The Function, Anatomy, and Evolutionary History ofthe Pterosaur Bauplan – a Taphonomic Approach

The output of Pterosaur research grows each year, with new work uncovering more and more information on this group and its function and extent in the evolutionary history of this planet. With no descendants and a unique manner of flight, however, pterosaurs can be an enigmatic group to study. Comparison to birds and bats, the two other volant vertebrate groups, comes with both benefits and drawbacks. This thesis considers two aspects of pterosaur research: pterosaur anatomy, a fundamental piece of our understanding of this group, and the use of quantitative taphonomy, a flexible tool argued here to be underutilised in research. By using three methods utilising quantitative taphonomy, novel results have been obtained on three different aspects of pterosaur palaeobiology. Firstly, by analysing patterns in the loss and disarticulation of skeletal elements, different patterns between pterodactyloids and nonpterodactyloids have emerged, wherein the loss of forelimb and hindlimb elements are correlated with different elements in pterodactyloids as compared to nonpterodactyloids, showing different patterns of disarticulation and loss across the two groups. Secondly, report of manus opposability in a recently described species are investigated systematically. Rates of digit rotation are compared across a broad range of taxa, providing a quantitative rather than anecdotal analysis of digit rotation. Thirdly, using novel methods, taphonomic posture in articulated specimens also indicate differences between pterodactyloids and non-pterodactyloids. By contrasting patterns of posture in pterosaurs with that of fossil birds and fossil bats, coupling or decoupling of the hind limbs, an under-studied area in pterosaur palaeobiology, could be studied through proxies in which the anatomy of the hind limbs is known. Results show that pterodactyloid patterns closely resemble fossil bird patterns, while nonpterodactyloid patterns closely resemble fossil bat patterns, supporting hypotheses of membrane spanning the non-pterodactyloid hind limbs. These studies all show that data can be derived from multiple types of taphonomic metric, and that quantitative taphonomy is highly valuable and flexible across taxonomic group.