Fun Segisaurus Facts For Kids

Anusuya Mukherjee
Oct 20, 2022 By Anusuya Mukherjee
Originally Published on Oct 25, 2021
Edited by Katherine Cook
Interesting Segisaurus facts include that it is the only dinosaur ever to be extracted from the Navajo Sandstone Formation.
Age: 3-18
Read time: 7.6 Min

Segisaurus, meaning 'Segi canyon lizard', was first described by Charles Lewis Camp in 1936. The findings were very helpful in understanding how the categories of bird-like dinosaurs used to be.

It was only after other findings that the true value of finding this dinosaur was recognised.

Even though the known specimen has partial remains like vertebrae, limb bones, and parts of hips and shoulder, it has been very useful in understanding the evolution of early theropods.

This is a huge success, given that it is very hard to find any remains from the Navajo Sandstone Formation of the Early Jurassic, and that is why this dinosaur is the only excavated dinosaur from the area. The specimen was first discovered in 1933 with the help of Max Littlesalt in the Tsegi Canyon of Arizona.

The beds in the Navajo Sandstone used to be from a time when the area used to be filled with sprawling dune fields covering the American west, and therefore it is hard to find any skeletons in this region. That is why finding the Segisaurus in such an impossible place was genuinely exceptional and miraculous.

Finding a partial skeleton was even better with the view point of studying the features of the species.

For more relatable content, check out these Condorraptor facts and Atrociraptor facts for kids.

Segisaurus Interesting Facts

How do you pronounce 'Segisaurus'?

The name of this theropod dinosaur, Segisaurus, is pronounced as 'Seg-e-sore-us'.

What type of dinosaur was a Segisaurus?

Segisaurus halli, genus Segisaurus, was a genus of small coelophysoid theropod dinosaur.

In which geological period did the Segisaurus roam the Earth?

According to the remains of the family of this theropod dinosaur, they are estimated to have lived in the world during the Early Jurassic period, approximately 183 million years ago. This dinosaur lived in the Pliensbachian-Toarcian period which extended from 190.8 million years ago - 174.1 million years ago.

When did Segisaurus become extinct?

According to their fossil discovery, unless otherwise noted, it has been approximated that the Segisaurus halli's last recorded appearance was around 174 million years ago in the Early Jurassic period. Around this time, the species of Segisaurus halli must have gone extinct during the Toarcian stage of the Jurassic.

Where did Segisaurus live?

According to the discovery of the fossils of Segisaurus halli, it has been concluded that the species must have lived in what would be the present-day Tsegi Canyon, Arizona, in the USA in Navajo Sandstone Formation.

What was the Segisaurus' habitat?

It is most likely that the Segisaurus would have preferred arid sandy regions. The Tsegi Canyon, Navajo Sandstone Formation, is located in the area which was once western Pangea.

It is believed that the west of Pangea was a landform, meaning that it was a region of windswept flat sandy desert that had little or no vegetation at all. It is also believed that such a habitat must have been the result of seasonal monsoons that occurred during the winter season.

Who did a Segisaurus live with?

It is hard to tell what other dinosaur species the Segisaurus must have lived with since Segisaurus halli is the only dinosaur to have ever been excavated from the area of Tsegi Canyon, Arizona, USA.

How long did a Segisaurus live?

Segisaurus halli dinosaurs are believed to have lived from the Pliensabachian to Toarcian of the Jurassic period, approximately between the range of 190 million years ago to 174 million years ago.

How did they reproduce?

The reproduction of this theropod dinosaur from the Early Jurassic period, Segisuarus halli, is believed to be oviparous. This means that they are believed to have reproduced by laying eggs. Not much is known about their reproductive habits and if they cared for their young ones.

Segisaurus Fun Facts

What did Segisaurus look like?

The structure of the dinosaur is bird-like, and the dinosaur had a flexible and elongated neck and stout body. The Segisaurus is believed to be three-toed with legs longer than their body length.

Just like their legs, Segisaurus' features must have included long tails and forearms as well.

Another feature about this dinosaur was that its collarbone was not unlike that of a bird, which further proved the arguments drawn by scientists that this dinosaur was related to avians.

However, the only known specimen is of a sub-adult, and the full size for an adult Segisaurus might not be known for a long time until new discoveries. In addition to this, clavicles found on the specimen of Segisaurus have not been known from other dinosaurs of the same era.

The Segisaurus with its hollow bones has been a very important find in order to study the evolution of early theropods.

How many bones did a Segisaurus have?

The fossil representation for Segisaurus halli dinosaurs consists of partial post cranial remains of a sub-adult. The fossil skeleton is in fragments with portions of the limbs, pelvis, and vertebrae.

In addition, there was also no cranial material located for the dinosaur unless otherwise noted. The Segisaurus halli is believed to have been closely related to the dinosaur species, Coelophysis.

