New Middle Silurian hexactinellid sponge from the Mackenzie Mountains, Northwest Territories, Canada

• Published in: Journal of Paleontology
• Main Authors: Rigby, J. Keith, Chatterton, Brian D. E.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1994
• Subjects: Paleontology; Northwest Territories; Canada; Walcott; Road River; Avalanche Lake; Mackenzie mountains
• Online Access: http://dx.doi.org/10.1017/s0022336000022812; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022336000022812

Several specimens of the small hexactinellid, Cyathophycus mackenziensis n. sp., were collected from pale brown, shaly mudstone of the Road River Formation. The sponges are of Wenlock age and were collected from near Avalanche Lake, Mackenzie Mountains, Northwest Territories, Canada. The small, steeply obconical sponges have skeletons in crudely ranked quadrules to at least third-order, with first-order openings generally 2 mm high and 1 mm wide. Successive orders decrease in stages approximately half that of larger elements. A moderately irregular dermal(?) layer with circular parietal gaps is suggested in some specimens. The new species is consistently finer textured than either the type species Cyathophycus reticulatus Walcott, 1879, or the later described Cyathophycus quebecensis Dawson, 1889.