Wanneria

Like all other members of the Olenelloidea superfamily, the eye-ridges spring from the back of the frontal lobe (L4) of the central area of the cephalon, that is called glabella.

The dorsal exoskeleton of Wanneria has an inverted egg shaped outline, approximately 1½ times longer than wide, ignoring the pleural spines, and is at its widest at the back of the cephalon.

The horizontal outline of the head (or cephalon) is semi-circular with the back (or posterior margin) perpendicular to the midline or somewhat arching backwards.

The rim of the cephalon is extended into backward pointing genal spines, that reach back to approximately the 4th thorax segment.

[1] Wanneria is close to the common ancestor of the Holmiidae, and of the clade comprising Fritzolenellus, Mummaspis, Laudonia, the Biceratopsinae and the Bristoliinae.