One of the most fascinating aspects of dinosaur paleontology is figuring out how a prehistoric animal lived and what it ate when it was alive.
By studying the dentition of a fossil species, scientists can determine whether it was a herbivore or carnivore.
Most of the dinosaurs discovered so far can be categorized neatly into either category.
But a few of them (about 1–2%) of dinosaurs fed on both plant and animal matter.
Omnivorous dinosaurs tend to have a mix of sharp teeth for cutting meat and blunt teeth for grinding plant matter.
We can also tell a dinosaur’s diet by studying its preserved stomach content and other parts of the digestive system.
Omnivorous dinosaurs are impressive because they generally have a greater chance of surviving during periods of scarcity compared to other types of dinosaurs.
In this article, we’ll list 15 of these dinosaurs and explain some of their most impressive qualities.
15. Oviraptor
| Name | Oviraptor |
| Name Meaning | “Egg thief” |
| Pronunciation | Oh-vee-RAP-tor |
| Era | Mesozoic – Late Cretaceous |
| Classification | Dinosauria, Saurischia, Theropoda |
| Diet | Omnivorous |
| Height | 1.2 meters (4 feet) |
| Length | 1.5-2 meters (5-6.5 feet) |
| Weight | 20–30 kilograms (44–66 pounds) |
| Location | Mongolia and China (Asia) |
When the Oviraptor was discovered in 1923, scientists immediately assumed it fed on the eggs of other dinosaurs and was named “egg-thief” accordingly.
Subsequent discoveries pointed out the error in this assumption, and the eggs found in association with this dinosaur were discovered to be its own.
This raised questions about the actual diet of this dinosaur.
More recent research suggests that the Oviraptor was most likely an omnivore, with a diet comprising a mix of plants, seeds, small animal prey, and shelled animals (mollusks and crustaceans), which it crushed with its toothless beak.
The lower jaws of the Oviraptor were found to be similar to that of parrots.
In contrast, the upper jaws were similar to that of turtles, leading to the conclusion that they were capable of feeding on plant and animal matter.
14. Gallimimus
| Name | Gallimimus |
| Name Meaning | “Emu Mimic” |
| Pronunciation | gal-lee-MEEM-us |
| Era | Mesozoic – Late Cretaceous |
| Classification | Dinosauria, Saurischia, Theropoda |
| Diet | Omnivorous |
| Height | 1.9 to 3 meters (6.23 to 9.84 feet) |
| Length | 4 to 8 meters (13.12 to 26.25 feet) |
| Weight | 200 to 400 kilograms (440.93 to 881.85 lbs) |
| Location | Mongolia |
Gallimimus was the largest of the bird-mimic dinosaurs (ornithomimids), standing about six feet tall at the hips and growing to a length of up to 20 feet.
This dinosaur was most likely an omnivore with a varied diet.
Its sharp beak suggests it could have consumed plants.
The beak of the Gallimimus was also found to be similar to that of a duck or goose.
This means it could feed on small animal or insect prey, which it swallowed whole.
Gallimimus was also quite agile and would have had no trouble keeping up with its prey.
The dinosaur lived in the semi-arid Gobi Desert during the Cretaceous Period, where the vegetation cover was quite limited.
Subsisting on insects, lizards, fruits, and seeds would have given it an advantage when food was scarce.
13. Troodon
| Name | Troodon |
| Name Meaning | “Wounding Tooth” |
| Pronunciation | TROH-oh-don |
| Era | Mesozoic – Late Cretaceous |
| Classification | Dinosauria, Saurischia & Theropoda |
| Diet | Omnivorous |
| Height | 0.9 to 2 meters (2.95 to 6.56 feet) |
| Length | 2 meters (6.56 feet) |
| Weight | 40 kilograms (88.18 lbs) |
| Location | Alaska (North America), Montana (USA), China (Asia) |
The Troodon and its closest relatives are famous for their high intelligence quotient (IQ).
This dinosaur is considered one of the most intelligent dinosaurs ever discovered.
It is believed to have had an omnivorous diet, which included small animals, insects, and plants.
As a predator, this dinosaur’s intelligence would have made it easier to hunt prey, and they were probably capable of advanced behavior such as pack hunting.
The dinosaur also ate plant fruits, seeds, and soft vegetation when they were available within its habitat.
The nature of this dinosaur’s dentition suggests that it preferred soft materials and was probably incapable of processing tough fibrous plant matter.
