Paleontologists have found a new yet extinct species of lizard and they believe that it may be the missing link that can help them understand how this group of animal evolved over the centuries.
The fossil of the Gueragama Sulamericana was found in Brazil and field experts say that the lizard roamed the Earth 80 million years ago.
Michael Caldwell, study author and professor of biological sciences from the University of Alberta (Canada), gave a statement saying that the newly discovered species is “a missing link in the sense of the paleobiogeography and possibly the origins of the group, so it’s pretty good evidence to suggest that back in the lower part of the Cretaceous, the southern part of Pangaea was still a kind of single continental chunk”.
Researchers have long said that present day iguanas are some of the most diverse lizards alive today. They’ve split them up in two (2) groups based on the shape on their teeth – Acrodontan Iguanians have them fused at the top of their jaw, whereas Non-acrodontan Iguanians don’t have their teeth fused at the top of their jaw. Acrodontan Iguanians live in the Old World, whereas Non-acrodontan Iguanians live in the New World.
Professor Caldwell also informed that there are about 1.700 species of iguanas in the word today, and that they are all “restricted to the New World” (from Southern United States to South America). But the odd part is that the iguana’s closest relatives are the chameleon and the bearded dragon, both Old World species.
The discovery of the Gueragama Sulamericana suggests that both the Acrodontan Iguanians and the Non-acrodontan Iguanians started out with a worldwide presence, as this is the first Acrodontan Iguanian to be found in the New World.
It’s an important finding because the distribution of animals and plants from the the Late Cretaceous offers valuable insight into the ancestry of the Pangaea from back when it was whole.
To reach these conclusions, professor Caldwell and his colleagues looked at the new fossil’s jaw and teeth. so far they’ve learned that the Gueragama Sulamericana is an old group of animals that most likely originated in the Southern Pangaean and split into the two (2) groups of Iguanians during the break up of the Pangaean.
Professor Caldwell explained that South America was isolated for a really long time (about 100 million years) and only bumped into North America around 5 million years ago. That’s when the north and the south started to exchange organisms.
He added that the discovery raises some biogeographic questions and faunal turnover questions that the scientific community has never considered before as Professor Caldwell stressed that the Gueragama Sulamericana “is an Old World lizard in the new world at a time when we weren’t expecting to find it”, and it opens doors for paleontologists as well as herpetologists to conduct further research.
He also pointed out that the group is much older than previously believed and that the next step for him and his team is to look at much older rock units in order to continue the discovery process.
The findings were published earlier this week, on Wednesday (August 26, 2015), in the journal Nature Communications.