Masiakasaurus

Chapter • Meet the dinosaur

Overview

Masiakasaurus knopfleri was a small, lightly built predatory dinosaur roughly the length of an adult human is tall – about 1.8 to 2.4 metres from snout to tail tip, weighing somewhere between 20 and 35 kilograms. Its most striking feature sits at the front of the mouth: the front teeth of the lower jaw project almost straight forwards rather than upwards, forming a set of curved, forward-raking hooks. Further back along the jaw the teeth become more conventional blade-like, serrated theropod teeth. No other known dinosaur has quite this dental arrangement. The rest of the animal was slender, with long gracile hind limbs, a long stiffened tail and relatively short arms. Masiakasaurus belongs to the noasaurids, a family of small ceratosaurs closely related to the far bulkier abelisaurids. Everything we say about its habits is inferred from the skeleton, since no trackways or gut contents are known. The forward-pointing front teeth were probably good at seizing and holding small, slippery prey, while the rear teeth did the slicing. Researchers have suggested a menu of fish, frogs, lizards, small mammals and perhaps insects, possibly supplemented with fruit or carrion. A picture of a quick, agile hunter working through low vegetation and along river margins is reasonable, but it remains an interpretation. Bone histology shows that the animal grew remarkably slowly for a theropod, reaching adult size only after roughly eight to ten years. The fossils come from the Maevarano Formation of north-western Madagascar and are about 70 million years old, placing them in the Maastrichtian stage at the end of the Cretaceous. The first bones were collected in 1996 during the Mahajanga Basin Project, and the species was formally described in 2001 by Scott Sampson, Matthew Carrano and Catherine Forster. The genus name comes from the Malagasy word masiaka, meaning vicious, while the species name honours Dire Straits musician Mark Knopfler, whose music was playing in camp when the key specimens turned up. A major 2011 monograph described a great deal of additional material and gave a nearly complete picture of the skeleton. Masiakasaurus shared its world with the much larger predator Majungasaurus, with titanosaurian sauropods such as Rapetosaurus, and with the peculiar bird Rahonavis. The landscape was a seasonal floodplain where long dry spells alternated with heavy rains, and many fossils lie entombed in deposits laid down by sudden debris flows.

Chapter • Where it lived

Habitat

Masiakasaurus lived around 70 million years ago, during the Maastrichtian stage at the close of the Cretaceous. Every known fossil comes from the Maevarano Formation in the Mahajanga Basin of north-western Madagascar, above all from localities near the village of Berivotra. The setting was a low-lying floodplain of meandering channels, sandbars and patchy woodland and scrub, under a strongly seasonal climate in which long droughts were broken by intense rainfall. Many skeletons were buried rapidly in debris-flow deposits, which is a major reason the preservation is so good.

Chapter • Wild behavior

Behavior & Ecology

Did you know?

Chapter • Scientific place

Taxonomy