Chaoyangsaurus | A Small Ceratopsian from the Late Jurassic

Step into the prehistoric world of Chaoyangsaurus, a fascinating herbivore that roamed the Earth during the Late Jurassic Period. This ancient creature, whose remains were discovered in what is modern day China, offers a unique glimpse into a world long gone. Explore the life and habitat of the Chaoyangsaurus to unearth its mysteries and understand its place in its fascinating ecosystem.

Chaoyangsaurus Key Facts

Meaning of nameChaoyang Lizard
Type SpeciesChaoyangsaurus youngi
When it Lived155.7 to 132.9 MYA
PeriodLate Jurassic
EpochLate/Upper Kimmeridgian to Valanginian
LengthApproximately 3.3 feet
HeightApproximately 1.6 feet
WeightApproximately 13.2 pounds
MobilityMoved on two legs
First Discovery1976 by Cheng Zhengwu
Described by1999 by Zhao Xijin, Cheng Zhengwu and Xu Xing
HolotypeIGCAGS V371
Location of first findErshijiazi, Chaoyang area, Liaoning Province, China

Chaoyangsaurus Origins, Taxonomy and Timeline

Chaoyangsaurus, or ‘Chaoyang Lizard’, as its name suggests, was a reptile that roamed the lush regions near Chaoyang City. This name is a tribute to the place that revealed its secrets to the world. As a member of the Ceratopsian group, this dinosaur belonged to a lineage known for their distinctive beaks and herbivorous diets.

Chaoyangsaurus | A Journey into the Late Jurassic World. Discover the world of Chaoyangsaurus, a small herbivore from the Late Jurassic, and delve into its life, habitat, and significance in paleontology.

In terms of taxonomy, this dinosaur falls under the Chaoyangsaurid family, a classification that highlights its unique characteristics and evolutionary path. The type species, Chaoyangsaurus youngi, represents a specific lineage within this fascinating family. It is the only species in the genus so far.

This creature could be found in the Late Jurassic, specifically from the Late Kimmeridgian to Valanginian Epochs. This era spanned from about 155.7 to 132.9 million years ago. It was a time of significant ecological and geological changes as the Jurassic became the Cretaceous. This habitat provided a rich backdrop for the evolution of diverse life forms like our subject.

Discovery & Fossil Evidence

The discovery began in 1976 in the verdant valleys of Ershijiazi, located in the Chaoyang area of Liaoning Province, China. Thanks to the keen eye of Cheng Zhengwu, this remarkable creature was brought to light, offering a new chapter in the story of the Late Jurassic period. The discovery of Chaoyangsaurus youngi has been a pivotal moment in the field of paleontology, particularly in our understanding of the ceratopsian lineage. Unearthed from the Tuchengzi Formation, this new specimen represents a significant shift in the timeline of ceratopsian history, pushing their existence back from the Early Cretaceous into the Middle or Late Jurassic Period.

Skeletal restoration showing known material
Skeletal restoration showing known material
Jaime A. Headden, CC BY 3.0, via Wikimedia Commons

In 1999, researchers Zhao Xijin, Cheng Zhengwu and Xu Xing delved deeper into the mystery of this dinosaur to provide a detailed description that would form the foundation of our current understanding. The holotype, IGCAGS V371, became the key to unlocking the secrets of this ancient herbivore. This specimen includes fragments of the skull and jaws, some neck vertebrae, and pieces of the forelimbs.

While not as abundant as some other species, these fossils provide crucial insights into its physical structure and lifestyle. Predominantly consisting of partial skeletons and isolated bones, these remains have been instrumental in piecing together the puzzle of its existence. The degree of preservation varies, but each fragment brings us closer to understanding this fascinating creature.

Chaoyangsaurus Size and Description

The physical characteristics of Chaoyangsaurus point to a dinosaur well-adapted to a herbivorous lifestyle. This creature likely had a small, compact body, supported by two sturdy legs. This enabled it to move swiftly through its environment. Its beak-like structure was designed for efficient foraging, while its tail likely provided balance and stability.

Size and Weight Estimates

Estimating the size and weight of Chaoyangsaurus is a task shrouded in a bit of mystery. While exact measurements are challenging to pinpoint, the consensus is that this dinosaur was relatively small compared to its contemporaries. Gregory S. Paul estimated its length to be approximately 3.3 feet and its weight to be around 13.2 pounds in 2010.

