The discovery of Hesperonychus was a long and tangled quest. One day, I was sorting through some microvertebrates from the Lance Formation, really old stuff, collected by Marsh during the Yale expeditions to Wyoming back in the late 1800s. I pulled out this little toe bone- it was virtually identical to a bone from the second toe- the one that bears the killer claw- of the large dromaeosaur Deinonychus, which was actually a few cases away in the same collections. But this one was from a small animal, about the size of a cat.