The ancestor of calcareous mammals discovered in China

2002/04/25 Carton Virto, Eider - Elhuyar Zientzia

• Paleontologia
• Arkeologia

Scandalous eomaia is important for two reasons: as can be seen in photography, because it is complete and is one of the oldest ancestors of calcareous mammals, among them us.

The treasure has been found in the prosperous Chinese site Yixian. It has found important fossils of the Cretaceous, such as feathered dinosaurs that have provoked great controversy. But Eomaia, more than a debate, has created joy. Until now there were only a few teeth of mammals so old.

Analyzing the teeth and skeleton of the fossil, the researchers concluded that it was a kind of line of calcareous mammals and that it was very primitive. When it comes to very thin slopes, the researchers believe that this animal had a short gestation and that, later, the process was completed as the modern martsupialios do, that is to say, that although the Eomaia belongs to the line of calcareous animals, it is a species at the beginning of the evolution of the line.

Currently, according to the form of fertilization, mammals are divided into three groups: carenous, martsupials and egg speakers. But it is believed that in the Cretaceous there were seven groups. Four disappeared and only the three mentioned above prospered.

The researchers believe that thanks to the Yixian site they will be able to portray the mammals of the time and discover why some continued ahead. For the moment, Eomaia is adapted to climb the trees, as the marsupials of the time. The lines that disappeared do not seem to have that capacity.

Did Eomaia save climbing skills? According to experts, until no more fossils have been found, this question cannot be answered with certainty. The next well preserved calcareous skeleton, 50 million years younger, had already appeared with cockpit adapted to run and jump. Intermediate fossils can have the key.