Mixtoscutella Grischenko & Gordon & Taylor & Kuklinski & Denisenko & Spencer-Jones & Ostrovsky 2022, n. gen.
Creators: name: Grischenko, Andrei V.
name: Gordon, Dennis P.
name: Taylor, Paul D.
name: Kuklinski, Piotr
name: Denisenko, Nina V.
name: Spencer-Jones, Mary E.
name: Ostrovsky, Andrew N.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Bryozoa
Gymnolaemata
Cheilostomatida
Lepraliellidae
Mixtoscutella

description: Genus Mixtoscutella n. gen.
Type species: Cellepora ovata Smitt, 1868, by original designation.
Diagnosis. Colony encrusting, multiserial, unilaminar.Frontal shield mixed, comprising a much-reduced umbonuloid area beneath suboral avicularium, corresponding externally to suboral avicularium, and extensive, uniformly pseudoporous lepralioid area. Primary orifice with or without lyrula, with condyles. Secondary orifice cormidial, with very low peristome. Suboral adventitious avicularium always present. Large adventitious avicularia present in some species. Ovicell hyperstomial, often becoming less prominent due to secondary calcification overgrowing ooecium; with pseudopores. Mural pore chambers and multiporous septula present. Basal wall fully calcified, without protuberances.
Etymology. The name refers to the mixed nature of the frontal shield.
Species included. Mixtoscutella ovata (Smitt, 1868a), M. ussowi (Kluge, 1908a), M. cancellata (Smitt, 1868a), M. harmsworthi (Waters, 1900), and M. androsovae (Gontar, 1979).
Remarks. Apart from two species examined in detail (M. ovata and M. ussowi) and transferred from Rhamphostomella (Figs 27, 28), we illustrate here three other taxa, including two little-known species (Fig. 29), that display a combination of characters (mixed frontal shield and suboral avicularium) warranting their placement in Mixtoscutella.
Mixtoscutella androsovae (Gontar, 1979) [= Smittina androsovae Gontar, 1979 (p. 244, fig. 4)] is known only from its type locality at Cape Nerpochka on the Pacific side of Simushir Island, middle Kuril Islands, from 30 m depth (paratype, ZIRAS 2 /43716) (Fig. 29A–C).
The high-boreal-Arctic species, M. harmsworthi (Waters, 1900) [= Schizoporella harmsworthi Waters, 1900 (p. 65, pl. 9, figs 10–12)], widely distributed in Arctic seas (see Kluge 1962 for details) has been detected in Avacha Gulf, eastern Kamchatka (ZIRAS 52/50568, KIENM Collection, RV Nazarovsk, Stn 141, 11 May 1988, 53°41.0ʹ N, 160°04.0ʹ E, depth 75 m) (Fig. 29D–F).
The rarely reported M. cancellata (Smitt, 1868) [= Escharella porifera forma cancellata Smitt, 1868a (p. 9, 75, pl. 24, figs 40, 41)], originally described from Spitsbergen (see also Nordgaard 1906; Kluge 1962; Kuklinski 2002b), has been documented from Point Barrow, Alaska (Osburn 1953) and the Chukchi Sea (Gontar 2010), and was recently found on the western slope of the Kamchatka Peninsula, Sea of Okhotsk (ZIRAS 1/50572, KIENM Collection, RV Agat, Stn 1–K–1, 1 June 2008, 58°00.0ʹ N, 155°43.0ʹ E, depth 285 m) (Fig. 29G–I).
description: Published as part of Grischenko, Andrei V., Gordon, Dennis P., Taylor, Paul D., Kuklinski, Piotr, Denisenko, Nina V., Spencer-Jones, Mary E. & Ostrovsky, Andrew N., 2022, Taxonomy, ecology and zoogeography of the Recent species of Rhamphostomella Lorenz, 1886 and Mixtoscutella n. gen. (Bryozoa, Cheilostomata), pp. 1-115 in Zootaxa 5131 (1) on pages 82-83, DOI: 10.11646/zootaxa.5131.1.1, http://zenodo.org/record/6521113