MADRID, Dec. 17 (Xinhua) -- The earliest known ancestor of the modern mammal, a creature vaguely resembling a dog, has been discovered on the Spanish island of Mallorca.
The discovery of the "gorgonopsid" was announced on Tuesday in a study published in "Nature Communications" by a team of scientists led by the Balearic Island Museum of Natural Sciences, the Catalan institute of Paleontology, and the Barcelona Autonomous University.
The gorgonopsian lived between 270 and 250 million years ago in the Permian period, before the Mesozoic Era, which includes the Triassic, Jurassic and Cretaceous periods when dinosaurs roamed the earth.
At the time, the region where now Mallorca is located formed part of the super-continent of Pangea and was situated around the latitude of the equator.
"Gorgonopsians are more closely related to mammals than to any other living animal, and although they have no modern descendants, nor are they our direct ancestors, they are related to species that were," explained Ken Angielczyk, one of the co-authors of the study.
Josep Fortuny, the main author of the article, said that is "very possible" that this "is the oldest gorgonopsid on the planet (...), all of the others that have been found are slightly younger."
The findings include most of the lower jaw and parts of the upper jaw from a skull that is almost 20 centimeters long and equipped with fearsome "saber-tooth" incisors.
Neck vertebrae, ribs and most of the beast's hind left leg have allowed scientists to deduce that the animal was around a meter and a half long, and walked with an upright gait similar to modern mammals -- not with the sprawled gait common among reptiles.
"If you saw this animal in the street, it would look a bit like a medium-sized dog, around the size of a Husky," noted Anglielczyk. However, the creature had not developed ears, a key trait in mammals, and was probably not covered in fur.
The gorgonopsids are thought to have died out in the mass extinction event that marked the end of the Permian period, around 251 million years ago.
This event, which was probably caused by massive volcanic activity lasting thousands of years, killed around 80 percent of marine species and 75 percent of all terrestrial vertebrate species. However, it opened the door for the arrival of dinosaurs and mammals during the subsequent Triassic period. ■