taxonID	type	description	language	source
03D1686A5A44A058E3E4D344FDD7909E.taxon	materials_examined	Type species: Riscodopa parva Gordon, 1989. Description Colony discoid, free living, budded radially, anchored by rhizoids originating from basal septular pores. Ancestrula either tatiform or similar to succeeding zooids. Zooid ori  ces with oral spines, paired lateral denticles and a proximal lyrula. Avicularia lateral and oral, sometimes proximal and associated with a mucro. Ovicell hyperstomial, prominent, with numerous small pores or tubercles, known or inferred not to be closed by the operculum. Remarks Species here assigned to Riscodopa fall into two groups; the Recent species, which have a tatiform ancestrula, and the fossil species, which do not. Genera which include species with diVerent kinds of ancestrula have been documented (Cook, 1985: 51), and the genus Mucropetraliella, which is usually characterized by the presence of a proximal mucro and avicularium, does include some species in which these do not occur (Cook and Chimonides, 1981 a: 117). Gordon (1989: 57) stipulated that there was ‘ no suboral aviculiferous mucro’ in Riscodopa. A mucro occurs in R. biincisa and R. paucipora, but is absent from R. parva, R. cotyla and R. hyalina. However, the similarities in colony form and basal septular pores suggest that all the species described here may be contained within the genus Riscodopa. In all species, the ancestrula is surrounded by a circlet of  ve or six primary autozooids. These appear to be budded as a distal pair or triad, followed by a proximal triad, which may be derived equally from the lateral zooids as well as from the ancestrula. Riscodopa parva and R. cotyla live, anchored by basal rhizoids, on particulate substrata in deep water (477 – 4059 and 320 – 660 m, respectively), from the New Zealand shelf; R. hyalina occurs oV the coast of New South Wales from 429 to 503 m. The numerous other fossil bryozoan species associated with R. biincisa and R. paucipora in the Tertiary samples from Victoria suggest, in contrast, that although similar kinds of particulate sea-bottom occurred in Australian Tertiary seas, it is very unlikely that any of these fossil forms lived in deep water (Wass et al., 1970). Similar apparent discrepancies between the known depth range of Recent species, and the depths inferred for their fossil congeners, occur among several groups of species in the Australian Tertiary, and have been noted for Selenariopsis (Bock and Cook, 1996), Siphonicytara (Bock and Cook, 2001) and for Chelidozoum and other species (Bock and Cook, in press). One possible explanation is that the hydrodynami c conditions of the shelf environments of the mid-Tertiary were much less agitated by wave activity than the modern shelf of southern Australia. This in turn, may be related to the narrower zone of open ocean that existed between Antarctica and Australia, or that the severe storms in this zone were less frequent or less intense during this interval of milder climate. The lack of strong bottom current or wave activity is also re ected in the presence of clay-rich sediments over large intervals and areas in the Tertiary, whereas clay-rich sediments are generally little-represented on the modern continental shelf.	en	Cook, P. L., Bock, P. E. (2002): Notes on astogeny of some Petraliellidae (Bryozoa) from Australia. Journal of Natural History 36 (13): 1601-1619, DOI: 10.1080/00222930110052463, URL: http://www.tandfonline.com/doi/abs/10.1080/00222930110052463
