The recent discovery of an ancient species of an adorable, chubby lizard helped scientists fill in the missing link in the evolution of lizards.
Paleontologists at the University of Alberta in Canada unearthed the 80-million-year-old remains of an extinct species of lizard in what is now known as the municipality of Cruzeiro do Oeste in Brazil.
In their paper published online on Aug. 26 in the journal Nature Communications, the researchers describe this newly found lizard species and how they identified the fossilized lizard by examining its tooth and jaw. They found that the ancient creature, named Gueragama sulamericana, holds clues to the history of iguanas.
"It's a missing link in the sense of the paleobiogeography and possibly the origins of the group," said Dr. Michael Caldwell, professor of biological sciences at the University, who also co-authored the paper. The biological sciences professor also said that the fossil likely originated from Southern Pangaea.
Five separate groups make up the lizard world, including specific types of lizards like the gecko and skink. Another group is that of iguanas, along with their close relatives. There are about 1,700 known species of lizard.
Down the stream of the animal kingdom, iguanas are further divided into two groups. One of which is the acrodontan group, where the teeth of iguanas are uniquely fused to the top of their jaws. The other is the pleurodont group, made up of iguanas whose teeth are fused to the side of the jaw.
The discovery of the lizard remains in Brazil now put a link to lizard evolution as seen in these two groups. Restricted to the Old World, the distribution of the chameleon and bearded dragon makes up the acrodontan group, covering Europe, Asia and Africa. Making up the New World, iguanas cover the pleurodonts group in the Caribbean and the Americas.
"As with many other scientific findings, this one raises a number of question we haven't previously considered," said a PhD student of Caldwell's Tiago Simoes who is the study's lead author. "This finding raises a number of biogeographic and faunal turnover questions of great interest to both paleontologists and herpetologists that we hope to answer in the future." In other words, unraveling the distribution of lizard species since Pangaea is an ongoing process."
