The Plesiosauria (It is a Greek word and its meaning is” near to” and Sauria) or Plesiosaurs are clade of Mesozoic marine reptiles or marine sauropsida, which belongs to the Sauropterygia.

Around 203 million years ago, Plesiosaurs initially showed up in the most recent Triassic Period, perhaps in the Rhaetian stage. During the Jurassic Period, they turned out to be particularly regular and were flourishing. But around 66 million years back, at the end of Cretaceous Period due to the Cretaceous–Paleogene extinction event they started. They had an overall maritime dispersion. The Plesiosauria after their complete growth gets length of 1.5 meters to 15 meters.

Plesiosaurs were among the primary fossil reptiles found. In the start of the nineteenth century, researchers acknowledged how unique and particular their manufacture was, and they were named as a separate order in 1835. The principal plesiosaurian family, the eponymous Plesiosaurus, was named in the first quarter of nineteenth century. From that point forward, more than a hundred legitimate species of Plesiosauria have been depicted. In the mid twenty-first century, the quantity of disclosures has expanded, prompting to an enhanced comprehension of their anatomy, connections and lifestyle.

Plesiosaurs had an expansive leveled body and a short tail. Their appendages had developed into four long flippers, which were controlled by solid muscles joined to wide hard plates framed by the shoulder support and the pelvis. The flippers made a flying development through the water. Plesiosaurs inhaled air, and bore live youthful; there are signs that they were warm-blooded.

Plesiosaurs indicated two primary morphological types. A few species of Plesiosaurs, with the “plesiosauromorph” manufacture, had (at times to a great degree) long necks and little heads; these were generally moderate and got little ocean creatures. Different species, some of them achieving a length of up to seventeen meters, had the “pliosauromorph” work with a short neck and a substantial head; these were zenith predators, quick seekers of extensive prey. The two sorts are identified with the customary strict division of the Plesiosauria into two suborders, the since quite a long necked Plesiosauroidea and the short-neck Pliosauroidea. Current research, notwithstanding, demonstrates that few long necked gatherings may have had some short-necked individuals or the other way around. In this manner, the absolutely clear terms “plesiosauromorph” and “pliosauromorph” have been presented, which don’t suggest an immediate relationship. “Plesiosauroidea” and “Pliosauroidea” today have a more constrained significance. The expression “plesiosaur” is appropriately used to allude to the Plesiosauria all in all, however casually it is now and then intended to demonstrate just the long necked structures, the old Plesiosauroidea. This post has been brought to you by The Natural History Museum located in Washington, D.C.