The big eyes of Brian Cooley’s Troodon sculpture at the Grande Prairie airport. Hesperornithoides was an early cousin of this creature
The symbol on the Philip J. Currie Dinosaur Museum’s logo is the skeleton of a troodontid dinosaur. A close look at that logo will tell you that troodontids were carnivorous dinosaurs with sharp teeth and claws, big eyes, and birdlike skeletons. Most of the earliest troodontids known to science were small feathered dinosaurs of the early Cretaceous, mostly from China, with larger predatory forms showing up in Mongolia and western North America in the later Cretaceous.However, a new and exciting member of this group has recently been described in the journal PeerJ by paleontologist Scott Hartman and colleagues. Hesperornithoides (“western bird-form”), the new dinosaur in question, lived during the late Jurassic in what’s now modern day Wyoming. It lived roughly 150 million years ago- a good 20-30 million years or so older than most of its closest relatives. To paleontologists, finding a particularly old member of a group of animals is a real treat. If you know what a certain lineage was like when it first evolved, you can better understand where it fits into the great dinosaur family tree, and how that lineage changed over time. Hesperornithoides is very handy for that.As a primitive troodontid, Hesperornithoides was fairly small, probably less than a meter long. Ironically, it was found in the same quarry as a specimen of Supersaurus, one of the largest dinosaurs known. The specimen is incomplete, but luckily many of the really important bones are preserved, including a good deal of the skull, some vertebrae, several limb bones, and even the wishbone.Hesperornithoides is really interesting to paleontologists for a few reasons. Being one of the geologically oldest troodontids known to science, and certainly the oldest known from North America from more than just teeth, Hesperornithoides is useful for filling in out our knowledge of the evolution of the Paraves- birds and their closest relatives. Hesperornithoides was undoubtedly feathered, but its skeleton shows that it couldn’t fly. This lends support to the idea that the earliest paravians like Hesperornithoides were small, flightless ground-dwellers. The authors of this study suggest that gliding or some degree of flight arose a few times in different paravian lineages, such as in the famous Microraptor, as well as in the earliest true birds.Hesperornithoides is also noteworthy because it lived in a time and place where lots of really big and really famous dinosaurs like Stegosaurus, Brontosaurus, and Allosaurus, are well known, but very few smaller animals have been found. This is likely due to a preservation bias in the rock unit these animals lived in, which favored the fossilization of big animals. There was certainly all sorts of neat smaller dinosaurs and other creatures running around in the late Jurassic of North America, and Hesperornithoides is proof of that.Upcomming Museum Events:July 26, 2:30 PM – 3:00 PM: Dino Story TimeJuly 27, 3:00 PM – 4:00 PM: Lecture Series with Corwin Sullivan – Cretaceous North: Exploring the Lost Dinosaurian World of the Peace RegionJuly 27, 6:00 PM – 8:00 PM: Summer Jams featuring Nick & NicoleAugust 2, 11:30 AM – 2:30 PM: Bonebed BBQ Fundraiser. Join us for a tasty barbeque at the Pipestone Creek Campground! Afterwards, you can go on an interactive Bonebed tour at 12:30pm or 1:30pm to see excavation in progress!Try your hand at working with real dinosaur bones. The Fossil Preparation Lab Volunteer program is running Tuesdays-Thursdays and the first Saturday of the month from 10 a.m. to 5 p.m., and Fridays from 1–7 p.m. For a posted schedule, see dinomuseum.ca/programs/public-programs/fossil-preparation-lab/.