Reptiles in South Wales

14 Aug 2020

At https://phys.org/news/2020-08-ancient-north-american-reptiles-island.html .... a study from the University of Bristol has uncovered fossils of small reptiles that lived in South Wales 205 million years ago. They are closely related to similar animals found in North America. The fossils come from a quarry site, collected in the 1950s but reassessed with modern equipment. They date from the Late Triassic period. It is claimed the quarry was at that time on an island in a tropical sea. Britain lay much closer to the equator in the Triassic. Apparently, at this point in time, the Atlantic had not opened up but was just beginning to unzip as continental drift pulled North America and Europe apart. On the other hand the End of Triassic event may have been the catalyst for the formation of the Atlantic. In either scenario the reptiles of South Wales would have been quite close, as far as mileage is concerned. The big mystery it seems is the Welsh reptiles are so much smaller than their American cousins. It is suggested they were living on a tropical island (where the quarry now exists) and dwarfism came into play ...

   ... for further info see https://doi.org/10.1016/j.pgeola.2020.04.005

At www.heritagedaily.com/2020/08/some-dinosaurs-could-fly-before-they-were-... ... which may put a spoke in the idea birds evolved smoothly from dinosaurs. Even the idea that birds and dinosaurs are closely related. A revision on the scale of the evolution from one to the other has been suggested by the study authors as feathered dinosaurs appear to refute the evolutionary model. However, it involves no great shift to the idea that raptors and troodontid theopods are the closest relatives to modern birds - and the idea that anchiornithine theropods are the earliest birds in the fossil record (even though they are dinosaurs). The problem they are confronted with is that dromaeosaurids were also able to fly. It is now proposed there were several evolutionary attempts to get animals to fly but only one, ancestral to birds, was entirely successful. Playing around with models on a computer screen and using fossils of all the dinosaurs, currently known about, led to an exercise in fitting together an evolutionary tree. It resembles a jig saw puzzle we might say, and they think they have fitted the pieces together, for better or for worse. Fun work if you can get it.

At www.heritagedaily.com/2020/08/searching-the-ancient-depths-of-a-reptilia... ... scientists investigating the genome of a reptile native to New Zealand  find patterns that may explain how the genomes of all vertebrates took shape. This is the same story as featured in an earlier post - concerning the tuatara.