Fun Stygimoloch Facts For Kids

Moumita Dutta
Feb 20, 2024 By Moumita Dutta
Originally Published on Nov 22, 2021
Edited by Luca Demetriou
Fact-checked by Sakshi Raturi
Stygimoloch facts are interesting.
Age: 3-18
Read time: 6.2 Min

The Stygimoloch is an extinct genus of the Late Cretaceous period that possibly lived in ancient North America. The meaning of the name Stygimoloch is a demon from the river Styx. Despite what the name suggests, these dinosaurs were not nearly as terrifying. They were herbivorous animals that grew up to the length of a full-grown adult person. It is believed that the Stygimiloch was in reality the juvenile species of the pachycephalosaur. The pachycephalosaur heads transform drastically as they age, the Stygimoloch possibly went through a similar transformation as they aged.

The unusual bony domed head of the animal also spurred some controversies in the field of paleontology, which suggested that the Stygimoloch was not actually a dinosaur species. However, their fossils were represented as a juvenile of a much larger but similar domed skull dinosaur called pachycephalosaurus. The pachycephalosaurus and the Stygimoloch lived during the same time and in the same place. Their phylogeny matches the phylogeny of the pachycephalosaurus, rather Galton and Sues concluded most of their characteristics based on their parents. To know more facts about the dinosaur, keep on reading the facts about the Stygimoloch.

For similar content check out, Buriolestes and Australovenator facts too.

Stygimoloch Interesting Facts

How do you pronounce 'Stygimoloch'?

The name Stygimoloch is pronounced as 'Stih-jih-moe-lock', it means the horned demon from the river styx.

What type of dinosaur was a Stygimoloch?

The stygimoloch dinosaurs were ornithischians of the order Ornithischia. The animals of the Animalia kingdom belonged to the family of pachycephalosaurs and were considered to be juveniles of the pachycephalosaurus. The Stygimoloch dinosaur is a part of the superfamily Pachycephalosauria.

In which geological period did the Stygimoloch roam the earth?

The Stygimiloch dinosaurs existed during the Late Cretaceous period on earth. The dinosaur was a part of the latest stage of the Cretaceous known as the Campanian age. They were found from 68 million years ago to 65 million years ago in North American lands.

When did the Stygimoloch become extinct?

The Stygimoloch was a dinosaur of the Late Cretaceous, they became extinct around 65 million years ago.

Where did a Stygimoloch live?

The Stygimoloch skeleton was recovered from the Hell Creek Formation, Ferris Formation, and Lance Formation. By examining their fossil distribution it can be concluded that they lived around present Montana.

What was a Stygimoloch's habitat?

The Stygimoloch preferred living in terrestrial habitats, they were plant-eating herbivore animals that predominantly lived in forests as well as on plains and savannas.

Who did a Stygimoloch live with?

The herbivorous plant-eating Stygimoloch genus was social in nature. They lived by forming small groups and herds and each herd was led by a dominant male. The juveniles became members of the herd as soon as they were born.

How long did a Stygimoloch live?

The Stygimoloch lived for a span of three million years on earth, they existed from 65-68 million years ago.

How did they reproduce?

The Stygimoloch horns did not have much destructive role, rather it was used in social activities. The Stygimoloch used the spikes of their skulls either as a defence mechanism against predators or during intra-species competition. The latter was mainly seen during the breeding period. Males were more aggressive than females and it increased during reproduction. The cranial spikes at the base of the dome became thick in rutting males. This induced the head-butting display of males to impress females and establish its dominance. The winner of the battle gained control over the female herd and bred with them. The eggs were generally lain on mountain tops by females. Most of the juvenile dinosaurs were a lineage of the dominant male with rare exceptions. The juveniles stay in herds as soon as they hatch. Before reaching adulthood, the male juveniles are chased off by the dominant male while the females stay within the herd. The practice of inbreeding is common for Stygimoloch.

Stygimoloch Fun Facts

What did a Stygimoloch look like?

