Evolution Nemegtomaia

preserved parts (left) , reconstruction (right) of skull of specimen mpc-d 107/15

the clade oviraptorosauria regarded group of non-avian (or non-bird) theropod dinosaurs, , similarity birds (aves) has been noted. fossils of oviraptorosaurs in family caenagnathidae have historically been confused of birds, , researchers have gone far consider oviraptorosaurs whole more closely related birds other non-avian dinosaurs. in 2002 lü , colleagues used unnamed nemegtomaia show similarities between birds , oviraptorosaurs, , found latter group closer birds bird-like dinosaurs such dromaeosaurs. therefore concluded oviraptorosaurs flightless birds rather non-avian dinosaurs, , noted boundary between birds , dinosaurs becoming more , more difficult delineate. other researchers have instead found dromaeosaurs , troodontids closely related birds, forming group paraves; oviraptorosaurs, therizinosaurs, , alvarezsaurs outside group. wider group includes oviraptorosaurs , paraves called pennaraptora, , group defined presence of pennaceous feathers (feathers stalk).

oviraptorosaurs known asia (where may have originated) , north america, , known deposits date campanian-maastrichtian ages of cretaceous period. group includes small large members, , characterised short skulls , beaks, elongated fingers, , short tails. basal (or primitive ) members had teeth, disappeared in derived members of group (those within superfamily caenagnathoidea, includes oviraptoridae). @ least partially herbivorous, , brooded nests in bird-like posture. though thought have been feathered, appear have been flightless. cranial crests appear have evolved convergently in different lineages within group. family oviraptoridae (to nemegtomaia belongs) consisted of small members, , exclusively known upper cretaceous of asia, genera having been discovered in gobi desert of mongolia , china. including nemegtomaia, @ least 9 oviraptorid genera have been discovered in relatively small geographical area in gobi desert.