Pappomonas Coccolith distal rim serrated - elements pentagonal; Coccosphere polymorphic, processes on only some coccoliths. Calices with 2-fold symmetry BCs without axial spine or node
Papposphaera Coccolith distal rim serrated - elements pentagonal; Coccosphere monomorphic, varimorphic, or dimorphic, calices with 4-fold (or, rarely, 3-fold) symmetry
Vexillarius Coccoliths narrow-rimmed muroliths; equatorial coccoliths with quadrate central process supported by transverse bar. Coccosphere dimorphic, equatorial coccoliths distinctive, BCs simple muroliths
Citation: Papposphaeraceae Jordan & Young, 1990 emend Andruleit & Young 2010Rank: FamilySynonyms: The group is sometimes informally refered to as "lightly-calcified coccolithophores". Taxonomic discussion: The Papposphaeraceae as originally described only included the genera Papposphaera and Pappomonas. Subsequently Andruleit & Young (2010) extended the family to include the narrow-rimmed muroliths group of Young et al. (2003)- i.e. the genera Kataspinifera, Picarola, Vexilarius and Wigwamma. Additional genera have since been described by Thomsen and co-workers - Formonsella, Porsilidia, and Ventimolina as well as the heterococcolith stage of Quaternariella. NB Some online databases suggest that the Papposphaeraceae should be considered a junior synonym of the Deflandriaceae (= Prediscosphaeraceae). As discussed by Jordan & Young (1990), this is an outdated suggestion made by Norris (1983) based on superficial similarities between Papposphaera and the Cretaceous genus Prediscosphaera.
Distinguishing features: Parent taxon (Coccolith families inc sed): 2N: Various heterococcolith groups not obviously related to the well-defined orders
N: mostly unknown This taxon: Narrow-rimmed muroliths, mostly with prominent central structures.
Morphology: As noted by Andruleit & Young (2010) five morphological features characterise this group
The coccoliths have simple narrow murolith rims, i.e. they have a narrow sub-vertical outer wall without flanges. In Pappomonas and Papposphaera the rim has a serrated upper margin whilst it is smooth in the other genera.
Rim structure. Typically the majority of the rim is formed of a single cycle of directly abutting elements with sub-vertical sutures. In addition a second cycle of elements occurs proximally, with one of these interposed elements between each of the larger elements.
Central area structure. Most species show either an axial cross or an axial cross plus additional elements.
Spine structure. The different genera have distinctly different central processes. In each case though these are hollow structures with quadrate cross-section.
Size. All these genera are characterized by production of small coccospheres (c. 5 µm excluding spines) and minute coccoliths (coccolith length typically 1–2 µm)
Ecology & Biogeography: These occur predominantly in the Arctic and Antarctic and in the deep photic zone at lower latitudes. Chloroplasts have not been observed in these taxa and they have well-developed haptonemata, so they are thought to be heterotrophic (Thomsen & Ostergaard 2015). Biology & life-cycles: Several species of Papposphaera and Pappomonas are known to have holococcolith stages from obsevations of combination coccospheres (e.g Thomsen et al. 1991). No species have been cultured succesfully. Phylogenetic relations: No molecular genetic data is available for this group. However, the fact that they form both typical holococcoliths and typical heterococcoliths in alternate life-cycle stages, strongly suggests they fall within the clade of holococcolith producing coccolithophores (Young et al. 2005, Andruleit & Young 2010).
The morphological data given here can be used on the advanced search page. See also these notes
Geological Range: Last occurrence (top): Extant Data source: Total of range of species in this database First occurrence (base): at base of Thanetian Stage (0% up, 59.2Ma, in Thanetian stage). Data source: Total of range of species in this database
Plot of occurrence data:
Range-bar - range as quoted above, pink interval top occurs in, green interval base occurs in.
Triangles indicate an event for which a precise placement has been suggested
Neptune data: this is a higher taxon page so Neptune data is not plotted. For the customisable plot option go to a genus page Parent: Coccolith families inc sed
References:
Andruleit, H. & Young, J. R. (2010). Kataspinifera baumannii: a new genus and species of deep photic coccolithophores resembling the non-calcifying haptophyte Chrysochromulina. Journal of Micropalaeontology. 29: 135-147. gsVO
Dunkley Jones, T., Bown, P. R. & Pearson, P. (2009). Exceptionally well preserved upper Eocene to lower Oligocene calcareous nannofossils (Prymnesiophycidae) from the Pande Formation (Kilwa Group), Tanzania. Journal of Systematic Palaeontology. 7(4): 359-411. gs
Jordan, R. W. & Young, J. R. (1990). Proposed changes to the classification system of living Coccolithophorids. INA Newsletter. 12(1): 15-18. gsVO
Norris, R. E. (1983). The family position of Papposphaera Tangen and Pappomonas Manton & Oates (Prymnesiophyceae) with records from the Indian Ocean. Phycologia. 22(2): 161-169. gs
Thomsen, H. A. & Ostergaard, J. B. (2015b). Coccolithophorids in Polar Waters: Trigonaspis spp. revisited. Acta Protozoologica. 54: 85-96. gsVO
Thomsen, H. A., Ostergaard, J. B. & Hansen, L. E. (1991). Heteromorphic life histories in Arctic coccolithophorids (Prymnesiophyceae). Journal of Phycology. 27: 634-642. gs
Young, J. R., Geisen, M. & Probert, I. (2005). A review of selected aspects of coccolithophore biology with implications for palaeobiodiversity estimation. Micropaleontology. 51(4): 267-288. gs
Papposphaeraceae compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 28-9-2021
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