Approximately 5.5 million years ago, several elephant-like animals called gomphotheres died near a river in North Florida. Even though these deaths likely happened at different times, all of their bodies ended up in the same place, along with other animals that had a similar fate.
Today, the river is gone, but the fossils left behind have provided paleontologists with a unique look into prehistoric life in Florida. In early 2022, researchers and volunteers began excavating the gomphotheres at the Montbrook Fossil Dig, which is expected to be a groundbreaking discovery.
According to Jonathan Bloch, a paleontologist at the Florida Museum of Natural History, this find is extraordinary. It is the most complete gomphothere skeleton from this time period in Florida and one of the best in North America.
The excavation began when Bloch and his team found parts of a gomphothere skeleton in the spring of 2022. Since isolated gomphothere bones had been found at Montbrook before, they didn’t expect anything out of the ordinary. However, a few days later, a volunteer digging nearby uncovered the articulated foot of a very large animal.
The team soon realized that there were not just one but several complete skeletons, including one adult and at least seven juveniles. They still need to fully excavate the specimens to determine their size accurately, but Bloch estimates that the adult gomphothere stood eight feet tall at the shoulders. The skull, including the tusks, measures over nine feet in length.
According to Rachel Narducci, another researcher at the Florida Museum, it is likely that the fossils were deposited or transported to the area over time. It doesn’t seem like all the gomphotheres died at once, as modern elephants travel in herds and are protective of their young. It appears that members of one or multiple herds got stuck in this spot at different times.
Excavations at Montbrook have been taking place since 2015 when fossils were discovered on Eddie Hodge’s property. The site has yielded a rich layer of fossils up to nine feet deep in some areas due to the fine sands and compacted clays.
The fossil beds are located inland from the Gulf of Mexico, but during the late Miocene when the bones were deposited, the area was closer to the sea. As a result, the fossils found there include camels, rhinoceroses, llamas, as well as fish, turtles, alligators, and burrowing shrimp from both freshwater and saltwater environments. Additionally, older marine species like sharks are occasionally found due to the ancient limestone formations.
Over the years, paleontologists working at Montbrook have made significant discoveries, including the oldest deer in North America, the oldest known skull of a smilodontine sabertoothed cat, and a new species of extinct heron. Other fossils from that time period, like bone-crushing dogs and short-faced bears, can also be found in the fossil bed. However, intact remains are rare, as most animals were transported by running water before being buried. The discovery of several complete gomphotheres was unexpected.
Elephants and their relatives, including gomphotheres, are called proboscideans. Before humans arrived, they were found on almost every major continent. Gomphotheres were particularly diverse and had a fossil record spanning over 20 million years. They first evolved in Africa, then spread to Europe and Asia. By 16 million years ago, they had reached North America via the Bering land bridge, and when the Isthmus of Panama formed 2.7 million years ago, gomphotheres were able to cross into South America.
During their journey, gomphotheres evolved unique features that helped them adapt to different environments. They varied in body size, and the shape of their tusks differed among species. Some gomphotheres had a second set of tusks attached to their lower jaws, and the tusks of platybelodon gomphotheres were flattened and joined, resembling massive buck teeth.
The gomphotheres found at Montbrook have a spiral band of enamel running along the length of each tusk, giving them a distinctive appearance. Only one group of gomphotheres had this unique banding pattern at that time, which allowed researchers to identify the Montbrook fossils as belonging to the genus Rhyncotherium, once widespread in North and Central America.
Gomphotheres thrived in open savannahs that were common in Africa, Eurasia, and the Americas. However, a global cooling trend starting around 14 million years ago led to the spread of grasslands, which gradually replaced the savannahs. This change in habitat caused a decline in gomphothere diversity. Some species adapted to a diet primarily consisting of grass, but at the end of the Miocene, mammoths and elephants emerged and displaced gomphotheres. By the time humans arrived in the Americas, only a few gomphothere species remained, and they soon went extinct due to climate change and hunting.
The discovery at Montbrook sheds new light on Rhynchotherium gomphotheres and provides scientists with valuable insights into the diverse fauna that once inhabited North America. The researchers’ goal is to assemble the complete skeleton and display it alongside the mammoth and mastodon at the Florida Museum of Natural History, sharing the exciting discovery with the public.