Stupendous Turtles Allow Answers Four Decades After Their Discovery

Summary: Accessing more fossils more accurately assembles stupendous turtles and their ancient ambience, according to an article in Science Advances Feb. 12, 2020.

stupendous turtle (Stupendimys geographicus) skeleton, with skull of Caninemys; American Museum of Natural History, New York City; Tuesday, Jan. 1, 1980, 00:29:08: Ryan Somma, CC BY SA 2.0 Generic, via Wikimedia Commons

Stupendous turtles assure answers to ancient freshwater, gender-exclusive, side-necked turtle accomplishments, in the article The Anatomy, Paleobiology, and Evolutionary Relationships of the Largest Extinct Side-Necked Turtle, in Science Advances Feb. 12, 2020.

The updated research brought evolutionary biologist Hansen; geologist Pardo; geologist and paleontologist Cadena; and paleontologists Aguilera-Socorro, Carrillo-Briceño, Sánchez, Sánchez-Villagra, Scheyer and Vanegas to the Colombia-Venezuela borders. Stupendous turtles claimed 13.12-foot (4-meter), 1.25-ton (1.13-tonne) bodies during the Miocene (from Greek μείων, "less" and καινός, "new") epoch 5.33 million to 23.03 million years ago. They displayed deeply concave (from Latin concavus, "curved [inwardly]") lower jaws; dominant upper jaws; and, if male, combat-conducive horns for cranial (from Greek κρανίον, "skull") support.

Stupendous turtles exhibited high-arched, saddle-shaped seventh and eighth-boned cervical (from Latin cervīx, "neck") vertebrae (from same-spelled Latin, "joint"); and bowed scapulae (from same-spelled Latin, "shoulder blades").

Stupendous turtles flourished knobby, low-arched carapaces (from Greek κάραβος, "beetle [like chitin-covered shell]") with unique collar-like, curled-up, front-centered, thickened, upturned neck-bone borders; and scalloped rear margins.

Stupendous turtles got 9.38-foot (2.86-meter-) long shells, the greatest known thus far and the first generated by freshwater turtles, previously gauged as smaller-shelled than marine turtles. They had massive, squat femurs (from Latin femur, "thigh"), flat-surfaced above and below, and humeruses (from Latin umerus, "upper-arm bone"), ridged uninterruptedly sideways and triangularly cross-sectioned. Stupendous turtles, identified by Roger Wood (born March 20, 1941), perhaps inherited Erymnochelyinae (from Greek ἐρυμνός, "steep," χέλῡς, "tortoise" and Latin -ina, "-like") clade immense sizes.

Front-facing horns on each side of their necks and world-largest turtle shells join in the co-authors' judgment of male stupendous turtles as non-stereotypic freshwater, side-necked turtles.

Physical and sexual maturity kindled sizes twice those of marine leatherbacks (Dermochelys coriacea), world-largest extant turtles, and second to 15.09-foot (4.6-meter-) long, sea-going, world-largest Archelon ischyros.

Stupendous turtles looked, albeit 100 times larger, most like their closest living relatives, big-headed Amazon river turtles (Peltocephalus dumerilianus) and logged the same diets, albeit larger-scaled. They maintained omnivorous (from Latin omnis, "all" and -vorus, "eating") mealtimes that mixed fruiting, seeding vegetation and small animals such as caimans, fish, molluscs and snakes. Stupendous turtles, named Stupendemys geographicus (from Latin stupendus, "stupendous"; Greek ἐμύς, "freshwater tortoise"; and Latin geōgraphicus, "geographic") for National Geographical Society funding, numbered among crocodilian prey.

Actual, embedded 2-inch (5.08-centimeter-) long crocodilian teeth; bite marks; punctured horns; and scarred horns observed obstreperous occasions of stupendous turtles opposing one another and their predators.

Plenteous home and territorial ranges permitted stupendous turtles, and predatory giant crocodilians, to peak in mature heights, lengths and weights and to pursue diverse, smaller prey.

Stupendous turtles queued up along lake and river bottoms in extensive freshwater and littoral ecosystems and large wetland systems of present-day Brazil, Colombia, Peru and Venezuela. The Andes Mountains rose and resulted in the separate running of the Amazon, Magdalena and Orinoco rivers through low-lying, seasonally flooded rainforests, flood plains and swamps. Stupendous turtles survive as 7-million to 13-million-year-old fossilized bones in the Tatacoa Desert and the Urumaco region respectively of Colombia and Venezuela in northern South America.

Stupendous turtles, with terrifying male-only horns and tremendous heads, limbs and shells, tell us about life cycles over the watery bottoms of ancient northern South America.

Desierto de la Tatacoa (Tatacoa Desert), southwestern Colombia, has yielded 7-million- to 13-million-year-old fossilized bones of stupendous turtles (Stupendemys geographicus); Monday, Jan. 4, 2010: Dog Electronic, CC BY SA 4.0 International, via Wikimedia Commons

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

Stupendimys geographicus skeleton, with skull of Caninemys; American Museum of Natural History, New York City; Tuesday, Jan. 1, 1980, 00:29:08: Ryan Somma, CC BY SA 2.0 Generic, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Stupendemys_geographicus.jpg; Ryan Somma (Ryan Somma), CC BY SA 2.0 Generic, via Flickr @ https://www.flickr.com/photos/14405058@N08/2801082083/

Desierto de la Tatacoa (Tatacoa Desert), southwestern Colombia, has yielded 7-million- to 13-million-year-old fossilized bones of stupendous turtles (Stupendemys geographicus); Monday, Jan. 4, 2010: Dog Electronic, CC BY SA 4.0 International, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Desierto_De_La_Tatacoa.jpg

For further information:

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