Organism · Dinosaurs
Masiakasaurus knopfleri
Fossil record age bounds · ≈ 72.2–66 Ma
Inferred life reconstruction
Masiakasaurus knopfleri
Overview
Masiakasaurus knopfleri is an unusual theropod dinosaur with forward-tilting front teeth. Bones of the head, dentition, trunk, and limbs reveal its appearance. Notice differences along the tooth row from the front of the mouth toward the rear.[1][2]
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Key facts
Front and rear teeth do not all share the same shape and direction. A pronounced forward inclination of the anterior teeth and changes along the row are described. It challenges the idea of dinosaur teeth as a single uniform form.[2]
Time and place
It is known from the Maevarano Formation near Berivotra village in present-day northwestern Madagascar. The material is Maastrichtian, in the Late Cretaceous. The Cretaceous as a whole spans roughly 140–66 million years ago.[2]
The time range describes source context, not the complete duration of this species.
Size, form and skeleton
The reference material is lower-jaw bone UA 8680, preserving several teeth. Later discoveries revealed more about the jaws and head. Trunk, limb, and tail elements have also been assigned to the species, allowing different regions to be compared together.[1][2]
The Natural History Museum in London gives a body length of approximately 2 m for the genus Masiakasaurus.[8]
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Habitat and reproduction
What questions arise when food-processing teeth differ within one jaw? Examining front and rear tooth rows separately reveals their construction more clearly. Research begins with differences in form to investigate this dinosaur’s life.[2]
Fossil discovery
The original description in 2001 was followed by a study of new material in 2011. The second study compared more head and body bones to examine noasaurid form. As specimens accumulate, questions expand beyond the unusual jaw first described.[1][2]
References
- 2001 study — The description of Masiakasaurus
- 2011 study — New material of Masiakasaurus
- 2001 study — The description of Masiakasaurus
- 2011 study — New material of Masiakasaurus
- Buckley, G. A. & Brochu, C. A. (1999), “An enigmatic new crocodile from the Upper Cretaceous of Madagascar,” Special Papers in Palaeontology 60, pp. 149–175.
- Turner, A. H. & Buckley, G. A. (2008), “Mahajangasuchus insignis (Crocodyliformes: Mesoeucrocodylia) Cranial Anatomy and New Data on the Origin of the Eusuchian-Style Palate,” Journal of Vertebrate Paleontology 28(2), 382–408.
- Pochat-Cottilloux2025 — Non-semiaquatic adaptations of extinct crocodylomorphs
- Natural History Museum, London — Masiakasaurus
Research questions
Can new fossils change the identification of existing specimens? Research on Masiakasaurus included corrections to the anatomical identities and assignments of some bones. Distinguishing similar fragments is important for understanding a dinosaur’s body.[2]
Observation
Move your gaze from the forward-tilting teeth at the front of the jaw to the rear tooth row. Then examine the neck, trunk, and limbs to compare the distinctive head with the body organization of a small theropod.[2]
Related organisms
Mahajangasuchus insignisCrocodylomorphsSource time context (not species duration) · ≈ 143–66 MaA dinosaur and a crocodyliform from the same Maevarano Formation
Masiakasaurus and Mahajangasuchus are known from latest Cretaceous material in the Maevarano Formation of present-day northwestern Madagascar. Examine the dinosaur’s forward-tilting front teeth and the crocodyliform’s broad, rounded lower jaw separately to compare different animals revealed by the same formation.