12. Heterodontosaurus
| Name | Heterodontosaurus |
| Name Meaning | “Different-toothed Lizard” |
| Pronunciation | He-te-roh-don-tuh-sore-us |
| Era | Mesozoic – Jurassic Period |
| Classification | Dinosauria, Ornithischia & Heterodontosauridae |
| Diet | Omnivorous |
| Height | 1.18 meters (3 feet) |
| Length | 1.75 meters (5 feet) |
| Weight | 0.0018-0.0034 metric tons (4-7.5 lbs) |
| Location | Lesotho & South Africa |
Heterodontosaurus was a small primitive dinosaur that lived during the Early Jurassic Period about 200 million years ago.
The dinosaur’s name translates as “different toothed lizard,” referring to its unusual heterodont dentition, which included three different types of teeth.
The upper jaw of the Heterodontosaurus had several small, incisor-like teeth.
These were followed by long, canine-like tusks, while the cheek teeth had a chisel-like appearance.
A heterodont dentition is the classic diagnostic feature of an omnivorous animal.
Heterodontosaurus also had long arms equipped with large, recurved claws and robust hindlimbs that would have favored swift motion.
A combination of these features suggests that this dinosaur could chase small prey and feed on plant materials when resources were scarce.
11. Erlikosaurus
| Name | Erlikosaurus |
| Name Meaning | “Erlik’s lizard” |
| Pronunciation | Er-lick-o-sore-us |
| Era | Mesozoic — Late Jurassic Period |
| Classification | Dinosauria, Saurischia, & Theropoda |
| Diet | Omnivorous |
| Height | 2.7 meters (8.8 feet) |
| Length | 3.4 meters (11 feet) |
| Weight | 150–250 kg (330–550 pounds) |
| Location | Asia |
Erlikosaurus is named after Erlik, the god of death and the underworld.
Despite such a terrifying identity, this dinosaur was not a fierce predator.
The structure of the dinosaur’s beak and skull suggest that it had a weak bite force compared to typical carnivorous theropods.
This has led to speculations that it probably fed predominantly on soft vegetation and other plant material.
Erlikosaurus also had a large gut for processing food, typical of plant-feeding dinosaurs.
However, it probably hunted small prey as well, including insects and small vertebrates.
The fragmentary nature of this dinosaur’s fossils makes it difficult to conclusively determine what it ate.
10. Masiakasaurus
| Name | Masiakasaurus |
| Name Meaning | “Vicious lizard” |
| Pronunciation | MAY-zha-kah-SORE-us |
| Era | Mesozoic — Late Cretaceous Period |
| Classification | Dinosauria, Saurischia, & Theropoda |
| Diet | Omnivorous |
| Height | 1.8–2.1 meters (6-7 feet) |
| Length | 1.8–2.1 meters (5.9–6.9 feet) |
| Weight | 20 kg (44 pounds) |
| Location | Madagascar (Africa) |
Masiakasaurus was a small theropod dinosaur that lived in Madagascar during the Late Cretaceous Period.
One of the most distinctive features of this dinosaur was its forward-projecting front teeth.
The teeth had different shapes and were of different sizes.
The front teeth were not suitable for tearing prey apart but were more effective for grasping.
The back teeth were more similar to that of other theropod dinosaurs, suggesting that they were more useful for cutting and slicing.
The unique dentition of the Masiakasaurus suggests that it had a specialized diet, which may have included fish and other small prey.
Some experts also think it was an omnivore capable of eating fruits and other plant materials.
9. Deinocheirus
| Name | Deinocheirus |
| Name Meaning | “Terrible Hand” |
| Pronunciation | DINE-oh-KIRE-us |
| Era | Mesozoic – Late Cretaceous |
| Classification | Dinosauria, Saurischia & Theropoda |
| Diet | Omnivorous |
| Height | 5 meters (16 feet) |
| Length | 11.0 m (36.0 ft) |
| Weight | 6.5 tons (7.2 short tons) |
| Location | Mongolia |
Deinocheirus is most famous for its enormous arms ending in large claws.
The dinosaur’s name itself translates as “terrible hands.”
The claws and hands were the only part of the dinosaur known for several decades until the discovery of a more complete specimen in 2014.
But despite the terrifying appearance of this dinosaur, Deinocheirus was not a devoted carnivore.
The diet of this dinosaur was mainly vegetation.
The large claws were useful for grasping plants and pulling them towards its mouth.
But it may have supplemented this with small amounts of meat occasionally.
Scientists once found fish scales in association with one Deinocheirus specimen, which suggests that this may have been a part of their diet as well.
