Driver FixRecommendedSound, Wi-Fi or graphics acting up? Check drivers firstFind missing or outdated drivers fast.Check DriversOctober DealsAmazon USOctober deal check: compare before you payAmazon US: current deals, useful picks and tech finds.Check DealsPC HealthRecommendedCrashes, freezes, slowdowns? Check your PC nowSpot repairable issues before they interrupt work.Check PC×
Skip to content
Entry 260Filed under Breeding

Two Ancient Shark Species Identified in Fossils at Mammoth Cave

Fossils from Mammoth Cave and Alabama reveal two ancient ctenacanth shark species. Their limestone is about 325 million years old, but the cave passages formed far later.
3-minute read By Animalso Team
Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.

Fossils from Mammoth Cave and nearby Alabama formations have revealed two previously undescribed ancient shark species: Troglocladodus trimblei and Glikmanius careforum. The National Park Service announced the discovery in 2024. The sharks lived in a shallow sea about 325 million years ago; they were not living animals found in the cave, and Mammoth Cave’s passages formed much later.

What the discovery includes

The fossils belong to ctenacanths, an extinct group of cartilaginous fishes related to sharks. The National Park Service (NPS) estimates that each species reached about 10–12 feet (3–3.6 metres) long. Those are estimates based on fossil evidence, not measurements of complete skeletons.

The announcement describes two new-to-science species, not three. Fossils attributed to both were found in Mammoth Cave and in formations in northern Alabama. The NPS release does not establish a population count or the number of individual sharks represented.

How the two species differ

Species Fossil evidence Estimated size What the fossils suggest
Troglocladodus trimblei Adult and juvenile teeth from Mammoth Cave’s St. Louis and Ste. Genevieve formations and Alabama’s Bangor Formation. The first specimen was a tooth found by Mammoth Cave Superintendent Barclay Trimble in 2019. About 10–12 feet, estimated by NPS in 2024; NPS compares its size with an oceanic whitetip shark. The teeth identify it as a ctenacanth shark. The available evidence does not establish a specific hunting strategy.
Glikmanius careforum Primarily teeth from several Mammoth Cave and Alabama formations, plus a young individual represented by a partial jaw and gills. About 10–12 feet, estimated by NPS in 2024; NPS compares its size with a lemon shark. Its jaw shape suggests a powerful bite. NPS says likely prey included smaller sharks, bony fish, and squid-like orthocones.

The jaw and gills attributed to a young G. careforum are particularly informative because shark skeletons are mostly cartilage, which rarely fossilizes. They provide unusual anatomical evidence, but they are not a complete shark body. The fossil record for T. trimblei described in the announcement consists of teeth.

Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.
#1 Best Overall
Sale
PowerTRC 3D Printed Skeleton Megalodon – Prehistoric Collectible Articulating Dinosaur 3D Figurine Desk Decoration for Teens and Adults, Made in USA
  • Museum-Inspired Fossil Replica – Expertly 3D printed to capture the intricate skeletal structure and realistic proportions of prehistoric dinosaurs, creating a display-worthy piece for enthusiasts and fossil fans alike.
  • Collector-Grade Display Quality – Designed with hobbyists and collectors in mind, this piece offers crisp detail and a professional finish that elevates any dinosaur or fossil collection.
  • Durable & Lightweight Construction – Made from premium PLA material for a sturdy yet easy-to-handle structure, ensuring long-lasting enjoyment without the fragility of real fossils.
  • Versatile Display Options – Ideal for showcasing on desks, bookshelves, display cases, or as part of themed décor in offices, libraries, or dedicated hobby rooms.
  • A Unique Conversation Starter – Whether placed in a home, workspace, or collection room, this fossil replica is sure to spark curiosity and admiration from anyone who sees it.

What the ancient sea was like

About 325 million years ago, during the Mississippian, much of the region now occupied by Kentucky and Alabama lay beneath a shallow, near-shore sea. NPS describes an ancient seaway connecting parts of what are now eastern North America, Europe, and northern Africa, before Pangaea formed.

The fossil-rich limestone formed in that marine setting. NPS says at least 70 species of ancient fish have been identified at Mammoth Cave. Paleontologist and shark fossil specialist John-Paul Hodnett has described a diverse assemblage of cartilaginous fishes, from large predators to small sharks living among seafloor crinoids.

