"Microeciella suborbicularus" has also been recently distinguished from "O. lobulata" and "O. dilatans", using this modern method of low vacuum scanning, with which it has been inaccurately synonymized with in the past. A new genus has also been recently discovered called "Junerossia" in the family Stomachetosellidae, along with 10 relatively new species of bryozoa such as "Alderina flaventa", "Corbulella extenuata", "Puellina septemcryptica", "Junerossia copiosa", "Calyptotheca kapaaensis", "Bryopesanser serratus", "Cribellopora souleorum", "Metacleidochasma verrucosa", "Disporella compta", and "Favosipora adunca". Counts of formally described species range between 4,000 and 4,500. The Gymnolaemata and especially Cheilostomata have the greatest numbers of species, possibly because of their wide range of specialist zooids. Under the Linnaean system of classification, which is still used as a convenient way to label groups of organisms, living members of the phylum Bryozoa are divided into:  Fossils of about 15,000 bryozoan species have been found. Bryozoans are among the three dominant groups of Paleozoic fossils. The oldest species with a mineralized skeleton occurs in the Lower Ordovician. It is likely that the first bryozoans appeared much earlier and were entirely soft-bodied, and the Ordovician fossils record the appearance of mineralized skeletons in this phylum. By the Arenigian stage of the Early Ordovician period, about , all the modern orders of stenolaemates were present, and the ctenostome order of gymnolaemates had appeared by the Middle Ordovician, about . The Early Ordovician fossils may also represent forms that had already become significantly different from the original members of the phylum. Ctenostomes with phosphatized soft tissue are known from the Devonian. Other types of filter feeders appeared around the same time, which suggests that some change made the environment more favorable for this lifestyle. Fossils of cheilostomates, another order of gymnolaemates, first appear in the Mid Jurassic, about , and these have been the most abundant and diverse bryozoans from the Cretaceous to the present.