Scientists discover three new ‘ancient shark’ species in the southern US

Researchers have recently announced the exciting discovery of three new ancient shark species, unearthed from fossil sites in Kentucky and Alabama. While modern sharks are often a source of intrigue and fear, these ancient varieties are thankfully no longer roaming the waters — much to the relief of ocean-goers. The team from the Paleontological Resources Inventory (PRI) has been diligently working since 2019, exploring fossils found in Mammoth Cave, Kentucky, and various formations across northern Alabama, leading to some significant findings.

The discoveries were divided into two fascinating groups. The first includes both juvenile and adult shark teeth unearthed from the St. Louis and Ste. Genevieve Formations at Mammoth Cave, as well as the Bangor Formation in Alabama. The second group is particularly intriguing, featuring a partial set of jaws and gills from Mammoth Cave, alongside additional teeth from the St. Louis, Ste. Geneveive, and Haney Formations at Mammoth Cave and the Hartselle and Bangor Formations in Alabama.

A news release from the National Park Service, dated February 1, 2024, highlighted that these fossils have been linked to two previously unknown ancient shark species.

The first of these species has been named Troglocladodus trimblei, aptly deriving its name from ‘Cave Branching Tooth’ to reflect its discovery location. It honors Barclay Trimble, the park superintendent who found the initial specimen, a solitary tooth, during an early PRI expedition in 2019. The Troglocladodus, similar in size to an oceanic white tip shark, measured approximately 10-12 feet in length.

The second newly identified species belongs to the Glikmanius genus. This finding is particularly groundbreaking as it shifts the timeline for this extinct genus of prehistoric shark, suggesting its existence began roughly 50 million years earlier than previously thought. Named in tribute to the Cave Research Foundation (CRF), who supported the research and discovered the Glikmanius jaws, this shark also spanned about 10-12 feet, akin to a Lemon Shark. Its robust jaw structure indicates it was a formidable predator, likely feeding on smaller sharks, bony fish, and squid-like orthocones.

Palaeohypotodus bizzocoi teeth. (EBERSOLE ET AL.)

The third species, discovered by Jun Ebersole, Director of Collections at McWane Science Center, has been designated as Palaeohypotodus bizzocoi. This exciting find occurred as Ebersole was examining a century-old box of shark teeth at the Geological Survey in Alabama, realizing that the unfamiliar teeth must represent a new species. This species, named in honor of the late Dr. Bruce Bizzoco, a dedicated archaeologist and volunteer at McWane Science Center, dates back to 65 million years ago, emerging just after the dinosaur extinction.

T. Lynn Harrell, a fellow team member and Paleontologist at the Geological Survey of Alabama in Tuscaloosa, emphasized the significance of these discoveries, noting their importance in understanding marine life recovery post-major extinction events. Such findings not only shed light on historical biodiversity but also help predict the impacts of current global challenges, such as climate change, on marine ecosystems.