An article published in the journal “Scientific Reports” describes a new species of lizard now extinct that lived in present-day Wyoming, in the USA, about 52 million years ago, in the Eocene period. Simon Scarpetta, a paleontology student at the University of Texas (UT) at Austin, named it Kopidosaurus perplexus because the various analyzes carried out on the available fossil skull give different results regarding its classification. The relationships also vary considerably depending on the type of analysis conducted, underlining the difficulties and uncertainties that may exist in both paleontology and biology field.

An article published in the “Journal of Systematic Palaeontology” reports the identification of a new species of mosasaur that lived between 66 and 72 million years ago, in the Cretaceous period. A team of researchers led by Catie Strong, a student in the Department of Biological Sciences at the University of Alberta, Canada, named it Gavialimimus almaghribensis after examining a skull and some bones discovered in a mine in present-day Morocco. The researchers noted the similarities of the teeth with those attributed to Platecarpus ptychodon, another mosasaur whose fossils were discovered in Morocco, but question the taxonomic validity of that species, so they created a whole new genus for the identified species.

An article published in the journal “Science” reports the study of the fossil remains of an ichthyosaur whose almost complete skeleton includes some sort of extras in the form of the fossil remains of another reptile, a thalattosaur of the species Xinpusaurus xingyiensis, in its stomach. A team of researchers examined these fossils discovered in China and dating back to the Triassic period attributing them to a Guizhouichthyosaurus tangae, a species belonging to the group of ichthyosaurs. There are arguments among paleontologists that they could be apex predators in their ecosystems, and the fact that an ichthyosaur devoured an animal as large as a thalattosaur is considered evidence that at least that species was indeed an apex predator.

An article published in the journal “Science Advances” reports a study on Stupendemys geographicus, a giant turtle that lived in today’s South America between 5 and 10 million years ago, in the Miocene period. A team of researchers led by Dr. Marcelo Sánchez of the University of Zurich studied a number of well-preserved carapaces of this animal that provided much more information than the fossils previously available, such as the fact that the males had horns. It was one of the largest turtles ever lived with a carapace that could be up to almost 3 meters long, lived in the areas around fresh water and was probably prey to the gigantic alligators of the genus Purussaurus.