X-Nico

unusual facts about trilobite zone



Biceratops

Biceratops nevadensis is known only from the lower part of the Pioche Shale (Upper Olenellus-zone) at the base of the Frenchman Mountain, Clark County, Nevada.

Dresbachian

The Dresbachian is defined by four trilobite zones: Cedaria-, Crepicephalus-, Aphelaspis- and Dunderbergia trilobite zones.

Elliptocephala

E. praenuntius occurs on the eastern Ellesmere Island, Canada, in what possibly belongs to the Lower Olenellus-zone (430 feet above the basis of the Kane Formation, 6 miles Northwest of the head of Scoresby Bay).

E. logani was excavated from the Middle Olenellus-zone of the Northwest Territories (type section of the type section of the Sekwi Formation, 0.2 miles Southeast of June Lake, Mackenzie Mountains, and the Illtyd Formation, Wernecke Mountains).

E. parvifrons was excavated from the Middle Olenellus-zone of the Northwest Territories (type section of the type section of the Sekwi Formation, 0.2 miles Southeast of June Lake, Mackenzie Mountains, and the Illtyd Formation, Wernecke Mountains).

E. sequomalus is found in the Middle Olenellus-zone of the Northwest Territories (type section of the type section of the Sekwi Formation, 0.2 miles Southeast of June Lake, Mackenzie Mountains).

E. laxocules occurs in the Middle Olenellus-zone of the Northwest Territories (type section of the type section of the Sekwi Formation, 0.2 miles Southeast of June Lake, Mackenzie Mountains).

Fritzolenellus

F. truemani was collected in the Lower Cambrian (lower Olenellus-zone) of Alberta, Canada (Mural Formation, in the talus slope immediately West of Mumm Peak, from the middle Mural Formation, 125 m above the base of that formation, just North of the Mount Robson Provincial Park boundary).

Mummaspis

M. occidens was collected in the Lower Cambrian (lower Olenellus-zone) of Alberta, Canada (Mural Formation, in the talus slope immediately West of Mumm Peak, and from the middle Mural Formation, 125 m above the base of that formation, just North of the Mount Robson Provincial Park boundary).


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