Agraulos


Agraulos is a genus of trilobite that lived during the Middle Cambrian in North America and Europe, particularly the Czech Republic. A. ceticephalus grew to approximately.

Etymology

Agraulos is derived from the Greek Ἄγραυλος, "country woman", wife of Kekrops.

Distribution

The exoskeleton of Agraulos is approximately inverted egg-shaped, about 1½× longer than wide, with the maximal width across the tips of the genal spines. The headshield is ⅜ of the total body length and is approximately semicircular although almost flat on the front and with two short spines pointing backward and about 35° outward. The central raised area of the cephalon tapers forward, is truncated at its front, weakly defined, and about ⅔× the length of the cephalon. Most specimens are found without the free cheeks. As in all trilobites, the natural fracture lines that aided in molting follow the inside of the visual surface of the eye, and from the back of the eye cut to the back of the cephalon with a gentle curve outwards and increasingly more backward. From the front of the eye the suture curves initially forward and eventually fully inward, coinciding with the frontal margin. This makes the remaining so-called cranidium weakly clock-shaped. The eyes are about ¼× as long as the glabella with its front aligned with the front of the glabella. Eyes, border furrow and furrows crossing the glabella are almost fully effaced. The articulate middle part of the body has 16 segments and the axis is about the same width as the ribs to its right and left, and these have rounded tips. The tailshield is very small, rectangular, about 15% of the width of the frontal segment of the thorax, 3½× wider than long, and the axis reaching slightly beyond the pleural fields.