2024-07-04 08:28:13
Gaiasia jennyae existed about 280 million years ago. years – that is, approximately 40 million years before the first dinosaurs appeared – and provides a glimpse into the early evolution of tetrapods – or four-legged vertebrates.
The animal’s skull is more than 0.6m long, and scientists estimate that the entire animal could have been 2.5m long – making it the largest creature of its kind, according to the researchers.
Scientists have described this swamp creature in a study published in the journal Nature.
„Gaiasia jennyae was much larger than a human and probably lived near the bottom of swamps and lakes,” says Jason Pardo, one of the authors of the study and a researcher at the Field Museum (USA).
G. Jenny had communicating jaws that allowed it to hunt prey. Researchers believe that this creature was likely an apex predator in its swampy ecosystem.
“It had a big, flat, toilet-seat-shaped head that allowed it to open its mouth and suck in prey,” Mr Pardo says. “He had huge bites, the whole front of his mouth is giant teeth.”
The researchers found the fossils in the Gai-As Formation in northwestern Namibia, which existed at the time G. Jenny, was the southern part of the supercontinent Gondwana. The research team found fossils of four individuals – skull fragments and spinal vertebrae.
“When we found this huge specimen, just lying in the outcrop as a giant concretion, it was a really amazing event,” recalls one of the authors of the study, Claudia Marsicano, a researcher at the University of Buenos Aires (Argentina). – As soon as I saw him, I realized that it was something completely different. We were all very excited.”
At the time he lived G. Jennypresent-day Namibia was further south—almost parallel to the northernmost point of present-day Antarctica—and the Ice Age was coming to an end.
While the lands near the equator began to dry out and new animals evolved in the newly created ecological niches, nearer the poles swamps remained where animals could preserve their more primitive features.
G. Jenny is stemmed (eng. stem) tetrapod – an early vertebrate with characteristics intermediate between fish and the first true tetrapods. Stem tetrapods still had signs of an aquatic environment—such as gills—and had limbs that were not yet fully developed for locomotion on land.
“It’s really surprising that Gaiasia is so archaic, says Mr. Pardo. “It was associated with organisms that went extinct probably 40 million years ago.”
G. Jenny shows that the animals that existed further south were radically different from those that lived closer to the equator, says the scientist. The success of such an animal during this critical geological period could help shed light on how the world changed to support different life forms.
“The more we look, the more answers we may find about these ancestral groups of animals that we care about – the ancestors of mammals and modern reptiles, for example,” Pardo says.
Parengta pagal „Live Science“.
2024-07-04 08:28:13