Bart......Ok for the sake of debate I will take the devils' advocate stance.



I agree that when standing in a corn field in the midwest looking at freshly caught sayi you would probably not think, "I have a catenifer here". Those eastern sayi are phenotypically all about melanoluecus. However when you drive west out of your normal collecting grounds and happen upon a big sayi in central new mexico what then? This group has always been problematic in that sayi intergrades with affinis and affinis intergrades with several of the other western groups. Is affinis in your sayi species complex (Pituophis sayi affinis) as some authors have suggested or is it part of the catennifer complex? Should affinis simply not be recognized and be classified as just another form of sayi? It is really not a simple solution. The most receint genetic work indicates that sayi is rightly placed in the catenifer complex but what of the fact that some ruthveni were found to be more related to sayi than to other ruthveni? Tell me an illinois sayi "looks" more like a vertebralis than it does a western melanoluecus, right?



Personally I grew up under the "Roger Conant regiem" and I am therefore more likely to default back to a three species taxonomy with P.melanoluecus, P. deppei and P. lineaticollis representing the genus.

It is in large part the complexity of this genus which I find attracive. Go to the ITES (intergrated taxonomic information systems) web site and look up Pituophis. You will see just how hotly contested the classification of this group of snakes has been since the 1700's!!!



And despite not ever having the pleasure of seeing a wild P.m.melanoluecus let alone the large numbers that some have seen I am still maintaining that some of the images of western northerns and ruthveni and eastern sayi bear a striking resemblence. Are there historic intergrade zones that have been lost via agriculture? Was there a historic connection that has been fractured via glacial activities over the past say 20,000 years?



Pituophis is a group that lends itself well to the study of biogeography. We will have trouble making sense of the "taxonomic snapshot" we are seeing today unless we look at the history of the group.





I think some one told me receintly that one researcher wants to group the pits in with the rats and completely dissolve the genus pituophis!!!







thanks for the saturday morning food for thought Bart....................







photo by R Nixon

[ Show Entire Thread ]