Antarctica discovery reveals oldest known mammal footprints

Paleontologists have discovered the oldest known evidence of a terrestrial carnivorous mammal in Antarctica. The fossilized footprints, found in the Fossil Hill Formation on King George Island, date back approximately 55.5 million years to the early Eocene period.

According to a study published in the journal Polar Biology, the specimen (cataloged as T-313) consists of natural molds of a hand and foot preserved in volcanic sediment. The best-preserved footprint measures roughly two centimeters in both length and width, displaying a digitigrade posture and a compact plantar pad.

Lead researcher Héctor Mansilla Vera of the Chilean Antarctic Institute (INACH) noted that the morphology suggests the animal had a minimum body mass of 1.3 kilograms. While the exact species cannot be confirmed, the size and shape suggest the tracks were made by a small sparassodont, an extinct group of hypercarnivorous mammals related to marsupials, similar in niche to a weasel or badger. This discovery challenges previous ecological reconstructions that identified terror birds as the primary terrestrial predators in the Antarctic Peninsula during that era.