Spiroloculina Mamo, 2016, sensu
Spiroloculina sp. cf. S. depressa d’Orbigny 1826 (Fig. 6:20, 21) Description. See Debenay (2012, p. 133, pl. 5). Remarks. This species was classified under S. depressa due to its rounded lateral view, nearly parallel sides giving a flat to slightly compressed cross-section and its round, terminal ap...
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| Format: | Other/Unknown Material |
| Language: | unknown |
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2016
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| Online Access: | https://zenodo.org/record/6067723 https://doi.org/10.5281/zenodo.6067723 |
| Summary: | Spiroloculina sp. cf. S. depressa d’Orbigny 1826 (Fig. 6:20, 21) Description. See Debenay (2012, p. 133, pl. 5). Remarks. This species was classified under S. depressa due to its rounded lateral view, nearly parallel sides giving a flat to slightly compressed cross-section and its round, terminal aperture on a short neck with a small lip and single tooth. Classification remains uncertain due to low abundance, the inflated peripheral chambers and the lack of both compression towards the test’s centre and of raised inner margins that are frequently found with this species (Cuvier et al. 1834; Debenay 2012). Despite the lack of raised margins and compression causing uncertainty with CG specimens, these features both vary within the species. For instance, compare specimens of Cuvier et al. (1834: pl. 6. fig. 7) and Debenay (2012: p. 133) with strongly raised inner margins between chambers to Brady’s (1884: pl. 9, fig. 7) and Cushman’s (1921, p. 81, fig. 2) where there are none. Spiroloculina sp. cf. S. depressa bears similarity to Spiroloculina sp. 1 in possessing a short neck and parallel sides, giving the test a flat cross-section. They differ in that Spiroloculina sp. 1 has massiline coiling and does not have inflated chambers and therefore a less rounded and more carinate periphery. D’Orbigny (1826) originally collected fossil forms of S. depressa from Castell’Arquato, Italy and has since been extensively reported globally (Bay of Biscay, Irish Sea, Guam, North Atlantic, United States, Mediterranean Sea, Japan, Red Sea—Brady 1884 and Gross 2014; Philippines—Cushman 1921b; New Caledonia from 10–411 m—Debenay 2012). Distribution within study area. Spiroloculina sp. cf. S. depressa does not occur in high abundance within the CG—no more than six specimens were collected per site. The greatest abundance was from site 53 of One Tree Lagoon 2 and was collected from only one site within Heron Lagoon. This species was absent from both Sykes Reef and the channel sample. Spiroloculina foveolata Egger 1893 (Fig. 7:1, 2) ... |
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