Gnathovorax cabreirai
- 演化之聲
- Jun 13
- 2 min read
Age
Triassic (Carnian)
233 Ma
Taxonomy
Kingdom：Animalia
Phylum：Chordata
Class：Reptilia
Order：Saurischia
Family：Herrerasauridae
Genus：Gnathovorax
Species：Gnathovorax cabreirai
Morphological description
Gnathovorax cabreirai is estimated to have reached nearly 3 metres in length and weighed around 100 kilograms, although some estimates suggest a body mass closer to 60 kilograms.
The premaxilla of Gnathovorax bears three teeth, differing from its close relative Herrerasaurus, which possessed four. Between the premaxilla and maxilla are two openings: a subnarial fenestra positioned low on the snout and a smaller fenestra located above it. The subnarial fenestra is common among herrerasaurids and theropods, whereas the additional opening is considered a distinctive feature of Gnathovorax.
The neck was relatively short, with keels along the lower margins of the cervical vertebrae, a feature shared with other herrerasaurids. The caudal vertebrae resemble those of Herrerasaurus, possessing elongated zygapophyses and upwardly inclined neural spines. The skeleton lacks the air-filled cavities associated with pneumaticity, indicating that Gnathovorax had not yet evolved extensive skeletal pneumatization.
Etymology
The generic name Gnathovorax combines the Greek word gnathos (“jaw”) with the Latin word vorax (“voracious” or “greedy”).
The species name honours the Brazilian palaeontologist Sérgio Furtado Cabreira, who discovered the specimen.
Biological interpretation
The holotype of Gnathovorax cabreirai was discovered in 2014 at the Marchezan site in São João do Polêsine, Rio Grande do Sul, Brazil. Catalogued as CAPPA/UFSM 0009, the specimen consists of an almost complete skeleton, with several elements still preserved in articulation. Only the left shoulder girdle and left forelimb are missing.
The skull also preserves evidence of craniofacial injuries, which may have resulted from biting and grasping during intraspecific combat.
Phylogenetic analyses place Gnathovorax within Herrerasauridae. The original description of the species recovered Herrerasauridae near the base of Saurischia, outside both Theropoda and Sauropodomorpha. Within Herrerasauridae, Gnathovorax, Herrerasaurus, and Sanjuansaurus form a polytomy.
Researchers suggest that during the Carnian Stage of the Late Triassic, herrerasaurids, including Gnathovorax, occupied the ecological niche of large terrestrial predators, whereas early sauropodomorphs primarily filled small-bodied predatory and omnivorous niches. It was not until the Norian, following the extinction of herrerasaurids and carnivorous sauropodomorphs, that theropod dinosaurs began to diversify and occupy predatory niches across multiple ecological levels.
（Author: Bai Leng）
Reference
1. Pacheco, C., Müller, R. T., Langer, M., Pretto, F. A., Kerber, L., da Silva, S. D. (2019). Gnathovorax cabreirai: a new early dinosaur and the origin and initial radiation of predatory dinosaurs. PeerJ.
2. Aureliano, T., Ghilardi, A. M., Müller, R. T., Kerber, L., Pretto, F. A., Fernandes, M. A., Ricardi-Branco, F., Wedel, M.J. (2022). The absence of an invasive air sac system in the earliest dinosaurs suggests multiple origins of vertebral pneumaticity. Scientific Reports.
3. Garcia, M. S., Martínez, R. N., Müller, R. T. (2025). Craniofacial lesions in the earliest predatory dinosaurs indicate intraspecific agonistic behaviour at the dawn of the dinosaur era. The Science of Nature.
-29.695, -53.795
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