Itagnostus Explained

Itagnostus is a genus of trilobite restricted to the Middle Cambrian. Its remains have been found in Asia, Australia, Europe, and North America.^[1]

Distribution

• Itagnostus elkedrensis occurs in the Middle Cambrian of Australia (Ptychagnostus praecurrens-zone, Xystridura templetonensis-zone, and Dinesus-stage, Elkedra; Triplagnostus gibbus-zone, Sandover Beds; both Northern Territory), the Russian Federation (Kounamkites-zone, Nekekit River; Liostracus allachjunensis-zone, Lena River).
• Itagnostus comis is found in the Middle Cambrian of Australia (Triplagnostus gibbus-zone, Sandover Beds, Northern Territory).

• Itagnostus gaspensis gaspensis is reported from the Middle Cambrian of the United States (Geddes Formation, Nevada; Ptychagnostus atavus-zone, Wheeler Formation, Drum Mountains, Utah), Canada (upper part, Grosses Roches, St. Laurence, Quebec), Russian Federation (Tomagnostus fissus-zone, Lena River).
• Itagnostus gaspensis taitzuhoensis has been excavated from the Middle Cambrian of Antarctica (lower part, Shackleton Mountains), Australia (Ptychagnostus praecurrens-zone, Elkedra, Northern Territory), North-China (Bailiella-Lioparia-zone, Hsuchang Formation).
• Itagnostus interstrictus interstrictus is present in the Middle Cambrian of Canada (Ptychagnostus punctuosus-zone, Cow head Group, Newfoundland), the United States (Bolaspidella (P. atavus)-zone, Tatonduk River, Hillard Peak, Alaska; lower part of the Bolaspidella-zone, Western-Utah; Wheeler Shale, Antelope Spring, House Range, Utah), the Russian Federation (Malokuonamsky Horizon, Tomagnostus fissus-zone, and Liostracus allachjunensis-zone, all Lena River).

• Itagnostus krusei is found in the Middle Cambrian of the Russian Federation (Kounamkites-zone, Lena River).
• Itagnostus oepiki has been collected in the Middle Cambrian of Australia (Triplagnostus gibbus-zone, Sandover Beds; Xystridura templetonensis-zone, Elkedra; both Northern Territory).
• Itagnostus walleyae is reported from the Middle Cambrian of Australia (Ptychagnostus praecurrens-zone, Elkedra, Northern Territory).
• Itagnostus sp. has been collected in the Middle Cambrian of the Russian Federation (Liosttracus allachjunensis-zone, Lena River).^[1]

External links

• Peronopsis in the Paleobiology Database
• Peronopsis at the Field Museum's Evolving Planet

Notes and References

1. Naimark. E.B.. 2012. Hundred species of the Genus Peronopsis Hawle et Corda, 1847. Paleontological Journal. 46. 9. 945–1057. 10.1134/S0031030112090018. 2012PalJ...46..945N. 85130465.