Irritator

About 6 to 8 metres (20 to 26 feet) long and weighed around 1 tonne (1.1 short tons). It was one of the smallest spinosaurids.1

It ate fish and other small animals, like today's crocodiles. A tooth was found stuck in a pterosaur neck bone, so it also ate pterosaurs, either by hunting or scavenging.1

Its name comes from the word 'irritation' because scientists were annoyed that fossil collectors had damaged and altered the skull before they could study it.1

Nobody knows for sure. No fossil feathers have been found with Irritator, and most spinosaurids are not known to have had feathers.1

It may have been semiaquatic, meaning it spent time in water. It lived in a coastal lagoon and probably hunted fish, like today's crocodiles.1

No, it was much smaller. Irritator was about 6 to 8 metres long, while T. rex could be over 12 metres long.1

One possible skeleton suggests it had a sail, like other spinosaurids, but since only a skull has been found, the sail is a guess.2

It lived during the Early Cretaceous Period, about 113 to 110 million years ago.1