Recent and fossil Lunulitidae (Bryozoa: Cheilostomata) 4. American and Australian species of Otionella

Abstract

The nominal, free living lunulitiform genus Otionella has been found to include two major groups of species, each one with a distinctive periancestrular pattern of primary zooids. The first group occurs in the Eocene of North America and includes the type species, O. perforata, and several other forms. The second group occurs in the Late Eocene to Recent of Australasia, and may prove to be generically distinct. Intermediate forms, such as O. parvula from the Argentinian Tertiary, are discussed, and a diverse fauna of 10 species from Australia is described. Although some of these species, like O. cupola, O. exigua and O. nitida, have long been known from Australia. it has only recently been recognized that three New Zealand forms, O. squamosa, O. zelandica and O. proberti, also occur in the Tertiary and/or Recent of Victoria, New South Wales, and Western Australia. In addition, four species are considered to be new. These include O. australis, O. auricula and O. minuta, which are probably closely related to one another, and to O. zelandica. The fourth species, O. browni, has a unique periancestrular budding pattern which resembles that of fossil Lunulites more than any form of ‘Australasian Otionella’. Although, in many ways, O. browni could be assigned to Lunulites sensu lato, it is included here in Otionella.