Crocodiles and Climate

21 Jun 2019

At https://phys.org/news/2019-06-crocs-climate-clock-ancient-reveal.html ... the ancient distribution of crocodiles could be used to reveal information about past climate. On the other hand, they may reveal more about earth changes. It seems some crocodilians are sensitive to changes in temperature - but other kinds of crocodile are not. Or that is the theory been promulgated. Mapping the distribution of the different species of crocodilia (ostensibly using fossilised remains) may reveal more about 'global' climate millions of years ago. Alligators and some other reptiles appear to have survived big changes in temperature (in some regions) but the emphasis here is on the end of Eocene event. Whatever the vector may have been it is ignored and instead, the researchers are only interested in the fact temperatures plummeted. Then, to compound the issue they point out some crocodilia went extinct - and therefore they were unable to adapt to climate change. As such, crocodilian diversity was affected - and note the 'in' word 'diversity', as in there should be diversity but crocodiles that did not survive the Eocene event are in some way maladjusted. At the same time, some species of crocodilia survived - even though they may have been depleted (a population drop). The authors clearly do not envisage a catastrophic event as responsible for the extinctions as that would spoil the link to climate change - or that is the impression given by the press release. The addition of climate change in research ensures publication is more likely but one would have to read the whole piece to get a handle on what is being said. Go to DOI:10.1080/02724634.2019.1617723 ... published in the Journal of Vertebrate Paleontology (2019). Catastrophism is clearly not factored into the research and it all seems a bit pointless - but you have to think on their terms as they are paleontologists (specialising in fossils) rather than catastrophists and are merely sticking to the mainstream song sheet. No doubt there is some revealing evidence to be extracted from the level of extinctions - locality of a possible catastrophic event for example, and magnitude. Fossils amay of course be the victims of catastrophic events, one might argue - but that is not the mainstream position. Note ... this is a simple assessment of the press release and may completely be proved wrong headed after reading the full article.

The full article can be downloaded at www.tandfonline.com/doi/full/10.1080/02724634.2019.1617723 ...