During the Early Cretaceous period, 123 million years ago, two small dinosaurs were resting in underground caves. Suddenly, the ground shook, the cave collapsed in an instant, and the baby dinosaur was buried alive before he could escape. Little did they know that their bones would turn into fossils and be discovered by humans, becoming the new Chinese dinosaur to be named in 2020.
China's Liaoning Province is a world-class paleontological fossil production area, especially the famous Rehe biota, exposing one after another shocking discoveries, including the Chinese dragon bird, the little robber dragon, the feather king dragon and so on.
Near the village of Lujiatun in western Liaoning Province, local farmers have found two dinosaur fossils, which were collected by the Liaoning Paleontological Museum at Northeastern University in Shenyang, numbered pmol ad0114 and pmol lfv022 (pmol is the abbreviation of the paleontological museum of liaoning).
Photo note: Fossils found near Lujiatun Village, image from Liaoning Paleontological Museum
The fossils from Lujiatun Village are quite complete, and the bones maintain a linked state, which can be said to be a fine product. A joint team of paleontologists from China, Argentina and Belgium studied the fossils, and the research paper "A new basal ornithopod dinosaur from the lower cretaceous of China" was published in the journal Peerj, and the dinosaur was named "Long-sleeping Dragon".
The genus name changmiania comes from the Chinese character "changmia", which represents the sleeping posture of its fossils. The model species of The Long-Sleeping Dragon was named Changmiania Liaoningensis, and the model species name was the Liaoning Province where its fossils were found.
The Long-Sleeping Dragon was a very small dinosaur, about 1.17 meters long and weighing only a few kilograms, which was the only size that could move in narrow underground caves. As a suborder of ornithopod dinosaurs in a basal position, the shape and structure of the long-sleeping dragon resembled the familiar prismatic dragon.
Photo note: Fossil and restoration of the long-sleeping dragon, picture from the Liaoning Paleontological Museum
The Long Sleepy Dragon has a large head, the shape of the head is pointed forward and wide, and the front is a beak made of hard matter. Despite its beak, the long-sleeping dragon still had incisors and longer canine teeth, but it has become significantly shorter than its ancestors. Most of the teeth of the long-sleeping dragon are grown in the cheeks, and the teeth are small leaf-shaped, able to chop and simply chew plants and other foods. The eye socket hole of the long-sleeping dragon is quite large, which proves that it has a pair of large eyes, and its vision must be very good.
Photo note: Fossil skull of a long-sleeping dragon, picture from Liaoning Paleontological Museum
The Long-Sleeping Dragon had a short neck and a strong body, with a long tail behind it. The forelimbs of the long-sleeping dragon are significantly shorter, and the hindlimbs are much longer, and it is a typical animal with bipedal standing and running on the hind limbs. Judging from the body structure of the Long Sleepy Dragon, it has a strong athletic ability and can run at high speed. Although no traces of hair have been found in the fossils, the dinosaurs of the Rehe biota generally had feathers, and we found that kulindadromeus, which was related to the long-sleeping dragon, also had feathers, so it was also covered with hair when restoring it. If you look closely at the restoration of the long-sleeping dragon, you will find that only the tail on its body is not hairy, but scales, which is also a reference to the restoration of the Gulinda Ben dragon.
Illustration: Restoration of Gulinda Benlong, picture from the Internet
The sleeping dragon not only retained the complete fossils, which can help us accurately restore its appearance, but more importantly, the two fossils found preserved the sleeping posture. From the sleeping position, the long-sleeping dragon is lying on the ground with its limbs folded, and its back, neck and skull are bent to one side. Because the tail of the long-sleeping dragon is relatively stiff and cannot be curled, it is extended backwards, which is different from the first kind of dragon (mei) that found that it maintains a sleeping posture, and the tail of the dragon is much more flexible and soft, and can surround the body in a circular shape.
Photo note: Fossils of the Dragon, picture from the Internet
The possibility that the sleeping dragon may have dug a hole is only speculation, because no direct evidence of its burrowing has been found, but considering the discovery of oryctodromeus cubicis in North America, paleontologists believe that the sleeping dragon also had similar habits, which also explains why the found long-sleeping dragons all maintained a sleeping posture, and the fossils were intact, just in line with the hypothesis that the cave collapsed and was buried.
Illustration: Restoration of the digging hole of the dragon, the picture is from the network
Although the Long Sleepy Dragon can dig holes, from the perspective of the structure of its limbs, it only has primary digging ability, and it cannot dig deep or very complex caves, and can only be regarded as the level of a primary digging technician. Why did the Long Sleepy Dragon dig a hole, and wouldn't it be freer to live on the ground? From the stratigraphic point of view, the long-sleeping dragon comes from the Lujiatun layer of the Yixian Formation of the Rehe Group, and the carnivorous dinosaurs found in the same formation include daliansaurus, slender tarposaurs (graciliraptor), sinusonasus (sinusonasus), and Chinese dragons (sinovenator). So many small and ferocious carnivorous dinosaurs live with the long-sleeping dragon, which shows that the long-sleeping dragon lives in a dangerous world, and the ground is so dangerous that it can only seek refuge underground. The habit of the long-sleeping dragon to dig a hole is definitely forced out, its large eyes are also to adapt to the dark environment in the cave, the long-sleeping dragon may also be a nocturnal animal, after all, the night is much safer than the day.
Illustration: A restoration of the Slender Thief, picture from the network
Photo note: A restoration of the Chinese dragon hunter, the picture comes from the network
In addition to the preservation of sleeping positions, another feature of the fossils of the long-sleeping dragon is the preservation of small stones in the stomach, most likely gastroliths. Gastroparagus was found in gasparinisaura, found in South America, to help dinosaurs grind plant fibers and speed up the digestive process. It seems that the long-sleeping dragon is full and resting in the cave, and the stomach stones in the stomach are accelerating the digestion of food.
Picture note: A small pebble in the stomach of a long-sleeping dragon, picture from the Liaoning Paleontological Museum
Caption: A model of Gaspary Nylon, picture from the web
Liaoning Long-Sleeping Dragon is a new Chinese dinosaur named in 2020, and its discovery gives us more information about the habits of dinosaurs, which slept underground for 123 million years until the study of paleontologists "woke it up"!
I would like to thank yang Yuqing, the first author of the research paper, for his review comments and the fossil photos provided by the Liaoning Paleontological Museum.
Resources:
yang, y.; wu, w.; dieudonné, p.; godefroit, p. (2020). "a new basal ornithopod dinosaur from the lower cretaceous of china". peerj. 8: e9832.
Image / Network (Intrusion and Deletion)
Text / Jiang's Little Thief Dragon (Jiang Hong)
Typography / Jiang's Little Thief Dragon