong to a new species.
The team, consisting of Ebersole, David Cicimurri, Curator of Natural History, South Carolina State Museum in Columbia, and T. Lynn Harrell Jr., Palaeontologist and Fossil Collections Curator at the Geological Survey of Alabama in Tuscaloosa, published their discovery in the open-access journal Fossil Record.
The shark is a new species of Palaeohypotodus (pronounced pale-ee-oh-hype-oh-toe-duss), which means “ancient small-eared tooth,” in reference to the small needle-like fangs present on the sides of the teeth. Scientists believe it may have looked like a modern sand tiger shark.
Living approximately 65-million-years ago in the Paleocene era, Palaeohypotodus bizzocoi was likely a leading predator as the oceans recovered following the death of the dinosaurs, when more than 75% of life on Earth went extinct.
In Alabama, much of the southern half of the state was covered by a shallow tropical to sub-tropical ocean during the Paleocene.
“This time period is understudied, which makes the discovery of this new shark species that much more significant,” Harrell says. “Shark discoveries like this one give us tremendous insights into how ocean life recovers after major extinction events and also allows us to potentially forecast how global events, like climate change, affect marine life today.”
As part of their study of this ancient fish, the team compared the fossil teeth to those of various living sharks, like Great Whites and Makos. According to Cicimurri, shark teeth differ in shape depending on where they are located in the mouth.
“By studying the jaws and teeth of living sharks, it allowed us to reconstruct the dentition of this ancient species and showed that it had a tooth arrangement that differed from any living shark,” Cicimurri says.
The new species has been named Palaeohypotodus bizzocoi for the late Dr. Bruce Bizzoco (1949-2022) of Birmingham, AL. Bizzoco served as a Dean at Shelton State Community College, archaeologist, and was a long-time volunteer at McWane Science Center.
This discovery is part of an ongoing project led by Ebersole and Cicimurri to document Alabama’s fossil fishes. Together, they have confirmed over 400 unique species of fossil sharks and bony fishes, which, according to Ebersole, makes Alabama one of the richest places in the world in terms of fossil fish diversity.
Ebersole JA, Cicimurri DJ, Harrell Jr. TL (2024) A new species of Palaeohypotodus Glickman, 1964 (Chondrichthyes, Lamniformes) from the lower Paleocene (Danian) Porters Creek Formation, Wilcox County, Alabama, USA. Fossil Record 27(1): 111-134. https://doi.org/10.3897/fr.27.e112800