Clawed Enigmas
Therizinosaurs are the most unusual group of theropods. They come in different sizes, from smaller Beipiaosaurus or Erlikosaurus to gigantic, pot bellied monsters like Nothronychus and Therizinosaurus, with its meter-long claws.
The long claws were probably used to strip trees down and/or as lethal weapons against other predators. Their defence method might have been rearing high on their back legs and slashing with their claws, very much like bears do today.
They were feathered, long necked and peculiarly postured, thanks to their very modified pelvis. Their adult remains are rare and most of the time incomplete, contrasting with the complete nesting egg clutches that have been found with perfectly preserved embryos inside.
From what we know by looking at their anatomy, these enigmas are the only theropod dinosaurs that might have been fully vegetarian! Therizinosaurs, with a sideways rotation of their hands thanks to the crescent-shape bone in their wrists, were relatives of Velociraptor. However, they were much more cumbersome with flattened, scissor-like claws more than ten times longer than Velociraptor.