Both Anisacanthus and Holodiscus are what level of classification?
Holodiscus Holodiscus (syn. "Sericotheca") is a genus of flowering plants in the family Rosaceae, native to the Americas, from southwestern British Columbia, Canada and the western United States south to Bolivia.
Acristavus Acristavus is a genus of saurolophine dinosaur. Fossils have been found from the Campanian Two Medicine Formation in Montana and Wahweap Formation in Utah, United States. The type species "A. gagslarsoni" was named in 2011. Unlike nearly all hadrosaurids except "Edmontosaurus", "Acristavus" lacked ornamentation on its skull. The discovery of "Acristavus" is paleontologically significant because it supports the position that the ancestor of all hadrosaurids did not possess cranial ornamentation, and that ornamentation was an adaptation that later arose interdependently in the subfamilies Saurolophinae and Lambeosaurinae. It is closely related to "Brachylophosaurus" and "Maiasaura", and was assigned to a new clade called Brachylophosaurini.