Footprints left by three ancient creatures found in diamond mine

[The title was written by my editor.]

Footprints dated to 118 million years ago were recently found in a diamond mine in Africa, and researchers suggest some are from a mammal that was larger than any thought to have lived during that time.

by John Tyburski

Copyright © Daily Digest News, KPR Media, LLC. All rights reserved.

First published at Daily Digest News on November 6, 2014

Scientists believe they have found the tracks of three members of the Cretaceous period, a prehistoric era dating back to about 118 million years ago. The tracks may be from a large, long-necked dinosaur, a crocodile-like creature, and mammal roughly the size of an adult raccoon. Researchers speculate that all three animals may have been attracted to the area, albeit at different times, by standing water.

The ancient tracks were found in Angola’s Catoca diamond mine, which is the fourth-largest diamond mine in the world. What are of particular interest are the tracks made by the mammal. Scientists have believed up to now that the largest living mammal of the Cretaceous period was only about the size of a squirrel or rat. However, the tracks found at Catoca mine indicate a substantially larger body size.

“Mammals evolved from very small-sized individuals,” said Marco Marzola, a paleontologist with the PaleoAngola Project, an international program investigating vertebrate paleontology in Angola. “The first mammals were the size of a squirrel or even smaller, like a mouse. They evolved to become bigger in size, but only after the time of the dinosaurs.”

Photos of the tracks have been published online. The tracks were first found by geologist Vladimir Pervov in December 2010 and number 69 total. An additional 18 tracks were found nearby, and two even show preserved skin impressions. These dinosaur tracks are likely from a sauropod, scientists say. Sauropods had long necks and were the largest terrestrial animals ever alive on Earth, according to the fossil record.

The mammalian tracks number almost 35 and exhibit five digits per paw measuring up to 0.6 inches. The longest digit on each paw as the middle digit. This animal seems to have walked flat-footed, bearing its weight on its entire paw, much like a bear, rather than on its tows like a dog or cat. The tracks indicate that it did not have claws.