New Lower Silurian (Llandovery) encrinurine trilobites from the Mackenzie Mountains, Canada
Abstract
Silicified encrinurine trilobites from Telychian strata of the Whittaker Formation east of Avalanche Lake, District of Mackenzie, Canada, includeBriania jeffersonin. gen. and sp. andJohntempleia pamaen. gen. and sp. Morphology ofBrianiasuggests an origin near the divergence ofPacificurusfrom thevariolarisplexus.Johntempleiaalso includes Rhuddanian-Aeronian diversity from Scotland, and is resolved as the basal branch of thepunctatusplexus.Briania jeffersoniandJohntempleia pamaeco-occur with rare taxa of thevariolarisplexus ("Nucleurus" spp. A and B) in a deep-water assemblage dominated byCromusand the odontopleuridStelckaspis.Stratigraphic range data for encrinurine genera identify the late Telychian to early Sheinwoodian as a time of taxonomic turnover.
- Publication:
-
Journal of Paleontology
- Pub Date:
- July 1994
- DOI:
- 10.1017/S0022336000026263
- Bibcode:
- 1994JPal...68..824E