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| Anonymous: Unedited TaxonConcept data | ||||||
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Subspecies Sphaeroidinellopsis subdehiscens paenedehiscens Blow 1969 | ||||||
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| Diagnosis / Definition: | ||||||
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Blow (1969): Description of holotype: Test large, consisting of an unknown number of chambers arranged in a low trochospire but with three chambers only present in the final whorl. Early chambers barely visible externally and the sutures between the penultimate whorl of chambers and the succeeding chamber completely obscured by clear imperforate shell material. Sutures between the chambers of the last whorl also largely obscured by the imperforate cortex but shallow troughs mark their approximate courses. The chambers are embracing and inflated, subglobular and, in the last whorl, increase rapidly as added. The embracing but inflated chambers are without distinct sutural furrows and this gives the test an ovate, smoothly rounded outline. The inner wall is densely perforate but the perforations do not open to the exterior except where the surface has been abraded or where the cortex has been dissolved. The primary aperture is an elongate, slit like opening extending from the umbilicus to almost over the dorsal peripheral shoulder. The aperture follows the line of the intercameral suture between the last and first chamber of the final whorl and is bordered by a crenulate and frilled margin of clear shell Material (i.e., the cortex). The abrasion and solution of the cortex is most noticeable on the dorsal side and over the last chamber. No supplementary dorsal aperture. Maximum diameter of holotype 0.72mm. |
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| Discussion / Comments: | ||||||
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Blow (1969): Remarks: Sphaeroidinellopsis subdehiscens paenedekiscens is distinguished from S. subdehiscens subdehiscens by possessing a relatively much longer primary aperture, a more tightly coiled test in which the chambers are more embracing and in lacking clearly defined, externally visible sutural commissures between any of the three final chambers. S. subdehiscens paenedehiscens is consistently much larger than subdehiscens (s.s.). S. subdehiscens paenedehiscens differs from Sphaeroidinella dehiscens dehiscens (including forma immatura) by not having a dorsal supplementary aperture notwithstanding the test size of the taxon may often exceed that of S. dehiscens dehiscens forma immatura. Reference also should be made to the discussion given in reference notes nos. 62 and 62a (pp. 415 418). Stratigraphical Range: From within the middle to later parts of Zone N.17 to within the earliest part of Zone N.20. The holotype is from sample ER.195, San San Clay member of the Bowden formation (s.l.), Drivers' River, northern coast of Jamaica; Zone N.19, Quilty (1976): Remarks: See also Sphaeroidinella dehiscens dehiscens form immatura. |
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| Synonym list: | ||||||
| Blow (1969): 1969 Sphaeroidinellopsis subdehiscens paenedehiscens Blow. - Blow : p.386 pl. 30, figs. 4,5,9
Quilty (1976): 1969 Sphaeroidinellopsis subdehiscens paenedehiscens Blow. - Blow : p.386 pl. 30, figs. 4-5,9
1976 Sphaeroidinellopsis subdehiscens paenedehiscens Blow. - Quilty : p.685 pl. 10, figs. 3-4
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| Was used in synonym list of: | ||||||
| References: | ||||||
Blow,W.H. (1969): Quilty,P.G.. (1976): |
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| Anonymous: Unedited TaxonConcept data | ||||||
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