The Genius Dinosaur
This dinosaur was probably one of the smartest dinosaurs to have lived. That’s because it has the biggest brain in comparison to its body (that is different from having the biggest brain, though). One of the most impressive discoveries was made by looking at the brain case – the part of the skull that holds the brain.
Most dinosaurs had brains that were smaller than the space that they had in the skull. But this dinosaur had a brain that filled the brain case. We know because the brain left an impression on the inside of the brain case. That means it filled the brain case and grew enough to put pressure on the skull and leave an impression – unusual in dinosaurs.
What Did it Eat?
Troodons, despite their small size, are theropods. And most theropods are carnivores. And there are several clues in the fossil remains to support this.
But Not Completely
There is some evidence that they were not completely carnivorous. This comes from the teeth. The teeth were unquestionably sharp and so at first glance seem to be a shoe in for a carnivore’s teeth. But on closer examination the teeth are different from most theropods. In fact they were once considered very similar to stegoceras teeth.
Now, many scientists consider them to be omnivorous, eating both plants and animals. This is supported partly by the shape of the jaw. The shape of the jaw is similar to an iguana. It is U-shaped. The iguana is a modern day plant eating reptile, so there is some reason to believe it could have been a plant eater as well.
Other Carnivorous Features
It had claws that had thumbs. Unlike other dinosaurs, the thumbs were opposable. This is strong evidence pointing towards hunting behaviour, because it could have held an animal that it was attacking. But there is more.
It had large forward pointing eyes. The forward pointing feature gives the dinosaur something called ‘binocular vision’. That means it could see things in 3-D. This is a very helpful ability if you are hunting, since you can see how far away things are. That helps you make better judgements when you are hunting, and increases the success rate.
The eyes were also very large. This suggests that they were possibly good at seeing at night. This dinosaur might have been partly nocturnal – awake at night. Perhaps it was a night hunter.
A Small Theropod
This dinosaur was quite small, so it would not have been hunting the big sauropods. It was 3 m long, and only about 50 kg. So if it was hunting, it was not hunting big dinosaurs.
It laid eggs in a nest. There were quite a few of them – up to 24 at a time. They were loosely organized in a circle pointing toward the center. By comparing the number of eggs and the body mass of this dinosaur, we can compare them to other animals, and make a guess that it probably left brooding the eggs to the males.
Far and Wide
It has left fossils as far north as Alaska, and as far south as New Mexico and Texas. We don’t know if these are all the same species of Troodon, or if they are slightly different species. We just don’t have enough fossils to know that yet. But it does seem to have been more successful farther north, toward Alaska than in the warmer southern climates. This may be due to having fewer larger predators like Tyrannosaurus rex to compete with.