Fun Hylaeosaurus Facts For Kids

Gurpuneet Kaur
Feb 29, 2024 By Gurpuneet Kaur
Originally Published on Sep 28, 2021
Edited by Christina Harrison
Fact-checked by Pradhanya Rao
Here are some fun and interesting Hylaeosaurus facts highlighting the uniqueness of the herbivorous armoured dinosaur that lived during the early Cretaceous period.
Age: 3-18
Read time: 6.5 Min

The discovery of the clade Dinosauria in the early 19th century brought to light the long-extinct species of dinosaurs. Sir Richard Owen, who is known for his remarkable work of interpreting fossils, discovered the first dinosaur followed by various other species from the clade Dinosauria. One of his discoveries was the genus Hylaeosaurus. As he coined the name of the dinosaur meaning 'terrible lizard', Gideon Mantell titled the name Hylaeosaurus which meant 'forest lizard' referring to the Tilgate forest in Wealden, Sussex where fossils of the dinosaur were uncovered. It was the basal member of the family Ankylosauridae living around 140-136 million years ago. The genus was recorded to be classified into four species while the Hylaeosaurus armatus is considered its type species. Other species from the genus documented are the Hylaeosaurus oweni, the Hylaeosaurus northhamptoni, and the Hylaeosaurus foxii. The Hylaeosaurus and Polacanthus were considered close relatives. The genus was also mentioned in 'The Geology of the South-east of England' by Gideon Mantell in 1833.

If the uniqueness of the Hylaeosaurus makes you interested in reading more about similar species, you can read about the Chungkingosaurus and the Rahonavis

Hylaeosaurus Interesting Facts

How do you pronounce 'Hylaeosaurus'?

The Hylaeosaurus pronunciation is 'hy-lee-o-sor-əs'. The generic name was coined by the English paleontologist Gideon Mantell (1833) meaning 'forest lizard'. It originated from the Greek term 'hylaios' and 'sauros' meaning 'belonging to the forest' and 'lizard', respectively. The binomial name refers to the Tilgate forest in Wealden, Sussex.

What type of dinosaur was a Hylaeosaurus?

The Hylaeosaurus was an armoured dinosaur living during the late Valanginian stage of the early Cretaceous epoch in England. It is known to have four subspecies including the Hylaeosaurus armatus, the Hylaeosaurus oweni, the Hylaeosaurus northhamptoni, and the Hylaeosaurus foxii. The Hylaeosaurus oweni was named to honor Richard Owen while the Hylaeosaurus northhamptoni was renamed the Regnosaurus and the Polacanthus was named the Hylaeosaurus foxii. Currently, the Hylaeosaurus armatus is considered the only valid type species under the genus.

In which geological period did the Hylaeosaurus roam the Earth?

The Hylaeosaurus lived around the late Valanginian stage of the early Cretaceous period, the geological period ranging from 140-136 million years ago. The discovery of Hylaeosaurus fossil remains covered in a limestone block dates back to 1832 and they were found in the Tilgate Forest in Wealden, West Sussex. The specimen was originally housed in the Natural History Museum of London.

When did the Hylaeosaurus become extinct?

The armoured dinosaur Hylaeosaurus lived 140-136 million years ago during the early Cretaceous epoch in and around England. While it was not believed to have had major threats, predation, habitat loss, natural calamities, and lack of food were considered some of the major causes of extinction of these dinosaurs living in England.

Where did a Hylaeosaurus live?

The Hylaeosaurus group of dinosaurs was present in states of the United Kingdom, primarily London in England. The discovery of specimen of fossils covered in a limestone block was in the Tilgate forest in England and fossils are preserved in The Natural History Museum of London.

What was a Hylaeosaurus's habitat?

As the generic name of the Hylaeosaurus comprises two Greek terms - 'hylaios' referring to 'woodland' or 'forest' and 'sauros' meaning 'lizard' - the habitat of the dinosaur was primarily woodlands and forests, while dinosaurs, in general, had a wide range of habitats comprising various woodlands, grasslands, deserts, forests, wetlands, and areas with plentiful vegetation.

Who did a Hylaeosaurus live with?

Dinosaurs either led a solitary life or lived in a pair, trio, or group. The Hylaeosaurus was considered a gregarious animal, so perhaps was usually found in a group. The dinosaur was known to have lived in pairs during its breeding or mating season.

How long did a Hylaeosaurus live?

Although one of the longest living animals were dinosaurs, the Hylaeosaurus does not have a known estimated life span.

How did they reproduce?

Dinosaurs were oviparous animals that laid amniotic eggs. As not much was learned by studying remains of these dinosaurs, the reproductive behavior is still a conundrum. Perhaps one day research will reveal details about this.

Hylaeosaurus Fun Facts

What did a Hylaeosaurus look like?

The Hylaeosaurus was first described by Gideon Mantell after studying the specimen of fossil remains discovered. The first lithograph was published by Gideon Mantell in 'The Geology of the South-East of England' in 1833, while another drawing of the Hylaeosaurus model was printed in the fourth edition of 'The Wonders of Geology' in 1840 by Mantell. Features of the dinosaur included several oval-shaped armor plates and spikes all over its body. It had a narrow head with horns over its head and a beak-like pointed snout. It had a heavy tail and short legs with five-toed feet. It had spikes along its shoulder, sides, and on the top of its body stretching towards its long tail. The appearance of the Hylaeosaurus was built according to fossils of the skull, the neck, shoulder vertebrae, its bony plates, jaw, teeth, and a limb bone. It was modeled after the modern lizard.