8. Gigantoraptor
| Name | Gigantoraptor |
| Name Meaning | “Gigantic plunderer” |
| Pronunciation | JY-gan-to-RAP-tor |
| Era | Mesozoic – Late Cretaceous |
| Classification | Dinosauria, Saurischia, Theropoda |
| Diet | Omnivorous |
| Height | 5–6 meters (16–20 feet) |
| Length | 8 meters (26 feet) |
| Weight | 1.5–2 tons (3,300–4,400 pounds) |
| Location | China and Mongolia (China) |
Despite the name, the Gigantoraptor was not a raptor (dromaeosaurid dinosaur).
Instead, it was an oviraptorosaur, a group of feathered dinosaurs that lived during the Cretaceous Period.
The Gigantoraptor is the largest member of this group, and like many of its relatives, it was most likely an omnivore.
It had large, toothless jaws with a bony beak.
The beak of the Gigantoraptor was deeper than that of other oviraptorosaurs, which suggests that it had a slightly different diet.
Experts think the Gigantoraptor was a non-selective omnivore.
Being able to feed on both plants and animals would have been very useful to keep up with the high dietary requirements needed to maintain its large size.
7. Avimimus
| Name | Avimimus |
| Name Meaning | “Bird-mimic” |
| Pronunciation | A-vee-mi-mus. |
| Era | Mesozoic — Late Cretaceous |
| Classification | Dinosauria, Ornithischia & Heterodontosauridae |
| Height | 0.6–0.9 meters (2–3 feet) |
| Length | 1.5 meters (5 feet) |
| Weight | 15 kilograms (33 pounds) |
| Location | Mongolia (Asia) |
As the name suggests, the Avimimus was a bird-like dinosaur.
It was just 1.5 meters (5 feet) long and had a relatively small skull.
Avimimus had a parrot-like beak with no teeth.
However, the fossil does preserve evidence of small tooth-like projections and small premaxillary teeth.
Avimimus had two slender legs and was probably capable of running as fast as an ostrich, an adaptation that would have been important for catching up to small prey.
It was most likely adapted to an omnivorous diet, which means it ate plant materials, eggs, small vertebrates, or even insects.
6. Citipati
| Name | Citipati |
| Name Meaning | “Funeral pyre lord” |
| Pronunciation | Si-ti-PAT-ee |
| Era | Mesozoic – Late Cretaceous |
| Classification | Dinosauria, Saurischia, Theropoda |
| Diet | Omnivorous or herbivorous |
| Height | 1.2 meters (4 feet) at the hip |
| Length | 2–3 meters (6.5–10 feet) |
| Weight | 83 kg (183 lb) |
| Location | Mongolia (Asia) |
Citipati was an oviraptorid dinosaur that lived in Asia during the Cretaceous Period.
This dinosaur is most famous for its relatively well-preserved fossils that show evidence of brooding behavior and parental care similar to that of many modern birds.
Like many oviraptorids, Citipati’s diet was composed predominantly of plant materials but may have also preyed on small animals.
One piece of evidence that supports this assumption is the discovery of the remains of two juvenile troodontids in a Citipati’s nest.
This suggests that the Citipati likely brought them as prey to the nest to feed its young.
Citipati had one of the strongest bites of all the oviraptorid dinosaurs.
5. Fruitadens
| Name | Fruitadens |
| Name Meaning | “Fruita teeth” |
| Pronunciation | Froo-tah-denz |
| Era | Mesozoic – Jurassic Period |
| Classification | Dinosauria, Ornithischia & Heterodontosauridae |
| Diet | Omnivorous |
| Length | 65–75 centimeters (26–30 inches) |
| Weight | 0.5–0.75 kilograms (1.1–1.7 pounds) |
| Location | USA (North America) |
Fruitadens was a heterodontosaurid dinosaur that lived during the Late Jurassic Period.
It is one of the smallest ornithischian dinosaurs ever discovered, with an average adult size of about 75 centimeters (30 inches) and a maximum weight of less than two pounds.
The dinosaur’s name translates as “Fruita teeth,” and it is a reference to the city of Fruita, Colorado, where the first fossil of this dinosaur was discovered.
Like other heterodontosaurid dinosaurs, Fruitadens had a unique dentition made up of teeth of different sizes.
This dinosaur’s dentition included enlarged canine-like teeth with smaller peg-like teeth in front of them.
Based on this dentition, the Fruitadens has been classified as an omnivorous dinosaur that fed on a diet of plants, small animals, and insects.
