67) THE NASAL ORGAN IN AMPHIBIA—HIGGINS 67 
preservation as far back as the Tertiary. Earlier than this all known fossil 
forms are caudate, with the exception of a single specimen, Pelion lyelli, 
found in the Carboniferous, which closely resembles recent Salientia. 
Should Pelion prove to be a primitive Anuran, then the Urodeles and the 
Anura have probably separated from the Stegocephalan ancestor as far 
back as the late Devonian or early Carboniferous period. 
