Ancient graveyard of extinct elephant relatives discovered in North Florida

They need to examine the recent finds more thoroughly, but the team believes the adult was incredibly tall, about eight feet, and its skull was almost nine feet long, including the tusks.

How did they get buried?

How they all ended up buried in the same location currently remains a mystery.

The museum's researchers believe they died at different times, possibly with a gap of hundreds of years, but their remains got deposited in the same location. Several theories are being considered, including the possibility that they were "transported" to this location.  

“We’ve never seen anything like this at Montbrook,” said Rachel Narducci, collection manager of vertebrate paleontology at the museum. Narducci added: “Usually, we find just one part of a skeleton at this site. The gomphotheres must have been buried quickly, or they may have been caught in a curve of the river where the flow was reduced.”

This fossil bed is nearly 30 miles from the Gulf of Mexico, but in the late Miocene period, it would have been close to the sea at the time the skeletons were buried.

As per the researchers, temperatures and sea levels were higher during this time period than they are now. Additionally, the Montbrook site is a treasure trove of ancient fossils due to a large number of animal remains, including those of camels, rhinoceroses, and turtles, that have been recovered. 

The ancient elephants

Their skeleton remains provide a glimpse into the life of modern elephants’ ancient ancestors. Elephants and their extinct relatives are referred to as proboscideans.

Gomphotheres were among the most diverse creatures to walk the Earth some millions of years ago. These giants first appeared in Africa nearly 23 million years ago, during the early Miocene period. They then expanded into parts of Europe and Asia. About 16 million years ago, the animals entered North America via the Bering land bridge.

It is likely that gomphotheres were “waiting on the shoreline” to cross into South America when the Isthmus of Panama sea level rose 2.7 million years ago.

In order to survive this long journey, the gomphotheres gradually evolved with respect to their surroundings.

“We all generally know what mastodons and woolly mammoths looked like, but gomphotheres aren’t nearly as easy to categorize,” Narducci said. “They had a variety of body sizes, and the shape of their tusks differed widely between species.”

Natural selection, for example, resulted in some gomphotheres having a second set of tusks attached to the lower jaw.

Moreover, the gomphotheres from Montbrook sported a unique spiral banding of enamel on each tusk. According to the researchers, only one such group of gomphotheres with this banding pattern has been known to exist. And this identification helped the team to narrow down its genus to Rhyncotherium, which dominated parts of North and Central America.

However, due to climate change and overhunting, this population began to gradually decline. The last gomphotheres and many other large mammals vanished at the end of the ice ages.