Noasauridae

Noasauridae was a very diverse group, with the two most complete members, Masiakasaurus and Limusaurus, showing unusual features very different from each other. Masiakasaurus had an unusually downturned jaw, with long and sharply pointed spoon-shaped teeth. Some of these teeth were nearly horizontal in orientation. Limusaurus, on the other hand, was completely toothless as an adult and likely possessed a horny beak. This large disparity means that it is difficult to find any skull features shared by members of Noasauridae as a whole. '', the most complete and well-known noasaurine|left Noasaurids had longer arms than their relatives the abelisaurids, whose arms were tiny and diminished. Although by no means as large or specialized as the arms of advanced bird-like theropods, noasaurid arms were nevertheless capable of movement and use, possibly even for hunting in large-clawed genera such as Noasaurus. Some genera such as Limusaurus did have somewhat reduced arms and hands, but far from the extent that abelisaurids acquired. Noasaurids were also nimble and lightly built, with feet showing adaptations for running such as a long central foot bone (metatarsal III). Noasaurids varied in size, from the small Velocisaurus which was under long, to much larger genera such as Elaphrosaurus and Deltadromeus, which were more than in length. In these genera as well as Deltadromeus, metatarsal IV (which connected to the outermost major toe) also became reduced in some respects. In all noasaurids, the mid caudals (vertebrae in the middle of the tail) had very low neural spines. The cervical (neck) vertebrae, on the other hand, were quite varied within this family. In noasaurines and a few other genera (such as Laevisuchus), the neural spines of vertebrae at the front of the neck were positioned towards the front part of their respective vertebrae. This is quite unusual compared to other theropods, which have neural spines roughly midway down their vertebrae. These genera also have long and spine-like epipophyses on the cervicals of most of the neck, although they diminish near the neck. Epipophyses are bony projections located above the postzygapophyses (joints on the rear edge of a vertebra connecting to the front edge of the following vertebra). Elaphrosaurines, on the other hand, have cervical epipophyses which are much more diminished or even absent in the case of Elaphrosaurus. Many noasaurids are only known from vertebrae, including both valid (Laevisuchus, Spinostropheus) and dubious (Composuchus, Jubbulpuria, Ornithomimoides, Coeluroides) genera. == Noasaurinae ==

Noasaurines are Late Cretaceous noasaurids known exclusively from southern continents and islands such as South America, Madagascar, and India (which was an island near Madagascar during the Cretaceous). In 2020 indeterminate remains were described from the Barremian-Aptian and Cenomanian of Australia. Members of this subfamily are definitively part of Noasauridae, although this group may not necessarily be elevated to subfamily status whenever elaphrosaurines are found to be outside of Noasauridae. Many members of this subfamily are quite fragmentary, and as a result the appearance and biology of the average noasaurine must be inferred from the most complete member of the group, Masiakasaurus. Rauhut & Carrano (2016) define Noasaurinae as "all noasaurids more closely related to Noasaurus than to Elaphrosaurus, Abelisaurus, Ceratosaurus, or Allosaurus". Masiakasaurus (and presumably other noasaurines) had a downturned lower jaw with long teeth splaying forwards. These teeth were spoon-shaped with sharply pointed tips and serrations along their outer edge. The rest of the teeth in the mouth were similar to the teeth of more conventional theropods. The rest of the body was also more similar to that of conventional theropods, with a neck, arms, and legs of moderate length. At least one noasaurine, the eponymous Noasaurus, had a large and deeply curved "sickle-shaped" claw of the hand. The diet of noasaurines is difficult to determine, with hypotheses ranging from fish to insects or other small animals. Rauhut & Carrano (2016) found only a single unambiguous trait used to diagnose noasaurines to the exception of other noasaurids. That trait is the fact that their metatarsal II has a diminished proximal (near) end. One noasaurine, Velocisaurus, took this trait even further, with both its metatarsal II and IV reduced to very thin rod-like bones along their entire length. == Elaphrosaurinae ==

'', an elaphrosaurine and also one of the largest putative noasaurids It is not entirely certain if elaphrosaurines are legitimate examples of noasaurids. Both Limusaurus and Elaphrosaurus have been considered basal ceratosaurians by many studies, with most of these studies considering them even more primitive than Ceratosaurus. ==Classification==

The following cladogram is based on the phylogenetic analysis conducted by Rauhut and Carrano in 2016, showing the relationships among the Noasauridae: recovered Dahalokely as a basal noasaurid. A 2017 study describing ontogenetic changes in Limusaurus and the effect of juvenile taxa on phylogenetic analyses provided various phylogenetic trees which varied based on which Limusaurus specimens were used. The structure of Noasauridae changed greatly depending on the age of the Limusaurus specimens, although Genusaurus and Deltadromeus were resolved as noasaurids in each diagnosis. In contrast, phylogenetic analysis by Hendrickx et al. (2024) recovered Elaphrosaurinae outside Abelisauroidea. |label1=Ceratosauria}} ==See also==