Board Thread:Off-Topic Discussion/@comment-29637681-20170514033014/@comment-28009263-20170614175810

"Austroraptor was a medium sized, moderately-build, ground-dwelling, bipedal carnivore, that could grow up to 5m (16.4 ft.) in lenght from head to tail..."

"...Gregory S. Paul estimated it's (Austroraptor) weight at 300 kg (~661 lb)..."

- Wikipedia

"Velociraptor was a mid-sized dromaeosaurid, with adults measuring up to 2.07m (6.8ft) long, 0.5m (1.6 ft) tall at the hip and weighing up to 15 kg (33 lb).."

-Wikipedia

So, even tho Wraak is lucky bitten, he didn't increase very much in size, about two kg heavier and not little increasement in size. His skull should not be able to resist that much pressure without breaking.