Some early actinocerids

Here are holotypes of three actinocerids (order Actinocerida) housed at the New Mexico Museum of Natural History and Science in Albquerque, N.M. They all belong to the Wutinoceratidae, which is an early actinocerid family and all three come from the Pallisaria zone in the Antelope Valley Limestone near Beatty, Nevada. They are, with museum catalogue numbers:

Adamsoceras leonardi P-42779
Cyrtonybyoceras adamsi P-42976
Wutinoceras huygenae P- 42877




All three are from the Whiterock stage at the beginning of the Middle Ordovician. Wutinoceras is considered the ancestral form, which gave rise to the other two, as well as to the Armenoceratidae and Actinoceratidae. Adamsoceras is thought to have given rise to the Ormoceratiae. Cyrtonybyoceras apparently left no descendants.