Conusphaera mexicana mexicana
Set number: 2948
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Set number: 2947
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Set number: 2946
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Set number: 2953
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Conusphaera mexicana mexicana Trejo, 1969
The large, truncated‑cone‑shaped species of Conusphaera is most commonly observed in side view because of its height‑to‑width ratio. The core segments are arranged axially and enclosed by a protolith wall. In plan view, the species appears subcircular.
Core segments in both side and plan views commonly display first‑order whitish‑yellow interference colours under crossed polars.
Conusphaera mexicana mexicana differs from Conusphaera rothii rothii in possessing straight axial core segments, in contrast to the distinctly spiralled arrangement characteristic of the latter.
Trejo, M. 1969. Conusphaera mexicana, un nuevo coccolitoforido del Jurassico Superior de Mexico. Revista del Instituto Mexicano del Petroleo 1: 5-15.
Holotype
Conusphaera mexicana
Trejo, 1969
Late Tithonian
Paciencia-101 Well, State of Veracruz, Mexico.