An Ultimate Guide to Micropachycephalosaurus: Small & Thick

Leave a comment / / Updated on: 8th October 2023

Name Meaning“Tiny, thick-headed lizard”Height0.3 to 0.6 meters (1–2 feet) at the hips
PronunciationMY-kro-PACK-ee-sef-uh-loh-SAWR-usLength1–2 meters (3–6.5 feet)
EraMesozoicLate CretaceousWeight2.3–4.5 kg (5–10 pounds)
Classification Dinosauria, Ornithischia, Ceratopsia LocationChina (Asia)

Micropachycephalosaurus Pictures

Micropachycephalosaurus | Dinosaurs20  via Jurassic Park Fandom

The Micropachycephalosaurus

Gage Beasley Prehistoric's Micropachycephalosaurus Concept
Gage Beasley Prehistoric’s Micropachycephalosaurus Concept

When we think of dinosaurs, what comes to mind is a beastly animal as tall as a story building that weighs several tons. 

While this is true for many dinosaurs, some of these prehistoric creatures didn’t grow to such an impressive size.

Some dinosaurs, like the Micropachycephalosaurus, were only about one meter long and weighed just a few kilograms.

But what this dinosaur lacks in size, it makes up for with a name that’s a mouthful to pronounce.

With 23 letters and nine syllables, this dinosaur has the longest name of any dinosaur. 

As the name “Micropachycephalosaurus” shows, this dinosaur was thought to be a smaller version of another dinosaur, “Pachycephalosaurus” when it was discovered in 1978. 

Gage Beasley Prehistoric's Micropachycephalosaurus Color Concept
Gage Beasley Prehistoric’s Micropachycephalosaurus Color Concept

Consequently, it was classified in the pachycephalosaur family and is considered the smallest member of this family. 

However, more recent studies now suggest that both dinosaurs were probably not related, effectively implying the dinosaur’s name was inaccurate. 

The name remains for now, with the absence of evidence to either confirm or refute its true identity. 

In this article, we provide an overview of one of the smallest dinosaurs to have ever lived, describing its physical appearance, where it lived, behavior, relationship with other dinosaurs, and cultural significance. 

Gage Beasley's Prehistoric Shirt Collection
Gage Beasley’s Prehistoric Shirt Collection
Gage Beasley's Prehistoric Plush Collection
Gage Beasley’s Prehistoric Plush Collection

Physical Characteristics

Gage Beasley' Prehistoric's Micropachycephalosaurus Size Comparison Chart
Gage Beasley’ Prehistoric’s Micropachycephalosaurus Size Comparison Chart

Micropachycephalosaurus was a diminutive dinosaur. 

Even at full adult size, this dinosaur had a maximum length of about 0.6 to one meter (2–3 feet). 

It stood at an average height of about 0.3 to 0.6 meters (1–2 feet) at the hips. 

This small size distinguished this dinosaur from larger members of the pachycephalosaur family, such as Pachycephalosaurus and Stygimoloch.

As a pachycephalosaur, the most distinctive feature of the Micropachycephalosaurus was its skull. 

Its skull was thickened and had a dome-like appearance. 

The top of the skull was rounded and protected its brain. 

In some pachycephalosaur species, the dome had numerous small nodes or bumps, which were probably indicative of sexual dimorphism or individual variation.

However, unlike its larger relatives, Micropachycephalosaurus did not appear to have had prominent spikes or thickened knobs on its skull. 

An artistic representation of the genus Mycropachycephalosaurus | DarkWerewolf via Wikipedia CC BY-SA 4.0

The dorsal and sacral vertebrae of this dinosaur did have some impressions of neural spines, which suggests that the dinosaur probably had low spines on its back and tail area. 

The original description of this dinosaur was based on fragmentary fossils, which included several postcranial skeletons and a few skull bones (parietal and squamosal).

However, subsequent examinations carried out in 2009 found the skull bones to be missing, casting doubt on the entire classification and the physical features reported for this dinosaur. 

Habitat and Distribution

Micropachycephalosaurus lived during the Late Cretaceous Period, around 70 million years ago. 

Fossils of this dinosaur have been found in Asia, specifically in the Shandong Province of present-day China. 

Fossils of this dinosaur have not been found anywhere else, which suggests that the geographic range of the Micropachycephalosaurus was limited to this region.

During the Late Cretaceous, the environment in which Micropachycephalosaurus lived was characterized by a warm and relatively stable global climate. 

The temperature was higher compared to modern times. 

The region where the Micropachycephalosaurus lived was likely part of a coastal plain or other types of lowland region when the dinosaur was alive. 

