Paleontologists discover new fossils of gigantic freshwater turtles, an international team of paleontologists has unearthed several well-preserved shells and the first known jaw specimen of Stupendemys Geographicus, a species of side-neck freshwater turtle that lived 5-10 million years ago (Miocence period). ) in South America.
Together, fossils shed new light on the biology, past distribution and phylogenetic position of the giant tortoise. Reconstitution of Stupendemys Geographicus male (front) and female (center-left), with the giant alligator Purussaurus mirandai and the great catfish Phractocephalus nassi.
Reconstitution of Stupendemys Geographicus male (front) and female (center-left), with the giant alligator Purussaurus mirandai and the great catfish Phractocephalus nassi. Image by Jaime Chirinos.
“Since the extinction of dinosaurs, northern neotropics have housed missing vertebrates today that were extremely large within their respective clades,” said team director Dr. Marcelo Sánchez, director of the Institute and Museum of Paleontology at the University of Zurich and colleagues.
“Among them are the largest snake, the alligator crocodile, the gavial and some of the largest rodents.” One of the most emblematic species of these species is the gigantic geographic turtle of Stupendemys, because it is the largest non-sea turtle ever known from a full shell.
“Stupendemys Geographicus was first described in 1976 from the Urumaco formation in northwestern Venezuela, but our knowledge of this animal was based on partial specimens that led to a problematic taxonomy, in particular due to the lack of specimens with elements skull and shell associates. “
Paleontologist Rodolfo Sánchez and an 8 million-year-old shell of Stupendemys male geography of Urumaco, Venezuela. Dr. Sánchez and his co-authors have discovered and examined new specimens of Stupendemys geography in the Urumaco region in Venezuela and in the La Tatacoa desert in Colombia.
The findings included the largest shell reported by any existing or extinct turtle, with a shell length of 2.4 m (8 feet) and an estimated mass of 1,145 kg, almost 100 times the size of its closest living relative.
“The shell of some Stupendemys Geographicus individuals has reached almost 3 m (10 feet), which makes it one of the largest turtles, if not the largest, that ever existed,” said Dr. Sanchez. In some specimens, the researchers observed a particular and unexpected feature: the horns.
The two types of shells indicate that there were two sexes of geographical Stupendemys: males with shells with horns and females with shells without horns, said Dr. Sanchez. This is the first time that a sexual dimorphism in the form of horned shells has been reported for one of the lateral neck turtles, one of the two main turtle groups in the world.
Scientists have also been able to review the evolutionary relationships of this species within the tree of life of the turtles. “Based on studies on the anatomy of turtles, we now know that some live turtles in the Amazon region are the closest living relatives,” said Dr. Sánchez.
In addition, new discoveries and research on existing fossils from Brazil, Colombia and Venezuela indicate a much wider geographical distribution of Stupendemys Geographicus than previously thought. The animal lived throughout the northern part of South America. “Despite its enormous size, the turtle had natural enemies,” the authors added.
In many regions, the presence of geographical Stupendemys coincides with Purussaurus, the largest alligators. It was probably a giant tortoise predator, not only for its size and food preferences, but also as suggested by bite marks and perforated bones in the fossilized shells of Stupendemys Geographicus. The research is described in an article in the journal Science Advances.
Paleontologists discover new fossils
Paleontologists discover new fossils of gigantic freshwater turtles and scientists have fossils to prove it. Huge extinct animals lived 5-10 million years ago. The freshwater turtle today is almost 100 times larger than its closest living relative.
The turtle roamed through present-day Venezuela and Colombia during the late Miocene era. Fossils of a giant tortoise that were as big as a car in South America, scientists said in a study published this week.
“It is the largest, if not the largest, tortoise ever,” said study lead author Marcelo, a paleontologist at the University of Zurich. The giant, extinct animals lived 5 million to 10 million years ago and were 9 1/2 feet, about the size and shape of a medium-sized automobile.
Known by the Latin name Stupendemys Geographics, the freshwater turtle today is almost 100 times larger than its closest living relative, the Amazon River’s big-headed turtle. She had a body mass of approximately 2,500 pounds.
Fossils suggest that the male of the species had horns, while the female did not. There are two types of indications that two sexes of stupendemies were present: horned spheres and female horned spheres, Sanchez said.
Artist’s concept of the giant tortoise Stupendemies Geographics: Male (front) and female (left) swim in fresh water. Horns, which are rare in turtles, can be used to protect their massive skulls during the man-to-man fight, the researchers said.
Predators include Purim, similar to a giant crocodile, known as Purusaurus, the study noted that turtle fossils cite not only the size and dietary preferences of the caymons, but also the bite marks and drilled bones. The turtles’ diet included fish, snakes, and mollusks.
The study findings have greatly expanded the known range of turtles, which developed in Venezuela and Colombia during the late Miocene era. Although the first giant tortoise specimens were identified from the remains discovered in Venezuela in 1976.
The giants’ knowledge of these reptiles has been stunted so far due to the lack of complete specimens. The study was published in the scientific journal Science Advance on Wednesday.