An article published in the journal “PeerJ” describes the study of fossils with an estimated age between 167 and 164 million years, dating to the Middle Jurassic, of Razanandrongobe sakalavae. It’s the oldest discovered among those belonging to the group of notosuchians, which lived until the Cretaceous period. A team led by Dr. Cristiano Dal Sasso of the Museum of Natural History in Milan studied the skull of this reptile discovering the power of its jaws and teeth comparable to those of T.rex.
The first bones of Razanandrongobe sakalavae were discovered in Madagascar in 2006 by paleontologists Simone Maganuco, Cristiano Dal Sasso and Giovanni Pasini. There were too few of them to accurately classify that animal and the researchers only established that it belonged to the group of arcosaurs.
A few years later, other bones attributed to the Razanandrongobe sakalavae were discovered which showed typical characteristics of crocodiles. Further analyzes convinced the researchers that the animal belonged to the group of notosuchians (Notosuchia) and the sebecosuchian (Sebecosuchia) family.
Notosuchians were a large group of crocodyliform (Crocodylomorpha) reptiles that included crocodiles and a number of their extinct relatives. Our knowledge of their origin and evolution is very limited so this is a case where the discovery of some more bone fragment can provide new information and clarify doubts such as those about relationships with other reptiles.
The study of Razanandrongobe sakalavae is all the more important because it’s the oldest notosuchian discovered so far. From the size of the bones discovered it also appears the largest with an estimated length of 5-6 meters. This species’ age suggests that these reptiles originated in the southeastern area of the ancient continent called Gondwana.
Unlike modern crocodiles, ancient notosuchians didn’t crawl but walked erect on their legs. However, the most interesting features were in the similarities of Razanandrongobe sakalavae’s jaws and in particular of their teeth with those of T.rex. At the same time, this animal had some features characteristic of omnivorous species suggesting that it could hunt other animals but also feed on plants.
This new research on Razanandrongobe sakalavae provided new information that will help paleontologists to better understand the origin and evolution of notosuchians. It’s one of the cases where there was a big gap in the knowledge about a group of organisms that was partially filled with the discovery of some bones.