The Dinosaur in Detail

The anatomy of Chaoyangsaurus youngi reveals distinctive characteristics that set it apart from its later counterparts. The quadratojugal, a bone in the cheek region, overlaps the posterior side of the quadrate shaft. This feature is not commonly seen in later Ceratopsians. Furthermore, the boss–or the area where a horn connects with bone–of the cheekbone is underdeveloped and smooth. This implies poorly developed horns on the cheeks.The entire skull is only 5.5 inches long. 

The teeth of this dinosaur are stereotypically herbivorous. The tip of its mouth was probably covered in a cutting beak, with forty-four teeth to help it process vegetation. Just behind the beak were two conical teeth, followed by flattened teeth in the back of the mouth.

Some characteristics of this dinosaur suggest a close relationship between Ceratopsia and Heterodontosauridae, two groups previously thought to be more distantly related. This connection opens up new avenues for exploring the evolutionary tree of Ornithischian dinosaurs, shedding light on the diverse and complex pathways that led to the rich variety of species we see in the fossil record. Chaoyangsaurus, therefore, not only enriches our knowledge of ceratopsian anatomy and evolution but also serves as a crucial link in unraveling the broader narrative of dinosaur evolution.

Interesting Points about Chaoyangsaurus

Chaoyangsaurus in its Natural Habitat

Imagine a world where dense forests and lush vegetation dominate the landscape. This was the realm of Chaoyangsaurus, a Late Jurassic Era marked by a rich diversity of plant life. This herbivore thrived in this environment and feasted on the abundant flora that characterized its habitat.

Its diet was primarily herbivorous and heavily shaped by the vegetation of its time. Its beak-like structure and teeth were perfectly adapted for this lifestyle, allowing it to efficiently consume a variety of plant materials. The locomotion of Chaoyangsaurus, likely on two legs, suggests a lifestyle that was both active and agile.

Its role in its ecosystem went beyond mere survival. As an herbivore, it likely played a part in shaping the landscape around it, contributing to the ecological balance by controlling plant growth. Its interactions with other species, be it through competition for resources or as part of a larger food web, reflect the dynamic nature of its environment.

Contemporary Dinosaurs

This period was a dynamic stage for various other contemporaries, including Euhelopus, Hudiesaurus, and Xuanhuaceratops. Each of these Asian dinosaurs played a unique role in the ecosystem and their interactions with Chaoyangsaurus tell a story of coexistence, competition, and survival.

Euhelopus, a sizable Sauropod, wandered the same realms as Chaoyangsaurus. Towering over the smaller Chaoyangsaurus, this gentle giant was likely a serene presence in the Jurassic forests and plains. Their interaction, if any, would have been passive as Euhelopus grazed on higher vegetation and left the lower shrubs and plants to Chaoyangsaurus. The size disparity between the two meant they were not competitors but rather co-inhabitants of a diverse landscape, each filling a different ecological niche.

Nearby, another huge sauropod roamed–Hudiesaurus. With its colossal size dwarfing even the Euhelopus, Hudiesaurus represented the epitome of the Jurassic giants. In this prehistoric setting where size could dictate survival, Chaoyangsaurus’s smaller stature and agility might have been advantageous in avoiding any direct competition with these behemoths. Their coexistence illustrates a balanced ecosystem where size and diet diversity allowed multiple species to flourish simultaneously.

In contrast, Xuanhuaceratops might have been a more direct peer to our Chaoyangsaurus. A fellow Ceratopsian and roughly the same size, these two herbivores could have competed for similar resources. Yet, their potential interactions also suggest a more complex relationship that might have involved social behaviors within and between species. This dynamic between similar-sized herbivores highlights the nuanced and intricate web of relationships that shaped the lives of these ancient creatures.

Frequently Asked Questions

What period did it live in?

It lived during the Late Jurassic Period, about 155.7 to 132.9 million years ago.

What type of dinosaur was it?

It was a small, herbivorous dinosaur belonging to the Cerapod group.

Where was this dinosaur discovered?

It was discovered in Ershijiazi, in the Chaoyang area of Liaoning Province, China.

What does its name mean?

Its name means ‘Chaoyang Lizard’, referring to the city near its discovery site.

Who first described this dinosaur?

It was first described in 1999 by Cheng, Zhao, and Xu Xing.

What makes this dinosaur significant?

Its discovery provides valuable insights into the evolution of Cerapods and the Late Jurassic ecosystem.


The information in this article is based on various sources, drawing on scientific research, fossil evidence, and expert analysis. The aim is to provide a comprehensive and accurate overview of Chaoyangsaurus. However, please be aware that our understanding of dinosaurs and their world is constantly evolving as new discoveries are made.

Article last fact checked: Joey Arboleda, 03-12-2024

Featured Image Credit: Nobu Tamura, CC BY 3.0, via Wikimedia Commons

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