How many species of theropod dinosaurs are known?
Theropoda
The smallest non-avialan theropod known from adult specimens is the troodontid Anchiornis huxleyi, at 110grams in weight and 34 centimeters (1ft) in length.[20] When modern birds are included, the bee hummingbird Mellisuga helenae is smallest at 1.9 g and 5.5cm (2.2in) long.[24]