326-1 An Evaluation of Flight Origin Using Phylogenetic Mapping in Oviraptorosaurian Families

Abstract:

Oviraptorosaurians, a group of theropod dinosaurs, are understood to be secondarily flightless, meaning they evolved from ancestors capable of flight and are widely regarded as extremely bird-like. Our goal was to assess the distribution and variation of flight-related traits to better understand the evolution of flight. We constructed a character matrix of traits known to be important for avian flight and mapped them onto a published phylogenetic tree representing the current understanding of Oviraptorosaurian relationships. Using ten representative taxa across three families (Oviraptoridae, Caudipteridae, and Caenagnathidae) and two outgroups (Archaeopteryx sp. And Velociraptor sp.). We learned that these traits showed considerable variation. Some traits, such as quill knobs, appear to have been lost once in an Oviraptorosaurian ancestor. Other traits, including the pygostyle and furcula, show significant variation, suggesting they are very labile traits. The ability of some traits to change easily suggests they may have other, non-avian functions. Although we were unable to determine whether the distribution of traits supported one flight origin hypothesis over another, there is support for current ideas that suggest avian flight may have evolved multiple times in the ancestors of birds and their flighted theropod relatives. 

© Copyright 2026 The Geological Society of America (GSA), all rights reserved.