Cambrian transgression and radiation linked to an Iapetus-Pacific oceanic connection?

Diversity partitioning during the Cambrian radiation

“…Its breakup was characterized by the opening of the Iapetus and AEgir oceans (55), resulting in the separation of Laurentia, Baltica, Siberia, and Gondwana, but also orogenies leading to the amalgamation of distinct cratonic blocks within Gondwana. The disassembly of Pannotia (particularly the separation between Laurentia and Gondwana) is suggested to have started close to the onset of the Cambrian radiation (Fortunian; ∼541 Ma) and ended before Cambrian Stage 3 (∼521 Ma) (20). This rapid disassembly of Pannotia corresponds well with the increase of geodisparity (Fig.…”

“…This increase was accompanied by profound continental reconfigurations often referred to as the breakup of the supercontinent Pannotia (20,53). Pannotia assembled in the interval from 650 to 550 Ma (54).…”

“…S4). Plate-tectonic configuration in the early Cambrian is poorly constrained (20), but the Neoproterozoic formation of Gondwana is well established (21,22). Beta diversity within Gondwana shows more muted fluctuations than global beta diversity.…”

New geophysical compilations link crustal block motion to Jurassic extension and strike-slip faulting in the Weddell Sea Rift System of West Antarctica

“…During Gondwana assembly in the late Neoproterozoic to earliest Paleozoic, the HEW is inferred to have been located at the junction between three distinct orogens; the East-African-Antarctic Orogen (EAAO), Saldanian and Ross orogens ( Fig. 2b), (Jacobs et al, 2015;Jacobs and Thomas, 2004), and may have been adjacent to Laurentia (Dalziel, 1997(Dalziel, , 2014. The EAAO may reflect final suturing between East and West Gondwana, although the true scale and location of this suture remains to be uniquely identified (Figs.…”

Radiogenic Sr and Stable C and O Isotopes Across Precambrian‐Cambrian Transition in Marine Carbonatic Phosphorites of Malyi Karatau (Kazakhstan)—Implications for Paleo‐environmental Change

“…Similar to other stratigraphic transitions, the Precambrian‐Cambrian (PЄ‐Є) transition is marked by a mass extinction of the Ediacaran (635–541 Ma) fauna (Laflamme et al, ). This was followed by a rapid diversification of metazoan life during the Cambrian (541–485 Ma; e.g., Na & Kiessling, ), commonly referred to as “Cambrian Explosion.” While the actual developments during the Cambrian Explosion are well documented, potential causal relations with changes in paleoecology or possible geodynamic triggers for this event are still debated (Bengtson & Zhao, ; Dalziel, ; Filippelli, ; Fox, ; Sperling et al, ; X. Zhang et al, ). These may include both abiotic factors, such as changing seawater composition (in particular changes in dissolved Ca 2+ , salinity, and pH), nutrient availability, ocean circulation, enhanced weathering, and continental runoff, as well as biotic factors such as the onset of predation or profound changes in biomineralization and bioturbation (Bottjer, ; Brasier, ; Chen et al, ; Mills & Canfield, ; Ohnemüller, ; Smith & Harper, ; X. Zhang et al, ).…”