Nannotax3 - ntax_cenozoic - D. multiradiatus group Nannotax3 - ntax_cenozoic - D. multiradiatus group

D. multiradiatus group


Classification: ntax_cenozoic -> Discoasterales -> Discoasteraceae -> Discoaster -> D. multiradiatus group
Sister taxa: D. brouweri group, D. pentaradiatus group, D. quinqueramus group, D. variabilis group, D. exilis group, D. musicus group, D. deflandrei group ⟩⟨ D. nodifer group, D. lodoensis group, D. multiradiatus group, D. araneus group, D. sp.

Daughter taxa (time control age-window is: 0-800Ma)
no prominent boss
Discoaster delicatus
Thin, delicate discoaster with 30-50 rays joined along most of their length with simple ray tips.
Discoaster multiradiatus
Large to very large rosette-shaped discoasters; 16-35 rays joined along most of their length with simple ray tips.
Discoaster protomultiradiatus
Like D. multiradiatus but with birefringent central cycle
Discoaster lenticularis
Small to medium sized (4-10 µm) rosette-shaped discoasters with thickened central area; 20-26 rays joined along their length with simple, blunt ray tips.
Discoaster wemmelensis
Small (4-6 µm), rosette-shaped discoaster with raised central area; 20-30 rays joined along most of their length with simple ray tips.
Discoaster mohleri
Medium sized rosette-shaped discoasters; 9-16 rays joined along most of their length with simple broad ray tips.
Discoaster nobilis
7-13 tapering rays with simple rounded tips that radiate with little free length from a large circular central area.
prominent boss on one side
Discoaster salisburgensis
Large to very large rosette-shaped discoasters with a prominent boss on one side only; 12-24 rays joined along most of their length with simple ray tips.
Discoaster barbadiensis
Rosette-shaped discoaster with short narrow stem on one side; 9-13 rays joined along most of their length and which taper sharply to a simple pointed ray tip;
Discoaster spinescens
Rosette-shaped discoaster, bearing a tall, thin spine on one side; ca 12 rays, joined along most of their length with triangular terminations, .
Discoaster kuepperi
Medium sized rosette-shaped discoasters with very large flaring boss on one side; 8-12 rays joined along most of their length with simple ray tips.
Discoaster splendidus
Flower shaped rosette discoaster with broad, flat, raised central area boss; 13-14 rays joined along ⅓-½ length and with broad rounded tips.
prominent boss on both sides
Discoaster diastypus
Large to very large rosette-shaped discoasters with prominent bosses on both sides; 9-16 rays joined along 1/2-2/3 length &typically curved.
Discoaster bifax
Small to medium sized rosette-shaped discoaster with a narrow stem on one side and flared boss on the other; ca.14 rays with simple tips

Taxonomy:

Citation: Discoaster multiradiatus group - informal grouping
Rank: species group

Distinguishing features:
Parent taxon (Discoaster): Radiate nannoliths with each ray formed of a discrete crystal-unit, with the c-axes perpendicular to the nannolith surface.
This taxon: Rosette shaped discoasters with little or no free rays (<1/3 length); typically >10 rays

Farinacci & Howe catalog pages:

Search data:
Lith size: 4->22µm;
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): at top of NP19-20 zone (100% up, 34.4Ma, in Priabonian stage). Data source: Total of ranges of the species in this database
First occurrence (base): within NP7 zone (58.7-58.97Ma, base in Thanetian stage). Data source: Total of ranges of species in this database

Plot of occurrence data:

References:


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D. multiradiatus group compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 2-12-2023

Taxon Search:
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Short stables page link: https://mikrotax.org/Nannotax3/index.php?id=421 Go to Archive.is to create a permanent copy of this page - citation notes



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