Paul Monfils wrote: [snip] A couple of weeks back there was a Conch-L discussion concerning the question whether subspecies necessarily have to be geographically isolated, and the prevailing opinion seemed to be that they do. However, the above example appears to be a case where subspecies are isolated not geographically but temporally. [a] Are there any ICZN rules governing such situations? [b] Is this a common practice? [c] Would it be reasonable to say that many recent fossil forms which resemble extant forms should be described as subspecies, rather than distinct species? [d] Does the nominate species have to be the "older" (extinct) form (as in the case above)? [e] What if the living form is named first? [f] Can a fossil form that preceded it be named as a subspecies of an extant species? Answers: (a) No. In fact, the ICZN does not single out fossils for special treatment in most cases. (b) Temporally defined subspecies are abundant in paleontology, and not just used by taxonomists. Subspecies are critically important to biostratigraphers, who make these fine distinctions in order to discern the ages of strata. (c) Yes, certainly. There are many examples from the Pliocene-Pleistocene beds in and near Sarasota, Florida. (d) No, it makes no difference. In practice, the living subspecies was usually named first, but it doesn't matter and there are examples of both. The rule of priority applies only to date of publication. (e) Then the living form is the name-bearer of that species. (f) Yes. I'm back from field work in Sylacauga, Alabama, where a meteor fell and hit a woman in the 1950's. She survived to sue her landlord over ownership of the stone (it hit the roof first and bounced around the room before hitting her on the thigh as she lay sleeping on a couch). And the meteorite is now on display a few hundred feet away from me in the Alabama Museum of Natural History. Hope you enjoyed the Leonids, everybody! Andrew K. Rindsberg Geological Survey of Alabama