Paleontologists in China have unearthed and examined three adult skeletons and five clutches of embryo-containing eggs of Qianlong shouhu, a previously unknown species of Early Jurassic sauropodomorph dinosaur. Most significantly, these fossils provide strong evidence for the earliest known leathery eggs.
Qianlong shouhu lived in what is now China during the Early Jurassic epoch, between 200 and 193 million years ago.
The dinosaur belongs to Sauropodomorpha, a group of plant-eating long-necked dinosaurs that includes the largest animals ever to walk the Earth.
The ancient creature was approximately 6 m (20 feet) long and weighed around 1 ton.
The fossilized remains of Qianlong shouhu — three adult skeletons and five clutches of eggs — were found in the Ziliujing Formation in Guizhou Province, southwestern China.
“The embryos display some differences from the adults, e.g., a proportionally longer skull, a more vertical anterior margin of the snout, and fewer teeth,” said China University of Geosciences paleontologist Fenglu Han and colleagues.
“Allometric analyses of limb ratios between the adult and embryonic specimens indicate that adult Qianlong shouhu was able to walk on its hindlimbs, but the babies were likely quadrupedal.”
“The general taphonomical and sedimentary features indicate that Qianlong shouhu might have practiced colonial nesting as a reproductive behavior, similar to other basal sauropodomorphs including Massospondylus and Mussaurus.”
According to the team, Qianlong shouhu had relatively large eggs with a relatively thick calcareous shell formed by prominent mammillary cones compared with other early-diverging sauropodomorph dinosaurs.
“Our results show that Qianlong shouhu possessed eggshell microstructures similar to other Cretaceous dinosaur egg fossils, which likely consisted of two layers — the mammillary layer and continuous layer — and had fully developed eggshell units,” the researchers said.
“The calcareous…
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