With the exception of "Compsognathus" they are large-bodied. Allosaurs form a distinct long-lived clade that share some cranial characters. They include the well known "Allosaurus" and "Sinraptor" among others. The great radiation of Theropoda into many different clades of Coelurosauria must have happened in the mid to late Jurassic, because "Archaeopteryx" was around in about 152-154 Ma, and cladistic analysis has shown that many other groups of Coelurosauria branched off before that. Fossil evidence from China suggests that the earliest feathers were found on the primitive Coelurosauria. The most primitive of these, e.g. on the tyrannosauroid "Dilong", were simply hollow-cored fibres that would have been useful for insulation but useless for flying. Occasional bones and cladistic analyses point to the Tyrannosauroidea branching off from the other Theropoda early, in the middle Jurassic, although nearly complete skeletons haven't yet appeared before "Eotyrannus" from 121-127 Ma, and the many close relatives of "Tyrannosaurus" itself don't appear before 84 Ma, near the end of the late Cretaceous. Ornithomimosauria fossils are known from 127 to 65 Ma. The earliest branch from the main line of Ornithomimosauria is believed to be "Harpymimus". The Therizinosauroidea are unusual theropods in being almost all vegetarian. Fossil Therizinosauroidea are known from 127 to 65 Ma. Maniraptorans include Oviraptorosauria, Deinonychosaurs and birds. They are characterized by an ulna with a curved shaft. Oviraptorosaurian fossils are known from 127 to 65 Ma. They have a toothless skull that is extremely modified. The skeleton has an unusually short tail. Deinonychosaurs, named after the enlarged sickle-shaped second digit of the foot, are closely related to birds. They have two distinct families, Troodontidae and Dromaeosauridae. Troodontid fossils are known from 127 to 65 Ma. They have a more slender build and longer limbs. The earliest named troodontid fossil known is "Sinornithoides". Dromaeosaurid fossils are known from about 127 to 65 Ma with the exception of "Utahraptor".