In other words, the pygostyles of oviraptorosaurs and Confuciusornis were likely weight-saving measures, and the specialized "true" pygostyles of ornithurans were adapted from these later to improve flight performance.
Noutras palabras, os pigóstilos dos ovirraptorosaurios e Confuciusornis eran probablemente mecanismos evolutivos para aforrar peso, e os "verdadeiros" pigóstilos especializados dos Ornithurae foron adaptacións derivadas posteriores para mellorar a execución do voo.