Order Phacopida, Family Acastidae
Time: Lower Devonian, Upper Emsian Age
is 62 mm long (curve measure) by 38 mm wide (including spines) on a 75
mm by 90 mm matrix
Tazoulait Formation, Jebel Ofaten, Morocco
Elegant example of an unusual trilobite termed “sail-spined”
by some due to the dramatic row of axial spines found in this species.
These spines were a good defense against the fish of their day, affording
quite a mouthful for any predator with the temerity to attack. With
the advent of a reliable source of electricity in Morocco, the quality
of preparation has improved dramatically over the past few years.
This one took a great deal of effort to prepare the many, many spines
free of matrix, a task that took some FIFTY hours to complete. The
matrix is quite hard, necessitating a steady hand and a good microscope
to expose the eye-catching specimen seen here. What is unusual about
this one is the interesting bicolored preservation. At some point
during diagenesis the chemistry of the groundwater changed result=in
in the yellow coloration to the anterior half of the specimen, changing
the color from the typical black to a yellow beige cast. This specimen
is truly stunning when viewed from any aspect, and is destined to
become the cornerstone of any collection, public or private.
click to enlarge