Mapusaurus: Research Database
Carcharodontosauridae (Theropoda) · Late Cretaceous (~97–93 MYA) · South America — Argentina (Cerro del Pueblo Formation)
Research Note: Mapusaurus is a giant carcharodontosaurid theropod from the Mid-Cretaceous of Patagonia, Argentina, and one of the largest known terrestrial predators. The type species Mapusaurus rosae was described in 2006 from a bonebed containing multiple individuals of varying sizes — providing the first direct evidence that large carcharodontosaurids may have hunted cooperatively in packs or family groups, analogous to modern wolves. This discovery fundamentally altered understanding of theropod social behaviour, as previously only smaller coelurosaurs were thought to exhibit cooperative hunting. At an estimated 10–13 metres in length, Mapusaurus would have been the apex predator of its ecosystem, competing with giant crocodyliforms and possibly other theropods.
| Research Finding | Status | Grade | Year | Method | Citation | Impact |
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A new giant carcharodontosaurid dinosaur from the Upper Cretaceous of Patagonia, Argentina — original description of Mapusaurus as a new genus and species of giant theropod, establishing its phylogenetic position within Carcharodontosauridae.
Coria & Bellorín 2006 provide the original description of Mapusaurus as a new giant carcharodontosaurid from the Cerro del Pueblo Formation, establishing its size, anatomy, and taxonomic distinction from other Gondwanan carcharodontosaurids
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Confirmed | A | 2006 | Fossil | Coria & Bellorín, PLOS ONE26 citations | Taxonomy |
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A large Cretaceous theropod from Patagonia, Argentina, and the evolution of giant carcharodontosaurids — analysis of Mapusaurus in the context of giant theropod evolution and the role of Carcharodontosauridae in Cretaceous Gondwanan ecosystems.
Novas & de Valais 2006 place Mapusaurus and other Patagonian carcharodontosaurids within the broader evolutionary context of giant theropod dinosaurs, establishing the phylogenetic position and ecological role of these apex predators in the Cretaceous of South America
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Confirmed | A | 2006 | Phylogenetic Analysis | Novas & de Valais, Naturwissenschaften104 citations | Phylogeny |
Active Debate: Cooperative Hunting, Size Estimates, and Ecosystem Role
Whether the Mapusaurus bonebed represents cooperative pack hunters or simply concurrent death events from flooding or drought is debated. Some researchers argue the multiple size classes present (from juveniles to adults) suggest family group structure, while others note that mass death events can occur through non-social mechanisms. Maximum size estimates for Mapusaurus vary from 10 to over 13 metres — the upper estimates would make it comparable to the largest known theropods. Its relationship with and relative size compared to other Patagonian giants like Tyrannotitan and Carcharodontosaurus is also being refined by new discoveries.
What We Still Don’t Know About Mapusaurus
- Complete skull: No complete skull is known; cranial reconstruction is composite.
- Forelimb morphology: Forelimbs are poorly known; their function in predation is debated.
- Colouration: Completely unknown.
- Precise size range: Size estimates vary widely due to incomplete remains.
- Social structure: Whether the bonebed represents cooperative social groups or mass mortality events is debated.
In Depth
Closely related to the massive predator Giganotosaurus, the discovery of seven Mapusaurus individuals in the same bone bed would question the notion that predatory dinosaurs were always solitary creatures. When the bone bed was excavated between 1997 and 2001, only the remains of Mapusaurus where found, and these individuals were all of different ages. These are two of the hallmarks that have led to this bone bed to be hailed as strong evidence to support the pack hunting predator hypothesis. Further, while it is not known what Mapusaurus targeted as a prey, it does hail from the same part of the world as the huge titanosaur Argentinosaurus. A full grown individual of this dinosaur would have been unassailable to just one of the known predators of the time, but a pack targeting the weaker perhaps not fully grown individuals would have had a chance of defeating it by attrition alone. This is of course just conjecture, and without further fossil finds, this is how this scenario will remain.
Analysis of the site however could cast doubt on potential gregarious behaviour as the area has been interpreted as a depositional area. This means that the bone bed may have been formed when a stream or river had swollen with flood water, and carried the Mapusaurus individuals down-stream and deposited them in a group arrangement. If true then this would be a great fluke of nature considering that only Mapusaurus and no other dinosaurs species were washed there.
What is known about Mapusaurus is that it is a member of the Carcharadontosauridae, a group known for its large members that can rival and even exceed the more famous Tyrannosaurus rex in size. The teeth on Mapusaurus where very much like those of its relative Giganotosaurus in that they were flat and curved with a serrated edge, perfect for slicing through flesh. This is in contrast to the teeth which are found in Tyrannosaurus which are conical and smooth, an adaption better suited to biting through bone.
Study of the teeth has led to further strengthening of the hypothesis that Mapusaurus could have preyed upon dinosaurs like Argentinosaurus that had bones that were simply too big to bite through. If the pack hunting theory is true then Mapusaurus may have worn down an Argentinosaurus with multiple bites. These wounds would that lead to blood loss and infection which would then bring the huge dinosaurs down.
Mapusaurus is a combination of the Mapuche word for earth, and the Greek word for lizard. The species name M. roseae has dual meaning, references both Rose Letwin, the dig sponsor, and the colour of the rocks that Mapusaurus was recovered from.
Further Reading
– A new carcharodontosaurid (Dinosauria, Theropoda) from the Upper Cretaceous of Argentina – Geodiversitas 28(1):71-118 – R. A. Coria & P. J. Currie – 2006. – New Information on the Cranial Anatomy of Acrocanthosaurus atokensis and Its Implications for the Phylogeny of Allosauroidea (Dinosauria: Theropoda). – PLoS ONE 6(3): e17932. – Drew R. Eddy & Julia A. Clarke – 2011. – Palaeopathological survey of a population of Mapusaurus (Theropoda: Carcharodontosauridae) from the Late Cretaceous Huincul Formation, Argentina – PLoS ONE 8(5):e63409:1-6 – P. R. Bell & R. A. Coria – 2013. – Cranial ontogenetic variation in Mapusaurus rosae (Dinosauria: Theropoda) and the probable role of heterocrony in carcharodontosaurid evolution. Palaeontol Z doi: 10.1007/s12542-014-0251-3. – J. L. Canale, F. E. Novas, L. Salgado & R. A. Coria – 2014.