03D1686A5A43A054E390D299FB939278.taxon	materials_examined	Other material examined MOV, Miocene, Victoria, Batesford, Cooriemungle, Paaratte and Princetown; South Australia, Mount Schanck; Oligocene, Victoria, Bird Rock (see Appendix). Description Riscodopa with non-tatiform ancestrula. Autozooid frontal shield reticulated, with 15 – 30 large frontal pores and two to four marginal septular pores, often concealed by calci  cation. Primary ori  ce with paired proximo-lateral denticles, a central lyrula and six oral spines. Lateral-oral avicularia paired, terminal on columnar processes, and a proximal avicularium terminal on a prominent mucro; rostra small, subtriangular or rounded, with a complete bar. Fully developed ovicells not seen. Basal walls with one or more large septular pores. Remarks The lectotype includes only three to four zooids, and the paralectotype (Waters’s  gured specimen) does not include an ancestrula. Many ancestrulate colonies occur in samples from Balcombe Bay, Princetown and Mount Schanck, and the early astogeny may be traced from these specimens. The ancestrula is not tatiform, but resembles later-budded zooids. The early budding pattern resembles that of R. parva and R. cotyla, and includes a distal ancestrular triad, followed by a proximal triad, completing a circum-ancestrular ring. The zooidal oral spines, lateral denticles and narrow, median lyrula are constantly present, but the avicularian columns are often worn. No ovicells have been reported, or have been found in the colonies examined, but several show that they were about to be developed. These ovicell traces occur in zooids of the fourth and subsequent astogenetic generations (see  gure 4). In R. cotyla, fully developed ovicells occur in the  fth generation, but there are only signs of early development in third and fourth generation zooids. This reversal of the usual astogenetic sequence in ovicell ontogeny is typical of the Petraliellidae (Cook and Chimonides, 1981 a). On the basal side of colonies, the ancestrula frequently shows a depression in the calci  cation of the basal wall, which may mark the position of the inferred primary rhizoid element. One, and sometimes two, large, basal septular pores occur in the walls of other zooids, and are inferred to mark the site of rhizoids in life. Some colonies also show a raised, curved, basal lamina surrounding the proximal end of each zooid, which also occurs in R. paucipora (see below).	en	Cook, P. L., Bock, P. E. (2002): Notes on astogeny of some Petraliellidae (Bryozoa) from Australia. Journal of Natural History 36 (13): 1601-1619, DOI: 10.1080/00222930110052463, URL: http://www.tandfonline.com/doi/abs/10.1080/00222930110052463
03D1686A5A4FA056E3FBD0F2FE2890DF.taxon	materials_examined	HOLOTYPE. MOV P 128374, Late Eocene, Browns Creek, Victoria. Etymology From paucus (Latin) — few, and porus (Latin) — hole, referring to the lack of frontal pseudopores. Description Riscodopa with non-tatiform ancestrula. Autozooids almost vertical, ori  ces occupying the major part of the frontal shield. Frontal shield imperforate except for a single series of marginal or submarginal pores, most of which appear to be frontal septular pores. Primary ori  ce large, subterminal, with paired lateral denticles, and a narrow, hammer-shaped lyrula, which together de  ne a pair of proximal sinuses. Five to six oral spines, proximal mucro small, with a terminal avicularium with a subtriangular rostrum, orientated proximally and frontally, and a complete bar. Paired disto-lateral avicularia on swollen subrostral chambers, orientated laterally. Basal surface of each zooid separated by a groove from its neighbours, with a curved lamina raised above its proximal end. Each wall with a crescent or small group of three to  ve septular pores arranged transversely in the mid-line. Ovicell not found. Measurements Length of ancestrula 0.28 mm. Length of zooids 0.23 – 0.38 mm. Width of primary ori  ce 0.17 – 0.19 mm. Remarks Only one colony has been found. The ancestrula is sunken; its basal wall is missing. The primary ori  ce is so large that the ancestrula almost appears to be tatiform. Although slightly damaged, the ori  ce shows one lateral denticle, which resembles a condyle, and a proximal avicularian mucro, but no trace of oral spines. The ancestrula is surrounded by a distal triad of primary zooids, and a proximolateral pair budded later in astogeny, one of which has an ori  ce occluded by calci  cation, which includes the spine bases. The zooid ori  ces are so large, and the frontal wall so restricted, that the network of pseudopores typical of other species of Riscodopa is absent. The marginal series appear to be all septular pores. The paired avicularia are