The end–Triassic mass extinction event (ca. 201 Myr ago) has received particular attention over recent decades since Sepkoski (1981) classified it as one of the ‘‘big five’’ biotic crises in Earth's history. In the geological record of Greenland and Sweden, 80% of the species of terrestrial plants disappeared at this boundary. In the last two centuries, Triassic–Jurassic plant remains from Skåne, southern Sweden, have been collected, curated, and studied. However, the paleoflora from the lowermost part of the Helsingborg Member (Lower Jurassic: Hettangian) is poorly understood. Here, a taxonomic study is presented of two novel plant assemblages collected from the Boserup beds (basal Hettangian) in NorraAlbert Quarry, Skåne. The exposures in Skåne are among the few localities in the world that record the terrestrial ecosystem aftermath of the end–Triassic extinction event. Plant macrofossils were studied using macrophotography and fluorescence microscopy. The flora is composed of sphenophytes(Neocalamites), ferns (Cladophlebis, Eboracia), ginkgophytes (Czekanowskia, Pseudotorellia,Ginkgoites), and conifers (Pityophyllum, Brachyphyllum). These earliest Jurassic assemblages were deposited in floodplain environments and revealed a relatively low diversity of flora in the aftermath of the end-Triassic extinction but a fast recovery later. Additionally, the flora was compared with the relative lowermost Jurassic beds in East Greenland, Poland, and Germany, disclosing that ginkgophytes were widely distributed across the northern region of Pangea.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:uu-504644 |
| Date | January 2023 |
| Creators | Quiroz Cabascango, Daniela Elizabeth |
| Publisher | Uppsala universitet, Paleobiologi |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | Examensarbete vid Institutionen för geovetenskaper, 1650-6553 |
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