A team of researchers and volunteers at the Florida Natural History Museum discovered an ancient 'elephant grave' containing the fossilized remains of a long-extinct ancestor of modern-day pachyderms. This discovery can also provide the largest animal specimen ever found in Florida, United States.
About 5.5 million years ago, a number of gomphotheres, ancestors of extinct elephants, died in or around prehistoric rivers that have now disappeared in northern Florida. Despite the possibility that the animals died at different times, hundreds of years apart, their bodies remained in the same location where they were 'buried' until early 2022.
At that time, the team found part of the skeleton of a gomphothere at the Montbrook fossil excavation site. A number of isolated fragments and bones were found at the site in the past, so there is no reason to ignore this site. A few days later, the volunteers found what appeared to be a large foot. Further work revealed that the find was part of the body of a gomphothere. Soon after, they found the entire skeleton, and it was a very exciting discovery for the team.
"This is a once-in-a-lifetime discovery. This is the most complete gomphothere skeleton from this time period in Florida and among the best in North America," said Jonathan Bloch, curator of vertebrate paleontology at the Florida Natural History Museum, quoted from IFL Science.
The animal is not alone. In the end, the team found the entire skeleton of one adult individual and at least seven juveniles. More in-depth research is needed before the team can accurately determine the animal's size. But Bloch is confident that the adult specimen was about 2.4 meters tall including the fangs, and the skull measured more than 2.7 meters. As an illustration, this animal is about the size of a modern African elephant. So far, the find is a record for a local gomphothere specimen.
"Modern elephants travel in herds and can be very protective of their young," explains Rachel Narducci, manager of the Florida Museum's vertebrate paleontology collection. "But in my opinion this is not a situation where they all died at once. It seems that members of one or several herds got stuck in this one place at different times," he explained.
"We've never seen anything like this at Montbrook. Usually, we only find one skeleton at this site. Gomphotheres must have been buried quickly, or they may have been trapped in a river bend with reduced flow," added Narducci.
Gomphotheres, along with modern elephants, are collectively called proboscidea. Elephants once abounded on most continents until humans arrived, and gomphotheres were among the most diverse.
These large mammals have a very long place in the fossil record, spanning more than 20 million years. They first appeared in Africa, then spread throughout Europe and Asia, finally crossing the Bering Land Bridge to North America. During this time, they developed various unique features that allowed them to survive wherever they settled.
"We all generally know what mastodons and woolly mammoths look like, but gomphotheres are not easy to categorize," Narducci said. "They have different body sizes, and the shape of their tusks is very different between species."
Usually, paleontologists use tusks as a way to identify a species. The gomphotheres at Montbrook have spiral bands of enamel that run along their tusks. Interestingly, only one group of gomphotheres with this pattern existed at the time, which allowed Bloch and Narducci to identify the species as belonging to the genus Rhyncotherium.
"A fossil site in southern California is the only other place in the US that has yielded large samples of Rhynchotherium juveniles and adults. We've learned a lot about the anatomy and biology of this group that we didn't know before, including new facts about the shape of its skull and tusks," said Bloch.
The discovery at Montbrook offers exciting prospects for future research and provides an opportunity to learn more about the large animals that roamed North America long ago.
"The best part is sharing this discovery process with so many volunteers from all over the state of Florida. Our goal is to assemble the skeleton of this monster and put it on display, taking its place alongside the iconic mammoths and mastodons already at the Florida Natural History Museum," said Bloch.