Abelisauroidea

Abelisauroidea is a clade of theropod dinosaurs within Ceratosauria that includes the families Abelisauridae and Noasauridae, along with related genera. They lived during the Cretaceous period, with fossils found primarily in the southern continents of Gondwana, including South America, Africa, Madagascar, and India. The group spans roughly from the Early to Late Cretaceous and occupied a variety of predatory niches in Gondwanan ecosystems.

Anatomy and notable features of abelisauroids vary, but they share certain characteristics. Many members, especially the Abelisauridae, have short, deep skulls and stout builds, and a tendency toward pronounced skull ornamentation. A hallmark of several abelisaurids is markedly reduced forelimbs, sometimes with two tiny fingers, as seen in well-known examples such as Carnotaurus. Noasaurids were generally smaller and more lightly built, with diverse dental and jaw adaptations. Some noasaurids, such as Masiakasaurus, exhibit unusual dentition that diverges from typical carnivorous theropods.

Distribution and ecology: Abelisauroids occupied a range of predatory roles from medium to large sizes. Their fossils indicate diverse habitats within Gondwana, and they coexisted with other theropods, including carcharodontosaurids. The southern geographic distribution and relative isolation contributed to their distinct evolutionary trajectory, with a decline in the large abelisaurids toward the end of the Cretaceous as faunas changed.

Classification and phylogeny: Abelisauroidea is a major clade within Ceratosauria. Its internal relationships are the subject of ongoing research and debate, but most analyses place Abelisauridae and Noasauridae as its primary families, along with several basal or transitional forms. New fossil discoveries continue to refine their evolutionary history and biogeography.