It is a primitive Nodosaurid with three long spines on its shoulder followed by shorter spines at the side of its neck.

How many bones did a Hylaeosaurus have?

Since fossil remains comprised about 50 pieces, it was described as a 'great consarn of bites and boanes' by Gideon Mantell. While the number of bones is yet not computed, the partial skeleton originally discovered comprises the Hylaeosaurus skull, the neck, shoulder vertebrae, several bony armor plates covering the shoulder, the jaw, teeth, and a limb bone.

How did they communicate?

Dinosaurs communicated vocally or using various gestures and motions. Dinosaurs usually made sounds to communicate with one other and also used various gestures such as tapping their feet, swaying their tail in the air, moving their head, or splashing water. Hylaeosaurus dinosaurs possibly used similar techniques to communicate, but the behavior of the species is poorly studied.

How big was a Hylaeosaurus?

In regards to the Hylaeosaurus size, the first estimate about the length of the Hylaeosaurus was recorded by George Mantell stating it to be as long as 25 ft (7.6 m). The length of the species of the Hylaeosaurus ranged between 10-25 ft (3-7.6 m).

How fast could a Hylaeosaurus move?

The speed of dinosaurs is measured by studying the distance between their footprints, and is proportionately related to their size, weight, and length. While the speed of the Hylaeosaurus is not recorded, its features indicate that it may have had a substantial speed.

How much did a Hylaeosaurus weigh?

The Hylaeosaurus weighed around 0.3-2.2 ton (300-1,996 kg).

What were the male and female names of the species?

Male and female dinosaurs do not have sex-specific names. Although this group of dinosaurs does not have specific binomial names highlighting the sex of the species, a female can be commonly called a saura, while a male is often called a saurus.

What would you call a baby Hylaeosaurus?

A baby Hylaeosaurus is referred to as a chick, hatchling, or a juvenile in layman's terms.

What did they eat?

The armoured dinosaur was known to feed upon an herbivore diet. The Hylaeosaurus diet primarily comprised plants, especially low-lying vegetation.

How aggressive were they?

The Hylaeosaurus was covered in rows of bony spines with at least three long spines around its shoulder. However, spikes over its body were not thought to have harmed others and the Hylaeosaurus was not believed to have had an aggressive temperament. Horn-covered plates also provided shelter from its predators, ensuring protection and a comparatively healthy life span.

Did you know...

The Hylaeosaurus history dates back to the 19th century. It was discovered by an English paleontologist, Gideon Mantell, in the 1830s and modeled it after the modern lizard. It has four subspecies recorded: the Hylaeosaurus armatus, the Hylaeosaurus oweni, the Hylaeosaurus northhamptoni, and the Hylaeosaurus foxii.

Who discovered the Hylaeosaurus?

The Hylaeosaurus was discovered by Gideon Mantell. It was one of the first three dinosaurs classified under the clade Dinosauria by Sir Richard Owen. It is classified into four subspecies with its type species being Hylaeosaurus armatus.

Which dinosaurs lived with them?

According to Gideon Mantell, the Hylaeosaurus was known to live with the Megalosaurus and the Iguanodon.

Here at Kidadl, we have carefully created lots of interesting family-friendly dinosaur facts for everyone to discover! Learn more about some other creatures from our Metriorhynchus facts and Ostafrikasaurus facts for kids.

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


Second image: Simon from United Kingdom

Hylaeosaurus Facts

What Did They Prey On?

Leaves, roots, fruits, flowers, stems, and shoots of plants

what Type of Animal were they?


Average Litter Size?


What Did They Look Like?

Green, brown, yellow, gray, black, blue, and white

How Much Did They Weigh?

0.3-2.2 ton (300-1,996 kg)

Skin Type

Scales and spikes

How Long Were They?

10-25 ft (3-7.6 m)

How Tall Were They?










Scientific Name

Hylaeosaurus armatus

What Were Their Main Threats?

Habitat loss, natural calamities, and predators

What Habitat Did They Live In?

Woodlands, grasslands, deserts, forests, wetlands, and areas with plentiful low-lying vegetation

Where Did They Live?

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Written by Gurpuneet Kaur

Bachelor of Arts specializing in Economics

Gurpuneet Kaur picture

Gurpuneet KaurBachelor of Arts specializing in Economics

As a skilled content writer, Gurpuneet has written and managed engaging content for multiple websites and companies. Driven by a passion for helping young people achieve their full potential, she brings a unique perspective to her work. She is currently pursuing a degree in Economics from Sri Guru Gobind Singh College Of Commerce. With extensive experience as a tutor, Gurpuneet has made a significant impact by providing guidance and academic support to students. Her dedication extends beyond tutoring as she has volunteered with Action India, where she offered medical assistance and educational aid to underprivileged communities. Additionally, Gurpuneet has contributed to the creation of student study guides for various educational agencies.

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