The effect of siliceous sponge deposition on Permian paleocommunity structure

• Published in: Paleobiology Vol. 49; no. 1; pp. 99 - 119
• Main Authors: Wistort, Zackery P., Ritterbush, Kathleen A.
• Format: Journal Article
• Language: English
• Published: New York, USA The Paleontological Society 01.02.2023; Cambridge University Press; Paleontological Society
• Subjects: Benthic fauna; Benthos; Biofacies; Bivalvia; Brachiopoda; Bryozoa; Carbonates; Chert; Cherts; cluster analysis; Clustering; Coasts; Collections; communities; Community structure; Composition; correspondence analysis; deposition; Digitization; Ecological effects; faunal list; faunal studies; Fossils; Gastropoda; Idaho; invertebrate; Lithology; lithostratigraphy; marine environment; Marine invertebrates; Mollusca; Montana; Multidimensional scaling; paleoecology; paleoenvironment; paleogeography; Paleontology; Paleozoic; Park City Formation; Permian; Phosphoria Basin; Phosphoria Formation; Porifera; Scaling; Sedimentary facies; Shedhorn Formation; silica; Sponges; statistical analysis; United States; Wyoming; Zoobenthos; Canada; Montana; Wyoming; United States > US; Idaho
• ISSN: 0094-8373; 1938-5331
• DOI: 10.1017/pab.2022.18

A dramatic shift from carbonate-rich to chert-rich marine strata occurred during the Permian and is frequently attributed to the increased activity of siliceous sponges and their biosiliceous sedimentation. The first-order ecologic consequences of this transition, if any, remain opaque. We analyze fossil occurrence data from the Phosphoria Basin (western North America) to test whether the presence of siliceous sponges, which are correlated with basin-wide chert strata, influenced the recruitment of benthic fauna. Using published lithologic descriptions, we categorized fossil collections by formation, facies, and lithology and used these data to code detrended correspondence analysis and nonmetric multidimensional scaling ordinations. We also analyzed the clustering of taxa into faunal units termed biofacies. Results from these analyses indicate that fossil collections occurring in chert and carbonate are closely associated in faunal composition and community structure. These collections preferentially occur in the inner- to mid-ramp facies, in agreement with previous studies. Although largely similar in composition, collections of chert and carbonate lithology exhibit differences in the frequency and abundance of accessory brachiopod taxa (e.g., Composita and Hustedia), possibly a result of greater biosiliceous sedimentary input.