4. Massospondylus
| Name | Massospondylus |
| Name Meaning | “Llonger vertebra” |
| Pronunciation | Mas-so-spon-de-lus. |
| Era | Mesozoic — Early Jurassic |
| Classification | Dinosauria, Saurischia, & Sauropodomorpha |
| Diet | Omnivorous |
| Height | 2.4 meters (7.8 feet) |
| Length | 6 meters (20 feet) |
| Weight | 1,000 kilograms (2,200 pounds) |
| Location | USA (North America) |
Massospondylus was a sauropodomorph dinosaur that lived during the Early Jurassic.
Although no conclusive evidence has been found for the Massospondylus’ diet, a varied diet that included both plant and animal is quite likely.
It was an ancestral relative of the sauropods (a group comprising some of the biggest herbivores that have ever lived).
Before developing the herbivorous feeding habit they were famous for, primitive sauropods like the Massospondylus were likely omnivores.
They had heterodont detention, which means their teeth had different shapes and sizes.
3. Harpymimus
| Name | Harpymimus |
| Name Meaning | “Harpy Mimic” |
| Pronunciation | Har-pee-mie-mus. |
| Era | Mesozoic — Cretaceous Period |
| Classification | Dinosauria, Saurischia, & Theropoda |
| Diet | Omnivorous |
| Height | 1.8 meters (6 feet) |
| Length | 2 meters (6.5 feet) |
| Weight | 50 kilograms (110 pounds) |
| Location | Mongolia (Asia) |
Harpymimus lived in parts of present-day Mongolia during the Cretaceous Period.
It was a basal ornithomimosaur and showed several primitive qualities not seen in its relatives that evolved much later.
The most notable primitive trait of this dinosaur was the fact that it had teeth in its jaws, unlike other ornithomimosaurs with toothless jaws.
Based on this dentition, the diet of the Harpymimus is often interpreted as omnivorous, which means it ate both plant and animal materials.
2. Caudipteryx
| Name | Caudipteryx |
| Name Meaning | “Tail feather” |
| Pronunciation | KAW-dip-TER-iks |
| Era | Mesozoic – Early Cretaceous |
| Classification | Dinosauria, Saurischia, Theropoda |
| Diet | Omnivorous |
| Height | 1m (3 feet) |
| Length | 72.5–89 centimeters (2.38–2.92 feet) |
| Weight | 5–10 kilograms (11–22 pounds) |
| Location | China (Asia) |
Caudipteryx was a feathered dinosaur about the same size as a modern peacock.
This dinosaur had so many bird-like features that scientists initially assumed it was a primitive bird.
One of the bird-like features found in this dinosaur was the possession of stomach stones (gastroliths) similar to those found in the stomachs of modern birds.
These gastroliths helped with the digestion of food materials.
Like many birds and several other bird-like dinosaurs, Caudipteryx was most likely an omnivore.
Fossils of the Caudipteryx were recovered from the Liaoning province of China, a region that also had several other similar feathered dinosaurs.
1. Thecodontosaurus
| Name | Thecodontosaurus |
| Name Meaning | “Socket-toothed lizard” |
| Pronunciation | Thee-co-don-toe-sore-us. |
| Era | Mesozoic — Triassic |
| Classification | Dinosauria, Saurischia, & Sauropodomorpha |
| Diet | Omnivorous |
| Height | 30 centimeters (12 inches) |
| Length | 1.2 meters (3.9 feet) |
| Weight | 11 kilograms (24 pounds) |
| Location | China (Asia) |
Thecodontosaurus was a relatively small bipedal dinosaur.
The first fossil of this dinosaur was found in 1834, which makes it one of the first dinosaurs ever discovered.
Thecodontosaurus lived during the Triassic and is considered one of the oldest dinosaurs ever discovered.
The diet of this dinosaur was composed mainly of plant materials, but it may have also eaten some meat as a part of its diet.
Sources:
- https://ucmp.berkeley.edu/diapsids/ornithischia/heterodontosaurus.html
- https://en.wikipedia.org/wiki/Gallimimus
- https://en.wikipedia.org/wiki/Erlikosaurus
- https://en.wikipedia.org/wiki/Avimimus
- https://en.wikipedia.org/wiki/Fruitadens
- https://en.wikipedia.org/wiki/Harpymimus
- https://www.britannica.com/animal/Caudipteryx
- https://en.wikipedia.org/wiki/Thecodontosaurus
About The Author
