Complex sentence: The name "Pantomesaxonia", originally introduced by, a German zoologist and racial theorist, was resurrected by by including sirenians and excluding South American ungulates, phenacodontids, and meniscotheriids from the original concept.
Split into simpler sentences: The name "Pantomesaxonia" was originally introduced by, a German zoologist and racial theorist. It was resurrected by by including sirenians and excluding South American ungulates, phenacodontids, and meniscotheriids from the original concept.