|Daughter taxa (time control age-window is: 0-800Ma)|
Very large (>12 µm) Chiasmolithus with simple diagonal cross bars that may be slightly rotated from diagonal.
Medium to large Chiasmolithus with narrow centro-distal cycle and simple, narrow diagonal cross bars.
Small to moderate Chiasmolithus with diagonal cross formed from two curving and two straight bars; two of the bars are offset. High degree of variability reported.
Medium to small Chiasmolithus with narrow central area spanned by narrow diagonal bars (two curving and two relatively straight).
Medium to small Chiasmolithus with narrow central area spanned by one straight diagonal cross bar and one that is strongly bent/hooked.
Distinguishing features: Upper-tube cycle weakly developed; cross bars with simple construction, no median exinction line
Farinacci & Howe catalog pages: Sullivania *
Morphology: The distal shield is normally wide and the upper tube elements are weakly developed, in some specimens the distal shield can be traced into the central area and usually the distal surface slopes into the central opening.
|Metrics||Lith size: 5->17µm;|
Last occurrence (top): in lower part of Rupelian Stage (17% up, 32.9Ma, in Rupelian stage). Data source: Total of range of species in this database
First occurrence (base): in lower part of Danian Stage (28% up, 64.8Ma, in Danian stage). Data source: Total of range of species in this database
Plot of occurrence data:
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=164 Go to Archive.is to create a permanent copy of this page - citation notes