Giant dinosaurs dug out of the cave

According to researchers, giant amphibian dinosaurs have once dug underground burrows to hibernate when water sources become scarce.

A fossil skeleton of Metaposaurus diagnosticus

The Metoposaurus diagnosticus weighs half a ton and is over 3m long. Researchers have found that the dry season, which spanned 230 million years ago, caused them to burrow and lie dormant underground to sustain life.

The burrowing behavior of Metoposaurus was discovered by Dorota Konietzko-Meie of Opole University (Poland) and Martin Sander of the University of Bonn (Germany), published in the Journal of Vertebrate Paleontology . From evidence such as Metaposaurus diagnosticus with flat, wide, broad head and large arm bones, the researchers concluded that in the rainy season, the species swam in the lake and when the dry season started, they burrowing underground. The researchers cut the bone layer of this species and found development rings, called annuli . Annuli is similar to wood grain, a bright ring and a dark ring showing a year of growth.

In other amphibian species, annuli usually consist of a wide range showing rapid growth in the rainy season and immediately adjacent to a narrow range to indicate slow growth in the dry season. But for Metoposaurus, after a long period of slow growth is a pause in the dry season.

Daily Mail page quoted Professor Konietzo-Meier: 'The long bones of species of Metoposaurus are very special. According to our interpretation it corresponds to a two-season climate, with a shorter, more favorable rainy season and a prolonged dry section when life conditions become more severe. '