A revision of the foraminiferalsubfamily Heterostegininae.

• F.T. Banner ^[1] ; R.L. Hodgkinson ^[1]
  1. [1] Micropalaeontology Section, Palaeontology Department, British Museum (Natural History), London, UK
• Localización: Revista española de micropaleontología, ISSN 0556-655X, Vol. 23, Nº. 2, 1991, págs. 101-140
• Idioma: inglés
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• Resumen

  • Within the subfamily Heterostegininae (Family Nummulitidae), defined on its possession of secondary septa, the genus Heterostegina d’Orbigny is emended following the proposal of a topotypic neotype for its type-species, H.depressa d’Orbigny. The subgenus H. (Vlerkina) Eames et al. is also emended following description of a new lectotype for its type-species, H. (V.) borneensis van der Vlerk. The genus Planostegina nov. (type-species H. costata d’Orbigny) is wholly evolute and evolved from Operculina in the Palaeocene. Heterostegina sensu stricto is maturo-evolute and had arisen by the Late Eocene. H. (Vlerkina) was wholly involute, had well developed lateral chamberlets, and ranged from Late Eocene to Early Miocene. Of similar range, Tansinhokella nov. (type-species Spiroclypeus yabei van der Vlerk) was also wholly involute, with strong lateral chamberlets, and had overlapping and embracing alar prolongations of its chambers (it was the ancestor to cubicula-bearing true Spiroclypeus).

    A topotypic neotype is proposed and described for H. (V.) pleurocentralis (Carter), and lectotypes are selected and described for H. (H.) suborbicularis d’Orbigny and T. yabei (van der Vlerk). The new species T. tatauensis is described from the Late Eocene.

    The biological functions and the reasons for the evolutionary development of Heterostegine skeletal structure are suggested.