An early pterosaur. Image credit: Adapted from Jagielska et al. (CCBY 4.0)
Long before bats and birds, there were the pterosaurs; the first vertebrates to have ever achieved powered flight, soaring through the skies at the dawn of the Age of Dinosaurs. Early species were modest in size, had toothed jaws and sported long, stiff tails that were mobile at the base and ended in tall, thin, soft tissues proposed to have had flight and display functions. However, these blade-like ‘vanes’ would have hindered the animals’ ability to fly if they had fluttered excessively. How early pterosaurs managed to maintain vane stiffness remains unclear, as these structures are absent in later species and in modern flying vertebrates.
Recently, an imaging technique called laser-stimulated fluorescence imaging has allowed researchers to uncover hidden soft tissue features in fossils, using high-power lasers to generate chemical maps of structures on or just below the surface of a specimen. Jagielska et al. relied on this approach to examine the tail vanes of four high-quality pterosaur fossils. This revealed a unique underlying lattice structure composed of thicker vertical elements interlinked with thinner fibres, which would have conferred stiffness during flight. However, this complex organization also suggests a multifunctional design, making it possible for the vanes to have been used as displays for communication or to attract a mate.
These findings deepen our understanding of early pterosaur flight innovations and the evolutionary pressures that shaped the success of the first powered fliers. By highlighting the value of laser imaging for uncovering soft tissue details in fossilised specimens, the work of Jagielska et al. opens avenues for further investigation into similar tissues, such as flight membranes.
