Newly Discovered Dinosaur Looks Like a Nightmare Goose
Paleontologists discovered a 71-million-year-old carnivorous dinosaur in southern Mongolia that they believe they had a body built for swimming and diving for prey. Although it looks a lot like a modern bird, it is actually a non-avian dinosaur, meaning it is likely an example of convergent evolution, a phenomenon in which unrelated creatures develop similar properties.
The dinosaur is called Natovenator polydontus, or “swimming hunter with many teeth.” Recent analysis of his fossilized remains indicate the animal was bipedal and built for diving. A full description of the newly discovered animal is published in communication biology.
“Finding semi-aquatic dinosaurs means that the ecological diversity in dinosaurs was very high,” Yuong-Nam Lee, a paleontologist at Seoul National University and the study’s lead author, wrote in an email to Gizmodo. “More than 30 different lineages of tetrapods have independently invaded aquatic ecosystems. Why not for dinosaurs?”
Besides his many teeth, N. polydontus had a slender body and a long neck. From the trunk up, the extinct dinosaur may have looked a lot like a goose or a cormorant, a modern one diving bird, but it had a long tail. The skeleton is incomplete – the researchers found the skull, spine, a forelimb and some of the two hind legs – but the animal’s morphology could be deduced from the remains found.
“The angle between each rib shaft and its associated articulating vertebra is very low, like many diving birds, but unlike terrestrial theropods,” Lee said. “Certain extant diving birds–such as alcids and phalacrocoacids–also have ribs projecting backwards. In these animals, posterior ribs aid swimming by making the body more streamlined.
Lee’s team hopes they can find the bird’s stomach contents to learn more about its diet. That kind of discovery is not without precedent; last year, paleontologists found the fossilized marine equivalent of a turducken in modern-day Germany.
Also last year, there was another team made up of many of the same researchers behind the new paper announced the discovery of an armored ankylosaurus from the same region in Mongolia. She posited that the ankylosaurs may have dug defensive trenches when threatened, a lot like modern horned lizards.
More fossils will need to be found to better test these ideas, but taken together, the fossils show the dynamics of Cretaceous biodiversity.
#Newly #Discovered #Dinosaur #Nightmare #Goose