Pappomonas


Classification: Coccolithophores -> Coccolith families inc sed -> Papposphaeraceae -> Pappomonas
Sister taxa: Balaniger, Formonsella, Kataspinifera, Pappomonas, Papposphaera, Picarola, Pocillithus, Pseudowigwamma, Quaternariella, Ventimolina, Vexillarius, Wigwamma,

Daughter taxa: (blue => in age window 0-800Ma)
Polar species
Similar to P. flabellifera but calyx blades nearly triangular, 5-9 rows of elements in BCs
Central area with concentric rings of crystallites;
CFC process ca. 2 µm high, with long stem supporting two blades.
BCs oval with 5 longitudinal bars and one crossbar CFCs circular with cross, stem supports two elements each with wing-like blades.
Central area with axial cross
CFC process ca. 2.0-2.5 µm high, with short stem supporting two large fan-like blades, one markedly larger than the other.
AACs have much reduced symmetrical central processes without a shaft and smaller distal appendages and may have baseplate calcification of 8 radial bars instead of 4.
Warm water species
Central area with two concentric rings and transverse bar; rim high;
CFC process ca. 2.5 µm high tipped by four short radiating rods.
Central area with axial cross and low central node
CFC process ca 3.5-5.0 µm high, long and slender with narrow conical calyx of four plates.
Central area with two concentric rings and transverse bar
CFC process ca. 2.5 µm high, straight without apical structure, additional ?CFCs have shorter spines (ca. 0.5 µm).
Central area with two concentric rings and transverse bar
CFC process 2.5- 3 µm high, slender square section curved rod without apical structure.
AACs, a few present with shorter rod.
Specimens which cannot be assigned to established species

Taxonomy:

Citation: Pappomonas Manton & Oates, 1975
Rank: Genus
Type species: Pappomonas flabellifera Manton & Oates 1975
Notes & discussion: Pappomonas was originally described as being dimorphic, with well-differentiated circum-flagellar coccoliths, whilst Papposphaera was described as  monomorphic. However, this distinction has broken down as varimorphic species have been recognised and species in which spines occur away from the circum-flagellar pole. the genera are now poorly separated and need revision (see e.g. Thomsen et al. 2016).

NB Pappomonas sp. type 2 of Cros & Fortuño, 2002 has now ben described, as Formonsella pyramidosa

Distinguishing features: Coccolith distal rim serrated - elements pentagonal;
Coccosphere polymorphic, processes on only some coccoliths. Calices with 2-fold symmetry
BCs without axial spine or node

Farinacci & Howe catalog pages: Pappomonas


Morphology remarks: Coccospheres polymorphic with up to three coccolith types:
  1. CFCs circular with prominent process.
  2. BCs elliptical without spines.
  3. AACs similar to CFCs with diminutive version of the process, not observed in all species
In all liths the outer rim elements have angular tops, forming serrated margin; central area and process structures vary between species.

Ecology & Biogeography: Best known from polar waters but diverse warm water species also occur (Cros & Fortuño 2002, Young et al. 2003) although most of them have not yet been formally described.

Biology & life-cycles: Combination coccospheres with Trigonaspis have been recognised in P. polybotrys and P. borealis (Thomsen et al. 1991, Thomsen & Ostergaard 2014, 2015)

See also: Trigonaspis - alternate life cycle phase of at least some species;

Search data:
TagsLITHS: murolith, elliptical, RIM: outer wall non-imbricate, rim-narrow, rim-top crenulate,
CSPH: oblate (broad), ovoid, spherical, CFC, CFC+process, polymorphic, DETAILS: ca_disjunct,
MetricsLith size: 0.5->1.5µm; Coccosphere size: 4->15µm;
Sources:
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Notes: NB We previously suggested on this website a range through to the Palaeogene but the fossil specimens on which this was based are now placed in a separate genus, Pocilithus [JRY 2016]
Last occurrence (top): Extant Data source: Total of range of species in this database
First occurrence (base): at top of No known fossil record modern (100% up, 0Ma, in stage). Data source: Total of range of species in this database

Plot of occurrence data:

References:

Manton, I. & Oates, K. (1975). Fine-structural observations on Papposphaera Tangen from the Southern Hemisphere and on Pappomonas gen. nov. from South Africa and Greenland. British Phycological Journal. 10(1): 93-109. gs

Thomsen, H. A. & Ostergaard, J. B. (2014b). Coccolithophorids in polar waters: Pappomonas spp. revisited. Acta Protozoologica. 53: 235-256. gs

Thomsen, H. A. & Ostergaard, J. B. (2015b). Coccolithophorids in Polar Waters: Trigonaspis spp. revisited. Acta Protozoologica. 54: 85-96. gs

Thomsen, H. A., Ostergaard, J. B. & Hansen, L. E. (1991). Heteromorphic life histories in Arctic coccolithophorids (Prymnesiophyceae). Journal of Phycology. 27: 634-642. gs

Thomsen, H. A., Heldal, M. & Ostergaard, J. B. (2016d). Coccolithophores in Polar Waters: Papposphaera sarion HET and HOL revisited. Micropaleontology. 61(6): 429-438. gs


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Pappomonas compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 6-12-2019

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Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=988 Go to Archive.is to create a permanent copy of this page - citation notes



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