What is "nielsenoceras"

Nielsenoceras is a Paraceltitid genus from the lower Upper Permian, known from sediments in west Texas. The genus is distinguished by exceptionally broad prongs of the ventral lobe and by the presence of a shallow groove on the outer flanks.

Paraceltitids (family Paraceltitidae) are ceratitid ammonoid cephalopods that lived during the Late Permian, near the end of the Paleozoic.