Paleontologists in the United States have identified a new species of mastodon after uncovering teeth that were noticeably smaller than those of the Mammut americanum (American Mastodon).
In a study featured in the journal PeerJ, researchers excavating at Diamond Valley Lake located near Hemet, California stumbled upon mastodon teeth that were oddly smaller and narrower compared to those found in other areas of the country.
Upon further examinations, they found that the pearly whites belonged to a different species of mastodon that scientists have not encountered before. They dubbed the new animal the Mammut pacificus (Pacific Mastodon).
"Finding a new ice age animal is like finding a new animal alive today," said Alton Dooley, executive director at Hemet's Western Science Center and lead author of the study.
Dooley and his colleagues also unveiled their discovery during a presentation at the center on Wednesday, March 27.
A New Mastodon Species In The United States
While half of California mastodons were unearthed in Diamond Valley Lake, the researchers believe the Pacific Mastodon was not exclusive to the region.
Dooley said they examined over 500 mastodons from different parts of North America and discovered that the Pacific variant was found all throughout California. They also came across three specimens found in Idaho.
If this was the case, then many of the mastodons featured in the Los Angeles Natural History Museum and other museums around California might actually be those of Mammut pacificus and not Mammut americanum.
Max Mastodon, the Western Science Center's own mascot, is most likely a Pacific Mastodon as well.
As far as American mastodons living in California, Dooley said they have found no evidence to suggest that the animal made it to the state.
The Pacific Mastodon's Narrow Teeth
The Ice Age is one of the most commonly studied period in the Earth's prehistory. Because of this, Dooley and his team were not expecting to find an entirely new species when set out for the project four years ago.
The researchers initially thought that mastodons that lived near the Diamond Valley Lake had to adapt to a certain environment, and those that inhabited similar areas in other parts of the United States would have relatively smaller teeth as well. However, this is not what they saw in their study.
All other places that the team examined had mastodon fossils with wide teeth. The only region that had variants of the animal with narrow teeth was California.
The researchers are still not sure why the Mammut pacificus had narrower teeth compared to its Mammut americanum cousin, especially since both species were considered grazing animals. It is likely a case of the Pacific Mastodons inheriting the narrow teeth trait from their ancestors, according to study coauthor Eric Scott.
"It's not necessarily a functional difference. It's more of a[n] ancestor descendant relationship they inherited," Scott noted.
"Why there was an initial difference we're not entirely sure."
Aside from having narrower teeth, the Pacific Mastodon also had thicker femurs and six vertebrae compared to the five vertebrae found in the American Mastodon. The Pacific variant also did not have lower tusks.
These consistent physical differences between the Pacific Mastodon and the American Mastodon over thousands of years are proof that they are indeed two distinct species, according to the researchers.