Dinosaur-Era Footprints Found In Angola Cave Include ‘Exceptionally Large’ Mystery Mammal

Nearly 70 distinct footprints from several prehistoric dinosaurs, mammals and a crocodile were recently unearthed at a diamond cave in Angola, making them the first tracks of their kind ever found in the African country. The impressions were left around 118 million years ago in sediment near what was once a lake and were probably left at different times, according to paleontologists who presented their findings Wednesday at the Society of Vertebrate Paleontology's annual meeting in Berlin.

One of the most impressive finds were the tracks of a mammal with five distinct digits that measured about 0.6 inches (1.5 centimeters) long and would have belonged to an animal about the size of a modern-day raccoon, according to LiveScience. Most early mammals were no larger than rats, making the discovery of an animal “exceptionally large for its time” a very rare find, researchers told LiveScience. It wasn’t until about 65 million years ago, after the extinction of the dinosaurs, that mammals began to evolve into their modern descendants.

Figuring out what kind of mammal made the rare footprints proved difficult. "We cannot narrow down to a species but we can say they do belong to – they were made by an exceptionally large mammal – that we can say for sure,” Marco Marzola, a paleontologist with the PaleoAngola Project, told IBTimes UK.

Nearby, 18 sauropod tracks were discovered in the sediment. Sauropods were long-necked dinosaurs with relatively small skulls and brains. Their bones and footprints have been found on all continents, except Antarctica, indicating they were geographically widespread, according to the University of California, Berkeley.

Scientists discovered the Angola diamond mine tracks in 2010 and 2011. "Incredibly, the society of Catoca [where the mine is located] stopped all activity in that sector of the mine," Marzola told Live Science. He said the miners “renounced potential income from their own mine just to promote science — to promote vertebrate paleontology in Angola and in Africa."