In this episode the gang discusses mimicry in the fossil record, which James uses as an excuse to introduce everyone to one of his “favorite” papers.  And as they stare into the gaping maw of mimicry in slack-jawed disbelief, grim smiling lips float back to them flashing pearly teeth in the dark and whispering one word.... mouths.

References

http://www.edinburghgeolsoc.org/edingeologist/z_42_08.html

Lamont, A. "Prolegomena to aggressive mimicry and protective resemblance in early fishes, chelicerates, trilobites and brachiopods." Scottish Journal of Science 1.2 (1969): 75-103.

Topper, Timothy P., et al. "Competition and mimicry: the curious case of chaetae in brachiopods from the middle Cambrian Burgess Shale." BMC evolutionary biology 15.1 (2015): 42