SSAR split Sistrurus tergeminus from Sistrurus catenatus taking
Desert Massasauga (Sistrurus catenatus ssp. edwardsii)
and Western Massasauga (Sistrurus catenatus ssp. tergeminus) with it. https://www.inaturalist.org/taxon_changes/18657
This leaves Eastern massasauga (Sistrurus catenatus ssp. catenatus) all alone so I'm collapsing it into Sistrurus catenatus
Crother, B. I. (ed.). 2008. Scientific and Standard English Names of Amphibians and Reptiles of North America North of Mexico, pp. 1–84. SSAR Herpetological Circular 37. (Link)
Unintended disagreements occur when a parent (B) is
thinned by swapping a child (E) to another part of the
taxonomic tree, resulting in existing IDs of the parent being interpreted
as disagreements with existing IDs of the swapped child.
Identification
ID 2 of taxon E will be an unintended disagreement with ID 1 of taxon B after the taxon swap
If thinning a parent results in more than 10 unintended disagreements, you
should split the parent after swapping the child to replace existing IDs
of the parent (B) with IDs that don't disagree.