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Late Carnian (Late Triassic) conodont and ammonoid paleontology of Wrangellia

University of British Columbia

The development of conodont biochronology for the Triassic Period is hindered by the lack of understanding of the genus Metapolygnathus Hayashi, 1968a and, to a lesser extent, Carniepigondolella Kozur, 2003. Specimens of these genera collected at Klaskino Inlet, British Columbia are described as species populations of M. polygnathiformis s.l., M. carpathicus, and M. nodosus and variations within these species populations are identified. The morphological variations on platform shape, relative strength of anterior platform nodes, the “communisti trend,” fused carinal nodes and an extra carinal node are shared between all species populations. Although it is beneficial to fully document the generic variability within Metapolygnathus, these variations should not be included in the genus description. Not all variations occur in all species of the genus and only three species were looked at in this thesis. The secondary focus of this thesis addresses the uncertain position of the allochthonous terrane Wrangellia in the Late Carnian. Using paleobiogeographic techniques, data on ammonoid genera occurrences were compiled for cratonic North America, Wrangellia, and the western Pacific, and then compared using the Dice coefficient. It is concluded that ammonoid similarity levels are too low to assess significance levels. Based on the collected data, however, it appears that the Wrangellian fauna is most similar to the fauna of the middle paleolatitude of the North American craton. This means that Wrangellia was probably in the eastern Pacific and at a mid-paleolatitude in the Late Carnian.

Thesis/Dissertation

application/pdf

2009-11-23

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/15529

Geological Sciences

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/