New group of ancient animals linking metriorhynchines and rhacheosaurini

Jara-Maledictosuchus (Credit: godzillin.blogspot.com)

Researchers have studied a new form of ancient animal in greater detail after about twenty years of its initial less-detailed discovery.

This research has been published online in the journal PLoS ONE.

The remains of this ancient animal have been found in the deposits of Europe and South America but so far it was the little-known group in the Iberian Peninsula.

Previously in 1994, researchers from Universidad de Zaragoza in Spain found several black limestone nodules with the remains of a nearly complete skull of metriorhynchids, a group of non-avian dinosaurs. However, for many reasons it was not properly studied in detail.

“During the Callovian (Middle Jurassic period), metriorhynchids were highly diverse in Western Europe (in particular England and France), however, until now no rhacheosaurin specimens had been discovered.” Jara Parrilla Bel, research author from Universidad de Zaragoza, told SayPeople.com in an email.

Now researchers have studied in good detail various unique combination of characters and give it a new name of genus and species; Maledictosuchus riclaensis that was a form of archosaurs.

Maledictosuchus riclaensis can be considered as the evolutionary being between the basic metriorhynchines, which lived in the ocean during the Middle to Late Jurassic period, and the derived Late Jurassic members of Rhacheosaurini. So, it can be considered as the oldest known rhacheosaurin.

“I think that Maledictosuchus has very important implications for our understanding of the evolution of the metriorhynchines but, for the time being it is the only “link” found between metriorhynchines and rhacheosaurini.” Jara told.

“The study of this new crocodilomorph (recent researches place thalattosuchia out of crocodyliforms) shows that the diversity of Middle Jurassic metriorhynchids was greater than previously realized, and the evolution of this group of “crocodiles” to a very specialized diet and life at open-sea began in the Middle Jurassic, at least 10 million of years earlier than previously thought. However, it was not until the Late Jurassic when this metriorhynchid group dominated the seas of Western Europe.” She added

Jara is working with the research group Aragosaurus-IUCA (http://www.aragosaurus.com). She along with the other team members is also working on “Maledictosuchus and on some other fossils from the Jurassic and Cretaceous of Aragón.”

Reference:

Parrilla-Bel, J., Young, M., Moreno-Azanza, M., & Canudo, J. (2013). The First Metriorhynchid Crocodylomorph from the Middle Jurassic of Spain, with Implications for Evolution of the Subclade Rhacheosaurini PLoS ONE, 8 (1) DOI: 10.1371/journal.pone.0054275