Rank #2
Prehistoric Planet Store 5.5 Inch Megalodon (Carcharodon megalodon) tooth, Black with Serrations (Replica) #126
  • IT FROM XUQCAH MATERIAL AND FOIMOJSK PAR ENT AND Thurder LOVER
  • Museum Quality Replica
  • Please thoroughly read discription

Why the fossils are in a cave younger than the sharks

The age of the fossils and the age of Mammoth Cave’s passages are different. The fossils were preserved in limestone roughly 325 million years old. NPS says the cave passages began developing about 10–15 million years ago, as weakly acidic water dissolved limestone along cracks. The fossils were therefore in ancient rock long before cave formation exposed them in passage walls and ceilings; they were not inside an existing cave for 325 million years.

Mammoth Cave is the world’s longest known cave. NPS reported 426 miles of mapped passages in 2022, after six miles were added to the survey. Mapped totals can change as exploration continues, so that figure should be read with its reporting year.

Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.
Rank #3
Sale
PowerTRC 3D Printed Skeleton Megalodon – Prehistoric Collectible Articulating Dinosaur 3D Figurine Desk Decoration for Teens and Adults, Made in USA
  • Museum-Inspired Fossil Replica – Expertly 3D printed to capture the intricate skeletal structure and realistic proportions of prehistoric dinosaurs, creating a display-worthy piece for enthusiasts and fossil fans alike.
  • Collector-Grade Display Quality – Designed with hobbyists and collectors in mind, this piece offers crisp detail and a professional finish that elevates any dinosaur or fossil collection.
  • Durable & Lightweight Construction – Made from premium PLA material for a sturdy yet easy-to-handle structure, ensuring long-lasting enjoyment without the fragility of real fossils.
  • Versatile Display Options – Ideal for showcasing on desks, bookshelves, display cases, or as part of themed décor in offices, libraries, or dedicated hobby rooms.
  • A Unique Conversation Starter – Whether placed in a home, workspace, or collection room, this fossil replica is sure to spark curiosity and admiration from anyone who sees it.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Support on Ko-Fi

What “sea monsters emerge” really means

“Sea monsters” and “emerge” are vivid headline language, not literal descriptions: these were extinct marine animals, and their fossils were identified in ancient rock exposed inside Mammoth Cave. Some specimens can appear strikingly well preserved, but that appearance is not evidence that they are recent or that a particular preservation process has been proven. The discovery announced by NPS in February 2024 concerns the two species described above.

Sources: National Park Service, “Two New Shark Species” (February 1, 2024); NPS Mammoth Cave paleontology; NPS Mammoth Cave cave formation; NPS, mapped cave length (2022); Live Science coverage (February 7, 2024).

Best Value
5.5 Inch Megalodon (Carcharodon megalodon) tooth, Ivory Color with Serrations(Replica)
  • Museum Quality Replica
  • 5.5 inches
  • Please thoroughly read discription
Rank #4
Sale
PowerTRC 3D Printed Skeleton Megalodon – Prehistoric Collectible Articulating Dinosaur 3D Figurine Desk Decoration for Teens and Adults, Made in USA
  • Museum-Inspired Fossil Replica – Expertly 3D printed to capture the intricate skeletal structure and realistic proportions of prehistoric dinosaurs, creating a display-worthy piece for enthusiasts and fossil fans alike.
  • Collector-Grade Display Quality – Designed with hobbyists and collectors in mind, this piece offers crisp detail and a professional finish that elevates any dinosaur or fossil collection.
  • Durable & Lightweight Construction – Made from premium PLA material for a sturdy yet easy-to-handle structure, ensuring long-lasting enjoyment without the fragility of real fossils.
  • Versatile Display Options – Ideal for showcasing on desks, bookshelves, display cases, or as part of themed décor in offices, libraries, or dedicated hobby rooms.
  • A Unique Conversation Starter – Whether placed in a home, workspace, or collection room, this fossil replica is sure to spark curiosity and admiration from anyone who sees it.

Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.

Leave a Reply

Your email address will not be published. Required fields are marked *

Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.

More from Field Notes

  1. Entry 01Disaster Preparedness for Pets: What to Plan and PackBreeding6 min
  2. Entry 02Holiday Pet Safety Tips: How to Keep Dogs and Cats Safe Through the HolidaysBreeding7 min
  3. Entry 03What to Buy for a New Rescue Dog: A First-Week Essentials GuideBreeding3 min
Recommended PC Tool
Recommended PC Tool
Windows Errors? Fix Them Before They SpreadFree repair scan
Outdated Drivers Are Slowing You DownFree scan - exact matches

Two free Windows tools

One Free Minute Could Fix That PC

Before you go - each of these free tools takes about a minute and tackles what quietly slows a Windows PC down.

Special offer. View Outbyte info, uninstall instructions, EULA, and Privacy Policy.