Hippodraco: The Early Cretaceous “Horse Dragon”

When we delve into the realm of dinosaurs, every discovery is like a puzzle piece, revealing more about the ancient world. Among these fascinating creatures is Hippodraco, a name that might not ring as many bells as the famed Tyrannosaurus or the gentle Brachiosaurus, but it holds its unique place in the cretaceous tapestry. This intriguing dinosaur, whose name translates to “Horse Dragon,” offers a glimpse into the diverse and complex ecosystem of the Early Cretaceous Period.

Hippodraco, first unearthed in the Cedar Mountain Formation in Utah, has captured the imagination of paleontologists and enthusiasts alike. Discovered in 2004 and later described in 2010, this dinosaur’s journey from a fossil in the ground to a recognized species is a testament to the meticulous work of paleontologists. Its classification within the Ornithopod group and the Iguanodontia family places it among a lineage of herbivorous dinosaurs known for their adaptability and survival skills.

Hippodraco Key Facts

Meaning of nameHorse Dragon
Type SpeciesHippodraco scutodens
When it LivedAround 124 to 118 Ma
PeriodEarly Cretaceous
EpochUpper Barremian – Lower Aptian
Length15.0 feet
Height4.0 to 5.0 feet
Weight500.4 to 1,000.9 pounds
MobilityMoved on two legs
First Discovery2004 by Andrew R. C. Milner
Described by2010 by Andrew McDonald and colleagues
HolotypeUMNH VP 20208
Location of first findCedar Mountain Formation, upper section of the Yellow Cat Member, Utah

Hippodraco Origins, Taxonomy and Timeline

The name Hippodraco, blending Greek and Latin roots, paints a vivid picture of a creature as majestic as a horse and as mythical as a dragon. This nomenclature, while evocative, also hints at the dinosaur’s physical attributes and perhaps its grace or agility. The fusion of ‘hippos’ (horse) and ‘draco’ (dragon) is not just a fanciful creation but a meaningful descriptor in the world of paleontology.

Life restoration illustration of the Hippodraco, a medium-sized herbivorous dinosaur from the Early Cretaceous period. This quadrupedal dinosaur is depicted with a robust body, long tail, and textured skin resembling scales. The Hippodraco, known for its unique jaw structure and feeding habits, primarily consumed plants and lived in what is now North America.

Belonging to the Styracosterna (Ornithischia: Iguanodontia), Hippodraco is part of a clade that thrived in the Cretaceous. These herbivorous dinosaurs, close to the hadrosaurs, were known for their bipedal stance, although some could also walk on all fours. The Iguanodontia, to which our subject belongs, is particularly noted for its members’ diverse range of sizes and adaptations.

The timeline of Hippodraco is set in the Early Cretaceous Period, from approximately 124 to 118 million years ago (MYA), was a time of significant evolutionary changes and diversification among dinosaurs. The fact that Hippodraco lived during this period adds to its significance in understanding the evolutionary history of iguanodonts.

Discovery & Fossil Evidence

The discovery of Hippodraco stands as a singular event in the field of paleontology, particularly in the study of Iguanodontids. Unearthed in 2004 by Andrew R. C. Milner in the Cedar Mountain Formation, Utah, this discovery brought to light a new species within the diverse world of dinosaurs. Hippodraco, classified as a single species, H. scutodens, is known from just one partial skeleton, which notably belonged to an immature individual.

Fossilized skull of the Hippodraco on display in a museum exhibit. This detailed fossil showcases the unique jaw structure and bone composition of this herbivorous dinosaur from the Early Cretaceous period. The Hippodraco, a quadrupedal plant-eater, lived in what is now North America and is known for its distinct cranial features.
Jens Lallensack, CC BY-SA 4.0, via Wikimedia Commons
Fossilized skull of H. scutodens displayed in a museum exhibit. This fossil highlights the distinctive cranial structure of H. scutodens, a herbivorous dinosaur from the Early Cretaceous period. Known for its unique jaw anatomy and plant-eating habits, this quadrupedal dinosaur roamed what is now North America.
ケラトプスユウタ, CC BY-SA 4.0, via Wikimedia Commons

The holotype specimen, UMNH VP 20208, is a crucial piece in understanding Hippodraco’s place in the dinosaur lineage. The fact that this specimen represents an immature individual adds a layer of complexity to the study, as it provides insights into the growth and development patterns of this species. The partial skeleton, while not complete, has been instrumental in piecing together the physical characteristics and potential behaviors of Hippodraco.

Unlike some other dinosaur discoveries, there have been no later finds of Hippodraco specimens. This lack of additional fossil evidence means that our understanding of this species is based solely on the initial discovery. Each bone and fragment of the holotype specimen thus carries significant weight in the scientific community’s efforts to reconstruct the life and environment of this Early Cretaceous herbivore. The singular nature of this find underscores the rarity and preciousness of fossil evidence in the field of paleontology.

