Same they are back to their best, as posted by
@Galen
The difference is, the Ripperdactyl warscroll specifically allows for bonus attacks to generate additional attacks:
Voracious Appetite: Each time a
model from this unit attacks with
its Vicious Beak and scores a hit,
immediately make another hit roll
against the same target. Carry on until a
hit roll does not score a hit, then make
any wound rolls.
Compare that to the Scar-Vet on Carnosaur command ability:
Saurian Savagery: The Scar-Veteran
looses an ear-splitting roar that drives
nearby saurus into a frenzy. If the
Saurus Scar-Veteran on Carnosaur
uses this ability, pick a SAURUS unit
within 15". Until your next hero phase,
whenever you roll a hit roll of 6 or more
for a model in that unit, that model can
immediately make one additional attack
using the same weapon.
The Scar-Vet warscroll doesn't specifically allow the additional attacks to generate additional attacks, so it can't over-ride the core rules. The Ripperdactly warscroll however does specifically allow for the bonus attacks to generate additional ones, so it can over-ride the core rules. Hence, from a straight rules perspective, Ripperdactyls can keep hitting indefinitely until they miss.