Researchers Find 11-Million-Year-Old Worm Lizard Skull

World's first complete skull of an ancient worm-lizard has been found in Spain.

The intact skull of the peculiar creature was found by Arnau Bolet from Institut Català de Paleontologia Miquel Crusafont and colleagues. The specimen shows that the worm lizards haven't changed much in last 11 million years.

Amphisbaenians or worm lizards are a poorly studied group of lizards. There are currently 169 known species of  the legless creatures; most of them are found in Africa and South America. Rhineura floridana is a worm lizard found in Florida.

Bolet and colleagues have found an intact specimen of the lizard in the Mediterranean. Analysis of the 0.44-inch specimen shows that it belongs to the family blanids and is a distinct species called Blanus mendezi, Livescience reported.

Previously, researchers had found incomplete parts of the lizards in the Mediterranean and had to rely on molecular studies to study the evolution of these strange creatures.

"Their fossil record was until now limited to isolated and usually fragmented bones," Bolet told Live Science in an email. "Thus, the study of a complete fossil skull more than 11 million years old was an unprecedented opportunity."

The lizard lived during Middle Miocene (11.6 million years ago). Its fossil was found in sediments excavated in 2011 in the Vallès-Penedès Basin in Spain's Catalonia region, according to Livescience.

Researchers combined molecular, paleontological, and biogeographic data to study the specimen. They found the species might have emerged soon after the split between two main (Eastern and Western Mediterranean) extant groups of blanids, according to Physorg.

"The use of CT-scan techniques applied to this superbly preserved worm lizard fossil skull has allowed an unprecedentedly detailed description for an early member of the family, providing insights into the evolutionary history of this poorly known group of reptiles," Bolet said.

The study is published in the journal PLOS One.