<h1 class="pgc-h-arrow-right" data-track="2" > Shanxi discovered the top marine killer 290 million years ago! </h1>
On August 25, Chinese paleontologists published a paper in the international academic journal Journal of Geology describing the fossils found in Yangquan City, Shanxi Province, belonging to a prehistoric shark that lived 290 million years ago.
<h1 class="pgc-h-arrow-right" data-track="44" > strange fossil under Yangquan</h1>
Located in the eastern part of Shanxi Province, Yangquan is an important coal-producing area in Shanxi Province, but the coal layers here are not thick and superimposed, and there are several layers of lime layers in the middle.
Photo note: Coal mine in Yangquan, Shanxi, picture from the internet
As we all know, coal is finally formed by the accumulation and decay of forests in ancient times for many years, and then after a long period of compaction and deterioration. Most of Shanxi's coal was formed during the late Carboniferous to early Permian periods, when Shanxi happened to be located on the seashore, and periodic intrusions left a marine lime layer in the coal layer. It is in the lime layer of these marine facies that paleontologists have found a large number of fossils of marine organisms such as echinoderms, brachiopods, cephalopods and so on.
In addition to the fossils listed above, paleontologists have found seven unique fossils in the Taiyuan Formation's Lime Layer in the Yangquan area, dating back to the Early Permian period, 298 million to 290 million years ago, which has aroused the interest of paleontologists. Gai Zhikun, an associate researcher from the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences, cooperated with Bai Zhijun of the Yangquan Municipal Bureau of Planning and Natural Resources, and Zhang Junwen of the Yangquan Branch of the Second Geological Survey Institute of Shanxi Province to study the fossils and try to uncover the secrets.
Image note: Fossils found in Yangquan, picture from the internet
<h1 class="pgc-h-arrow-right" data-track="43" >-flap tooth shark preys on real sharks</h1>
After research, paleontologists judged that these fossils belonged to the flap tooth shark, which is a very primitive shark species, which was named by the famous British paleontologist Richard Owen in 1840, and then found in many parts of North America and Europe, with as many as 13 species, and the flap tooth found in Yangquan, Shanxi, belongs to the Ohio flap tooth shark (Petalodus). ohioensis）。
Photo note: Gai Zhikun, associate researcher of paleontologist who led the study, picture from the internet
Image note: Fossils of flap-toothed sharks, image from the web
Based on the size of the teeth, paleontologists judged that these sharks were between 3 and 5 meters long, which was considered large creatures at the time. The flap-toothed shark has a streamlined body with a large head, a pair of large eyes on either side of the head, and a mouth full of strong teeth. Unlike today's sharks, the dorsal fin of the flap-toothed shark is short and wide, the pectoral fin is huge, and the shape of the ventral and caudal fins is also relatively primitive.
Illustration: A restoration of the flap-toothed shark, picture from the internet
Image note: Restoration of the shape of the members of the order Flavonodontis, picture from the internet
Why do flap-toothed sharks look like this? That's because the flap-tooth shark is not one with today's sharks. The current classification believes that the flap tooth shark belongs to the euchollic bone class, which is more primitive than the plate gill suborder and the whole head subclass in the cartilaginous fish class, and almost all the sharks in the ocean today belong to the plate gill subclass, so although there is a "shark" in the name of the flap tooth shark, the relationship with sharks is actually not close. Paleontologists have always believed that the entire order of flap-tooth sharks, including the flap-tooth shark, is a slow-moving benthic shark, but the fossils found in Yangquan, Shanxi have changed this view.
<h1 class="pgc-h-arrow-right" data-track="45" > The Permian great white shark</h1>
There are 17 species that have been named and described as a whole, but most of them retain only fossilized teeth, so there is little information on the restoration of their shape. The only surviving members of the order Flavondae with intact fossils are the Belantsea shark found in the United States and the Janassa shark found in Germany and the United Kingdom. In the case of the Belanthi shark, for example, because the fossils preserved the contours of its body, paleontologists found that it resembled a poisonous scorpion in the ocean today, lying on the bottom of the sea like a stone. The Gianasa shark has a more streamlined appearance, but at first glance it is a slow-moving shark that spends all day on the ocean floor feeding on brachiopods and bivalves.
Image note: Fossils of the Belanthi shark, image from the Internet
Image note: Restoration of the Belanthi shark, picture from the Internet
Unlike most members of the family, the flap-toothed shark is highly capable of swimming and is an active predator. The reason why the flap tooth shark is very strong in swimming is because paleontologists have only found fossils of the flap tooth shark in North America before the fossils found in Yangquan, Shanxi, and the fossils of the same shark have been found in two places so far apart, which is enough to prove that they have swam over a long distance; as for the flap tooth shark, it is because the bladed edges on the crown of the teeth and the ridge stripes on the root of the teeth have been found in the fossils of their teeth, which are cutting and fixing structures. Apparently evolved to facilitate the hunting of active and large animals.
Illustration: Paleogeographic distribution of the genus Flaptooth shark in the Permian Ural period, image from the network
The fossil flap-tooth shark found in Yangquan, Shanxi, was the first time this shark was found in China, and the study of this discovery proved that the flap-tooth shark was not a slow-moving benthic animal like previously speculated, they not only had the ability to migrate across the ocean, but also preyed on other marine life like today's great white shark, and was the top killer in the ocean at that time.
Restoration of the flap tooth shark found this time, by Yang Dinghua
Resources:
1.Halsey W. Miller, Jr.; Transactions of the Kansas Academy of Science (1903-) Vol. 60, No. 1 (Spring, 1957), pp. 82-85
2.Report on the Geology of the County of Londonderry, and of Parts of Tyrone and Fermanagh. Memoirs of the Geological Survey of the United Kingdom, district mem. Geol. Surv. Ireland, Dublin, xxxi + 784 pp., A. Milliken, 1843, 784pp
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