Daughter taxa (time control age-window is: 0-800Ma)![]() | ||||
![]() | ![]() | ![]() | Youngilithus arcaeformis Polygonal, medium-sized, non-birefringent holococcolith with a narrow rim spanned by diagonal cross-bars. The rim is coffin-shaped (like a diamond with flattened ends) and usually shows small marginal projections. | |
Youngilithus bipons Rhomboid liths with small, marginal projections from the rim and two oblique, parallel, central area bars. Low birefringence image in XPL. | ||||
![]() | ![]() | ![]() | ![]() | Youngilithus oblongatus A rectangular, medium-sized, non-birefringent holococcolith with lateral rim projections. The sides of the rectangle are formed from narrow crystallographically distinct units, and some specimens have an internal transverse bar. |
![]() | ![]() | ![]() | ![]() | Youngilithus pyxis A rectangular to square, box-like holococcolith constructed from four crystallographically distinct units, with at least two protrusions on each side. |
![]() | Youngilithus quadraeformis Square, medium-sized, non-birefringent holoccolith with a narrow rim with small marginal projections, spanned by cross bars parallel with the sides. | |||
Youngilithus transversipons Elongate rhomboid liths with three oblique, parallel, central area bars. Low birefringence image in XPL. | ||||
Youngilithus sp. Specimens which cannot be assigned to any established species |
Taxonomy:
Distinguishing features: Geometrically shaped non-birefringent holococcoliths typically possessing lateral rim spines and central area bars.
Farinacci & Howe catalog pages: Youngilithus *
Search data:Tags | LITHS: holococcolith, hollow, CROSS-POLARS: V-prominent, |
Metrics | Lith size: 3->8µm; |
Geological Range:
Last occurrence (top): in lower part of Bartonian Stage (22% up, 40.4Ma, in Bartonian stage). Data source: Total of range of species in this database
First occurrence (base): at base of Selandian Stage (4% up, 61.5Ma, in Selandian stage). Data source: Total of range of species in this database
Plot of occurrence data:
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Youngilithus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 9-3-2021
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=1502 Go to Archive.is to create a permanent copy of this page - citation notes |