HIDING IN PLAIN SIGHT: DISSECTING BBQ-STYLE CHICKEN WINGS IN AN INTRODUCTORY GEOLOGY COURSE TO DISCOVER THE ALULA AND OTHER DINOSAUR–BIRD EVOLUTIONARY LINKS

The goal of object-based exercises in the geology classroom is to engage students in active, experiential learning. Manipulating objects allows students to gain proficiency in making careful observations before drawing inferences about the specimens under study. Such an approach, involving in-class, pair-share examinations of fossils, has been successful in an introductory geology course for promoting a deeper understanding of Mesozoic–Cenozoic vertebrate evolution. A new classroom exercise enhances students’ appreciation for evidence of evolution, specifically in modern organisms with which everyone is familiar. During the dissection of a popular college late-night snack (bbq-style chicken wings), students discover what is hidden in plain sight: the alula and other anatomical features that link birds to their evolutionary predecessors, the dinosaurs.

For the 15-minute dissection, students work in pairs, don latex gloves, and use a plastic fork and knife. Each pair receives a room-temperature, baked, bone-in, skin-on chicken wing (with tips intact). After orienting their specimen (right vs. left wing, front vs. back), students dissect to the bone. Then they label all major skeletal features from the shoulder to the wrist, comparing the anatomy of the chicken’s arm with their own. Once the wrist is identified, students easily discover the prominent alula on the chicken’s modified hand. Skeletal diagrams of theropod dinos allow students to recognize—with considerable astonishment—that the alula is the theropod’s remnant thumb and tiny claw, which are incompletely fused to the bird’s other digits. The dissected specimens give flight to discussions about homologous vs. analogous structures, form and function, and the evolution of exaptations in dinosaurs’ living descendants. Moreover, the dissection exercise inspires students to stay ever vigilant to the evidence of evolution that is hidden in plain view everywhere.