Huntoniatonia
Huntoniatonia is a genus of trilobites, extinct marine arthropods that lived in the Lochkovian stage of the Early Devonian. They could grow up to about 15 cm long.
Like other trilobites in their group, Huntoniatonia had large eyes with many calcite lenses arranged in vertical rows, a feature known as schizochroal eyes. The eyes were half-circle shaped and located just behind the front part of the head.
The head (cephalon) had a broad, flat front edge that extended forward a bit, resembling a dolphin. The central raised area (glabella) had a wide, forward-extending section, and the eyes began just behind the frontal lobe and ended near the occipital ring.
Head sutures ran from behind the eyes to the edge of the head, creating free cheeks (librigenae).
The body’s middle section (thorax) had 11 segments, with stout genal spines curving backward toward the seventh segment.
The tail shield (pygidium) had 12–13 rings, and the central axis extended into a spine with about 10 ribs that did not reach the edge. The overall margin of the pygidium was smooth.
Huntoniatonia may represent a transitional form between Silurian Dalmanites and Devonian Odontochile.
The genus was renamed from Huntonia to Huntoniatonia in 2003 because the name Huntonia was already used for another animal (an isopod).
Species include H. huntonensis, H. oklahomae, H. lingulifer, H. purduei, and H. xylabium.
This page was last edited on 2 February 2026, at 16:46 (CET).