We talked about animals that ate meat and animals that ate plants. What about those that ate both? These animals are omnivorous. They had a varied diet made up of both plants and prey.
The Oviraptor was a toothless dinosaur. It lived about 80 million years ago. It was small at five feet long from nose to tail. It is not clear what it ate, but due to its sharp beak scientists think it ate nuts, seeds, and shellfish.
Most people think all dinosaurs were scaly, but this dinosaur was feathered. It also had limbs similar to wings. But this dinosaur was flightless. Those wing-like limbs were most likely used for protecting their eggs from the sun, rain, and wind. Like many animals today, these dinosaurs also displayed their plumage to attract mates.
The name Oviraptor means "egg thief" or "egg seizer". This dinosaur got its name because its remains were first found on top of a nest. Scientists thought it died trying to steal another dinosaur's eggs. But now we know that it died trying to protect its own nest instead.
The Gastornis was a large flightless bird. It was from the late Paleocene epoch, 66 to 56 million years ago. It reached up to 2 metres tall. It had brightly coloured plumage on the back of its head like a crest. The rest of its body was covered in blue-green feathers.
It had a stocky head. It also had a huge beak that was shaped like a hatchet. Its beak was perfect for crushing seeds and ripping off leaves. We are not sure what this dinosaur ate. Some scientists think it was a predator and hunted small prey. People cannot agree on what kind of predator it was. Some think the Gastornis was an apex predator. Others do not think it was fast enough and the Gastornis was more likely an ambush hunter.
The Gastornis did not live in groups. It lived alone most of the time, and it was very territorial. If another Gastornis got close to its nest, the mother protected her nest and her eggs.
Many of us think of crocodiles as being dangerous meat-eating creatures. While studying the teeth of prehistoric crocodiles, scientists found that they weren't always carnivores. In fact, the study showed that they were most likely herbivores and omnivores. Carnivores have teeth that are sharp and pointy. Herbivores and omnivores have teeth that are used for grinding plants.
Different prehistoric crocodiles ate different vegetation. The prehistoric crocodiles had teeth that were more squared. These squared teeth allowed the crocodile to eat plants and stems. But these plant-eating creatures died 66 million years ago, while the meat-eating ones continued to live.
By studying the different teeth, it shows that crocodiles had varied diets. They lived in niches along with other mammals and other plant-eating animals.
Like many animals that once roamed Earth, a lot of them died due to changes in the climate. These changes shifted the space and food that the animals needed to live. Others simply became extinct due to stronger animals taking over their food supply and homes. It is hard to picture what it would be like if these animals lived on.