Catalog - Lipsonia Catalog - Lipsonia

CATALOG OF ORIGINAL DESCRIPTIONS: Lipsonia Georgescu & Abramovich, 2008

This page provides data from the catalog of type descriptions. The catalog is sorted alphabetically. Use the current identification link to go back to the main database.


Higher levels: pf_cat -> L -> Lipsonia
Other pages this level: Laeviella, Laeviheterohelix, Lazarusina, Leupoldina, Lilliputianella, Lilliputianelloides, Lipsonia, Liuella, Liuenella, Loeblichella, Lunatriella

Lipsonia lipsonae Georgescu&Abramovich 2008

Lipsonia

Citation: Lipsonia Georgescu & Abramovich, 2008
taxonomic rank: Genus
Type age (chronostrat): Equatorial Central Pacific (Shatsky Rise), western United States (California) and northwestern Mexico (Baja California).
Type locality: Upper Maastrichtian, namely the upper part of the Pseudoguembelina hariaensis Biozone as defined by Robaszynski & Caron (1995).

Current identification:


Original Description

Type species. Lipsonia lipsonae nov. sp.
Diagnosis. Multiserial  planktic  foraminifer  with raised sutures throughout and  coarse  irregular  ornamentation of  the  earlier part  of the test and smooth  in the portion  with the last-formed chamberlet  sets.
Description. Test  is  flabelliform  in  shape,  with  a  very  short biserial stage followed by a well-developed multiserial one consisting of up to ten chamberlet  sets following the progressive chamber. Chambers are semicircular to subcircular,  bordered  by raised sutures  throughout. The  test  has  quasi-parallel  sides in edge view and distinct  thickening  in the earlier part due to the addition of successive layers of calcite. Aperture  is multiple  in the adult stage, with circular to ovate transverse walls. Ornamentation consists of coarse  and  irregular  structures  on  the earlier  part  of the  test;  the  last-formed  chambers  are  smooth. Test wall is calcareous,  hyaline, with variable  porosity,  macroperforate  with vuggy pores in the earlier part and microperforate to finely perforate in the adult.


Etymology:
Genus named in honour of Dr S. Lipson-Benitah (Geological Survey of Israel) for her outstanding contribution to knowledge of Cretaceous planktic foraminifera.

Extra details from original publication

Remarks. Only  two  Cretaceous   serial  planktic  foraminiferal genera  present  raised  sutures:  Sigalia  and  Lipsonia  nov.  Although   the  two  are  nearly  homeomorphs,  they  differ  in  a number of features, such as: (i) the multiserial stage is better developed  in Lipsonia  (up  to  ten  chamberlet  sets) when  compared  to Sigalia (maximum  six chamberlet  sets); (ii) test ornamentation in Lipsonia is completely  devoid  of costae,  whereas fine costae are present in all species of Sigalia; (iii) the thickened early part of the test differs sharply in the two genera: it is completely  irregular  in  Lipsonia  and  with  a  radial  pattern  in Sigalia. The finely costate  surface and raised sutures  of Sigalia suggest that the origin of this genus should be most likely in the costate contemporaneous Heterohelix sphenoides Masters,  1976, as suggested by Nederbragt (1991). The complete absence of costate  ornamentation rules out a costate  ancestor  for Lipsonia (Fig. 2). The two genera are separated  by a significant time gap, which encompasses the Campanian–Lower Maastrichtian stratigraphical interval (approximately 17 Ma). This gap is calculated from the last occurrence of Sigalia (Santonian, top of the Dicarinella asymetrica Biozone) to the first evolutionary occurrence of Lipsonia lipsonae (Upper  Maastrichtian,  Pseudoguem- belina hariaensis Biozone). Accordingly,  it can be inferred  that the two genera apparently evolved as the result of iterative evolution. The raised sutures are distinctive for Lipsonia when compared with Ventilabrella. There are significant differences between the smooth Lipsonia and strongly ornamented Planoglobulina, the latter  presenting  either strong  longitudinal  costae or   small-sized   structures    arranged    following   a   vermicular pattern

Species included. The genus is so far monospecific.

Phylogenetic relationships. The origins of Lipsonia nov. gen. are unknown. The absence of the costate  ornamentation suggests a possible ancestry among the non-ornamented Laeviheterohelix species, such as L. glabrans (Cushman, 1938) and L. dentata (Stenestad,  1968). However,  these two species have compressed tests  and,  for  this  reason,   cannot   be  considered   among  the potential  direct ancestors  of Lipsonia.

References:

Georgescu, M. D. & Abramovich, S. (2008a). A new serial Cretaceous planktic foraminifer (Family Heterohelicidae Cushman, 1927) from the Upper Maastrichtian of the equatorial Central Pacific. Journal of Micropalaeontology. 27: 117-123. gs


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Lipsonia compiled by the pforams@mikrotax project team viewed: 12-11-2024

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