{"id":86163,"date":"2023-06-12T10:08:35","date_gmt":"2023-06-12T14:08:35","guid":{"rendered":"https:\/\/naturalsciences.org\/calendar\/?post_type=news&p=86163"},"modified":"2023-07-05T11:44:48","modified_gmt":"2023-07-05T15:44:48","slug":"new-dino-iani-was-face-of-a-changing-planet","status":"publish","type":"news","link":"https:\/\/naturalsciences.org\/calendar\/news\/new-dino-iani-was-face-of-a-changing-planet\/","title":{"rendered":"New Dino, \u2018Iani,\u2019 Was Face of a Changing Planet"},"content":{"rendered":"

\"Life<\/a>Life reconstruction of a juvenile Iani smithi<\/em>. Illustration: Jorge Gonzalez. CC-BY-NC. Click image for larger version.<\/span><\/p>\n

By Tracey Peake<\/a>, NCSU News<\/a><\/em><\/p>\n

A newly discovered plant-eating dinosaur may have been a species\u2019 \u201clast gasp\u201d during a period when Earth\u2019s warming climate forced massive changes to global dinosaur populations.<\/p>\n

The specimen, named Iani smithi<\/em> after Janus, the two-faced Roman god of change, was an early ornithopod, a group of dinosaurs that ultimately gave rise to the more commonly known duckbill dinosaurs such as Parasaurolophus<\/em> and Edmontosaurus<\/em>. Researchers recovered most of the juvenile dinosaur\u2019s skeleton \u2014 including skull, vertebrae and limbs \u2014 from Utah\u2019s Cedar Mountain Formation.<\/p>\n

Iani smithi<\/em> lived in what is now Utah during the mid-Cretaceous, approximately 99 million years ago. The dinosaur\u2019s most striking feature is its powerful jaw, with teeth designed for chewing through tough plant material.<\/p>\n

\"The<\/a>The lower jaw and teeth of new dinosaur Iani smithi<\/em>. Photo: National Geographic, Mark Thiessen and Becky Hale. CC-BY-NC. Click image for larger version.<\/span><\/p>\n

The mid-Cretaceous was a time of big changes, which had big effects on dinosaur populations. Increased atmospheric carbon dioxide during this time caused the Earth to warm and sea levels to rise, corralling dinosaurs on smaller and smaller landmasses. It was so warm that rainforests thrived at the poles. Flowering plant life took over coastal areas and supplanted normal food sources for herbivores.<\/p>\n

In North America, giant plant-eating sauropods \u2013 once titans of the landscape \u2013 were disappearing, along with their allosaurian predators. At the same time, smaller plant eaters, like early duckbills and horned dinosaurs, and feathered theropods like tyrannosaurs and enormous oviraptorosaurs, were arriving from Asia.<\/p>\n

\"Drawers<\/a>Drawers of Iani smithi<\/em> bones in the collections at the NC Museum of Natural Sciences. Photo: National Geographic, Mark Thiessen and Becky Hale. CC-BY-NC. Click image for larger version.<\/span><\/p>\n

Enter Iani smithi<\/em>, unique not only because it\u2019s newly discovered, but also because of its rarity in the North American fossil record and its position in dinosaur history.<\/p>\n

\u201cFinding Iani<\/em> was a streak of luck. We knew something like it lived in this ecosystem because isolated teeth had been collected here and there, but we weren\u2019t expecting to stumble upon such a beautiful skeleton, especially from this time in Earth\u2019s history. Having a nearly complete skull was invaluable for piecing the story together,\u201d says Lindsay Zanno, associate research professor at North Carolina State University, head of paleontology at the North Carolina Museum of Natural Sciences, and corresponding author of the work.<\/p>\n

Zanno and her team used the well-preserved skeleton to analyze the evolutionary relationships of Iani<\/em> and were surprised \u2014 and a bit skeptical \u2014 of the results.<\/p>\n

\u201cWe recovered Iani<\/em> as an early rhabdodontomorph, a lineage of ornithopods known almost exclusively from Europe,\u201d Zanno says. \u201cRecently, paleontologists proposed that another North American dinosaur, Tenontosaurus<\/em> \u2014 which was as common as cattle in the Early Cretaceous \u2014 belongs to this group, as well as some Australian critters. If Iani<\/em> holds up as a rhabdodontomorph, it raises a lot of cool questions.\u201d<\/p>\n

Key among these is, could Iani<\/em> be a last gasp, a witness to the end of a once successful lineage? Zanno thinks that studying this fossil in the context of environmental and biodiversity changes during the mid-Cretaceous will give us more insight into the history of our planet.<\/p>\n