What is adequate evidence for mass procurement of ungulates in zooarchaeology?

For more than 40 years, zooarchaeologists have explored possible criteria for distinguishing ungulate mass procurement (killing of many animals in one event) from bonebed sites. However, beyond age distributions, there has been little debate about what evidence is sufficient to accept the hypothesis of mass procurement. Here I discuss possible lines of evidence under the broad categories of threshold bone count, human-caused mortality, single depositional episode, and single mortality event. I argue that none of these is adequate by itself, but acceptable proof might emerge from multiple, converging lines of evidence