Paleontologists in Kentucky and Alabama discovered fossils belonging to three new species of ancient sharks. These long-dead predatory fish lived during a time when the region was covered by a shallow subtropical sea and a waterway 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 is described in a study published February 7 in the open access journal The fossil record. Palaeohypotodus translates to “ancient little-eared tooth” and had small needle-like slits on the sides of the teeth. The discovery of her ghost teeth is suspected to have happened by accident.
“A few years ago, I was looking through the historic fossil collections at the Alabama Geological Survey 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 species of fossil fish over the past decade, I found it strange that these teeth were from a shark I was unfamiliar with.”
After examining the teeth, Ebersole discovered that they likely belonged to a new species. It lived approximately 65 million years ago, during the Paleocene epoch. This happens just after the dinosaurs began to die out and more than 75 percent of life on Earth disappeared. The team believes this P. bizzocoi it was a top predator at a time when ocean life was beginning to recover.
“This time period is understudied, which makes the discovery of this new shark species all the more significant,” Lynn Harrell, Jr., a study co-author and curator of fossil collections at the Alabama Geological Survey, said in a statement. “Shark discoveries like this give us incredible insight into how ocean life recovers from major extinction events and also allows us to potentially predict how global events, such as climate change, affect marine life today.”
325 million year old sea 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 from fossils collected in deposits from Mammoth Cave in Kentucky and northern Alabama. Both these types of sharks lived about 325 million years ago and there are dozens of them. These ancient cousins of modern sharks all had spines used for defense.
Scientists found juvenile teeth that belonged to him Troglocladodus trimblei. It was likely about 10 to 12 meters long, about the same size as a modern oceanic great white shark. Name Troglocladodus means “cave branching tooth”, referring to its “forked-looking” chalks.
Glikmanius careforum pushes the origin of this Glicmanius The genus Ctenacanth dates back over 50 million years earlier than expected. It was identified by teeth and a partial set of jaws and gills belonging to a juvenile Glicmanius. Scientists estimate that it also reached a length of 10 to 12 feet. From the shape of its jaw, it likely had a powerful bite that it used to hunt 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 ancient nearshore habitats. The region was once an ancient sea route connecting present-day eastern North America, Europe and northern Africa. The waterway later disappeared when the supercontinent Pangea formed.
Over 400 unique species of sharks and bony fishes have already been discovered in Alabama alone, making it a very diverse fish fossil deposit. Ongoing research such as the Paleontological Resource Inventory at Mammoth Cave National Park may continue to uncover even more new fossil sharks.