Ratsnake Taxonomy

This is about Pantherophis, the ratsnakes endemic to the eastern regions of North America.

SSAR and CNAH substituted P. alleghaniensis for P. spiloides, and resurrected P. quadrivittatus.

For the eastern part of the USA we now have:

P. alleghaniensis — Central Ratsnake
P. quadrivittatus — Yellow Ratsnake

The geographic range of P. spiloides (Gray Ratsnake) extended further east and therefore overlapped with the locality of Holbrook’s type specimen (Coluber alleghaniensis, 1836) of P. alleghaniensis in Virginia. Thus, the former P. spiloides (Gray Ratsnake) becomes P. alleghaniensis, and the former P. alleghaniensis (Eastern Ratsnake) becomes P. quadrivittatus (Yellow Ratsnake) .

As I understand it, P. spiloides (Gray Ratsnake) is not a valid taxon anymore, and the species complex Eastern/Gray is no longer appropriate.

I don’t know what will happen with the ratsnakes along the Atlantic coast in a few of the southern states. When you look at the distribution map, it seems possible that a species complex Central/Yellow exists. The complex Eastern/Gray was used because there were two genetic lineages involved. It is unclear to me how this revision of the taxa solved the issue of Burbrink’s genetic lineages. Do we now have a single species (P. alleghaniensis) that represents a ‘hybrid’?

New SSAR name list (9th edition, published in March 2025):
https://ssarherps.org/publications/north-american-checklist/

https://cnah.org/taxon.aspx?taxon=Pantherophis_alleghaniensis

https://snakeevolution.org/rangemaps/ratrangereduced.jpg

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Hi John, welcome to the iNaturalist forum. To discuss how specific species/taxa should be treated on iNaturalist it’s best to create a flag on the taxon so that everyone can discuss it together there. One reason being that not everyone uses the forum, another is so that there is a record of the discussion attached to the taxon. To create a flag on a taxon you can go to the taxon page then click curation and flag for curation.

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