Sb element of Phragmodus undatus
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- Estimated Age: about 450 million years old.
- Comments: Scale Bar is 0.5 mm. Dayton Area,
Ordovician Silurian Boundary -- teaching materials courtesy of Jeff
Bauer. Sb element of Phragmodus undatus. Lateral costae assymetrically
disposed; cusp and element twisted. Photo BN1A05M04 was taken with
the big microscope, and shows the cross-section shape of the cusp and costae.
The oral costa actually corresponds to point A, and the aboral costa
to point B. The same picture was taken again as a mosaic for
BN1A05M05, and rotated downward for BN1A05M06 to show the cross section
of the large denticle. BN1A05M07 was painted with water color China
White. This non-trasparent color did not wsh off completely, and was
an unfortunate choice. Depth-of-field distortion ruins stereoscopic
image from large microscope where were assembled from mosaic images.
BN1A05M08 uses Windsor Blue as color which has the disadvantage of being
rather granular and glittery.
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