Baculogypsina Sacco 1893
Creators: name: Mamo, Briony L.
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Chromista
Foraminifera
Globothalamea
Rotaliida
Calcarinidae
Baculogypsina

description: Baculogypsina Sacco 1893
Baculogypsina sphaerulata (Parker & Jones 1860) (Fig. 24:1–4)
1860 Orbitolina sphaerulata Parker & Jones, p. 33, fig. 8.
1924 Baculogypsina sphaerulatus (Parker & Jones); Cushman, p. 44, pl. 15, figs 1–3. 1965 Baculogypsina sphaerulata (Parker & Jones); Jell et al., p. 278, pl. 44, fig. 6. 1984 Baculogypsina sphaerulata (Parker & Jones); Hallock, p. 251, fig. 1: 12.
1992a Baculogypsina sphaerulata (Parker & Jones); Hatta & Ujiié, p. 199, pl. 44, figs 3–5. 1995 Baculogypsina sphaerulata (Parker & Jones); Lobegeier, p. 84, pl. 6, fig. 9.
1999 Baculogypsina sphaerulata (Parker & Jones); Hohenegger et al., p. 153, fig. 27. 2002 Baculogypsina sphaerulata (Parker & Jones); Lobegeier, p. 215, pl. 2, figs 15–17. 2002 Baculogypsina sphaerulata (Parker & Jones); Yordanova & Hohenegger, p. 198, pl. 33, figs 4–6. 2003 Baculogypsina sphaerulata (Parker & Jones); Langer & Lipps, p. 151, fig. 7Df. 2004 Baculogypsina sphaerulata (Parker & Jones); Saraswati et al., p. 341, pl. 1, fig. 7. 2012 Baculogypsina sphaerulata (Parker & Jones); Debenay, p. 234, pl. 22.
Description. See Cushman (1924, p. 44, pl. 15, figs 1–3), Hohenegger et al. (1999, p. 153, fig. 27) and Yordanova & Hohenegger (2002, p. 198, pl. 33, figs 4–6).
Remarks. This taxon is characterised by a large, biconvex test with the initial planispiral growth stage being followed by cyclic chamber addition, often on the horizontal plane, giving the test a spherical shape. The test has four to nine spines developed from the inner embryonic spiral and the ornament consists of numerous pustules scattered over the test (Fig. 24:1–4).
Baculogypsina sphaerulata (Parker & Jones 1860) shows intraspecific variation in the number of spines (either five or more than six) protruding from inner side of the test and the extent to which the exterior chambers cover the spines. In some instances, the outermost test wall partially extends up the spines resulting in a tapering appearance (Cushman 1924; Lobegeier 1995; Yordanova & Hohenegger 2002; Langer & Lipps 2003; Saraswati et al. 2004; Debenay 2012). In other cases, the spines form distinct protrusions that appear unrelated to the outer test wall (Hatta & Ujiié 1992a; Hohenegger et al. 1999; Debenay 2012). Within CG collected specimens both tapering forms with five spines (Fig. 23:4, 5) and protruding forms with six or more spines were collected (Fig. 23:2, 3).
Baculogypsina sphaerulata is closest to Baculogypsinoides spinosus Yabe & Hanzawa 1930. Both taxa have a similar internal structure, chamber arrangement and protruding spines. However, B. spinosus only has three to four spines and these tend to be proportionately thicker in relation to test size; supplementary spines also cover the external test surface.
The type specimens of B. sphaerulata were collected from New Zealand, Fiji and New Caledonia (Parker & Jones 1860; Ellis & Messina 1940). Based on material collected off Utileo Reef, Pago Pago Harbour, Samoa, Cushman (1924) observed that B. sphaerulata is not widely distributed and prefers shallow water environments. This taxon has a predominantly western Pacific distribution (GBR—Jell et al. 1965, Lobegeier 1995; Palau, Western Caroline Islands—Hallock 1984; Ryukyu Island Arc—Hatta & Ujiié 1992a, Hohenegger et al. 1999, Yordanova & Hohenegger 2002, Saraswati et al. 2004; Papua New Guinea—Langer and Lipps 2003; New Caledonia—Debenay 2012). This species is almost exclusively found within shallow waters (<5 m) living on algal thalli or growing on coral in areas with high coral coverage including the inner reef flat and reef crest areas (Jell et al. 1965; Hallock 1984; Debenay 2012).
Distribution within study area. Baculogypsina sphaerulata is the second most abundant species from the CG. Collected from all reefs, except for the channel sample, the distribution of B. sphaerulata conforms to previous observations that it is a common species in shallow, intertidal waters, and only occurs in relatively low abundance in deeper lagoonal settings (Cushman 1924; Jell et al. 1965; Hallock 1984; Hohenegger et al. 1999; Yordanova & Hohenegger 2002). For instance, the two sites with highest abundance of B. sphaerulata in Wistari Lagoon were the two shallowest sites where abundance was twenty to thirty times higher. Interestingly, on Heron Reef flat the greatest abundance was found on the reef crest or outermost inner reef flat at site 8, along ST/HW transect or at sites 13 and 15 along Transect 2. At site 28, Sykes Reef, the average number of specimens per site was similarly high (215 specimens per site).
description: Published as part of Mamo, Briony L., 2016, Benthic Foraminifera from the Capricorn Group, Great Barrier Reef, Australia, pp. 1-123 in Zootaxa 4215 (1) on pages 100-102, DOI: 10.11646/zootaxa.4215.1.1, http://zenodo.org/record/272923