Viviparous snakes existed 47 million years ago.
This is proven by a find from the Messel Pit, which was examined by an Argentine-German team with the participation of Senckenberg researchers.
In the fossil of a pygmy boa about 50 centimeters long, the paleontologists discovered the skull bones of at least two embryos. They were more developed than those found in unlaid eggs.
Also, the small snakes lay well behind where the adult animal's stomach once stood.
Had it been swallowed prey, its bones would have been decomposed in the gut.
From all this, the scientists conclude that it is the fossilization of a pregnant, viviparous female.
According to Senckenberg, this is the world's first fossil evidence of the existence of viviparous snakes.
Even today, a number of lizard and snake species do not lay eggs, but give birth to their offspring directly.
Related to the dwarf boas of Central America
The Messel boa is named Messelophis variatus and is one of the most common snake species found in the pit.
The species is related to today's dwarf boas of Central America.
These reptiles are also viviparous.
This is actually a good survival strategy for colder regions, since the offspring are better protected from temperature fluctuations in the warm womb.
Many of today's viviparous lizards and snakes evolved in rather colder regions.
At the time of the Eocene, however, there was a greenhouse climate with average temperatures of 20 degrees in the Messelsee area.
Scientists have not yet found out why the boas did not lay any eggs.
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