Volant Fossil Vertebrates: Potential for Bioinspired Flight Technology

Animal flight is ecologically important and has a long evolutionary history. It has evolved independently in many distantly related clades of animals. Powered flight has evolved only three times in vertebrates, making it evolutionarily rare. Major recent fossil discoveries have provided key data on fossil flying vertebrates and critical insights regarding the evolution and different arrangements of animal flight surfaces. Combined with new methodologies, these discoveries have paved the way for potentially expanding biomimetic and biologically inspired designs to incorporate lessons from fossil taxa. Here, we review the latest knowledge and literature regarding flight performance in fossil vertebrates. We then synthesise key elements to provide an overview of those cases where fossil flyers might provide new insights for applied sciences. Powered flight evolved independently in three groups of vertebrates: birds, bats, and extinct flying reptiles known as pterosaurs.The flight surface in flying vertebrates is morphologically variable, ranging from a feathered wing with highly adapted flight feathers (birds) to elongated digits with membrane stretched between (bats), and to a single elongated digit with a large membrane stretched to the body (pterosaurs).More unique morphologies are now known from the fossil record with hybrid structures including membranous feathered wings and four-winged biplane-like animals.The fossil record provides ever increasing examples for inspiration in mechanical design and without its use we ignore 250 million years of gliding and flying morphologies.Future biomechanical studies of unique fossil morphologies may impact mechanical design.