Swamplands | bombuscreative via iStock

It was characterized by swamps and wetlands, providing an ideal habitat for various amphibians, reptiles, and other dinosaur species.

In this ancient ecosystem, the flora would have included various vegetation, including ferns, conifers, and flowering plants that served as food for herbivorous dinosaurs like the Micropachycephalosaurus and other plant-eating dinosaurs. 

Given the size of the Micropachycephalosaurus, it likely favored forested areas within this region with a dense vegetation cover. 

This would provide suitable food sources while making it easier to hide from predators. 

Behavior and Diet

Micropachycephalosaurus on white background
Micropachycephalosaurus on white background | Image via SciRes

Micropachycephalosaurus was a bipedal dinosaur which means it walked on its hind legs alone. 

The forelimbs of this dinosaur were reduced and not very useful for walking or grasping objects. 

They were probably held close to the dinosaur’s body while walking or running. 

The relatively small size and lightweight build of this Micropachycephalosaurus would have made it swift and agile. 

It had a long tail which was useful for maintaining balance while moving. 

There is limited evidence regarding Micropachycephalosaurus’ social behavior. 

However, we can assume that, like most of its close relatives and other herbivorous dinosaurs, it might have exhibited some level of social interaction. 

Pachycephalosaurus wyomingensis
Pachycephalosaurus wyomingensis | DataBase Center for Life Science via Wikipedia CC BY 4.0

Pachycephalosaurs, in general, are known to have lived in small groups or family units, which improved their chances against predators.

Having a complex social structure like this also improved mating opportunities and raising offspring.  

This might have been the case for Micropachycephalosaurus as well.

This dinosaur was most likely a herbivorous dinosaur. 

Its small size and tooth structure suggest that it had a specialized diet that included softer plant materials, such as fern fronds and cycad leaves, rather than tougher vegetation like coniferous needles or woody plants. 

Its size would have also limited its foraging range to plants in the forest understory. 

Micropachycephalosaurus artist sketch
Micropachycephalosaurus artist sketch | AveryShazz via Reddit

Like other herbivorous dinosaurs, Micropachycephalosaurus had a beak-like snout and sharp teeth suitable for biting off plant material. 

It also had sharp, leaf-shaped teeth in its jaws, effective for nipping or clipping vegetation. 

Obtaining food for this small dinosaur might have required moving across vast areas of its habitat. 

Being relatively small, it had access to areas that larger herbivores probably ignored, increasing its foraging opportunities. 

Life Cycle

The lifecycle and reproductive habits of the Micropachycephalosaurus were probably comparable to that of other pachycephalosaurs. 

They reproduced sexually, but very little is known about the mating behavior of this dinosaur. 

Micropachycephalosaurus colored artist sketch | Image clip via Q Brothers Youtube

After mating, female Micropachycephalosaurus would likely have found suitable nesting sites to lay eggs. 

This was most likely in hidden areas within dense vegetation cover. 

Smaller animals tend to lay more eggs than bigger ones, so while larger dinosaurs would have laid a few eggs, the Micropachycephalosaurus probably laid multiple eggs per clutch. 

It isn’t certain if parents stayed around to incubate the eggs or if they were allowed to hatch on their own naturally. 

After hatching, Micropachycephalosaurus juveniles would have been vulnerable to predation and environmental hazards. 

To improve their chances of survival, these young dinosaurs relied on their parents for care or protection during the early stages of their life. 

As they grew, they would have undergone significant changes in their physical appearance and behavior.

Based on observations of other related dinosaurs, Micropachycephalosaurus may have experienced rapid growth during its early years, reaching sexual maturity in a relatively short period compared to some other dinosaurs.

Evolution and History

The evolutionary history of the Micropachycephalosaurus is a bit difficult to trace because of the ongoing controversies about the dinosaur’s classification. 

Micropachycephalosaurus roaming inside the dinosaur forest
Micropachycephalosaurus roaming inside the dinosaur forest | Discovery Channel UK via Twitter Public Domain

Initially, the dinosaur was classified as a pachycephalosaur, a group of herbivorous dinosaurs characterized by thickened, dome-shaped skulls. 

However, a re-examination of the original fossil specimen of this dinosaur found no direct evidence of a thickened skull. 

The cranial bones of this dinosaur mentioned in the original description were missing from the museum collection. 

Due to the lack of evidence to confirm its status as a pachycephalosaur, scientists now think it would be better placed in the ceratopsid family, along with other horned and frilled dinosaurs like the Triceratops

This is not entirely far-fetched since both groups of dinosaurs (ceratopsians and pachycephalosaurid dinosaurs) share a common ancestry. 