The Stygimoloch is a medium-sized unusual dinosaur of the Late Cretaceous. They were regarded as one of the members of the pachycephalosaur dinosaurs with clusters of bony spikes on the back of the dome-shaped skull. The cruel meaning of their name is based on the horns and the spikes on the head of the dinosaurs which give them a terrifying appearance. In reality, these plant-eating species were not that dangerous and had a moderate size. They also had small hornets around their nose. Their skulls were characterized by spikes on the back. The Stygimoloch had a single horn which was surrounded on the side by two or three horns of smaller length.

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

The bipedal Stygimoloch belonged to the superfamily Pachycephalosauria.

How many bones did a Stygimoloch have?

The total number of bones present in the body of a Stygimoloch is unknown. They are recognized from the thick Stygimoloch skull and partial neck frill fragments.

How did they communicate?

Communication was believed to be vocal and visual like all dinosaur species.

How big was a Stygimoloch?

The Stygimoloch size ranged between 7-10 ft (2-3 m). They were two feet taller in length than the ostrich-like

How fast could a Stygimoloch move?

The Stygimoloch could move as fast as an ostrich. The speed of these bipedal dinosaurs ranged between 20-30 mph (32-48.2 kph).

How much did a Stygimoloch weigh?

The weight of a Stygimoloch was approximately 170 lb (77 kg).

What were the male and female names of the species?

Male and female dinosaurs do not have a specific name. Both of them are referred to as Stygimoloch.

What would you call a baby Stygimoloch?

A juvenile dinosaur is referred to as a nestling.

What did they eat?

The Stygimoloch consumed a herbivorous diet. Their diet included plant matters.

How aggressive were they?

The Stygimoloch were herbivore dinosaurs with a plant-based diet. They were not aggressive in nature generally despite their terrifying appearance. However, they indulged in head-butting as a defense against attacking predators.

Did you know...

In Christian culture, the horns and scales on the head evoke the conception of a demon. Therefore, the name Stygimoloch translates to a horned demon from the river Styx in English.

What does the name 'Stygimoloch' mean?

The Stygimoloch was named after its unusual dome-shaped bony head and other fragmentary fossils of neck frill that were discovered from North America. Despite their harmless nature, their name meant a demon from the river Styx. The name is a combination of two Greek terms, Styx and Moloch. The name Stygimoloch denotes the Styx river that is believed to run through the underground in Greek mythology. The fossils of the dinosaur were obtained from the Hell Creek Formation, the underground river Styx is in reference to their actual location of discovery. Moloch is the name of a Canaanite god in the Bible that has an unusual appearance, it refers to the bizarre dome skull and bony spikes of the animal.

Who named the Stygimoloch?

The scientists of the University of Berkley found a specimen of a robust skull while exploring the Hell Creek Formation of Montana in 1973. The discovered skull specimen was thick and it had distinctive horns protruding from the back of it. At first, the thick skull fragment was assigned to the pachycephalosaurs and no other research was conducted regarding the fossil. Later in 1983, British and German paleontologists named Peter Galton and Hans-Dieter Sues respectively published a comprehensive report on the pachycephalosaurs fossil remains. Peter Galton and Hans-Dieter Sues also classified the skull that was discovered from Montana as Stygimoloch's skull. They named their type species as Stygimoloch spinifer.

Here at Kidadl, we have carefully created lots of interesting family-friendly dinosaur facts for everyone to discover! For more relatable content, check out these Mahakala fun facts, or Antetonitrus facts for kids.

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

Fun Stygimoloch Facts For Kids

How Much Did They Weigh?

170 lb (77 kg)

Skin Type

Bumpy skin with horns

How Long Were They?

7-10 ft (2-3 m)

How Tall Were They?










Scientific Name

Stygimoloch spinifer

What Were Their Main Threats?

Natural disasters
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Written by Moumita Dutta

Bachelor of Arts specializing in Journalism and Mass Communication, Postgraduate Diploma in Sports Management

Moumita Dutta picture

Moumita DuttaBachelor of Arts specializing in Journalism and Mass Communication, Postgraduate Diploma in Sports Management

A content writer and editor with a passion for sports, Moumita has honed her skills in producing compelling match reports and stories about sporting heroes. She holds a degree in Journalism and Mass Communication from the Indian Institute of Social Welfare and Business Management, Calcutta University, alongside a postgraduate diploma in Sports Management.

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