In 1907, American paleontologist Ermine Cowles Case suggested that the skull of "Edaphosaurus" might belong with skeletons called "Naosaurus", based on a specimen found in 1906 that appeared to associate elements of both. In 1913, Samuel Wendell Williston and Case described the new species "Edaphosaurus novomexicanus" from a fairly complete specimen unearthed in New Mexico in 1910, in which a sailbacked "Naosaurus"-type skeleton was found with a small "Edaphosaurus"-type skull. The older generic name "Edaphosaurus" Cope, 1882 became the valid one.