17 Fin-tastic Facts About The Leptocleidus For Kids

Monika Sharma
Jan 31, 2023 By Monika Sharma
Originally Published on Sep 27, 2021
Edited by Katherine Cook
Fact-checked by Gowri Rao
Leptocleidus facts are about this dinosaur with four flaps, helping them swim better
Age: 3-18
Read time: 6.1 Min

Marine creatures from the Cretaceous time, also known as pliosaurs, play an important role when understanding the various dinosaur categories. Leptocleidus was a marine reptile which means 'slender clavicle'. They were around 10 ft (3.0 m) long in size and a range of content is available about them. They had a large set of clavicles and small scapulae, which resembled many creatures from the early Jurassic period. The history of these dinosaurs goes back to around several hundred million years ago. The specific climate that they survived in is unknown but these dinosaurs were aquatic.

The location where the Leptocleidus are found the most is in England and other areas of Europe. They are the only known pliosaur and no other species under them has been registered until now. This genus is known to be a freshwater pliosaur. Their existence first came into our knowledge during the early 20th century and their name is derived from the Greek language. Seeing pictures of this creature shows that they might not have been very majestic or huge like other dinosaurs. They were very small and they did not explore much of the oceans, in fact, many researchers believe that they might have just lived in one location or site and often roamed in freshwater lakes. There are plenty of reasons to consider that this is a valid argument as they are much smaller in size compared to most sea creatures that lived during the Cretaceous or Jurassic time. This means they were easy prey in an ocean site.

To learn more about such interesting creatures, make sure to check out our other articles on Libonectes and Liopleurodon.

Leptocleidus Interesting Facts

Was the Leptocleidus a dinosaur?

The Leptocleidus is a kind of sea reptile or marine reptile. They used to live with other dinosaurs but they are not dinosaurs unless otherwise noted. The first fossil of Leptocleidus came into discovery during 1922. Not much is known about this type of marine reptiles as it is the only species registered under plesiosaur.

How do you pronounce 'Leptocleidus'?

Leptocleidus dinosaurs hunted down fish, squids, or other such small freshwater species. There is very little knowledge about this reptile in history but a considerable amount of content is available on this plesiosaur. This genus is very easy to pronounce, 'LEPTO-cle-dus'.

What type of marine reptile was a Leptocleidus?

Leptocleidus is a Greek word that means 'slender clavicle'. They are from the plesiosaur clan and Leptocleidus was a type of piscivore.

In which geological period did the Leptocleidus live?

Leptocleidus lived in the Early Cretaceous period. They resemble a lot of other dinosaurs from the early Jurassic period as well. Several categories in thee marine genus such as L. clemai and L.superstes are related to Leptocleidus.

When did the Leptocleidus become extinct?

They became extinct during the end of the Cretaceous period. Many dinosaurs of all categories faced ultimate extinction due to natural calamities such as asteroid collisions and inhabitable environments.

Where did a Leptocleidus live?

Their habitat site is placed near England or Europe. Several locations such as the Cape province of South Africa are also written in history as a place for this plesiosaur. One other site, Wright in England, can also be considered to be their ideal home.

What was a Leptocleidus' habitat?

Leptocleidus is a freshwater plesiosaur. They didn't go deep in the ocean, rather they just kept their exploratory habits to small rivers where they were away from large predators. Habitats such as shallow lagoons, or mouths of large waters in the places such as the British Isles are also though to have been their home.

Who did a Leptocleidus live with?

This plesiosaur coexisted with plenty of dinosaurs although they are not dinosaurs themselves. Leptocleidus may have lived with other family members or other species of their type as well unless otherwise noted. Current day animals such as spinner dolphins and Amazon river dolphins share a lot of history with the Leptocleidus.

How long did a Leptocleidus live?

This type of marine reptile had a lifespan of around 10-12 years like any fish from in the modern day. The Leptocleidus were a lot like dolphins of the current day.

How did they reproduce?

According to researchers, plesiosaur reptiles are too heavy to be able to drag themselves to a beach and lay eggs. During the Early Cretaceous period or even the reptiles of the early Jurassic, reproduction lasted a long time and they used to give direct birth to babies. The same behavior is seen in dolphins as well.

Leptocleidus Fun Facts

What did a Leptocleidus look like?

