Florida is well-known amongst paleontologists as a wealthy supply of shark fossils. However information of such finds across the state haven’t been examined systematically — till now.
Researchers not too long ago analyzed 1000’s of fossil specimens within the assortment of the Florida Museum of Pure Historical past in Gainesville, and in doing so, added 20 new shark species to the state’s fossil report.
Victor Perez, an assistant curator of paleontology at Calvert Marine Museum in Solomons, Maryland, launched the fossil investigation to establish and fill any gaps in Florida’s chondrichthyan information. Chondrichthyans are a big and numerous class of fishes with cartilage skeletons, reminiscent of sharks and rays.
“This examine acknowledged 40% extra taxa than the earlier overview of Florida’s chondrichthyan fossil report,” Perez wrote within the examine. “Whereas the documentation of the chondrichthyan fossil report of the Florida Platform [an underwater plateau supporting the Florida peninsula] has improved considerably, this examine discovered quite a few gaps in sampling the place further taxa are prone to be recovered.”
The examine authors examined a complete of 107,698 shark and ray fossils from the state, which have been a part of the fossil assortment on the Florida Museum. They recorded 70 species, of which 20 have been added to Florida’s chondrichthyan fossil report for the primary time.
Florida holds the unofficial title of “shark tooth capital of the world” because of the portions of fossil shark enamel which are discovered there, based on Perez. As a result of sharks’ skeletons are largely cartilage, they sometimes do not mineralize to supply fossils. By comparability, their high-calcium enamel are incessantly preserved within the fossil report, based on the Florida Museum.
Because the Eocene epoch (56 million to 33.9 million years in the past) transitioned into the Oligocene epoch (33.9 million to 23 million years in the past), shifts in world local weather led to modifications within the varieties of shark species that dominated in historical ecosystems.
Many mackerel shark species, which had lengthy, skinny enamel suited to catching fast-moving prey, grew to become extinct throughout this time, doubtless as a result of the local weather cooled, researchers reported in 2019 within the journal Proceedings of the Nationwide Academy of Sciences. That enabled floor sharks — which have specialised serrated enamel for catching a greater variety of prey — to populate ecosystems that mackerel sharks as soon as dominated, as competitors for sources declined. Floor sharks’ success story continues to this present day; a number of the most acquainted fashionable shark species, reminiscent of hammerhead sharks (within the household Sphyrnidae) bull sharks (Carcharhinus leucas) and tiger sharks (Galeocerdo cuvier), are examples of floor sharks.
A lot of the specimens that the scientists analyzed for the examine had been donated to the museum by novice fossil hunters, and signify sharks and rays that lived in varied places throughout the state between 45 million and 10,000 years in the past.
In Florida, fossils from the Eocene and the Oligocene are poorly documented, and the researchers’ findings “will probably be a terrific useful resource to assist collectors acknowledge if they’ve one thing new,” Calvert Marine Museum representatives stated in an announcement.
The findings have been printed April 18 within the journal Paleobiology.
Initially printed on Dwell Science.