An article published in the journal “Nature Communications” describes a study on Pahvantia hastasta, a relative of today’s arthropods that lived about half a billion years ago, in the Cambrian period. Stephen Pates of the British University of Oxford and Rudy Lerosey-Aubril of the Australian New England University examined fossils discovered many years ago in the mountains of today’s Utah, USA, after extensive preparatory work. They believe that this species belonged to the group of radiodonts, that it fed on microplankton and that this type of aquatic animal contributed to kickstart the diversification of life forms on the seabed in the Cambrian Explosion.

An article published in the journal “Nature Ecology & Evolution” describes a study on marine reptiles that lived in a sea area that crossed today’s northern Europe called Jurassic Sub-Boreal Seaway during the Jurassic period. A team of paleontologists coordinated by the University of Edinburgh analyzed the shape and size of teeth that belonged to reptile that lived over a period of 18 million years, discovering that the marine predators living in deep waters prospered when sea levels rose while species they lived in shallow waters declined or even became extinct.

An article published in the journal “Nature” describes a research on the origin and evolution of mammals’ great brains. Eva Hoffman and Timothy Rowe of the University of Texas at Austin’s Jackson School of Geosciences examined fossils of Kayentatherium wellesi, a relative of today’s mammals that lived in the Jurassic period, concluding that a key moment in their evolution was a kind of trading brood power for brain power.

An article published in the “Journal of Paleontology” describes a research on the theropod dinosaurs whose fossils date back to the Late Cretaceous and were found at the site of Ellisdale, in New Jersey, USA. Chase Brownstein of the Stamford Museum and Nature Center studied fossils belonging to various families: adrosauroids (Hadrosauroidea), tyrannosaurids (Tyrannosauridae), dromaeosaurids (Dromaeosauridae) and ornithomimosaurs (Ornithomimosauria). The Ellisdale site is sometimes overlooked but these findings can provide information on the diversification of theropods throughout North America.

An article published in the journal “Current Biology” describes the discovery of two species of dinosaurs belonging to the Alvarezsauria group, which shares many characteristics with modern birds, in north-western China. A team of researchers studied the fossils of the species that were named Xiyunykus pengi and Bannykus wulatensis recognizing some characteristics intermediate between the oldest species of that group and others that lived several million years later, showing for example how the morphology of their arms evolved slowly.