Nannotax3 - ntax_main - Retecapsa angustiforata

Citation: Retecapsa angustiforata Black, 1971

Synonyms:

Retecapsa brightoni Black, 1971 [cf. Bralower et al. 1989]
Retecapsa levis Black, 1971 [cf. Bralower et al. 1989]
Retecapsa neocomiana Black, 1971 [cf. Bralower et al. 1989]
Cretarhabdus angustiforatus (Black 1971) Bukry 1973 [cf. Bralower et al. 1989]
Cretarhabdus angustiforatus (Black 1971) Bukry 1973 emend Bralower et al. (1989)
Cretarhabdus octoperforatus Forchheimer 1972 [cf. Bralower et al. 1989]
Heterorhabdus sinuosus Noël 1970 [cf. Neptune database synonymy]
Hayesites bulbus Thierstein 1972 - isolated calyx of spine [cf. Applegate & Bergen 1988]
Discoaster? atlanticus Wilcoxon, 1972 - isolated calyx of spine [cf. Applegate & Bergen 1988]
Rucinolithus radiatus Worsley 1973 - isolated calyx of spine [cf. Applegate & Bergen 1988]
Retecapsa radiata (Worsley) Applegate and Bergen, 1988 - isolated calyx of spine

Alongside R. angustiforata, Black (1971) described two other species, Retecapsa brightoni and Retecapsa neocomiana, which were subsequently utilised by Roth (1978). However, these are considered synonymous with R. angustiforata here.

Taxonomic discussion: R. angustiforata spines can have very large apical calices and detached calices have been described as separate nannoliths - as explained by Applegate & Bergen (1988). It was suggested by Applegate & Bergen (1988) that the detached calices should be referred to as Retecapsa radiata but this suggestion does not seem to have been widely followed, and is not really compatible with rigorous taxonomy. Nonetheless separately identifying and counting the calices is worthwhile.

Distinguishing features:
Parent taxon (Retecapsa): Cretarhabdids with central area spanned by an axial cross with lateral bars.
This taxon: Cretarhabdids with axial cross & 1 lateral bar per quadrant; central area relatively wide (>1/3 the shield width). All bars of similar breadth and brightness and all 8 holes of similar size.

Retecapsa with a relatively wide central area (>1/3 the minimum diameter of the distal shield) spanned by an axial cross with one centrally-placed broad lateral bar in each quadrant. A particularly diagnostic feature is that all the central area bars are equally broad and birefringent. The 8 central area holes are of relatively equal size.

R. schizobrachiata is differentiated by the unequal size of its central openings (the four central openings are much larger than the terminal openings), and R. octofenestratus by its narrow central area (<1/3 the minimum diameter of the distal shield.

See also: Rucinolithus - nannoliths with similar form to the calyx of R. angustiforata;

Geological Range:
Notes: Recorded thoughout the Cretaceous but illustrated specimens with very large calices seem to be consistently from the Early Cretaceous. Bown et al. 1988 (fig 5.4, p.98) recorded a range of Berriasian to Early Aptian in the Boreal Early Cretaceous.
Last occurrence (top): within Maastrichtian Stage (66.04-72.17Ma, top in Maastrichtian stage). Data source: Burnett 1998
First occurrence (base): at base of BC1 zone (0% up, 138.8Ma, in Berriasian stage). Data source: Bown et al. 1998 - zonal marker

References:

Applegate, J. L. & Bergen, J. A. (1988). Cretaceous calcareous nannofossil biostratigraphy of sediments recovered from the Galicia Margin, ODP Leg 103. Proceedings of the Ocean Drilling Program, Scientific Results. 103: 293-348. gs O

Black, M. (1971a). Coccoliths of the Speeton Clay and Sutterby Marl. Proceedings of the Yorkshire Geological Society. 38: 381-424. gs

Bown, P. R. (2005c). Early to Mid-Cretaceous Calcareous Nannoplankton from the Northwest Pacific Ocean, Leg 198, Shatsky Rise. Proceedings of the Ocean Drilling Program, Scientific Results. 198: 1-82. gs O

Bown, P. R., Rutledge, D. C., Crux, J. A. & Gallagher, L. T. (1998). Lower Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series . 86-131. gs O

