Taxonomy Online - Carboniferous spores part I - Species details


Species name
Raistrickia condylosa Higgs, 1975

Description
Radial, trilete, acamerate, miospores. Amb circular-subcircular. Trilete mark distinct or obscured by ornament, sutures simple, straight, extending between half and two-thirds spore radius. Exine 1–3 µm thick, bearing prominent baculose ornament, which may be densely or sparsely distributed but reduced on the proximal surface. Elements with slender shaft, long, parallel sided, slightly curved; surmounted by rounded or more commonly bulbous termination. Pointed elements rare. Bases of individual elements normally discrete but may fuse laterally to form low ridges 1–3 µm in height. Elements 5–30 µm long, 1–4 µm in width, bases 3–7 µm in diameter and bulbous terminations up to 6 µm wide.

Other descriptions
Higgs, 1975, p. 396, pl. 2, figs. 15–16. Higgs, Clayton and Keegan, 1988, p. 56, pl. 4, figs. 15–16

Size
Equatorial diameter excluding projecting ornament 66(87)120 µm

Remarks
Raistrickia strumosa Playford 1976 has a similar style of ornament to R. condylosa but its elements are more robust and more densely distributed. Acanthotriletes halei Varma 1969 appears superficially similar but may be distinguished by possessing longer sutures and pointed ornamentation elements.

Range
Mississippian; Tournaisian; PC to CM biozones (unpublished information)

Images

MPK 7415 MPK 7415 Figure 38a
Cementstone Group, Bracken Bay, Heads of Ayr, Ayrshire, Scotland; Tournaisian, CM Biozone, Sample MPA 29832, Specimen MPK 7415. Subcircular trilete miospore, sutures obscured by dense baculate ornament. Bacula long slender with broad bases that are often confluent with adjacent elements. Terminations of bacula rounded or expanded and bulbous. Specimen maximum dimension 70 µm.


MPK 7416 MPK 7416 Figure 38b
Pinskey Gill Beds, Wygarth Gill Borehole, Ravenstonedale, Cumbria, England; Tournaisian, CM Biozone, Sample MPA 292, Specimen MPK 7416. Oblique compression showing absence of baculate ornament from contact areas. Baculate elements densely distributed, particularly in the equatorial region. Individual elements long, slender, sometimes bent with rounded or bulbous terminations. Specimen maximum dimension 73 µm.