Age: Upper Ordovician (460.9 million years ago - 443.7 million years ago)
Location: Ontario, Canada
Isotelus is a genus of asaphid trilobites from the middle and upper Ordovician period, fairly common in the Northeastern United States, northwest Manitoba, southwestern Quebec and southeastern Ontario. One species, Isotelus rex, is currently the world's largest trilobite ever found as a complete fossil. Isotellus also happens to be Ohio’s state fossil.