However, while the Coelophysis had hollow bones, the Segisaurus, on the other hand, had solid bones instead.

This questioned the scientists' belief that the Segisaurus was a theropod. When the specimen was further investigated in 2005, it was proved that the Segisaurus had hollow bones instead of solid bones, making the scientists believe that the Segisaurus was more closely related to the Procompsognathus.

How did they communicate?

It is unknown how this small theropod with long tail precisely communicated with each other or dinosaurs of different species.

In the review of prehistoric animal sounds, Philip J. Senter, an American paleontologist and a professor of Zoology at Fayetteville State University, very popularly known for his researchfocusing on dinosaur paleobiology, believed that these dinosaurs used to communicate by hissing, grinding mandibles against upper jaws, rubbing scales together, clapping their jaws together, and by the use of environmental materials like splashing against water.

It is also believed that these dinosaurs communicated vocally and visually. These two modes of communication would have been most used during defensive posturing, courtship behavior, and territory fights.

According to the same assumption, it is believed that the head crests of some species like Corythosaurus and Parasaurolophus were used to amplify grunts or bellow.

How big was a Segisaurus?

The Segisaurus' size was estimated to have been roughly the size of a goose with a long tail. The Segisaurus is believed to have been 3.3 ft (1 m) in length and 1.65 ft (1.5 m) in height.

How fast could a Segisaurus move?

This bird-like small theropod was an actively mobile primitive bipedal theropod. In addition to this, the Segisaurus is believed to be a nimble dinosaur, which means that this dinosaur had the ability to move quickly, easily, and lightly.

How much did a Segisaurus weigh?

Based on the classification of the bird-like specimen collected, this theropod's weight is estimated to have weighed in the range of around 8.8-15.4 lb (4-7 kg).

What were the male and female names of the species?

Female and male Segisaurus halli dinosaurs are not given any different names.

What would you call a baby Segisaurus?

Since this theropod reproduced by laying eggs and the new ones were born when the eggs hatched, a baby Segisaurus halli can be called a hatchling or nestling. This generalized term can be used for all dinosaurs since they all hatched from eggs.

In the case of theropods, dinosaurs that resemble birds, a baby theropod can also be referred to as a chick.

What did they eat?

The Segisaurus was a nimble creature that was originally insectivorous in nature. But it has also been speculated over time that this dinosaur might have also relied on meat substitutes as well. Therefore it is believed that the Segisaurus' diet consisted of primary insects and sometimes possibly small animals.

How aggressive were they?

Segisaurus dinosaurs ate insects and occasionally scavenged for small animals as well. Given the eating behavior of this dinosaur, it is safe to assume that this dinosaur must have been a little aggressive in nature to survive in the wild.

Did you know...

Charles Lewis Camp, when the specimen for Segisaurus was found, described its posture as a 'sitting hen' based on the position in which the remains of the dinosaur were found. It is believed that other theropods used this position to sleep or stay in shelter during sand or ash storms.

How did the Segisaurus get its name?

Segisaurus, meaning 'Segi canyon lizard', is the only known specimen for Segisaurus, which was discovered in 1933 in the Early Jurassic strata in Tsegi Canyon, Arizona. Segisaurus was the only dinosaur to have ever been excavated from the area, giving it the name 'Segisaurus'. The species was later described by the paleontologist Charles Lewis Camp in 1936.

How did Segisaurus get discovered?

The specimen was first discovered by Max Littlesalt in 1933. Max Littlesalt was a Navajo Indian who used to keep their livestock in the Tsegi Canyon.

When a group of scientists came into the canyon on an expedition, the fossil remains from this Navajo Sandstone Formation were brought to their attention by Max and were the only dinosaur species to have been found and excavated from the area.

However, after it was discovered and then first described by Charles Lewis Camp in 1936, the holotype was ignored for the next 50 years.

After being ignored for so long, the specimen was finally investigated again, and discoveries around the dinosaur were made. The new findings suggest that the Segisaurus is very important in order to understand the evolution of early theropods.

Here at Kidadl, we have carefully created lots of interesting family-friendly animal facts for everyone to discover! Learn more about some other dinosaurs from our Neimongosaurus interesting facts and Austroraptor surprising facts pages.

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

Main image by Nobu Tamura

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Written by Anusuya Mukherjee

Bachelor of Arts and Law specializing in Political Science and Intellectual Property Rights

Anusuya Mukherjee picture

Anusuya MukherjeeBachelor of Arts and Law specializing in Political Science and Intellectual Property Rights

With a wealth of international experience spanning Europe, Africa, North America, and the Middle East, Anusuya brings a unique perspective to her work as a Content Assistant and Content Updating Coordinator. She holds a law degree from India and has practiced law in India and Kuwait. Anusuya is a fan of rap music and enjoys a good cup of coffee in her free time. Currently, she is working on her novel, "Mr. Ivory Merchant".

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