Maniraptora

Maniraptora is a clade of coelurosaurian theropod dinosaurs that includes the birds and their closest non-avian relatives. First appearing in the Jurassic, the group comprises several lineages: dromaeosaurids (raptors), troodontids, oviraptorosaurs, therizinosaurs, and the avialans (true birds). The exact composition of Maniraptora has varied with new discoveries, and some analyses place ornithomimosaurs outside the group while others propose broader definitions that encompass them; nonetheless, the clade is widely recognized as the branch of theropods most closely related to birds.

Members of Maniraptora generally share features of the forelimbs and wrists that allowed more versatile grasping and manipulation, and many members show advanced feathering. Fossil evidence demonstrates extensive integumentary structures, including filamentous feathers in several non-avian members, supporting the interpretation of feathered ancestors of birds.

The timeline begins in the Jurassic, with early maniraptorans in Asia and elsewhere; by the Late Jurassic and into the Cretaceous, diverse forms existed, including agile predators like dromaeosaurids and troodontids, as well as herbivorous-omnivorous therizinosaurs and oviraptorosaurs. Avialae, the lineage leading to modern birds, appears within Maniraptora and eventually gives rise to all living birds.

In modern understanding, birds occupy the crown group Avialae within Maniraptora, representing the survival and diversification of this clade after the extinction of many non-avian dinosaurs. Maniraptorans are a major focus of research for clues about the origin of flight, feather evolution, and dinosaurian biology.