Brookula charleenae Schwabe & Engl, 2008, sp. nov.
Brookula charleenae sp. nov. (Figs 5–6) Type material Holotype (ZSM Mol 20070879), leg. Michael Schrödl, March 22 2002, during the ANT XIX/ 4 (ANDEEP II) expedition. Two paratypes (ZSM Mol 20070880) from type locality, all specimens were fixed and preserved in 75 % ethanol except for the SEMmounted...
Main Authors: | , |
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Format: | Other/Unknown Material |
Language: | unknown |
Published: |
2008
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Subjects: | |
Online Access: | https://zenodo.org/record/5631751 https://doi.org/10.5281/zenodo.5631751 |
Summary: | Brookula charleenae sp. nov. (Figs 5–6) Type material Holotype (ZSM Mol 20070879), leg. Michael Schrödl, March 22 2002, during the ANT XIX/ 4 (ANDEEP II) expedition. Two paratypes (ZSM Mol 20070880) from type locality, all specimens were fixed and preserved in 75 % ethanol except for the SEMmounted holotype. Type locality: Antarctica, South Sandwich Islands, St. PS 61 / 140 –08 (58 ° 15.98 ’S 24 ° 53.72 ’W to 58 ° 16.13 ’S 24 ° 53.87 ’W), 2947–2970 m (Fig. 6). Etymology: The species is named after the first author’s daughter Charleen Schwabe. Description: Shell minute, reaching 1.42 mm long and 1.25 mm wide (Fig. 5 A), globosely turbinate, fragile, white in color, with roundly inflated whorls, slightly expanded laterally, low spired, spire angle ranges from 70 ° (holotype) to 81 ° (larger paratype). Protoconch (Figs 5 C, D) of 1.5 whorls, 278 µm in diameter, 220 µm high, globose, sculptured with fine anastomosing threads, forming reticulate pattern. Teleoconch (Fig. 5 A) of up to 2.75 whorls with convex profile. Suture deeply constricted. Last adult whorl globose, slightly expanded laterally. Aperture circular, peritreme holostomate, with thin lip. Shell base roundly inflated. Umbilicus (Fig. 5 B) narrow, circular, deep. Axial sculpture of narrow ribs, 28 on last whorl in the holotype, 27 on the penultimate whorl, deeply entering the umbilicus. Ribs regularly spaced, rounded, nearly lamellous, interspaces between them about three times rib width. Spiral sculpture of numerous flat threads, twelve on first teleoconch whorl, about 42 on last adult whorl, narrower than axial ribs, partly doublespaced, not overlaying axil ribs distally. Operculum circular, multispiral, with centric nucleus. Comparisons: Brookula pfefferi Powell, 1951: despite nearly the same shell proportions, the new species can be easily separated from B. pfefferi by 1) the absence of spiral cords on the shell base, 2) the higher number of spiral threads on the last adult whorl (42 vs 20–26), 3) the smaller protoconch (278 vs 330–400 µm). ... |
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