2008 Hayes Lecture 
When Raptors Ruled, a Journey back across Deep Time

Bill and Kris Parsons

For the past fifteen years Bill and Kris Parsons, as well as a dedicated crew of volunteer friends, have been hunting vertebrate fossils throughout the Lower Cretaceous badlands of central and western Montana. Starting out with just a roll of maps, a couple of rock hammers in backpacks, an old Toyota pickup, and using only such funding as could be found in their own wallets, over the past decade their persistence in the field and in the laboratory has uncovered several interesting discoveries. They include several new specimens of Deinonychus, Speilberg's Jurassic Park velociraptors.

Their research has revealed many new and surprising aspects of the anatomy, life stages and possible behavior of these "Raptor-like" dinosaurs.  From skull bones that may tell their age to surprisingly flexible tails, this research has added many fascinating fragments of information to our overall knowledge of these dinosaurs. Some of their more exciting discoveries include describing that these dinosaurs exhibited determinate growth, which is where an individual creature stops growing at the onset of adulthood. Determinate growth is an extremely common character in birds and mammals, but in creatures such as almost all other dinosaurs, growth continued throughout their entire lifespan. Also, they discovered the within the genus Deinonychus sexual reproductive maturity occurred before reaching full adult size. This discovery has since been confirmed within other dinosaur taxa. 

 With the discovery of juvenile and very young adult forms of Deinonychus, it would appear that the juveniles possessed longer arms in proportion to their bodies than what are found on the adults. This discovery, along with certain unique characters of the foot bones, may indicate that juvenile Deinonychus might have climbed trees in order to escape the many dangers of growing up in the Mesozoic. In particular, a unique finger bone that Bill and Kris discovered on the second finger of Deinonychus indicates that not only did they possess feathers, but at the very least, within their immediate ancestry they were descended from creatures that had achieved an avian form of flight. 

Recently, they and their crew have also uncovered the gut contents of Deinonychus. Within these pellet-like nodules they have found tiny theropod (meat eating) dinosaur bones as well as fairly clear evidence that Deinonychus was in fact a cannibal. Along with both adult and juvenile raptors Bill and Kris have found evidence of giant lungfish, (relatively) small sauropods, big mammals, a new form of armored dinosaur, and both adult and juvenile specimens of a plant eating dinosaur that appears to have been a lunch time favorite for these small but very successful "raptor" dinosaurs.
 Still, the discovery of any one dinosaur is like finding a single page torn from a forgotten book.  It is only when all the disparate pieces finally begin to come together that the real color of  a truly lost world is revealed. The long range intent of this research is to help span the vastness of deep time and contribute to the creation of an ever more detailed and accurate scientific vision of that ancient world from which and through which all, that now is, somehow or other successfully emerged.