Amphilichas shideleri

Classification
Phylum: Arthropoda
Class: Trilobita
Order: Lichida
Family: Lichidae
Genus: Amphilichas
Species: Amphilichas shideleri (Foerste, 1920)

Stratigraphic OccurrencesA.shideleri_strat

Geographic Occurrences

Map point data provided by iDigBio.

Stratigraphic Description

Sequences (Formations)

  • C5 Sequence (Lower Whitewater, Liberty)

Identification in Hand Sample

  • General outline is falcate.
  • Anterior part of outer margin of both fragments the curvature is concave.
  • Outer margin is coarsely striated.

Amphilichas shideleri from the McMillan Formation of Georgetown, Ohio (glabella on right, OUIP 646)

Published Description

Foerste (1919):

  • Two fragments, both interpreted as right free cheeks of some Lichad. The general outline is falcate, but along the anterior part of the outer margin of both fragments, the curvature is concave. Along its entire length, this outer margin is coarsely striated, the width of the striated border varying from 2 mm. near the posterior end of the free cheek to about 5 mm. along its concave curvature. Posteriorly, these striae are directed diagonally outward and backward. Along the concavely curved part, the striae bend up and down in an evenly concave manner. The remainder of the free cheek, in each specimen, is coarsely papillated, the apex of many of the papillae droop diagonally downward in a sort of “tear-drop” manner. The inner margin of the tip of the free cheeks shows coarse striae, similar to those along the outer border, but diverging only slightly from this inner margin in direction; these striae can be seen only along the posterior part of the inner margin, within 4 mm. from the tip of the free cheek. In one of these two fragments, the lower surface of the free cheek was freed from the matrix. This surface is coarsely striated with anastomosing lines, and at its proximal end, it shows the inner limit of the test on the lower side of the free cheek. In removing the matrix, the anterior end of the free cheek, with its concave outer margin, was broken off.