Before dinosaurs came along, one of Earth’s top predators was a salamanderlike amphibian that lived in tropical areas of the supercontinent Pangaea. Fossils unearthed from a 30- to 40-centimeter-thick bone bed in southern Portugal suggest the creature was more than 2 meters long, weighed as much as 100 kilograms, and had a broad flat head the size and shape of a toilet seat. The newly described species (artist's representation shown), which lived between 220 million and 230 million years ago, was one of the largest in a group of amphibians known as metoposaurs and is the first known in this region from well-preserved fossils, the researchers report online today in the Journal of Vertebrate Paleontology. The species has been dubbed Metoposaurus algarvensis to honor the Algarve region of Portugal, where the fossils were unearthed. (Even though the genus name contains the Greek word saur, which translates as “lizard,” these creatures and their kin were amphibians.) The 4-square-meter area of the bone bed already excavated has yielded 10 skulls and hundreds of remains, suggesting that the creatures became concentrated in one area and then died when the lake they inhabited dried up, the researchers say. Because the beasts had spindly limbs probably insufficient to support their weight, they likely remained in the water most of the time, feeding on fish but possibly snacking on small ancestors of dinosaurs or mammals that wandered too near the waterside. Similar bone beds that include other species of metoposaurs have been found in what are now Africa, Europe, and North America—a hint that climate at the time was highly unpredictable and prone to lengthy droughts.
By Sid Perkins
Posted in Paleontology