The stays of a newly found stegosaur with enormous backplates, lengthy tail spikes and a teensy head belong to one of many oldest dinosaurs of its form on file, a brand new examine finds.
The armored dinosaur, a newfound species known as Bashanosaurus primitivus, lived throughout the Center Jurassic interval (174.1 million to 163.5 million years in the past) in what’s now China. As one of many oldest stegosaurs on file, its discovery provides extra proof that these plant-eating dinosaurs presumably originated in Asia, the researchers mentioned.
“Bashanosaurus primitivus is without doubt one of the earliest information of Stegosauria on this planet up to now,” examine co-lead researcher Ning Li, a scientist on the Chongqing Laboratory of Geoheritage Safety and Analysis in China, informed Reside Science in an e mail.
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The invention of B. primitivus‘ stays started in 2015, when a shepherd named Zheng Zhou discovered a bone-like stone in Chongqing, in southeast China. He informed Li’s lab, which confirmed that the “stone” was truly a dinosaur fossil. After excavating the location at Laojun Village for 2 years, Li and his colleagues discovered a exceptional mishmashed assortment of dinosaur bones — about 5,000 in all — that included the fossils belonging to the newly described stegosaur.
“It is like the place I work at Dinosaur Nationwide Monument [in Utah], the place they’re getting a number of completely different sorts of dinosaurs preserved in a single gigantic bone mattress,” ReBecca Hunt-Foster, a paleontologist at Dinosaur Nationwide Monument who was not concerned within the examine, informed Reside Science. “I am curious to see what else they get out of that website.”
The staff named the 168 million-year-old herbivorous beast Bashanosaurus for “Bashan,” the traditional identify of Chongqing, and primitivus, which is Latin for “first.” Throughout its lifetime, B. primitivus measured greater than 9 toes (2.8 meters) lengthy from snout to tail. This can be a little smaller than later stegosaurs, Hunt-Foster famous.
Based mostly on an evaluation of the sediments the place B. primitivus was discovered, the staff decided that the stegosaur lived in a delta by a shallow lake throughout a scorching drought, Li mentioned.
The traditional beast joins a rising variety of identified stegosaurs. These dinosaurs, of which there are 14 identified species, lived on each continent besides Antarctica and Australia. The brand new species has a couple of variations from its relations — together with the bases of its armor plates, that are thicker and curve outward, not like the plates on the backs of its later relations, Li mentioned.
“Bashanosaurus might be distinguished from different Center Jurassic stegosaurs, and clearly is a brand new species,” Li mentioned. “Nevertheless, it does have similarities with among the first armored dinosaurs, that are over 20 million years older.”
The opposite earliest identified stegosaurs, Chungkingosaurus (Chongqing “lizard”) and Huayangosaurus (Huayang “lizard”), are additionally from the Center to Late Jurassic Shaximiao Formation in China, which Li mentioned might trace that stegosaurs originated in Asia.
The brand new spiky dinosaur “is a fairly vital animal for determining stegosaur evolution,” mentioned Andrew Farke, the director of the Raymond M. Alf Museum of Paleontology in Claremont, California, who was not concerned with the brand new examine. “Though this group is so iconic, we nonetheless have a ton to find out about their preliminary evolution.” By finding out B. primitivus, scientists can find out how early stegosaurs did — or didn’t — resemble their better-known descendants, he added.
As for whether or not stegosaurs originated in Asia, that is nonetheless up within the air. “There may be additionally an early stegosaur of about the identical age identified from South America, so I think that the worldwide image might have been fairly difficult,” Farke informed Reside Science in an e mail. “We simply do not have the fossils but.”
The examine was revealed on-line Thursday (March 3) within the Journal of Vertebrate Paleontology.
Initially revealed on Reside Science.