New Lower Silurian (Llandovery) encrinurine trilobites from the Mackenzie Mountains, Canada

• Published in: Journal of Paleontology
• Main Author: Edgecombe, Gregory D.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1994
• Subjects: Paleontology; Canada; Avalanche Lake; Mackenzie mountains
• Online Access: http://dx.doi.org/10.1017/s0022336000026263; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022336000026263

Silicified encrinurine trilobites from Telychian strata of the Whittaker Formation east of Avalanche Lake, District of Mackenzie, Canada, include Briania jeffersoni n. gen. and sp. and Johntempleia pamae n. gen. and sp. Morphology of Briania suggests an origin near the divergence of Pacificurus from the variolaris plexus. Johntempleia also includes Rhuddanian–Aeronian diversity from Scotland, and is resolved as the basal branch of the punctatus plexus. Briania jeffersoni and Johntempleia pamae co-occur with rare taxa of the variolaris plexus (“ Nucleurus ” spp. A and B) in a deep-water assemblage dominated by Cromus and the odontopleurid Stelckaspis. Stratigraphic range data for encrinurine genera identify the late Telychian to early Sheinwoodian as a time of taxonomic turnover.