Plesiosaurus dolichodeirus (Greek: πλησίος (plesios), near to + σαῦρος (sauros), lizard) is an extinct, large marine sauropterygian reptile that lived during the early part of the Jurassic Period, and is known by nearly complete skeletons from the Lias of England, United Kingdom. It is distinguishable by its small head, long and slender neck, broad turtle-like body, a short tail, and two pairs of large, elongated paddles. It lends its name to the order Plesiosauria, of which it is an early, but fairly typical member.

It has been hypothesized that Plesiosaurus and/or Mosasaurus fossils formed the basis of "sea serpent" myths such as Tiamat and Cetus.

Plesiosaurus in Chicxulub Asteroid Missed[]

Plessies still swam the oceans in the modern era. People hunted plessies (and mossies) for their meat and liver oil. However, plessies were dangerous animals and could easily kill people.[1] As air breathers, plessies hunted by raising their large necks out of the water, catching flying fish and seabirds. Milvil once saw a plessy catch a terry he thought to large to bring down; the plessy grabbed it out of the sky and dove.[2]

Paleontologists were interested in the ancestors of the modern plessy. One paleontologist, Trinka, assembled a fossil skeleton of an ancient plessy. However, he put the skull on the end of the tail, rather than the neck, much to the amusement of his rival, Ontinil.[3]

Frontiersman Rekek thought they looked like giant snakes that ate a dinner platter and then grew paddles on it.[4]

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  1. Analog, May/June 2019, Vol. CXXXIX, nos. 5 & 6, pg. 14.
  2. Analog, Vol. CXXXX, Nos 1 & 2, January/February, 2020, pgs. 58.
  3. Analog, May/June 2019, pg. 13.
  4. Ibid., pg. 14.