All living things have to eat in order to survive, and dinosaurs were no exception. Still, you'd be surprised at the specialized diets pursued by some dinosaurs, and the sheer variety of prey and foliage eaten by the average carnivore and herbivore. Here's a list of dinosaurs' top 10 favorite foods.
1. Other Dinosaurs
It was a dinosaur-eat-dinosaur world back during the Jurassic and Cretaceous periods: large, lumbering theropods like Allosaurus and Carnotaurus made a specialty of chowing down on other herbivores and carnivores, though it's unclear whether certain meat-eaters (such as Tyrannosaurus Rex) actively hunted their prey or settled for scavenging already-dead carcasses.
2. Fish, Sharks and Marine Reptiles
Oddly enough, some of the biggest, fiercest theropods of South America and Africa subsisted on sharks, marine reptiles and (mostly) fish. Judging by its long, narrow, crocodile-like snout, the biggest meat-eating dinosaur that ever lived, Spinosaurus, preferred seafood, as did its close relatives Suchomimus and Baryonyx.
3. Mesozoic Mammals
Many people are surprised to learn that the earliest mammals lived alongside the dinosaurs. These small, quivering, mouse- and cat-sized furballs featured on the lunch menu of small theropods (mostly raptors and "dino-birds"), but at least one Cretaceous mammal, Repenomamus, is known to have feasted on the occasional dinosaur itself!
4. Birds and Pterosaurs
To date, the evidence is scarce for dinosaurs having eaten prehistoric birds or pterosaurs (in fact, it's more often the case that larger pterosaurs preyed on smaller dinosaurs!) Still, there's no question that these flying animals were occasionally munched on by theropods, perhaps not while they were alive, but after they had died of natural causes and plunged to the ground.
Because they weren't equipped for taking down larger prey, many of the small, birdlike, feathered theropods of the Mesozoic Era specialized in easy-to-find bugs. One recently discovered dino-bird, Linhenykus, possessed a single claw on each of its forearms, which it presumably used to dig into termite mounds and anthills!
Way back during the Permian period, about 300 to 250 million years ago, cycads were among the first plants to colonize dry land--and these strange, stubby, fernlike "gymnosperms" were soon feasted on by herbivorous dinosaurs large and small. Some species of cycad have persisted down to the present day, mostly restricted to tropical climates.
Along with cycads, above, ginkgoes were some of the first plants to colonize the world's continents. During the Jurassic and Cretaceous periods, these 30-foot-high trees grew in thick forests, and helped to spur the evolution of the long-necked sauropods that feasted on them. Today, sadly, only one species of ginkgo remains, the medicinally useful Ginkgo biloba.
Every bit as ancient as cycads and ginkgoes, ferns were particularly appealing to low-slung herbivorous dinosaurs (like stegosaurs and ankylosaurs), for the simple fact that most species didn't grow that far off the ground. Unlike their ancient cousins, ferns have prospered in modern times, with over 12,000 named species--perhaps because there aren't any dinosaurs left to eat them!
Along with ginkgoes, above, conifers were some of the first trees to evolve on dry land. Today, these cone-bearing trees are represented by such familiar species as cedars, firs, cypresses and pines; hundreds of millions of years ago, conifers were a dietary mainstay of plant-eating dinosaurs, which munched their way through the the immense conifer forests of the northern hemisphere.
10. Flowering Plants
Evolutionarily speaking, flowering plants are a relatively recent development, with the earliest fossilized specimens dating to the early Cretaceous period. Flowers quickly supplanted cycads and ginkgoes as a source of nutrition for plant-eating dinosaurs; at least one duck-billed genus, Brachylophosaurus, is known to have feasted on flowers as well as ferns and conifers.