Masiakasaurus

*Masiakasaurus knopfleri*

***Masiakasaurus knopfleri*** is a genus of small predatory theropod dinosaurs from the Late Cretaceous of Madagascar. In Malagasy, masiaka means "vicious"; thus, the genus name means "vicious lizard". The type species, *Masiakasaurus knopfleri*, was named after the musician Mark Knopfler, whose music inspired the expedition crew. It was named in 2001 by Scott D. Sampson, Matthew Carrano, and Catherine A. Forster. Unlike most theropods, the front teeth of M. knopfleri projected forward instead of straight down. This unique dentition suggests that they had a specialized diet, perhaps including fish and other small prey. Other bones of the skeleton indicate that *Masiakasaurus* were bipedal, with much shorter forelimbs than hindlimbs. *M. knopfleri* reached an estimated adult body length of around 2 meters (about 6–7 feet).
*Masiakasaurus* lived around 70.7-65.5 million years ago, along with animals such as *Majungasaurus*, *Rapetosaurus*, and *Rahonavis*. *Masiakasaurus* was a member of the group Noasauridae, small predatory ceratosaurs found primarily in South America.

## Description

*Masiakasaurus* were small-bodied ceratosaurs that grew up to around 1.8 to 2 metres (5.9 to 6.6 feet) in length. The most distinctive characteristic of *Masiakasaurus* is the forward-projecting, or procumbent, front teeth. The teeth are heterodont, meaning that they have different shapes along the jaw. The first four dentary teeth of the lower jaw project forward, with the first tooth angled only 10° from horizontal. These teeth are long and spoon-shaped with hooked edges. They have carinae, or sharp edges, that are weakly serrated. Serrations are more evident in the posterior teeth, which are also recurved and laterally compressed. The margin of the dentary curves downward so that the tooth sockets of the front teeth are directed forward. The front teeth of the upper jaw are also procumbent, and the margin of the premaxilla curves slightly upward to direct them outward.

Unlike the skulls of abelisaurids, which are very deep, the skull of *Masiakasaurus* is long and low. The lacrimal and postorbital bones around the eye are textured with bumpy projections. Not including the highly modified jaws and teeth, the skull of *Masiakasaurus* possesses many general ceratosaurian characteristics. Overall, its morphology is intermediate between abelisaurids and more basal ceratosaurs.[3]
The neck is relatively narrow in comparison to abelisaurids. While many theropods have s-shaped necks, the back of the neck of *Masiakasaurus* is positioned almost horizontally, giving it a slighter curve. Like those of other abelisauroids, the vertebrae are heavily pneumaticized, or hollowed, and have relatively short neural spines. Pneumaticity is limited to the neck and foremost back vertebrae, however. Pneumatic cavities are also present in the braincase.

The scapulocoracoid, a bone that makes up the pectoral girdle, is large and broad. While abelisaurids have arms that are extremely reduced in size, *Masiakasaurus* and other noasaurids had longer forelimbs. The humerus is slender and the bones of the hand are relatively short. The related genus *Noasaurus* has a raptorial ungual which was originally interpreted as a sickle-like claw on the foot, but has more recently been considered a claw of the hand. The penultimate phalanx, a finger bone that immediately precedes the raptorial ungual in *Noasaurus*, is also known in *Masiakasaurus* and has a similar appearance. The enlarged ungual, however, is unknown in *Masiakasaurus*.

## History

Remains of *Masiakasaurus* have been found in the Late Cretaceous Maevarano Formation in northwestern Madagascar and were first described in the journal Nature in 2001. Fragmentary bones comprising around 40% of the skeleton were collected near the village of Berivotra. Several parts of the skull, including the distinctive teeth, were found. The humerus, pubis, hind limbs, and several vertebrae were also collected.

In 2011, additional specimens of *Masiakasaurus* were described. The braincase, premaxilla, facial bones, ribcage, portions of the hands and pectoral girdle, and much of the cervical and dorsal vertebral column were described for the first time. The discovery of this new material clarified many aspects of noasaurid anatomy, but did not allow for a detailed study of its evolutionary relationships among ceratosaurs. With the new material, around 65% of the skeleton is currently known.

## Classification

In its initial 2001 description, *Masiakasaurus* was classified as a basal abelisauroid related to *Laevisuchus* and *Noasaurus*, two poorly-known genera named in 1933 and 1980, respectively.[1] In the following year, Carrano et al. (2002) placed *Masiakasaurus* along with *Laevisuchus* and *Noasaurus* in the family Noasauridae. They conducted a phylogenetic analysis of abelisauroids using characteristics from *Masiakasaurus*. Below is a cladogram from their study showing the phylogenetic placement of *Masiakasaurus*

## Paleobiology

Carrano et al. (2002) distinguished two forms of *Masiakasaurus*, a robust form and a gracile form. The robust morph includes specimens with thicker bones and more pronounced projections for the attachment of ligaments and muscles. The gracile form includes specimens that are more slender and have less pronounced muscle attachments. It also has unfused tibiae, unlike the fused tibiae of the robust form. These two varieties may be an indication of sexual dimorphism in *Masiakasaurus*, but they may also represent two distinct populations. One specimen of *Masiakasaurus*, a right scapulocoracoid, bears holes that may be puncture marks from predation or scavenging. *Majungasaurus*, a large abelisaurid from the Maevarano Formation, may have preyed upon *Masiakasaurus*. The holes may also have been the result of an infection.

### Diet

The procument front teeth of *Masiakasaurus* were likely an adaptation for grasping small prey. They would have been unsuitable for tearing larger food apart. In the front of the jaws, carinae are restricted to the base of the teeth and would not have been used to tear prey. The back teeth, however, share the same general characteristics as those of most other theropods, suggesting that they served a similar function in *Masiakasaurus* such as cutting and slicing. Several feeding behaviors have been proposed for *Masiakasaurus* on the basis of its unusual dentition. Because the front teeth would have been well suited for grasping, *Masiakasaurus* may have consumed small vertebrates, invertebrates, and possibly even fruits. It may also have been piscivorous, catching fish with the ends of its jaws and cutting and tearing them with its back teeth.

## JPInstitute.com Description

Masiakasaurus was a very strange looking dinosaur. Its front teeth stuck almost straight out from the front of its mouth. This feature was present on some flying reptiles, but it has never been found on a dinosaur.
Discovered by a team of scientists working in Madagascar, scientists think that it may have eaten a lot of fish, as the teeth could have been used to spear them in shallow water.

Masiakasaurus knopfleri was named after Dire Straits guitarist Mark Knopfler, whose music inspired the field team.

## Appearance in other media

### *Jurassic Park*

* Masiakasaurus appeared in Jurassic Park III: Park Builder.
* *Masiakasaurus* appears in *Jurassic World: Alive* as a Omega.

## Links

https://web.archive.org/web/20030405111304/http://www.jpinstitute.com/dinopedia/dinocards/dc\_masia.html
https://web.archive.org/web/20080706164337/http://kids.yahoo.com/dinosaurs/287--Masiakasaurus