Chickens Wear Prosthetic Dinosaur Tails, For Science
Simulating ancient gaits with barnyard fowl
by Colin Lecher, Posted 02.06.2014
Researchers from the Universidad de Chile wanted to study dinosaur strutting, but there being few dinosaurs available, stuck a prosthetic tail on the creatures’ fowl analog, raising them from birth to adapt for walking in a more dinosaur-like way.
"These results indicate a shift from the standard bird, knee-driven bipedal locomotion to a more hip-driven locomotion, typical of crocodilians (the only other extant archosaur group), mammals, and hypothetically, bipedal non-avian dinosaurs," the researchers write in the study. So although we don’t quite have any dinosaurs to double check, the scientists are pretty sure this is a fair representation of how dinos strolled.
This incredibly cool new study by Gossi et al, published today in PLOSone, has researched whether chickens walk differently if they have a long, heavy tail, reminiscent of the type of tail present in non-avian dinosaurs. Giving them such a tail artificially (while controlling for weight) actually causes them to walk differently! Check out the paper, it’s open-access.
From the abstract:
Birds still share many traits with their dinosaur ancestors, making them the best living group to reconstruct certain aspects of non-avian theropod biology. Bipedal, digitigrade locomotion and parasagittal hindlimb movement are some of those inherited traits. Living birds, however, maintain an unusually crouched hindlimb posture and locomotion powered by knee flexion, in contrast to the inferred primitive condition of non-avian theropods: more upright posture and limb movement powered by femur retraction. Such functional differences, which are associated with a gradual, anterior shift of the centre of mass in theropods along the bird line, make the use of extant birds to study non-avian theropod locomotion problematic. Here we show that, by experimentally manipulating the location of the centre of mass in living birds, it is possible to recreate limb posture and kinematics inferred for extinct bipedal dinosaurs. Chickens raised wearing artificial tails, and consequently with more posteriorly located centre of mass, showed a more vertical orientation of the femur during standing and increased femoral displacement during locomotion. Our results support the hypothesis that gradual changes in the location of the centre of mass resulted in more crouched hindlimb postures and a shift from hip-driven to knee-driven limb movements through theropod evolution. This study suggests that, through careful experimental manipulations during the growth phase of ontogeny, extant birds can potentially be used to gain important insights into previously unexplored aspects of bipedal non-avian theropod locomotion.
so freaking awesome
'Top hat' Deinonychus
Work in progress: Displaying Jeholornis prima. Inspired by display behavior of Great Argus.
Therapods of North America: Acheroraptor temertyorum
A Hell Creek velociraptorine, depicted here in the winter, devouring a juvenile Thescelosaurus
I love snow paintings for some reason.