While this is most widely known in mantises, similarly modified legs can be found in some crustaceans (e.g., mantis shrimp), and various insect families, such as Mantispidae, Belostomatidae, Nepidae, and Naucoridae (all members of these groups have raptorial forelegs).
The presence of few, large-sized stomach stones in birds and in other non-avian dinosaurs usually indicates a mainly carnivorous diet, suggesting that B. guoi may have had a raptorial ecology.
Birds are divided into three groups: raptorial land birds (uccelli terrestri rapaci), other land birds (uccelli terrestri non rapaci), and waterbirds (uccelli aquatica).