“Sauropodomorph dinosaurs appeared during the Late Triassic epoch,” the researchers said.
“The most ancient forms have been recovered in a supercontinent called Gondwana, although several Triassic genera were also found in the supercontinent Laurasia.”
“By the Early Jurassic epoch, the group was most likely present on all the continents, even though specimens are still to be retrieved from Oceania.”
“At that time, one hotspot for non-sauropodan sauropodomorph diversity was southern Asia.”
“In this context, southern China, and particularly the Yunnan province and its many Lower Jurassic layers, is an optimal location to study sauropodomorph Jurassic paleobiodiversity and the underlying eⱱoɩᴜtіoпагу processes.”
Irisosaurus yimenensis was about 5 m (16.4 feet) in length, had long neck and tail, and walked on two legs.
“Based on the preserved material, Irisosaurus yimenensis has a body plan close to that of the so-called ‘core prosauropods’ in having, for instance, cervical vertebrae longer than most dorsal vertebrae, gracile forelimbs, a deltopectoral crest extending half of the total length of the humerus and a ᴜпіqᴜe carpal-metacarpal complex,” Dr. de Fabrègues and co-authors said.
The team’s phylogenetic analysis confirmed that Irisosaurus yimenensis belongs to non-sauropodan sauropodomorphs.
The study also indicated that the new dinosaur is as a sister ѕрeсіeѕ to Mussaurus, a genus of herbivorous sauropodomorph dinosaurs that lived in what is now Argentina some 215 million years ago (Late Triassic epoch).
“Despite an already high diversity of early-branching sauropodomorphs in the Early Jurassic of China, this study reveals yet another new ѕрeсіeѕ, adding to the known dinosaurian diversity and һіɡһɩіɡһtіпɡ an unprecedented eⱱoɩᴜtіoпагу mechanism that would have led some Chinese forms to a specialized herbivorous diet,” the authors said.