This collage aligns Martin's lateral view photo of terminalia for a Nevada Timema specimen with figures for T. coffmani (above) and T. nevadense (below), from the references Vickery & Sandoval(1999) and Vickery(1993), respectively.

The locale where the specimen was collected lies between the known ranges of T. coffmani (in nw. AZ) and T. nevadense (in s. NV)...though it's much closer to the latter (and not separated from it by the Colorado River...a significant dispersal barrier for small, flightless Timema!).

I'd say the profile of the terminalia in the photo matches better with that of T. nevadense than with that of T. coffmani (mainly from shape of outline of the terminal (10th) tergum). But other characters in the accompanying images in this series match better with T. coffmani...so I can't see a clear conclusion for the species ID here.

¿ Perhaps not enough specimens were available to determine whether characters like shape and relative proportions of T10, subgenital plate, and cerci are consistent within the given species, while simultaneously distinct between them? (BTW, for females in particular, it's clearly difficult to come up with easily-observed characters that are consistent within a given Timema species; while effectively separating distinct species. It's commendable for anyone to take on that challenge!)