Fossil Evidence
Many fossils have been discovered in recent years, particularly in China. Many of the feathered dinosaurs belong to this clade. In particular, a fossil of the Alvarezsauridae Shuvuuia has a version of keratin consistent with that of avian feathers.
Many nearly complete fossil maniraptoriforms are known from the late Jurassic. Archaeopteryx is known from Bavaria at 155-150 Ma. Ornitholestes, the troodontid WDC DML 110, Coelurus fragilis and Tanycolagreus topwilsoni are all known from the Morrison Formation in Wyoming at about 150 Ma. The Daohugou biota, including Anchiornis and Epidexipteryx, is the earliest record of maniraptoriformes, dating to about 160 Ma. One possible maniraptoriform, Eshanosaurus, lived even earlier, during the Early Jurassic, though its identification is controversial.
The wide range of fossils in the early Cretaceous and morphological evidence suggests that the main branches of maniraptoriform differentiation were separate before the end of the Jurassic.
Until recently, the relatives of Tyrannosaurus were thought to be maniraptoriforms, but this now seems unlikely.
Read more about this topic: Maniraptoriformes
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