Alligators haven’t changed in millions of years, study finds

While most of today’s predators have honed their hunting attributes over the last few million years, the American alligator stopped a long time ago– and they seem to be getting along just fine.

A new study, published in the journal Palaeogeography, Palaeoclimatology, Palaeoecology, has revealed these prehistoric-looking animals have been virtually untouched by significant evolutionary change for 8 million years or more, and the animal may be up to 6 million years older than previously thought.

Apart from some sharks and a couple of others, a small number of living vertebrate species have such a long period of time in the fossil record with such little change.

“If we could step back in time 8 million years, you’d basically see the same animal crawling around then as you would see today in the Southeast. Even 30 million years ago, they didn’t look much different,” study author Evan Whiting, a vertebrate paleontologist, said in a press release. “We were surprised to find fossil alligators from this deep in time that actually belong to the living species, rather than an extinct one.”

Inspired by the Past

Study authors said their work was inspired by an ancient alligator skull– scientists originally thought it was an extinct species, but soon realized it was nearly identical to modern alligators. Whiting contrasted the ancient skull with fossils and modern alligator skeletons to examine the genus and trace any significant shifts in alligator physiology.

The researchers also used carbon and oxygen compositions of teeth from both ancient alligators and the larger, extinct crocodile Gavialosuchus americanus. The presence of alligator and Gavialosuchus fossils at multiple Florida locations suggests the two species may have lived alongside each other.

Whiting described the alligator as a survivor, tolerating sea-level changes and extreme transformations in climate that would have prompted some less-adaptive animals to quickly change or become extinct. These days, however, he said alligators must deal with an unparalleled threat – humans.

Despite their durability and adaptability, alligators were virtually hunted out of existence in the early 20th century. The Endangered Species Act has noticeably enhanced the amount of alligators in the wild, but there are still continuing confrontational encounters between humans and alligators and the large reptile’s habitats are being damaged or wiped out.

“The same traits that allowed alligators to remain virtually the same through numerous environmental changes over millions of years can become a bit of a problem when they try to adapt to humans,” Whiting said. “Their adaptive nature is why we have alligators in swimming pools or crawling around golf courses.”

Whiting said he hopes that by offering a more total evolutionary background of the alligator, his study supplies the foundation for preserving habitats where alligators have ruled for millions of years.

“If we know from the fossil record that alligators have thrived in certain types of habitats since deep in time, we know which habitats to focus conservation and management efforts on today,” Whiting said.

—–

Image credit: Thinkstock

The post Alligators haven’t changed in millions of years, study finds appeared first on Redorbit.

redOrbit.com
offers Science, Space, Technology, Health news, videos, images and reference information. For the latest science news, space news, technology news, health news visit redOrbit.com frequently. Learn something new every day.”