Fun Plesiopleurodon Facts For Kids

Ritwik Bhuyan
Feb 20, 2024 By Ritwik Bhuyan
Originally Published on Sep 25, 2021
Edited by Kidadl Team
Fact-checked by Sakshi Raturi
Plesiopleurodon facts include that this species is a member of the family Polycotylidae that used to thrive in marine environments of North America.
Age: 3-18
Read time: 6.6 Min

This is an extinct genus of reptiles living in a marine environment belonging to the order Plesiosauria. They were present in the Mesozoic era and were part of the superorder Sauropterygia. The species in the genus was probably found in the late Cretaceous period of North America. The Plesiopleurodon fossil found consisted of a complete skull with a mandible, a coracoid, and cervical vertebrae. Based on this specimen, Kenneth Carpenter named the genus Plesiopleurodon. It is actually a culmination of three Greek words: Plesios meaning 'near to', the word pleuro meaning 'side', and don meaning 'tooth'. When Kenneth Carpenter named the specimen, he mentioned that P. wellesi closely resembles the Liopleurodon ferox among all Pliosaurs. The Liopleurodon ferox was from the Oxfordian period of Europe. Many even consider the Plesiopleurodon a Pliosaur from the early Cretaceous period of Europe and North America. Due to the short neck, it was earlier considered a Pliosaur; however, even with this common trait in Pliosaurs, the genus is put in the order Plesiosauria.

It was found that not all Pliosaur species had short necks and similarly not all Plesiosaurs had long necks. A member of the family Polycotylidae, the Plesiopleurodon is distinguished by the short neck, few teeth, and an elongated head. This is clearly different from other Plesiosaurs. This short-necked Plesiosaur had a length of around 42 ft (12.8 m). The polycotylid was found in the Haily Shales formation (member of Belle Fourche, dated to the Cenomanian age). The fossil was probably found in the region of Europe and the region of North America.

There are many species and genera of dinosaurs, reptiles, birds, and animals that have roamed this planet when we did not even exist on it. Fossils have been found in fragments, but that has not been enough to know about the species fully in detail. For more relatable content, check out these Kaiwhekea facts and Kimmerosaurus fun facts for kids.

Plesiopleurodon Interesting Facts

Was the Plesiopleurodon a dinosaur?

These were marine reptiles, although the time span in the history of the related Pliosaur and Plesiosaur polycotylid puts them in the early and the late Cretaceous period. They co-existed with dinosaurs.

How do you pronounce 'Plesiopleurodon'?

The pronunciation of the name Plesiopleurodon is 'Ples- sio-plu-rodon'.

What type of marine reptile was a Plesiopleurodon?

This is actually an extinct genus of marine reptiles found in the Mesozoic age. They lived near the bottom surface of water bodies. This large reptile was considered a Pliosaur Plesiosaurid which was related to the Liopleurodon. It was thought to be living in the middle to early Cretaceous period, except it was later found to be living in the lower Cenomanian stage which is the late Cretaceous period.

This Jurassic Pliosaur information is based upon a fossil found of a complete skull, lower jaws, a right coracoid, and neck vertebrae.

In which geological period did the Plesiopleurodon live?

The geological period when the Plesiopleurodon (meaning near sided tooth) roamed the planet is described as the late Cretaceous period. It was known to live in the depth of water bodies similar to Jurassic Pliosaurs, and not near the surface.

When did the Plesiopleurodon become extinct?

The temporal range of the described species is the late Cretaceous period. The period (early Cenomanian age ‬of the Cretaceous period) that these reptiles existed is from 99.6 million years ago to 93.5 million years ago.

Where did a Plesiopleurodon live?

Fossils of the Plesiopleurodon were collected in the Belle Fourche shale formation. This is situated in Rattlesnake Hills of Wyoming, USA . This species was known to live in North America, except some even claimed to find it in Europe. The data collected by the Carnegie Museum puts the species as being from the Hailey shales formation.

The only known fossil of the Plesiopleurodon consists of a complete skull, lower jaws, neck vertebrae, and a coracoid.

What was a Plesiopleurodon's habitat?

They lived in a marine habitat with other species. They also fed on smaller marine species in open seas.

Who did a Plesiopleurodon live with?

There is no information on the company these reptiles used to keep. They probably hunted alone or maybe stayed in pairs, judging by the size of the species.

How long did a Plesiopleurodon live?

