Earliest vertebrate living tree discovered

First climber already had extended fingers and a prehensile tail

Photo of one of the best preserved skeletons of Suminia getmanovi © Diane Sco / Field Museum
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260 million years ago - long before the dinosaurs ruled the earth - our ancestors had already conquered the trees: fossil paleontologists conclude
of a distant mammalian ancestor who already had a gripping hand with extended fingers and an opposable thumb. He is thus the earliest known climbing vertebrate.

Paleontologists have discovered several skulls and more than a dozen vertebrate skeletons in a single block of red sandstone from the Russian Kirov region. The well-preserved fossils, dated to an age of approximately 260 million years, are well preserved and come from both adult and juvenile mammals of an early ancestor of mammals, Suminia getmanovi.

Gripper fingers and thumb opposite

A closer examination of the skeletons, carried out by Jörg Fröbisch, a paleontologist at the Field Museum in Chicago, revealed a peculiarity of these approximately 50 centimeters large animals: their fingers were unusually long and the tail designed as a prehensile tail. Together with the movable, the fingers opposite - and thus "opposable" - this thumb indicates a climbing lifestyle.

Treetop as a new niche

This is surprising, because even the paleontologist would not have expected any tree-dwelling vertebrates in this early era. "It's a surprise, but it makes sense, " says the researcher. "This was a new niche for the vertebrates. There was food there and they could protect themselves from the predators on the ground. "For the first time in the vertebrate evolution, the animals were given access to a new area of ​​life high in the tops of the trees, benefiting from fewer predators and less competition.

Establishment of modern food chain hierarchies

At the same time, the new skeletal study also provides the first fossil evidence of a distribution of food resources among small, tree-living and large, herbivores. This apparently happened shortly after the modern ecosystems with many herbivores and few top predators had established themselves. Previously, in the era shortly after the departure of the organisms, these food chains did not yet exist. At that time there were only a few herbivores on land, most animals were insect eaters or fed aquatic. display

(Field Museum Chicago, 30.07.2009 - NPO)