Utaurora is an extinct genus of opabiniid, which were bizarre stem-arthropods closely related to true arthropods and radiodonts; the type species is U. comosa. The animal's fossils come from the Cambrian of Utah. This genus is so far the only other known unquestionable opabiniid, with the other being Opabinia itself. There are other animals like Myoscolex and Mieridduryn that could be opabiniids, but the classification of those two genera is still debated.

Radiodonta is an extinct order of stem-group arthropods that was successful worldwide during the Cambrian period. They may be referred to as radiodonts, radiodontans, radiodontids, anomalocarids, or anomalocaridids, although the last two originally refer to the family Anomalocarididae, which previously included all species of this order but is now restricted to only a few species. Radiodonts are distinguished by their distinctive frontal appendages, which are morphologically diverse and used for a variety of functions. Radiodonts included the earliest large predators known, but they also included sediment sifters and filter feeders. Some of the most famous species of radiodonts are the Cambrian taxa Anomalocaris canadensis, Hurdia victoria, Peytoia nathorsti, Titanokorys gainessii, Cambroraster falcatus and Amplectobelua symbrachiata, the Ordovician Aegirocassis benmoulai and the Devonian Schinderhannes bartelsi.