Skip to main content

Paleo Profile: Martin's Sea Turtle

This Cretaceous chelonian is close to the origin of the hard-shelled sea turtles that still swim the oceans

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


Northern Alabama and Mississippi might not seem like the sort of places you'd go looking for sea turtles. These places are a little far from the coast to expect a sighting of the shelled seagoers. But that only holds true for the modern reptiles, of course. Sea levels were higher around 72 million years ago, a shallow seaway splitting North America in two and coasts sitting far inland of where they are today. Sea turtles swam through these ancient waters, as underscored by a new species just named by paleontologist Drew Gentry and colleagues.

The fossil turtle, Peritresius martini, was a bit of a surprise. Paleontologists had long known of another Peritresius species - called Peritresius ornatus - but fossil shell pieces found in Alabama and Mississippi led Gentry and coauthors to propose a second, distinct species. One of the ways paleontologists can tell them apart is in the ornamentation of their shells, the previously-known species having "sculptured" shell bones while Peritresius martini does not.

Despite hailing from the heyday of Cretaceous dinosaurs, though, Peritresius martini probably wouldn't have looked like unusual to our modern eyes. It was about the size of a modern green sea turtle, and, as Gentry and colleagues conclude, and this reptile was along the evolutionary stem connected to today's hard-shelled sea turtles. Looking back, Peritresius was an early glimmer of the chelonian grace of today's hawksbills and loggerheads. 


On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.


A restoration of Peritresius martini. Credit: Drew Gentry

Name: Peritresius martini

Meaning: Peritresius is an existing genus of sea turtle, and martini honors the fossil's discoverer George Martin. 

Age: Cretaceous, about 72 million years old.

Where in the world?: Alabama and Mississippi, USA.

What sort of organism?: A sea turtle related to the origin of today's hard-shelled sea turtles.

How much of the organism’s is known?: Shell pieces from multiple individuals.

Reference:

Gentry, A., Parham, J., Ehret, D., Ebersole, J. 2018. A new species of Peritresius Leidy 1856 (Testudines: Pan-Cheloniidae) from the Late Cretaceous (Campanian) of Alabama, USA, and the occurrence of the genus within the Mississippi Embayment of North America. PLOS ONE. doi: 10.1371/journal.pone.0195651

More Paleo Profiles: 

The Light-Footed Lizard The Maoming Cat Knight’s Egyptian Bat The La Luna Snake The Rio do Rasto Tooth Bob Weir's Otter Egypt's Canine Beast The Vastan Mine Tapir Pangu's Wing The Dawn Megamouth The Genga Lizard The Micro Lion The Mystery Titanosaur The Echo Hunter The Lo Hueco Titan The Three-Branched Cicada The Monster of Minden The Pig-Footed Bandicoot Hayden's Rattlesnake Demon The Evasive Ostrich Seer The Paradoxical Mega Shark The Tiny Beardogs The Armored Fish King North America's Pangolin The Invisible-Tusked Elephant The Mud Dragon The Spike-Toothed Salmon The Dream Coast Crocodile Buriol's Robber Ozimek's Flyer The Northern Naustoceratopsian The High Arctic Flyer The Tomatillo From the End of the World The Short-Faced Hyena The Mighty Traveler from Egg Mountain Keilhau's Ichthyosaur Mexico's Ancient Horned Face Mauricio Fernández's Plesiosaur New Zealand's Giant Dawn Penguin The Orange Sea Lion Mongolia's Ginkgo Cousin The Geni River Frog Isabel Berry's Dinosaur The Whale Caiman The Moab Lizard Yang Zhongjian's Lizard The Little Anubis The Shuangbai Lizard The Wyvern Dinosaur The "Need Helmet" Dinosaur The Jianianhua Dragon The Liaoning Hunter The Dalian Lizard Crompton's Aleodon Jenkins' Amphibian Serpent From the Chinle The Large Ancestor Lizard The Crown Tooth Currie's Alberta Hunter The Elephant Bird Mimic The Crested Thief The Hiding Hunter The Horned Lizard The Silk Bird The Sieve-Toothed Plesiosaur The Defenseless Snout Burian's Lizard The Small Whaitsiid The Beautiful Bird The Fierce Cat The Older One From Melksham The King of the Miocene Iberian Giraffes Miera's Lizard The Traveling Sloth The Sand Whale Shouten's Marsupial Lion The Rhaetian Lizard The Mountain Dolphin The Bryant's Shark The Rainbow Dinosaur Kootenay Bristle Worm The Masaoura Lizard The Chimera Spider The Chad Cat The Jinyun Shield The Fish From China The Sobrarbe Siren The Shortened Face The Climbing Dwarf