Bralower, T. J. & Siesser, W. G. (1992). Cretaceous calcareous nannofossil biostratigraphy of Sites 761, 762, and 763, Exmouth and Wombat Plateaus, northwest Australia. Proceedings of the Ocean Drilling Program, Scientific Results. 122: 529-556. gs

Bralower, T. J., Monechi, S. & Thierstein, H. R. (1989). Calcareous nannofossil zonation of the Jurassic-Cretaceous boundary interval and correlation with the geomagnetic polarity timescale. Marine Micropaleontology. 14: 153-235. gs

Burnett, J. A. (1998). Upper Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series . 132-199. gs O

Covington, J. M. & Wise, S. W. (1987). Calcareous nannofossil biostratigraphy of a Lower Cretaceous deep-sea fan complex: Deep Sea Drilling Project Leg 93 Site 603, lower continental rise off Cape Hatteras. Initial Reports of the Deep Sea Drilling Project. 93: 617-660. gs O

Crux, J. A. (1989). Biostratigraphy and palaeogeographical applications of Lower Cretaceous nannofossils from north-western Europe. In, Crux, J. A. & van Heck, S. E. (eds) Nannofossils and their applications: Proceedings of the 2nd INA Conference, London 1987. British Micropalaeontological Society Publication Series . 143-211. gs

de Kaenel, E. & Bergen, J. A. (1996b). Mesozoic calcareous nannofossil biostratigraphy from sites 897, 899, and 901, Iberia Abyssal Plain: New biostratigraphic evidence. Proceedings of the Ocean Drilling Program, Scientific Results. 149: 27-59. gs O

Grün, W. & Allemann, F. (1975). The Lower Cretaceous of Caravaca (Spain): Berriasian Calcareous Nannoplankton of the Miravetes Section (Subbetic Zone, Prov. of Murcia). Eclogae Geologicae Helvetiae. 68: 147-211. gs O

Lambert, B. (1987). Nannofossiles calcaires de l'Albien supérieur et du Vraconnien du Cameroun méridional. Cahiers de Micropaléontologie. 2(2): 33-60. gs O

Lees, J. A. & Bown, P. R. (2005). Upper Cretaceous calcareous nannofossil biostratigraphy, ODP Leg 198 (Shatsky Rise, Northwest Pacific Ocean). Proceedings of the Ocean Drilling Program, Scientific Results. 198: 1-60. gs

Linnert, C., Mutterlose, J. & Erbacher, J. (2010). Calcareous nannofossils of the Cenomanian/Turonian boundary interval from the Boreal Realm (Wunstorf, northwest Germany). Marine Micropaleontology. 74: 38-58. gs

Mutterlose, J. & Wise, S. W. (1990). Lower Cretaceous nannofossil biostratigraphy of ODP Leg 113 Holes 692B and 693A, continental slope off east Antarctica, Weddell Sea. Proceedings of the Ocean Drilling Program, Scientific Results. 113: 325-351. gs

Roth, P. H. & Thierstein, H. R. (1972). Calcareous nannoplankton: Leg 14 of the Deep Sea Drilling Project. Initial Reports of the Deep Sea Drilling Project. 12: 546-559. gs O

Roth, P. H. (1978). Cretaceous nannoplankton biostratigraphy and oceanography of the northwestern Atlantic Ocean. Initial Reports of the Deep Sea Drilling Project. 44: 731-760. gs

Thibault, N. (2010). Calcareous nannofossils from the boreal Upper Campanian- Maastrichtian chalk of Denmark. Journal of Nannoplankton Research. 31(1): 39-56. gs

Thomsen, E. (1987). Lower Cretaceous calcareous nannofossil biostratigraphy in the Danish Central Trough. Danmarks Geologiske Undersøgelse. 20: 1-89. gs

Wise, S. W. & Wind, F. H. (1977). Mesozoic and Cenozoic calcareous nannofossils recovered by DSDP Leg 36 drilling on the Falkland Plateau, south-west Atlantic sector of the Southern Ocean. Initial Reports of the Deep Sea Drilling Project. 36(269-491): -. gs O

Wise, S. W. (1983). Mesozoic and Cenozoic calcareous nannofossils recovered by DSDP Leg 71 in the Falkland Plateau region, Southwest Atlantic Ocean. Initial Reports of the Deep Sea Drilling Project. 71: 481-550. gs O

Retecapsa angustiforata

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