Isotelus is a genus of asaphidtrilobites from the Middle and Late 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, and was probably exceeded in size only by Hungioides bohemicus, in which the specimens probably exceeding Isotelus rex in size are only known from partial remains.[1]
A specimen of Isotelus rex, from Churchill, Manitoba, is the largest complete trilobite ever found. Discovered by Dave Rudkin (Royal Ontario Museum), Robert Elias (University of Manitoba), Graham Young (Manitoba Museum) and Edward Dobrzanske (Manitoba Museum) in 1999, it measures Шаблон:Convert in length, Шаблон:Convert in maximum width (across the cephalon) and Шаблон:Convert in maximum height (at the posterior midpoint of the cephalon).[2][3][4]
A number of species have been described:
I. aktchokensis Weber, 1948
I. bradleyi Amati, 2014
I. copenhagenensis Ross, Jr. & Shaw 1972
I. frognoensis Owen, 1981
I. gigas Dekay, 1824
I. harrisi Raymond, 1905 (synonym I. platymarginatus Raymond, 1910)
I. iowensis Owen, 1852
I. kimmswickensis Bradley, 1930
I. maximus Locke, 1838
I. megistos Locke, 1842
I. parvirugosus Chatterton & Ludvigsen, 1976
I. skapaneidos Amati, 2014
I. susae Whitfield, 1882
I. violaensis Amati, 2014
I. walcotti Walcott, 1918 (synonym I. planus De Mott, 1963)
