< h1 class = "pgc-h-arrow-right" > the last ichthyosaur, witnessing the end of the Mesozoic marine family</h1>
Keywords: Ichthyosaur Cretaceous Paleontology Marine Reptiles Dinosaur Age Fossils
Ichthyosaurs are the most famous family of sea climbers of the Mesozoic Era, and they are named for their streamlined shape like fish. Although they once chased the waves in the ocean, ichthyosaurs did not persist until the end of the Mesozoic Era, they disappeared in the early Late Cretaceous, so who was the last ichthyosaur?
Saratov Oblast is located in the southwest of Russia, bordering Kazakhstan, from which the Volga River flows. Geographically, saratov oblast is located inland europe, but fossils of ancient marine life have been found. At the end of the last century, paleontologist Evgeniy Pervushov discovered a fossil (number SSU 104a/24) in the Saratov region that belonged to the incomplete skull of an ichthyosaur.
Illustration: Location of Saratov Oblast, picture from the internet
Photo note: Fossils found in Saratov Oblast, picture from the Internet
In 1998, paleontologists named the ichthyosaurs found in the Saratov Oblast as Pervushovisaurus, which can also be translated as Pelvusov Ichthyosaurus, whose genus names come from "Pervushov" and "saurus", meaning "Pervusov's lizard", and the name is dedicated to the fossil discoverer Pervusov.
Photo note: It is not easy to find an unclear photo of Pervusov, which comes from the Internet
Judging by the fossil strata found, Ichthyosaurus lived between 99.7 million and 94.3 million years ago, living in the earliest days of the Late Cretaceous, and its discovery also broke the assertion that ichthyosaurs did not extend into the Late Cretaceous (Late Cretaceous).
Everyone must be very curious, as the last ichthyosaur, what is unique about The Ichthyosaurus? The answer is a more high degree of adaptation to marine life. About 5.5 meters long and weighing about 2 tons, The Ichthyosaurus was large, most of which was a pointed snout, with two rows of sharp teeth growing in its slender mouth, exposing its predatory nature. There are a pair of nostrils on both sides of the mouth of Ichthyosaurus, and it is through the nostrils that they breathe air, and don't forget that Ichthyosaurus is a reptile that breathes through the lungs. Behind the nostrils, there is a pair of large, round eyes, indicating that Ichthyosaurus had excellent vision and was able to rely on vision to find prey in low-light environments.
Image note: Restoration of The Ichthyosaurus Paprika, picture from the Internet
The body streamline of Ichthyosaurus was not as fat as that of Ichthyosaurs of the Triassic and Jurassic, which effectively reduced the resistance encountered when swimming in the body. Like other ichthyosaurs, Ichthyosaurus had a triangular dorsal fin on its back, two pairs of fin-like limbs on either side of its body, one in front of the other, and a large crescent-shaped tail behind it. The body structure of the Ichthyosaurus showed that it had strong swimming abilities, just like today's dolphins.
Taxonomically , Ichthyosaurus belongs to the platypterygiinae under the family Ichthyosaurus macrocycae. In addition to its discoveries in Russia, paleontologists have also found fossils of Ichthyosaurus perceptii in Cambridge, England, which belongs to the second species of the genus Ichthyosaurus: P. campylodon。 At least from the fossil point of view, Ichthyosaurus was mainly distributed in the early Cretaceous European waters, when the formation of the Atlantic Ocean penetrated deep into Europe, making it a paradise for marine life.
Photo note: Fossils of Ichthyosaurus perceptus found in the UK, image from the Internet
As the last ichthyosaur, Ichthyosaurus did not show decline, and judging from the large number of preserved fossil teeth, its teeth were conical, the top was sharp, suitable for puncture, and it was a sharp tool for fishing. The piercing teeth, combined with the high-speed body, all represented that the Ichthyosaurus was able to travel at high speed through the ocean and prey on fish, just like today's swordfish.
Note: Fossil teeth of Ichthyosaurus Papri, picture from the internet
Photo note: A Peysper's ichthyosaur swimming in the ocean, picture from the Internet
Illustration Note: An analysis of the teeth and feeding habits of ichthyosaurs, the picture comes from the Internet
As an almost perfect speed hunter, no trace of ichthyosaur was found after Pesche Ichthyosaurus, and it became the last Ichthyosaur. In 2016, an article titled "Fish-shaped marine reptile extinction and decline in evolution rate and global environmental upheaval" was published in Nature Communications, researchers believe that the extinction of ichthyosaurs was indirectly caused by rising temperatures and sea levels during the Cretaceous period, because climate and environmental changes affected the food sources, breeding grounds, migration routes, etc. of ichthyosaurs, coupled with competition from sharks, which eventually led to the extinction of ichthyosaurs.
It has to be admitted that the Ichthyosaur family has evolved the most perfect body structure adapted to the ocean, but this great family of marine reptiles disappeared into the vast sea 27 million years before the Cretaceous mass extinction, leaving us with infinite regrets.
Picture note: A flat-palmed fish dragon swimming in the middle of the sea, the picture comes from the Internet
Resources:
1.Arkhangel’sky, M. S., 1998, On the Ichthyosaurian Genus Platypterygius: Palaeontological Journal, v. 32, n. 6, p. 611-615.
2.Fischer, Valentin; Arkhangelsky, Maxim S.; Naish, Darren; Stenshin, Ilya M.; Uspensky, Gleb N.; Godefroit, Pascal (2014). "Simbirskiasaurus and Pervushovisaurus reassessed: implications for the taxonomy and cranial osteology of Cretaceous platypterygiine ichthyosaurs". Zoological Journal of the Linnean Society. 171 (4): 822–841. doi:10.1111/zoj.12158.
3.Storrs, G. W., M. S. Arkhangel'skii and V. M. Efimov. 2000. Mesozoic marine reptiles of Russia and other former Soviet republics. pages 187-210 In Benton, M. J., M. A. Shiskin, D. M. Unwin and E. N. Kurochkin, (eds.), The Age of Dinosaurs in Russia and Mongolia, Cambridge University Press, Cambridge.
Image / Network (Intrusion and Deletion)
Text / Paleontological Exploration (Jiang Hong)
Typography / Paleontological exploration