Earliest Triassic metazoan bioconstructions from East Greenland reveal a pioneering benthic community in the immediate aftermath of the end-Permian mass extinctionShow others and affiliations
Responsible organisation
2018 (English)In: Global and Planetary Change, ISSN 0921-8181, E-ISSN 1872-6364, Vol. 167, p. 87-98Article in journal (Refereed) Published
Abstract [en]
Marine benthic ecosystems collapsed during the catastrophic end-Permian mass extinction, and subsequently endured a protracted phase of biotic recovery under harsh environmental conditions. In particular, metazoan reef communities almost totally disappeared and were replaced by microbe-dominated mounds during the latest Permian-earliest Triassic. Here we report the stratigraphically oldest exclusively metazoan bioconstructions from earliest Triassic (mid-Induan) strata in East Greenland - these formed within the first ca 300 ka after the Permian-Triassic boundary. Unlike the multitaxic sponge-microbe and bivalve-based buildups recorded from the Early Triassic peri-paleoequatorial Panthalassan and Tethyan margins, the East Greenland bioaccumulations developed within a restricted Boreal mid-paleolatitude seaway, and comprised a monospecific primary framework of microconchid 'lophophorate tubes with shell fragments and phosphatic debris cemented by biogenic calcite. Prostrate growth of the microconchids likely facilitated their accretion into successive sheet-like biostromes and small bioherms. These are associated with a regional paleoenvironmental shift towards well-oxygenated bottom waters, and locally punctuated sedimentation that created a favorable habitat. Although microconchids were both abundant and geographically widespread throughout the earliest Triassic, such buildups formed solely by these metazoans have not been reported from that time frame outside the Boreal Realm. These apparently flourished in the absence of more stable complex communities, and suggest that a locally variable, rather than ubiquitously sequential revival of metazoan bioconstruction activity took place in the immediate aftermath of the end-Permian extinction. However, these may also suggest that ecological recovery of benthic marine ecosystems following the end-Permian mass extinction might have started earlier in higher paleolatitudes.
Place, publisher, year, edition, pages
2018. Vol. 167, p. 87-98
Keywords [en]
Microconchids, Boreal Realm, Reefs, Build-ups, Paleoecology, Biotic crisis
National Category
Other Earth and Related Environmental Sciences
Research subject
SWEDARCTIC; SWEDARCTIC 2016, Östra Grönland 2016; SWEDARCTIC 2015, East Greenland 2015
Identifiers
URN: urn:nbn:se:polar:diva-8763DOI: 10.1016/j.gloplacha.2018.05.009ISI: 000438322900007OAI: oai:DiVA.org:polar-8763DiVA, id: diva2:1605896
Funder
Swedish Polar Research SecretariatWallenberg Foundations2018-10-082021-10-26Bibliographically approved