A Leptocleidus was very small in size compared to another type of large plesiosaur. They were around 10 ft (3 m) in size and had four flaps and a very narrow and thin face with around 21 teeth on side of their maxilla and a total of 35 teeth on their mandible. They had a thin triangular shape head and their crest ran from their ridge to their nose, that is their nasal region. They were around 10 ft (3 m) in length and had a deep depression at the center of their neck vertebrae. They are also known as the smallest known species of plesiosaur from the Cretaceous time period due to their length. Their location played an important role in their small size.

They had a triangular-shaped skull and a number of sharp teeth.

How many bones did a Leptocleidus have?

Leptocleidus means 'slender clavicle' and these reptiles from the Early Cretaceous time are found in any location where there was freshwater present. They did not explore much and remained in one shallow water sites. According to various scientists, the Leptocleidus had around more than 600 pieces of bones, however the exact number is not known as the pieces discovered have been crushed. Nonetheless, if all the pieces are glued they will form 232 bones, also counting the skull. Almost all plesiosaurs had the same number of bones.

How did they communicate?

During the end of the Triassic period and the start of the Cretaceous period, any freshwater location or shallow site were ruled by a group of marine reptiles which are known as plesiosaurs. In any river site, these reptiles communicateed through signals, calls, or visuals signs.

How big was a Leptocleidus?

Seeing the pictures of the Leptocleidus, it's very easy to feel underwhelmed as they were not very huge in size and had a length of 10 ft (3 m). They were very small. They were almost equal in size to an Irrawaddy dolphin or a Atlantic spotted dolphin.

How fast could a Leptocleidus move?

In their habitat site, they could move very fast and their four flaps were very helpful when swimming.

How much did a Leptocleidus weigh?

A Leptocleidus could weigh anywhere around 500 lb (226.8 kg) or more depending on the size of a healthy adult Leptocleidus.

What were the male and female names of the species?

Male and female Leptocleidus dinosaurs are addressed in a similar way. They are both the same in size and anatomy.

What would you call a baby Leptocleidus?

A baby Leptocleidus is called hatchling or a nestling.

What did they eat?

They were a piscivore type of plesiosaur. They fed on small fishes or squids.

How aggressive were they?

They are generally not considered to have been aggressive.

Did you know...

The Leptocleidus are known as relatives to lungfish.

Where were the Leptocleidus' bones found?

They were found in many areas, mostly close to European seas. They were even found in places such as Australia and America.

What does the term Leptocleidus mean?

The term means 'slender clavicle', which comes from Greek.

Delve into some family-friendly prehistoric animal facts for everyone to discover! Learn more about some other creatures from here at Kidadl, we have carefully created lots of interesting facts on our Uberabatitan fun facts and Herrerasaurus facts for kids pages.

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

Main image by Dmitry Bogdanov

Second image by Nobu Tamura

17 Fin-tastic Facts About The Leptocleidus For Kids

What Did They Prey On?

Fish or big fishes

what Type of Animal were they?


Average Litter Size?


What Did They Look Like?

Brownish white

How Much Did They Weigh?

500 lb (226.8 kg)

Skin Type

Slimy scales

How Long Were They?

10 ft (3 m)

How Tall Were They?










Scientific Name

Leptocleidus capensis

What Were Their Main Threats?

Natural disasters

What Habitat Did They Live In?

Shallow lagoons and freshwater

Where Did They Live?

Western Australia
We Want Your Photos!
We Want Your Photos!

We Want Your Photos!

Do you have a photo you are happy to share that would improve this article?
Email your photos

More for You

See All

Written by Monika Sharma

Bachelor of Science specializing in Electronics and Telecommunication

Monika Sharma picture

Monika SharmaBachelor of Science specializing in Electronics and Telecommunication

With a passion for crafting engaging and informative content, Monika brings a wealth of writing experience to our team. Her Bachelors in Electronics and Telecommunications from Symbiosis Institute Of Technology adds a unique perspective to her work, allowing her to effectively communicate complex ideas in a clear and concise manner. Over the past two years, Monika has perfected her writing skills through her roles as a content writer, content manager, and digital marketer for reputable companies in both the USA and India. This hands-on experience has provided her with a deep understanding of industry trends and best practices, ensuring that the content she produces is always of the highest quality. She stays current with the latest field developments,continuously refining her skills to deliver exceptional content.

Read full bio >
Read the DisclaimerFact Correction