What did Dinosaurs Eat

Jane Allyson's image for:
"What did Dinosaurs Eat"
Image by: 

Through studying the bone structure, teeth, stomach contents, physiology and location of dinosaur fossils, scientists can gain great knowledge about the kind of food these ancient lizards lived on.

Dinosaurs are divided into two orders: the
Saurischia ( lizard-hipped) and
Ornithischia (birdhipped). They can then can be split into three types; herbivore, carnivores and omnivores and can be defined as being land archosaurs
(known as "ruling lizards") with an upright gait. Creatures such as the sea-living Plesiosaurs, Mosasaurs, and the dolphin-like Ichthyosaurs, were not dinosaurs at all and are in fact more closely related to the lizards and turtles of modern times than the bird like dinosaurs of the Mesozoic Era.

Thanks to over a hundred years of intensive excavation of sedimentary rock dating to the late Triassic period, (227 million to 206 million years ago) the scientific world have amassed a plethora of fossils (including fossilized dung known as coprolite) showing a diverse range of genera and species, giving testimony to the fact that the dinosaur had many different lifestyles and diet.

The Herbivores:

Iguanadon (iguana teeth) lived 135-125 million years ago and was the first dinosaur to be discovered. This herbivore was thought to have chomped its way through cycads, conifers, and ginkgos.

Plateosaurus (flat lizard) was a very common herbivore that had five-fingered hands with a clawed thumb and possessed a long neck that was suited to tugging at tall tree tops such as those of conifers and cycads.

formerly (we used to know it as Brontosaurus
or deceptive lizard) was a dinosaur that measured between 70 and 90 feet, with a head of merely 2 foot long. They lived mainly on conifers, but they were also partial ginkos, club mosses, horsetails and ferns.

Hadrosaurus (bulky lizard) was the world's first mounted dinosaur skeleton. It possessed a toothless duckbill with many cheek teeth, ideal for chewing tough leaves and twigs.

(double-beamed) was a gigantic 90 feet long, this was one of the longest land animals. Scientists believe it spent most of its waking hours eating, to sustain the huge bulk of the body. Their teeth were blunt and so swallowed leaves and plants as a whole with no chewing involved. It is believed that their main diet was conifers, as they grew in abundance during the Jurassic era. They could also have used their long necks gather ferns that grew in wet, swampy areas.

Mamenchisaurus (Mamenchin
lizard) possessed an amazing 46 feet long neck, which is the longest of any animal that has ever lived on the Earth. Small fragments of skull show teeth of a heavy nature which would indicate a plant eating ability. These teeth would have made short work of the coarser, harder parts of plants and would have been especially good for shredding cycads and other fibrous fronds.

Ankylosaurus (bent/crooked lizard) was the most heavily armed dinosaur, and was covered with plates, studs and spikes. The diet of ankylosaurids is generally thought to be vegetation. Although it has been suggested that they were insectivorous, its weight and bulk suggest that it followed an herbivorous diet. Possessing a muzzle that can be compared to a hippopotamus, it suggests that ankylosaurids were also non-selective grazers.

Stegosaurus (plated lizard) weighed three-ton and had the brain the size of a walnut. Its teeth structure and physiology point to a vegetarian diet and probably ate ferns, smaller club mosses, cycads, horsetails, and bushy conifers.

Triceratops (three-horned face) had four stumpy legs and used the three horns on its head for protection. It started life as an egg and was a herd animal. Its cheek teeth indicate a vegetarian diet and probably rooted out cycads, palms, and other low-lying plants with its tough, toothless beak.

Seismosaurus (seismic lizard) is considered to be the largest dinosaur, measured a staggering 120 feet long and once standing about 18 feet high. It possessed blunt, peg-like teeth, which indicated a foliage stripping diet and it is surmised it must have had to eat a tremendous amount of plant matter to sustain itself. Fossil evidence shows us that it had stones in its stomach to help digest the tough plant material which was probably swallowed whole. The dominant plant of the period was conifers which would probably have been its main food source, and other food would have included gingkos, seed ferns, cycads, ferns, club mosses, and horsetails.

The Carnivores:

(meaning hollow form) was a 9-foot long meat eater. It was an agile creature that hunted in packs. Fossilized stomach remains indicate that it could have been a scavenger and was most certainly a cannibal. Its diet consisted of small reptiles, fish, and other Coelophysis.

Allosaurus (different lizard) the biggest meat-eater of the period, measuring about 40 feet long and was a fierce predator that may have hunted in groups. It probably preyed upon stegosaurs and iguanodons and medium-sized sauropods, including sick or injured large sauropods like Apatosaurus and many others of its contemporaries. Evidence of Allosaurus tooth marks has been found on the vertebra of an apatosaurus bone which does not dismiss the possibility that it may also have been a scavenger.

Compsognathus (pretty jaw) is the smallest-known dinosaur and was about the same size as a chicken. Fossil evidence has shown the skeleton of a lizard within the abdominal cavity of this tiny dinosaur, which would indicate a carnivorous diet.

Giganotosaurus carolinii: (giant southern lizard) measured about 45 feet long and weighed approximately 8 tons, it is the largest carnivore ever found and its diet consisted of large plant eating herbivores.

Tyrannosaurus rex
(tyrant lizard) was king of the dinosaurs of the late Cretaceous period. A coprolite found by a team in Canada led by Karen Chin contained chunks of bones from an herbivorous dinosaur which may have been part of the head frill of a Triceratops. Evidence of healed T. rex tooth marks on the tail of a hadrosaur suggests that T. rex
was an active predator that relied on its powerful back legs to chase and bring down its prey by biting chunks out of its victims.

The Omnivores:

Eoraptor (dawn thief) is the earliest-known dinosaur. It walked on two feet and was a fairly fast runner. Using tooth and sharp claw to tear its prey apart, it mainly lived on small animals. Scientists have determined that it was also a scavenger. As it possessed both carnivorous and herbivorous teeth, it could be surmised as being omnivorous.

Troodon (wounding tooth) had the largest brain-to-body ratio of the dinosaurs and could have been as intelligent as modern birds. Troodon had really sharp, broad teeth with serrated edges. The jaw fits together in a way that is similar to the modern day iguana. Its diet could have consisted of smaller animals and perhaps a large amount of plant material which is signified by the considerable wear found to the serrated edges of the teeth a sign that heavy duty plant mastication had taken place.

Orinthomimus (bird mimic) could have been the early forerunner of the Ostrich and was the fastest dinosaur, being able to run at a speed of approximately 40 to 50 miles an hour.
Ornithomimus ate insects, small reptiles and mammals, eggs, fruit, and leaves.


When Did the Dinosaurs Live?

Dinosaur Information pages:

More about this author: Jane Allyson

From Around the Web