Taxon Concept provided by
  Home |   Search
 
   TaxonConcept data set details:
 
 
Back to Search
Anonymous: Unedited TaxonConcept data
Notice: This catalogue page may contain unedited data.

Species Hedbergella rischi Moullade 1974


Discussion / Comments:
Bellier & Moullade (2002):
Initially fully described and illustrated, hut left in open nomenclature under the name "Hedbergella (Hedbergella) sp., aft. infracretacea'" (Moullade, 1966), this biostratigraphically significant middle Albian morphotype was subsequently formerly named (Moullade, 1974) within a short note referring to the description of 1966. This two-step process probably explains why Hedbergella rischi was not included in the usual planktonic foraminiferal handbooks (Caton, 1985; BouDagher-Fadel et al., 1997), and is rarely mentioned (Br6h6ret et al., 1986; Sigal, 1987; Premoli Silva and Sliter, 1995). Hedbergella rischi, typically a 5 to 6-chambered species, evolved from the P. infracretacea-like morphogroup in the middle Albian and differs mainly from the latter by a slightly faster increase of the spire height and thus size of the last chambers, and by a slightly more open umbilicus. In the upper Albian, some evolved 6.5 1o 7-chambered specimens of H. rischi show progressive morphological similarities with Ticinella primula LUTERBACHER, 1963, but are still devoid of sutural accessory apertures. As ill the Vocontian material (Moullade, 1966), samples from Holes 1050C and 1052E provide all the intermediate morphological stages between the two taxa; this gradational evolution can be interpreted as evidence of their phylogenetic relationship. Hedbergella yezoana TMCa_YANAGI and IWAMOTO, 1962 (nora. transl. ; initially described from the upper Albian of Japan as lledbergella trocoidea (GANDOLFI) subsp, yezoana) differs from typical H. rischi by having 7 to 8 chambers, instead of 5 to 6. Morphologically H. yezoana resembles also T. primuht but on the basis of its initial description appears to be devoid of accessory apertures. This species was not identified within our material and might be endemic to Japan.
Synonym list:
Moullade et al. (2002):
1966 Hedbergella (Hedbergella) sp. aff. infracretacea Glaessner. - Moullade : 89, 90 pl 8 figs 6-16
1969 Hedbergella (Hedbergella) aff. infracretacea Glaessner. - Risch : p.102 pl 8 figs 4-6
1974 Hedbergella rischi Moullade. - Moullade : p.1816
Bellier & Moullade (2002):
1966 Hedbergella (Hedbergella) sp. aff. infracretacea Glaessner. - Moullade : 89-90 pl. 8; fig. 6-16
1969 Hedbergella (Hedbergella) aff. infracretacea Glaessner. - Risch : p.102 pl. 8; fig. 4-6
1974 Hedbergella n sp. rischi Moullade. - Moullade : p.1816
non 1984 Hedbergella cf. rischi Moullade. - Leckie : p.599 pl. 7; fig. 11-12
2002 Hedbergella rischi Moullade. - Bellier & Moullade : p.21 pl. 1; fig. 1-6
References:

Moullade,M. (1966):
Etude stratigraphique et micropaléontologique du Crétacé inférieur de la "fosse vocontienne" . Documents des Laboratoires de Géologie de la Faculté des Sciences de Lyon Vol. 15 p. 1-369

Risch,H. (1969):
Stratigraphie der höheren Unterkreide der bayerischen Kalkalpen mit Hilfe von Mikrofossilien. Dissertation. p. 180

Moullade,M. (1974):
Zones de Foraminifères du Crétacé inférieur mésogéen . Comptes Rendus de l’Académie des Sciences, Paris (Série D) Vol. 278 p. 1813–1816

Leckie,M.R. (1984):
Mid-Cretaceous planktonic foraminiferal biostratigraphy off Morocco, Deep Sea Drilling Project Leg 79, Sites 545 and 547 . Initial Reports of the Deep Sea Drilling Project Vol. 79 p. 579–620

Bellier,J.P. and Moullade,M. (2002):
Lower Cretaceous Planktonik Foraminiferal Biostratigraphy Of The Western North Atlantic (ODP LEG 171B), And Taxonomic Clarification Of Key Index Species . Revue de Micropaleontologie Vol. 45(1) p. 9-26

Moullade,M.; Bellier,J.P. and Tronchetti,G. (2002):
Hierarchy of criteria, evolutionary processes and taxonomic simplification in the classification of Lower Cretaceous planktonic foraminifera . Cretaceous Research Vol. 23 p. 111-148
Anonymous: Unedited TaxonConcept data
Creative Commons Attribution 2.5 License
This work is licensed under a Creative Commons Attribution 2.5 License.
Back to Search
Taxon relations
pdf
Ranking (experimental)