not raised on columnar processes as in R. biincisa. The presence of an avicularium on the ancestrula is unusual but has been reported in other species (Hayward and Cook, 1979: 77). The basal septular pores diVer from those of R. biincisa in being more numerous and arranged in a crescent across the mid-line of the zooid. The curved proximal lamina is less robust, but similar to that occurring in some specimens of R. biincisa. It suggests that while the rest of the basal calci  ed wall is an interior wall, the rhizoids of R. biincisa and R. paucipora may have had a swollen origin surrounded by a rim of exterior calci  ed wall, which included several septular pores, like those of Parastichopora (Cook and Chimonides 1981 a). The rhizoids of R. parva, R. cotyla and R. hyalina are numerous, but only one is produced by each septular pore.	en	Cook, P. L., Bock, P. E. (2002): Notes on astogeny of some Petraliellidae (Bryozoa) from Australia. Journal of Natural History 36 (13): 1601-1619, DOI: 10.1080/00222930110052463, URL: http://www.tandfonline.com/doi/abs/10.1080/00222930110052463
03D1686A5A4DA057E3E9D341FE84963B.taxon	materials_examined	HOLOTYPE. MOV F 52874, SEAS (South Eastern Australian Slope, ‘ Franklin’ Cruise), Station SLOPE 2, oV Nowra, New South Wales, 34 ss 57.09 ¾ S, 151 ss 8.00 ¾ E, 503 m, 11 July 1986, epibenthic sled, bryozoa and shell bottom. PARATYPES. MOV F 52875, SLOPE 2 as above, and MOV F 52876, SLOPE 56, from 34 ss 55.79 ¾ S, 151 ss 08.06 ¾ E, 429 m to 34 ss 56.06 ¾ S, 151 ss 06.86 ¾ E, 466 m, 22 October 1988, epibenthic sled, muddy coarse shell bottom. Etymology From hyalinos (Greek) — glassy, referring to the semi-transparent calci  cation. Description Riscodopa with tatiform ancestrula with nine marginal spines. Colony fan-shaped at  rst, becoming lunulitiform later in astogeny, ancestrula surrounded by a ring of six zooids. Autozooids small, semi-erect, very thinly calci  ed; frontal shield with 20 – 40 pseudopores and two to four frontal septular pores. Primary ori  ce large, with paired proximo-lateral denticles, and a small, variably shaped lyrula, which may occasionally be absent. Four oral spines, the lateral pair with large spine bases; no proximal mucro. Paired latero-oral avicularia, with subtriangular mandibles orientated laterally. Ovicells present, or developing on zooids of the third to fourth astogenetic generation. Basal walls with a single, large, multiporous septular pore, placed just distally to the centre, giving rise to a rhizoid. Measurements Length of ancestrula 0.42 mm. Length of zooids 0.31 – 0.52 mm. Width of primary ori  ce 0.16 – 0.18 mm. Remarks The specimens comprise four colonies, two of which are fractured and incomplete. They measure 1.5, 3.0, 3.5 and 5.0 mm in diameter, and include nine, 30, 30 and 31 zooids, respectively. Only one colony (MOV F 52876) has a lunulitiform shape, and has the only complete ovicell present. This is prominent, longer than wide, with a straight proximal edge and  nely tuberculate surface. The smallest colony, which has an ancestrula, has not yet developed a complete ring of primary zooids ( gure 14). A single rhizoid appears to have been produced by one of the second generation zooids, but accumulations of particles make this diYcult to see clearly, and the colonies are so delicate that it is not possible to remove the cuticular parts without damaging the zooids. Numerous rhizoids, 1.0 – 1.50 mm long, occur in the three larger colonies, each arising from one of the basal septular pores. The zooidal ori  ces are the same size as those of R. parva, but appear proportionately larger because of the smaller extent of the frontal shield. Riscodopa hyalina lacks a proximal mucro, and the lateral denticles and lyrula are less strongly developed than in other species. The oral avicularia are also similar to those of R. parva, but are placed more proximally.	en	Cook, P. L., Bock, P. E. (2002): Notes on astogeny of some Petraliellidae (Bryozoa) from Australia. Journal of Natural History 36 (13): 1601-1619, DOI: 10.1080/00222930110052463, URL: http://www.tandfonline.com/doi/abs/10.1080/00222930110052463