Photo montage of several representing ornithischians suborder dinosaurs
Photo montage of several representing ornithischians suborder dinosaurs | Daderot via Wikipedia CC BY-SA 4.0

They’re both bird-hipped dinosaurs which means they’re members of the ornithischian‭ suborder. 

The Ceratopsian order branched off earlier, with some ancestral forms present as early as the Jurassic Period but persisted until the end of the Cretaceous Period. 

The pachycephalosaurids, on the other hand, evolved during the Cretaceous Period

The single most important diagnostic feature needed to determine the exact classification of this dinosaur is the skull.

The discovery of additional specimens in the future may allow scientists to determine where it truly stands in the future. 

Interactions With Other Species

Micropachycephalosaurus in a mod game from Jurassic World Evolution | Image via NexusMods

As a small herbivorous dinosaur, Micropachycephalosaurus would have faced significant threats in its environment. 

This was mainly in the form of small dromaeosaurid and troodontid dinosaurs in its ecosystem. 

While a few larger predators, such as the tyrannosaurs, may have been present, they most likely didn’t go after small prey like the Micropachycephalosaurus

Dromaeosaurids and troodontids, on the other hand, were well-adapted to hunting smaller prey, and the Micropachycephalosaurus could have been on their menu.

This dinosaur would have had to rely on its speed and agility to evade these predators. 

Life restoration of Hesperosuchus, a member of the crocodylomorphs species | Nobu Tamura via Wikipedia CC BY 2.5

Apart from dinosaurs, other predators, such as large crocodylomorphs, may have been present in this ecosystem as well, and they probably preyed on small dinosaurs like this occasionally. 

The Late Cretaceous ecosystem of Asia likely had several other herbivorous dinosaurs apart from the Micropachycephalosaurus, such as the hadrosaurs (duck-billed dinosaurs) and other ceratopsian dinosaurs. 

These herbivores likely shared similar dietary preferences, meaning they would have had to compete for food and other resources.

But given the size of the Micropachycephalosaurus, it probably focused on plants in the understory that other dinosaurs didn’t feed on, giving it an edge over its competitors. 

Cultural Significance

Micropachycephalosaurus was one of the smallest dinosaurs to have ever lived. 

Micropachycephalosaurus hiding in sight | Image via NexusMods

Being a dwarf in a world of giants probably didn’t have a lot of benefits in the real world.

But today, the Micropachycephalosaurus’ status as a diminutive dinosaur earns it notable mentions in various online articles, books, documentaries, and other dinosaur-themed materials.

Even in the scientific community, dinosaurs that defy the norm like this often attain some sort of celebrity status, attracting interest from researchers. 

Unfortunately, limited fossil evidence has made it difficult to fully study this dinosaur and understand many aspects of its life. 

But the major reason why this dinosaur is so popular with the general public is its extremely long name. 

Micropachycephalosaurus is the longest dinosaur genus name, and the binomial name “Micropachycephalosaurus hongtuyanensis” is even longer, with 37 letters in total. 

So while this dinosaur was probably not very impressive in real life, it is still commonly referenced in conversations about the smallest dinosaurs ever discovered and on the list of dinosaurs with the longest name. 


Micropachycephalosaurus was a small-sized dinosaur that lived in China during the Late Cretaceous Period. 

It is one of the smallest dinosaurs to have ever lived, with a maximum length of about one meter. 

Micropachycephalosaurus was an agile herbivore that fed on conifers, cycads, and other primitive plants in the understory of its late cretaceous forest habitat.

The true identity and classification of this dinosaur have been a little difficult to ascertain due to a lack of fossil evidence. 

It was initially classified as a pachycephalosaur but is now considered a ceratopsian dinosaur. 

The dinosaur is well-known to the general public today due to its small size and its extremely long name. 


Who found Micropachycephalosaurus?

Micropachycephalosaurus was discovered by Chinese paleontologist Dong Zhiming. 

Is Micropachycephalosaurus the smallest dinosaur?

No. Although it is one of the smallest dinosaurs ever discovered, Micropachycephalosaurus isn’t the smallest dinosaur ever. 

Some other diminutive dinosaurs, like the Epidexipteryx and Mahakala, were smaller than this dinosaur. 

What does Micropachycephalosaurus mean? 

The name “Micropachycephalosaurus” means “small, thick-headed lizard.” 

The name refers to this dinosaur’s small size and its likely relationship with the pachycephalosaurs. 


About The Author

Leave a Reply

Discover more from Gage Beasley Prehistoric | Recapping Timeless Creatures

Subscribe now to keep reading and get access to the full archive.

Continue reading

Scroll to Top