2. Proceratopyge conifrons (Wallerius), 3. Peronopsis insignis, 4. Lejopyge laevigata,
5. Hypagnostus parvifrons and 6. Hypagnostus sulifer.
Middle and basal upper Cambrian
Gudhem, Västergötland, Sweden
Width of pygidium on Proceratopyge conifrons 11 mm