Fossil Turtle Shell as Thick as a 400 page Book
A paper published in the scientific publication “The Journal of Vertebrate Palaeontology” provides new information on the unique fauna that existed in South American rain-forests as animals evolved to exploit the niches left vacant by the dinosaurs following the mass extinction event of 65 million years ago.
Scientists from the Smithsonian Tropical Research Institute and the Florida Museum of Natural History report their discoveries, including the finding of new species of ancient turtle, with one particular Chelonian sporting a shell as thick as a phone directory. Speculating on why a turtle would need such a strong and thick carapace, the researchers point out that as well as predatory crocodiles, this turtle lived in the same habitat as Titanoboa (Titanoboa cerrejonensis) the largest snake known from the fossil record.
Following the major extinctions at the end of the Cretaceous new forms of life emerged. The Palaeogene and the later Neogene periods may be referred to as the “Age of Mammals” as mammals rapidly diversified and became the dominant mega-fauna in most habitats. However, in the early part of the Palaeogene, known as the Palaeocene there was considerable global warming. Average world temperatures on land climbed to a staggering 28 degrees Celsius and much of the Earth became covered in tropical rain forests. Under these conditions reptiles flourished and many types grew to enormous sizes and assumed the mantle of being “top of the food chain”. Animals like the monstrous Titanoboa were formidable predators, and this perhaps explains why turtles developed super-thick shells.
The sixty million year old fossilised shell has come from the Cerrejón coal mine in Columbia. The mine contains fossil rich strata that is helping to show scientists the fauna and flora of prehistoric South America. The turtle shell is almost 4 cm thick and nearly a metre in diameter. This fossil is one of a number of fossil turtle remains that have been discovered at the site.
The scientists have named this new species Cerejonemys wayuunaiki – after the mining area and the Wayuu, the name of the local people, from this part of Columbia. With a huge snake, a constrictor such as Titanoboa on the prowl, the extra thick shell could have provided some protection. Palaeontologists have estimated that this snake may have reached lengths in excess of 16 metres long, much larger than any extant species of snake.
To read more about Titanoboa: Titanoboa – Huge Snake of the Palaeocene Epoch.
Comparison of Vertebrae – Titanoboa cerrejonensis and an Extant Anaconda
Picture Credit: Nature
Commenting on the importance of the American based team’s work, Carlos Jarmillo, staff scientist at the Smithsonian Tropical Research Institute stated:
“The fossils from Cerrejón provide a snapshot of the first modern rain-forest in South America — after the big Cretaceous extinctions and before the Andes rose, modern river basins formed and the Panama land bridge connected North and South America.”
A number of other turtle species have been discovered at the site, the hard shells of turtles having a particularly high chance of being preserved under the prevailing rain- forest conditions, especially if they were deposited close to water sources. The scientists are currently working on their finds and expect to name and describe a number of new species in the near future.