Open-ended problems are a very effective tool for engaging student interest. In this paper, we report a physics activity that provides insight into the lifestyle of theropod dinosaurs. This activity generates great enthusiasm among the students since virtually everyone is interested in dinosaurs. In the spirit of the "spherical cow" approach to difficult problems, we consider the problem at the simplest level. This type of approach is very important since it helps students learn how to estimate answers for many "real-world" problems. At the end of the activity, we discuss how the calculations could be improved by including more effects.