At https://phys.org/news/2023-02-fossil-discovery-reveals-complex-ecosystems.html … in this piece we are at the Permian-Triassic boundary event, and its accompanying mass extinction of life. Some 80 per cent of life forms are said to have been killed. Were they all wiped out – or just some of them. In the aftermath the mainstream postition is that that life was largely eliminated as far as major species are concerned, for up to 10 million years, as evolution sought to re-establish life on earth. A not unreasonable diagnosis. However, simply because there is a record of die-offs in the fossil record, does this necessarily mean kindred fossils were entirely killed off. The new study seeks to show that life did not die off, and some species lived in the aftermath only to be overwhelmed a short while later, within less that one million years. The discovery of fossils said to date back to 250.8 million years ago, near Guizhou in China, suggests complex ecosystems were present on earth less than a million years after the extinction event – or that is the hypothesis. On the other hand, thinking outside the boundaries of the research programme, the sedimentary layer may not be separated by that amount of time. It may even be part and parcel of the catastrophic event, sediments laid down at the time, quickly rather than slowly, as in the gradualist agenda. It may be that the geological column is designed to repudiate the idea of catastrophic events, and this relies on always dating sedimentary layers as slow processes rather than rapid events. Perhaps not all of them but a pinch of salt might be required that would unfortunately cast a cynical eye on the article as a whole. Pity.
The Guizhou fossils come from an ocean ecosytem, possibly laid down in a giant tidal wave. Fossils include boney fish, ray finned fish, crabs, lobster, shrimp, and various molluscs. Radiometric dating methodology was used to date the rocks where the fossils were discovered, See also https://doi.org/10.1126/science.adf1622 … or https://www.science.org/doi/10.1126/science.adf1622 …
See also https://doi.org/10.1038/d41586-023-00383-9 … an article on the same cache of fossils but written by different authors, where we learn that volcanic ash is also a feture of the 250.8 million year old deposit. Here, Guizhou becomes Guiyang, too. Some nice images.
Over at https://phys.org/news/2023-02-lgm-refugia-deciduous-oak.html … which is also China oriented, but much closer to our time. Oaks are important genera in forests around the world, especially in mid latitude regions of the northern hemisphere. Deciduous oaks are supposedly under threat from rising temperatures. In the new study they have attempted to model refugia where oak obviously survived the Ice Ages – in particular the Late Glacial Maximum [LGM]. Mountains in northern and central China are potential refugia as global warming heats up the planet to an insufferable level. This idea is implanted in the model. This is because deciduous oak had a large distribution during the LGM, followed by northward migration in the early Holocene. The assumption here is that China was cold during the LGM, signicantly colder in the north. This goes back to the idea of an ice sheet across most of the northern hemisphere in the LGM, of which there is little evidence in Asia. Yet again, models based on assumptions that may not be true. If Siberia harboured enough pasture for huge herds of mammals there is no reason not to think the oak forest had been a common habitat of northern and central China, without a need of refugia, in the narrow sense of that word.