Phacopid Trilobite with Most Unusual Color Preservation

Description: This is a most unusual trilobite. Notice the pleasing café au lait color, and the regular darkened spots to the exoskeleton. These markings have been interpreted as the positions of internal muscle attachments. The current hypothesis is that the dark spots are actually preserved melanophores which could expand and contract, allowing the trilobite to change color as it moved about the seafloor surface much like the extant Plaice and Sole. These colors are of natural, rather than diagenic origin. The specimens were initially collected from a site on the border with Pennsylvania several decades ago, and to my knowledge specimens such as these have not been offered commercially until recently. This fine partially enrolled example is self-displayed on a matrix pedestal which has a flattened base. The pygidium is present but not attached. See my other offerings for enrolled examples.

For another example, see:
Thomas E. Whiteley et al, Trilobites of New York, Plate 103.
References: Paleontology Vol. 11, Part 4, 1968 pp 498-9
Geology, 05/2013; 41(5): pp 607-61