The holotype skeleton of Gnathovorax is so well preserved that its describers were able to reconstruct a digital endocast of the brain.
It possessed a large floccular fossa lobe (FFL) of the cerebellum, a portion of the brain generally (but not universally) considered useful for motor control of the eye, head, and neck.
These features mean that most paleontologists consider a large FFL to be indicative of an active predatory lifestyle, explaining why it is reduced in later sauropodomorphs but not in most theropods.
This soft tissue data provided by Gnathovorax is congruent with other evidence for carnivory in herrerasaurids, such as the structure of their teeth and claws.
The tooth proportions of herrerasaurids and basal carnivorous sauropodomorphs each overlap slightly with theropods according to a morphological variation analysis, but herrerasaurids and sauropodomorphs do not overlap with each other.
It is inferred that during the Carnian stage of the Triassic, herrerasaurids occupied large predatory niches while small basal sauropodomorphs occupied small carnivorous and omnivorous niches.
After the extinction of herrerasaurids and carnivorous sauropodomorphs in the Norian, theropods became the dominant predatory dinosaurs at multiple size tiers, encouraging sauropodomorphs to acquire larger, more herbivory-focused ecologies.
The holotype skeleton of Gnathovorax is so well preserved that its describers were able to reconstruct a digital endocast of the brain. It possessed a large floccular fossa lobe (FFL) of the cerebellum, a portion of the brain generally (but not universally) considered useful for motor control of the eye, head, and neck. These features mean that most paleontologists consider a large FFL to be indicative of an active predatory lifestyle, explaining why it is reduced in later sauropodomorphs but not in most theropods. This soft tissue data provided by Gnathovorax is congruent with other evidence for carnivory in herrerasaurids, such as the structure of their teeth and claws. The tooth proportions of herrerasaurids and basal carnivorous sauropodomorphs each overlap slightly with theropods according to a morphological variation analysis, but herrerasaurids and sauropodomorphs do not overlap with each other. It is inferred that during the Carnian stage of the Triassic, herrerasaurids occupied large predatory niches while small basal sauropodomorphs occupied small carnivorous and omnivorous niches. After the extinction of herrerasaurids and carnivorous sauropodomorphs in the Norian, theropods became the dominant predatory dinosaurs at multiple size tiers, encouraging sauropodomorphs to acquire larger, more herbivory-focused ecologies.
Gnathovorax