NEST SCRAPE BEHAVIOR IN LARGE THEROPODS: FROM COLORADO OUTCROP TO DUTCH SHOWCASE: VISITORS EXPERIENCE ANCIENT DINOSAUR DISPLAY BEHAVIOR FROM FOSSIL EVIDENCE

The Naturalis Biodiversity Center (the national museum of natural history in Leiden, Netherlands) has developed a unique, interactive exhibit featuring dinosaur courtship behavior. The "Dinosaur Dance Exhibit" is based on the discovery of a previously unknown category of large dinosaur trace fossil. Ostednichnus bilobatus ("bilobed display trace") consists of parallel, double gouges, some with the clear impressions of three-toed Irenesauripus-like theropod tracks. This new ichnotaxon in the Late Albian-Cenomanian Dakota Sandstone provides evidence for dinosaur mating displays previously only speculated upon. Like birds, nonavian theropod dinosaurs, may have also engaged in energetic displays, based on the discovery of extensive areas containing dozens of large scrapes. Found in BLM National Conservation Areas in western Colorado, these ichnites are evidence of dinosaur display rituals similar to those of modern ground nesting birds that engage in courtships displays known as "nest scrape "displays or "scrape ceremonies," where males show off to females by prancing, scraping the ground, and excavating “pseudo nests" in "display arenas." O. bilobatus provides evidence that large nonavian theropod dinosaurs may have also engaged in courtship activities near the shores of the Cretaceous Western Interior Seaway.

The Naturalis exhibition philosophy is that interactive displays should not just be “hands-on," but “social-on" as well. To that end, the new trace fossil inspired the “Dinosaur Dance Exhibit" which also includes a full-size 3D-print of O. bilobatus. Because the traces could not be removed without damage, noninvasive, state-of-the-art, 3D digital photogrammetric data capture techniques were used to document, interpret, and manage the trace-bearing surfaces. The photogrammetric 3D data allowed O. bilobatus to be digitally transmitted from Colorado to the Netherlands, where it was printed and put on display. The Dutch exhibit also includes information on ritualistic display behavior in extant birds as a biological parallel and inspiration for the interactive venue, where the dance moves of players are tracked, analyzed, and fed into an animation of a synchronously dancing dinosaur silhouette. Hopefully, this exhibit will stimulate interest and enthusiasm in the amazing diversity of nature.