Hippodraco Size and Description

Hippodraco, a relatively small member of the iguanodontid group, presents an interesting case study in dinosaur morphology. Its physical structure, as revealed by fossil evidence, suggests a creature adept at navigating its Early Cretaceous environment. The well-preserved left side of its skull, contrasted with the fragmented right side, offers a unique glimpse into its cranial anatomy. Notably, the large orbital in the skull suggests that the holotype specimen was immature, hinting at potential growth and development stages of this species.

The dentary and teeth of Hippodraco, particularly the shield-shaped crowns, provide insights into its feeding habits and diet as a herbivore. Additionally, the resemblance of its lacrimal bone to those of Dakotadon and Theiophytalia indicates a close relationship within the iguanodontid lineage. These physical characteristics not only define Hippodraco but also contribute to our broader understanding of ornithopod evolution and diversity.

Size and Weight of Type Species

Size comparison between a human silhouette and the Hippodraco dinosaur. This visual representation highlights the relative scale of the Hippodraco, a herbivorous dinosaur from the Early Cretaceous period. The Hippodraco is shown as a medium-sized quadrupedal dinosaur, emphasizing its considerable length and height compared to an adult human.
PaleoNeolitic, CC0, via Wikimedia Commons

Hippodraco’s size, with the holotype reaching approximately 15.0 feet in length, makes it a smaller iguanodontid. This size estimate, coupled with a weight range estimated by Holtz between 500 to 1,000 pounds, paints a picture of a relatively lightweight and agile dinosaur. The gracile nature of most of its body remains, such as the right humerus and scapula, further supports this characterization.

The fragmented and irregular surfaces of the right tibia and femur, along with the nearly complete metatarsus, draw parallels to the anatomy of Camptosaurus and Iguanodon. These comparisons not only help in reconstructing Hippodraco’s physical appearance but also in understanding its locomotion and adaptability. The vertebrae, indicative of a characteristic Iguanodont body shape, further emphasize its place within this diverse and widespread group of herbivorous dinosaurs.

Contemporary Dinosaurs

Imagine a world millions of years ago, where the ancient landscapes of what we now call North America were teeming with life, a world where Hippodraco, a relatively modest-sized herbivore, roamed. Picture this creature, not as large as some of its contemporaries, but still a notable presence, grazing peacefully. In the same realm, there were giants like Cedrorestes, Brontomerus and Iguanacolossus, larger and likely more imposing than our main character. These giants, with their towering frames, would have roamed the same areas, perhaps causing the smaller Hippodraco to tread carefully, always mindful of not encroaching too much on the feeding grounds of these larger herbivores.

Interesting Points about Hippodraco

Hippodraco in its Natural Habitat

The Early Cretaceous Period, the era when Hippodraco roamed, was a time of significant environmental and climatic changes. The landscape was likely diverse, with a mix of lush forests, open plains, and possibly wetlands. This variety in terrain would have provided ample food sources for a herbivore like Hippodraco.

As a herbivore, Hippodraco’s diet would have primarily consisted of the vegetation available in its habitat. Its teeth and jaw structure, typical of Ornithopods, were likely well-suited for grinding and processing plant material. The bipedal locomotion of Hippodraco suggests it could have foraged for food both on the ground and possibly from lower branches of trees or shrubs.

The social behavior of Hippodraco is not definitively known, but it could have lived in groups or herds, as seen in other Ornithopods. Living in groups could have provided advantages in terms of protection from predators and efficiency in foraging. The potential impact of Hippodraco on its ecosystem, whether through grazing habits or other interactions, adds another layer of intrigue to its study.

Frequently Asked Questions

What does the name of this dinosaur mean?

Hippodraco means “Horse Dragon,” a name derived from Greek and Latin roots that reflect its unique characteristics.

When was this dinosaur discovered?

It was discovered in 2004 by Andrew R. C. Milner in the Cedar Mountain Formation, Utah.

What type of dinosaur is Hippodraco?

Hippodraco is an iguanodont, a group of herbivorous dinosaurs known for their bipedal locomotion.

What period did Hippodraco live in?

This dinosaur lived during the Early Cretaceous Period, approximately 124 to 118 million years ago.

Where was the first Hippodraco fossil found?

The first fossil was found in the Cedar Mountain Formation in Utah, a region rich in dinosaur fossils.

What is known about Hippodraco’s diet?

As a herbivore, Hippodraco’s diet would have consisted of various plant materials available in its habitat.


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 Hippodraco. However, please be aware that our understanding of dinosaurs and their world is constantly evolving as new discoveries are made.

This article was last fact-checked: Joey Arboleda, 11-29-2023

Featured Image Credit: Lukas Panzarin, CC BY 2.5, via Wikimedia Commons