New fossil discoveries of feathered dinosaurs in the last two decades have put the origin and

evolution of powered flight (propulsion with wing flapping) in birds into new scientific perspectives,

including discussions of an early four-winged flight configuration and secondary loss of flight in

different feathered theropod dinosaurs. Types of locomotion and other biological information like

growth rates, ontogenetic stages, or habitat preference, are reflected at several structural levels of

an organism, including its bone tissues. This makes bone histology a powerful source of information

for inferring function-related modifications in extinct vertebrates.

My ongoing project aims to obtain a better understanding of the evolution of locomotor abilities

and potential aerial skills of extinct dinosaur-bird transitional forms. For that I section bones of

extant birds and bats, and extinct bird-like dinosaurs to investigate potential functional signals in the

bone tissues. The research focuses on histological traits that can be linked to different capabilities of

powered flight, secondary flightlessness, as well as the differences in ontogenetic timing of the first

take-off. This provides the basis for inferences drawn from the bone tissue of bird-like dinosaurs

towards a more detailed insight into their paleobiology, including hotly discussed questions such as

when, how many times, and in which dinosaur lineages powered flight might have evolved or

disappeared secondarily.