'Pocket' Sauropod Dinosaur Reveals More about Giant's Evolution

Sauropods were the largest animals to ever walk across the face of the Earth. At about 40 meters long and 100 tons in weight with their long necks and small heads, these creatures grazed on vegetation millions of years ago. Now, researchers have uncovered the fossil remains of a "pocket" sauropod, which reveal a bit more about the evolution of this large dinosaur.

The new "tiny" sauropod is only six meters long and weighs just .8 tons. Discovered at a quarry in northern Germany, the fossils are some of the best sauropod remains ever discovered.

In the Late Jurassic about 150 million years ago, Europe was an archipelago, and most reptile fossils from the continent were those of marine species. The few dinosaur remains discovered would have been washed into the sea from islands including the small sauropod, called Europasaurus. It would have lived on one of these islands, which explains why it evolved as a dwarf island species.

Earlier analysis of backbone remains suggested the existence of two different types of Europasaurus. Now, researchers have been able to confirm this dimorphism.

Why does it occur? The two types of examples could be male and female sauropods. Another theory is that the populations from two different islands have been preserved in the quarry, and that the populations were separated in time by several thousand years.

The findings reveal a bit more about the evolutionary dwarfing of Europasaurus. This, in turns, sheds light on the unique gigantism of sauropod dinosaurs.

The findings are published in the Journal of Systematic Palaeontology.