Primitive Snake

Pachyophis woodwardi. Bilek, Bosnia and Herzegovina. 100 million years.

One of the most primitive and oldest snakes in the world. This specimen was used for the first scientific description of the species Pachyophis woodwardi in 1923 (holotype).

100 MILLION YEARS
Pachyophis was a marine snake. Its thick ribs acted like lead weights to counter its buoyancy in the water. Although significantly different from modern snakes, it was correctly identified in 1923 by its first scientific describer, the naturalist Baron Nopcsa. “Despite all the curious features of its structure, its teeth and the number of ribs indicate that Pachyophis was a true snake!”
Snakes have had an eventful history. Land-living four-legged reptiles were the ancestors of the marine saurians from which the marine snake Pachyophis evolved. In the Cretaceous period, while Pachyophis was swimming in the oceans, its relatives were conquering the land. Primitive snakes like Pachyophis died out at the end of the Mesozoic era, and modern snakes only returned to the sea in the latest chapter of the Earth’s history, the Neocene.
The evolution of snakes shows that the evolution of an order is not always in one specific direction. The repeated transitions from water to land and back also left traces in the skeleton, although these are not always unambiguous.
This is why primitive snakes still pose a riddle for researchers: did the members of the Pachyophis species have hind limbs or not?