Like many children of his generation, Wann Langston, Jr. was captivated by fossils of extinct dinosaurs when he was a young boy. Wann was one of the minority in whom those childhood passions did not fade or transform into other pursuits, and he was among a highly select few who nurtured those passions sufficiently to devote a lifetime to the study of vertebrate fossils. Wann's success in his chosen profession can be measured in a variety of ways, but to us the most important metric is the influence that he had both on his peers and on the younger generations who followed his lead in carving a career in palaeontology. It is impossible to quantify success with reference only to such influence, but if our personal experience is any measure, then his success was great indeed. Wann inspired us in many ways through our own careers, often in subtle ways that we became aware of only later in our lives, after we came to know him personally, listened to his stories, and experienced that ‘ah-ha!’ moment of realisation… “Oh! Wann did that!” It is abundantly clear to us that we are not the only ones on whom he has made such a mark.

When we first proffered the notion of a Festschrift volume for Wann there was immediate enthusiasm. We should not have been surprised at the ease with which we were able to recruit contributors; we should have anticipated the enthusiastic response. Initially we focused on including his students, co-authors, and graduates of The University of Texas at Austin. However, when word got out among the community of vertebrate palaeontologists that we were making this effort, we quickly were inundated with voluntary contributors. Unfortunately, in our initial efforts to keep the volume a secret from our honouree, we certainly missed authors who wished to honour Wann with a contribution. We hope all of them accept our apologies for our oversight, and understand that we did not intentionally exclude anyone.

During the initial phases of developing this project we were motivated, in part, by the mischievous sense of fun to be had in scurrying around in a bustle of activity that we tried, successfully, to hide our efforts from the honouree. There were constant reminders to authors and reviewers that “Wann doesn't know.” Ultimately, however, it was not loose lips, but Wann's perspicacity that penetrated our attempts at secrecy. As far as we know, Wann was unaware of our plans and activities until sometime in the latter quarter of 2012. In the end we were not disappointed, but rather amused with his discovery. When executing the sometimes onerous task of compiling, editing and producing a collection of written works such as this, editors may, at one point or another, be forced to ask themselves “why are we doing this?” We ultimately were spared that (collective) awkward moment of introspection by Wann himself. When he did get beyond mere suspicion that we were working on a volume in his honour, he asked with his characteristic and rather unceremonious style “Why would you want to do a thing like that?”

The answer to that question can, we think, best be found in the pages that follow. Included here are discussions of empirical and conceptual issues surrounding fossil vertebrates whose taxonomic breadth spans much of Tetrapoda, and whose chronological range extends from the Permian through the Quaternary. This volume stands as a small testimony of our respect and admiration for our colleague and friend.

Wann Langston, Jr. died on Sunday, April 7, 2013, just two days after a special symposium held in his honour at the South–Central Section meeting of the Geological Society of America held in Austin, Texas. We are saddened that he died before this work was published, but are pleased that he knew of its existence, and was able himself to contribute to its improvement. When he was hospitalised briefly in December 2012, we provided Wann with a printed collection of abstracts of the contributed papers. He returned them two days later with copious editorial marks and comments, stating “It's too long. No one's going to read it.” We, however, know that it could have been much, much longer.