Paleontologists in Kentucky and Alabama discovered fossils belonging to three new ancient shark species. These long-dead predatory fish lived during a time when the region was covered by a shallow sub-tropical sea and a waterways that connected ancient land masses older than Pangea.
[Related: Prehistoric shark called Kentucky home 337 million years ago.]
An accidental dental discovery
One of the new sharks is the species Palaeohypotodus bizzocoi and it is described in a study published February 7 in the open-access journal Fossil Record. Palaeohypotodus translates to “ancient small-eared tooth,” and it had small needle-like fangs on the sides of the teeth. Finding its fanged teeth allegedly happened by accident.
“A few years ago, I was looking through the historical fossil collections at the Geological Survey in Alabama and came across a small box of shark teeth that were collected over 100 years ago in Wilcox County,” Jun Ebersole, study co-author and Director of Collections at the McWane Science Center, said in a statement. “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 recognize.”
Upon investigating the teeth, Ebersole found that it likely belonged to a new species. It lived roughly 65 million years ago, during the Paleocene Epoch. This is just after the dinosaurs began to die out and more than 75 percent of life on Earth went extinct. The team believes that P. bizzocoi was a leading predator at a time that ocean life was beginning to recover.
“This time period is understudied, which makes the discovery of this new shark species that much more signiﬁcant,” Lynn Harrell, Jr, a study co-author fossil collections curator at the Geological Survey of Alabama, said in a statement. “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.”
325 million-year-old seaway sharks
On February 1, paleontologists from Mammoth Cave National Park announced the discovery of two new species of ancient shark. According to the National Park Service, Troglocladodus trimblei and Glikmanius careforum, were identified by fossils collected in deposits from Mammoth Cave in Kentucky and northern Alabama. Both of these shark species lived about 325 million years ago and are ctenacanths. These ancient cousins of modern sharks all had barbs on their spines used for defense.
Scientists found juvenile teeth that belonged to Troglocladodus trimblei. It was likely about 10 to 12 feet long, roughly the same size of a modern oceanic white tip shark. The name Troglocladodus means “cave branching tooth,” in reference to its “forky-looking” chompers.
Glikmanius careforum pushes the origins of this Glikmanius genus of ctenacanth back over 50 million years earlier than expected. It was identified from teeth and a partial set of jaws and gills that belonged to a young Glikmanius. Scientists estimate that it also reached lengths of 10 to 12 feet. By the shape of its jaw, it likely would have had a powerful bite that it used for hunting bony fish, squid-like orthocones, and smaller sharks.
[Related: The ‘meg’ may have been longer and less chonky than previously thought.]
Both species would have hunted the ancient near-shore habitats. The region was once an ancient seaway that connected present day eastern North America, Europe, and northern Africa. The waterway later disappeared as the supercontinent Pangea formed.
Over 400 unique species of sharks and bony fishes have already been uncovered in Alabama alone, making it a very diverse fish fossil deposit. Ongoing research like the Paleontological Resources Inventory at Mammoth Cave National Park could continue to uncover even more new fossil sharks.