I'm sorry, 7th ed. wilson and Swan also record 2 supranasals for impar but Cogger mentions the anterior pair of supranasals fused to the upper labial in the key but then in the text that there are 5 scales between the rostral and the frontal shield which would suggest only one pair of supranasals. Very confusing. Happy to go with one pair for impar but that still does not help here. My gut feeling is it is impar but with no proof to lock it in. It will be interesting to see if any other unmarked specimens turn up. Look closely at the supranasals! cheers John