Although the life span of the species is not known and cannot be determined with the limited information archived from the fossil found, they probably lived around 50-70 years.

How did they reproduce?

There is no information provided on the reproduction of this species. Many have said that members of this genus gave birth to a single young but not much is known except this. Hopefully with future articles, we will get to know more about the reproduction of the species.

Plesiopleurodon Fun Facts

What did a Plesiopleurodon look like?

The species was known to have eight pairs of teeth. Teeth in cross-section look circular in structure and smooth in texture on the outer surface. Neck vertebrae had single-headed ribs which were double in Jurassic Pliosaurs. Cervical ribs were seen with one head. There was a long and slender interpectoral bar on the coracoid. The interpectoral bar was longer than any seen in Pliosaurs. The skull is said to have been around 28 in (71.1 cm) long. Cervical vertebrae were not long but wider and had equal height and length. A shorter neck and longer jaws were probably present in the species.

Plesiopleurodon facts are interesting.
*We've been unable to source an image of a Plesiopleurodon and have used an image of an Edmontonia dinosaur instead. If you are able to provide us with a royalty-free image of a Plesiopleurodon, we would be happy to credit you. Please contact us at

How many bones did a Plesiopleurodon have?

The number of bones of the species is not known as only a couple of bone fragments have been discovered to date. We might get a clearer idea once a full skeletal structure of the Plesiopleurodon is discovered in the future.

How did they communicate?

There is no information to analyse the mode of communication of this species. They probably communicated vocally, visually, and chemically like other reptiles. Some even show physical stances to attract mates or fend off predators.

How big was a Plesiopleurodon?

The Plesiopleurodon size was estimated to be around 42 ft (12.8 m) in length. The skull size is known to have been around 28 in (71.1 cm) long.

How fast could a Plesiopleurodon move?

The speed of the species is not known. But the shape of the body along with flippers probably made them quite swift and easy to maneuver the water in seas.

How much did a Plesiopleurodon weigh?

The weight of the species is not known as the whole skeleton of the reptile has not been recovered yet.

What were the male and female names of the species?

There is no information stating male and female names of the species. They were probably known by their scientific names.

What would you call a baby Plesiopleurodon?

The name of the baby of a Plesiopleurodon reptile is not given. It was probably denoted as a young.

What did they eat?

They were carnivores and fed on fish and other living organisms below the water. The jaw and teeth helped them grasp their prey easily.

How aggressive were they?

They were probably aggressive but not much information is provided regarding the temperament of the species.

Did you know...

Although considered an early Cretaceous period member of Pliosaurs, it was later discovered with the range of fossils found that the species actually is a Plesiosaur.

There have been many references of this reptile in games and shows and it has become quite a popular character in recent times. Even some of the research on the species is based upon facts found on these different mediums.

Who discovered the Plesiopleurodon?

We know that Kenneth Carpenter named the genus based on the specimen retrieved of the reptile.

Did the Plesiopleurodon breathe air?

We know members of Plesiosaurs breathed air with the help of their long neck helping the body remain underwater while the neck was used to breathe above water. There is no information if the Plesiopleurodon breathed air but as they had short necks, its breathing method would have been different.

Here at Kidadl, we have carefully created lots of interesting family-friendly prehistoric animal facts for everyone to discover! Learn more about some other creatures from our Zarafasaura fun facts, or Simolestes facts for kids.

You can even occupy yourself at home by coloring in one of our free printable Plesiopleurodon coloring pages.

Main image by Dmitry Bogdanov.

Fun Plesiopleurodon Facts For Kids

How Much Did They Weigh?


Skin Type

Smooth skin

How Long Were They?

Estimated to be around 42 ft (12.8 m) long

How Tall Were They?










Scientific Name

Plesiopleurodon wellesi

What Were Their Main Threats?

Natural disasters
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Written by Ritwik Bhuyan

Bachelor of Arts specializing in English

Ritwik Bhuyan picture

Ritwik BhuyanBachelor of Arts specializing in English

A skilled content writer, Ritwik holds a Bachelor's degree in English from Delhi University. He has refined his writing abilities through his past experience at PenVelope and his current role at Kidadl. In addition to his proficiency in writing, Ritwik has pursued his passion for flying by achieving CPL training and becoming a licensed commercial pilot. This diverse skill set highlights his commitment to exploring multiple fields. Ritwik's experience in the aviation industry has provided him with a unique perspective and attention to detail, which he brings to his writing.

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