Notosuchus is an extinct genus of South American notosuchian crocodylomorph. It is terrestrial, living in the Coniacian or Santonian stages of the Late Cretaceous of what is now Argentina.
Notosuchus is first encountered in a Saltasaurus nesting ground, with one attacking a nest that an Alvarezsaurus was attacking, scaring off the theropod and grabbing the egg of Alpha. However, before it can crush the egg, a sentry scares the predator away. That night, when all the eggs hatch and the chicks run into the forest, hordes of Notosuchus and Alvarezsaurus attack the chicks through the darkness. In the morning, Alpha and a surviving group are encountered by a Notosuchus, and are nearly killed; however, a member of the herd of adult Saltasaurus suddenly appears and scares off the crocodilian.
Later when Alpha returns to lay her own eggs, a Notosuchus is already there.
- Notosuchus is actually five million years older than shown in the series.