Dictyocephalus middouri


Classification: rads_cenozoic -> Theoperidae -> Theoperidae inc sed -> Dictyocephalus middouri
Sister taxa: Anthocorys, Anthocyrtella, Aphetocyrtis, Cassideus, Conarachnium, Cyrtolagena, D. middouri, Dictyopodium, Diplocyclas, Eurystomoskevos, Lithapium, Lithomitrissa, Lophoconus, Lophocorys, Phrenocodon, Sethochytris, Sethoconus, Stichocampe, Theocorys, Udan

Taxonomy

Citation: Dictyocephalus middouri Nishimura 1992
Rank: species
Basionym: Dictyocephalus middouri
Taxonomic discussion: Dictyocephalus Ehrenberg is a lophophaenid (Plagiacanthidae), thus genus assignment by Nishimura incorrect. Multisegment, small simple cephalis indicates Theoperidae but wings/feet and segment shape are unusual combination, correct genus is unclear-dbl 20.8.20.

Catalog entries: Dictyocephalus middouri

Original description: Shell of four or more segments, the first three segments conical; first segment hemispherical, porous, with cylindrical apical horn. Collar stricture with four collar pores internally, moderately expressed externally. Cephalic structure has A, V, two L, and D; V rises obliquely upwards. Two l included in septal ring. Second and third segments with subcircular pores similar in size and arrangement. Three cylindrical ribs from the junction of first and second segments extend as solid lateral wings. Fourth or subsequent segments subcylindrical with pores that are quite irregular in size and arrangement and distal margin ragged.

(Based on 15 specimens) Overall height 90-170 µ, height of cephalis and thorax 48-70 µ, maximum width of thorax 55-83 µ and of cephalis 26-33 µ. Distinguishing characters (rw): This species is distinguished from Pterocyrtidium genriettae, n. sp., by the first three segments forming a conical section, not the first two segments.

Description

Biogeography and Palaeobiology

Biostratigraphic distribution

Geological Range:
Last occurrence (top): within Paleogene Period (23.03-66.04Ma, top in Chattian stage). Data source: Lazarus et al. 2015 - "P age group"
First occurrence (base): within Paleogene Period (23.03-66.04Ma, base in Danian stage). Data source: Lazarus et al. 2015 - "P age group"

Plot of occurrence data:

References:

Nishimura, A. (1992). Paleocene radiolarian biostratigraphy in the northeast Atlantic at Site 384, Leg 43, of the Deep Sea Drilling Project. Micropaleontology. 38(4): 317-362. gs


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Dictyocephalus middouri compiled by the radiolaria@mikrotax project team viewed: 21-4-2021

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Short stable page link: https://mikrotax.org/radiolaria/index.php?id=203866 Go to Archive.is to create a permanent copy of this page - citation notes



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