Beitrag
Orbitolinella depressa Henson, 1948: A porcelaneous, not an agglutinated larger benthic foraminifer
Schlagintweit, Felix; Consorti, Lorenzo; Piuz, André
Palaeontographica Abteilung A Band 331 Lieferung 1-3 (2025), p. 39 - 48
47 Literaturangaben
veröffentlicht: Jul 29, 2025
Online veröffentlicht: Jul 10, 2025
Manuskript akzeptiert: Jul 8, 2025
Manuskript erhalten: May 26, 2025
DOI: 10.1127/pala/0167
Abstract
The larger foraminifer Orbitolinella depressa Henson, 1948 is currently treated as an agglutinated member of the family Orbitolinidae (subfamily Dictyoconinae) although placed into the Peneroplidae with “calcareous-porcellaneous wall” by Henson (1950). Based on new observations in thin sections provided here, a possible assignment to the Praerhapydioninidae is proposed, thus re-instating the taxon within the porcelaneous group. Orbitolinella represents an orbitoliniform isomorph displaying conical test morphology with a complex inner structure. Likewise, typical test features of agglutinated taxa such as bi-/triseriality (genera Tarburina Schlagintweit et al. or Serrakielina Schlagintweit & Rashidi) or the occurrence of an exoskeleton (genus Reticulotaberina Nafarieh et al. or Praetaberina Consorti et al.) have also been evidenced from porcelaneous taxa. A lectotype of Orbitolinella is herein designated from the original illustrations, namely an axial section of a syntype as no holotype was selected by Henson. The genus Birbalina Sahni & Sastri, 1957 is considered a junior synonym of Orbitolinella O. depressa is paleogeographically restricted to the Arabian Plate (SW Iran, Iraq, Qatar, Oman) and India (Eastern Bhutan). Our own and literature data suggest a late early to early late Cenomanian age for the strata containing O. depressa.
Schlagworte
Larger benthic foraminifera • Wall structure • Taxonomy • Upper Cretaceous