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 720 millimetres (28 in) in length, 400 millimetres (16 in) in maximum width (across the cephalon) and 70 millimetres (3 in) 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)
^Gutiérrez-Marco, Juan C.; Sá, Artur A.; García-Bellido, Diego C.; Rábano, Isabel; Valério, Manuel (2009). "Giant trilobites and trilobite clusters from the Ordovician of Portugal". Geology. 37 (5): 443–446. Bibcode:2009Geo....37..443G. doi:10.1130/g25513a.1. ISSN 1943-2682.
^Rudkin, D.A.; Young, G.A.; Elias, R.J.; Dobrzanske, E.P. (2003). "The World's biggest Trilobite: Isotelus rex new species from the Upper Ordovician of northern Manitoba, Canada". Journal of Paleontology. 70 (1): 99–112. doi:10.1666/0022-3360(2003)077<0099:TWBTIR>2.0.CO;2. ISSN 0022-3360.
^S. M. Gon III (2005-08-17). "The World's Largest Trilobites".
^P. Z. Myers (2005-04-25). . Archived from the original on 2007-11-12.
^Babcock, L. E. (1996). "Chapter 8. Phylum Arthropoda, Class Trilobita". Fossils of Ohio. Columbus, Ohio: Ohio Division of Geological Survey, Bulletin 70. pp. 90–113. ISBN0-931079-05-5.{{cite book}}: CS1 maint: date and year (link)
April 10, 2024
isotelus, genus, asaphid, trilobites, from, middle, late, ordovician, period, fairly, common, northeastern, united, states, northwest, manitoba, southwestern, quebec, southeastern, ontario, species, currently, world, largest, trilobite, ever, found, complete, . Isotelus is a genus of asaphid trilobites 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 IsotelusTemporal range Middle Ordovician Late Ordovician PreꞒ Ꞓ O S D C P T J K Pg NIsotelus gigas fossil at the Smithsonian National Museum of Natural HistoryScientific classificationDomain EukaryotaKingdom AnimaliaPhylum ArthropodaClass TrilobitaOrder AsaphidaFamily AsaphidaeGenus IsotelusDekay 1824SpeciesSee textDiscovery and naming edit nbsp Cast of Isotelus rexA 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 720 millimetres 28 in in length 400 millimetres 16 in in maximum width across the cephalon and 70 millimetres 3 in 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 amp 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 amp Ludvigsen 1976 I skapaneidos Amati 2014 I susae Whitfield 1882 I violaensis Amati 2014 I walcotti Walcott 1918 synonym I planus De Mott 1963 Many specimens have been found in Ohio where Isotelus is the State Invertebrate Fossil 5 6 References edit Gutierrez Marco Juan C Sa Artur A Garcia Bellido Diego C Rabano Isabel Valerio Manuel 2009 Giant trilobites and trilobite clusters from the Ordovician of Portugal Geology 37 5 443 446 Bibcode 2009Geo 37 443G doi 10 1130 g25513a 1 ISSN 1943 2682 Rudkin D A Young G A Elias R J Dobrzanske E P 2003 The World s biggest Trilobite Isotelus rex new species from the Upper Ordovician of northern Manitoba Canada Journal of Paleontology 70 1 99 112 doi 10 1666 0022 3360 2003 077 lt 0099 TWBTIR gt 2 0 CO 2 ISSN 0022 3360 S M Gon III 2005 08 17 The World s Largest Trilobites P Z Myers 2005 04 25 Isotelus rex biggest trilobite ever Archived from the original on 2007 11 12 Ohio s State Fossil Isotelus Babcock L E 1996 Chapter 8 Phylum Arthropoda Class Trilobita Fossils of Ohio Columbus Ohio Ohio Division of Geological Survey Bulletin 70 pp 90 113 ISBN 0 931079 05 5 a href Template Cite book html title Template Cite book cite book a CS1 maint date and year link Retrieved from https en wikipedia org w index php title Isotelus amp oldid 1210558983, wikipedia, wiki, book, books, library,
