Majungasaurus crenatissimus

Majungasaurus crenatissimus was a carnivorous theropod dinosaur belonging to the Abelisauridae family that lived during the Late Cretaceous, approximately 70 to 66 million years ago (Maastrichtian), on the present-day island of Madagascar. Its remains come mainly from the Maevarano Formation, a series of fluvial deposits and floodplains representing semi-arid ecosystems with marked climatic seasonality.

It was a medium-sized predator among theropods, with an estimated body length of 6 to 7 meters and a mass of approximately 1 to 1.5 tons. It had a robust build, with a relatively deep torso, a muscular neck, and a long tail that acted as a counterbalance during bipedal locomotion. Its hind limbs were strong and well-developed, adapted to support its body weight and provide power during walking or short bursts of speed.

The skull is one of the most distinctive features of Majungasaurus . It was short, tall, and remarkably robust, with thickened and heavily ornamented cranial bones. The dorsal region of the skull featured a bulbous structure or low horn formed by the nasal bones, likely covered with keratinous tissue in life. The external surface of the facial bones exhibits rough, vascularized textures, suggesting the presence of specialized keratinous coverings or integuments.

The jaws were armed with large, laterally compressed, and recurved teeth with serrated edges that facilitated the cutting of meat. The specific epithet crenatissimus refers precisely to the prominent denticulations of these teeth. Cranial biomechanics indicate a powerful bite, with adaptations that allowed it to withstand strong stresses during the capture and dismemberment of prey.

A notable characteristic of abelisaurids, clearly visible in Majungasaurus , is the extreme reduction of the forelimbs. The arms were very short, and the hands likely possessed reduced fingers with limited functionality. In contrast, the neck was particularly muscular, suggesting that much of the force used during predation came from the movement of the head and neck rather than the forelimbs.

The postcranial skeleton shows robust vertebrae with complex articulation systems that provided rigidity and stability to the trunk. The tail was long and muscular, contributing to body balance during locomotion. The hind limbs ended in three-toed feet with strong claws, typical of predatory theropods.

The taphonomic study of the fossil remains has revealed direct evidence of cannibalism within the species: some Majungasaurus bones show tooth marks that match in size and morphology with those of this same taxon. This behavior was likely related to seasonal environmental conditions and irregular resource availability in Madagascar's ecosystems during the Late Cretaceous.

From an evolutionary perspective, Majungasaurus crenatissimus is one of the best-known abelisaurids thanks to the abundance of fossil material, including relatively complete skulls and numerous postcranial remains. Its anatomy provides key information about the specialization of abelisaurids as dominant predators in the Gondwanan ecosystems of the Late Cretaceous, where they occupied ecological niches equivalent to those of the large tyrannosaurids in Laurasia.

Approximate measurements of the Majungasaurus:

• 1:35 Scale Assembly Kit
  • Length 151 mm
  • Height 100 mm
  • Width 131 mm
  • Snout-tail length 222 mm