BBC Focus Magazine Malaysia
BBC Focus Magazine
Ancient reptile ‘well-preserved’ in stomach of slightly larger reptile - BBC Focus Magazine
A five-metre-long ichthyosaur ate a four-metre-long thalattosaur around 240 million years ago.
A 240 million-year-old fossil has revealed that dolphin-like ichthyosaurs could gobble up animals almost as big as themselves. Its the first direct evidence of megapredation one large animal eating another in the ancient world. Ichthyosaurs were marine reptiles that lived during the time of the dinosaurs. The fossilised ichthyosaur in this new study was uncovered in a quarry in southwestern China. Its an almost complete skeleton, around five metres long, with the bones of another marine reptile called a thalattosaur preserved inside its stomach. Read more about ichthyosaurs: The thalattosaur was around four metres long and more lizard-like than the ichthyosaur, with four paddling limbs. The bones found in the ichthyosaurs belly correspond to the thalattosaurs middle section, from its front to back limbs. Our ichthyosaurs stomach contents werent etched by stomach acid, so it must have died quite soon after ingesting this food item, said study co-author Dr Ryosuke Motani, a paleobiologist at the University of California, Davis. The stomach of the ichthyosaur contains the mid-section of another marine reptile that in life would have been only slight smaller © Da-Yong Jiang et al/ iScience The researchers dont know for sure whether the ichthyosaur killed the animal itself, or whether it was scavenging following another animals kill. But several pieces of evidence suggest that it was a direct kill, including the fact that the nutritious torso and legs were still intact this probably wouldnt have been the case if another predator had got there first. The quarry where the ichthyosaur was uncovered, now part of the Xingyi Geopark Museum © Ryosuke Motani/University of California The ichthyosaur had relatively small, peg-like teeth, which suggest that, rather than neatly slicing through its victim, it would have gripped it before ripping or tearing it apart. Present-day apex predators such as orcas, leopard seals and crocodiles use a similar technique. The ichthyosaurs teeth, with the broken white line indicating the approximate gum line of the upper jaw © Jiang et al/iScience Now, we can say for sure that [ichthyosaurs] did eat large animals, said Motani. This also suggests that megapredation was probably more common than we previously thought. Reader Q&A: Why were dinosaurs so big? Asked by: David Paylor, Oxford Dinosaurs lived during the Triassic, Jurassic and Cretaceous. During these periods, the climate was much warmer, with CO levels over four times higher than today. This produced abundant plant life, and herbivorous dinosaurs may have evolved large bodies partly because there was enough food to support them. But being large also helps to protect against predators. The giant sauropods had to eat plants as fast as they could, to grow big enough to be safe from carnivores like T. rex and Spinosaurus. Meanwhile, the carnivores were becoming larger just so they could tackle their enormous prey. Another possibility is that the herbivorous dinosaurs were ectothermic (cold blooded), and being huge helped them regulate their temperature. This theory is problematic though because evidence increasingly suggests that the large carnivores were endothermic (warm blooded), which means that dinosaurs would have evolved two different metabolic systems, side by side. Read more:
The coronavirus may not have originated in China, says Oxford professor - BBC Focus Magazine
Dr Tom Jefferson called for investigation into the presence of SARS-CoV-2 in sewage, as traces have been found that pre-date China's first COVID-19 case.
The coronavirus may have been lying dormant across the world until emerging under favourable environmental conditions, rather than originating in China, an expert has claimed. Dr Tom Jefferson, from the Centre for Evidence-Based Medicine (CEBM) at Oxford University, has pointed to a string of recent discoveries of the viruss presence around the world before it emerged in Asia as growing evidence of its true origin as a global organism that was waiting for favourable conditions to finally emerge. Traces of COVID-19 have been found in sewage samples from Spain, Italy and Brazil which pre-date its discovery in China. A preprint study, which has not been peer reviewed, claims to have found the presence of SARS-CoV-2 genomes in a Barcelona sewage sample from 12 March 2019. Read more about coronavirus in sewage: In an interview with The Daily Telegraph, Dr Jefferson has called for an investigation into how and why the virus seems to thrive in environments such as food factories and meatpacking plants. Along with CEBM director Professor Carl Heneghan, Dr Jefferson believes this could potentially uncover new transmission routes, such as through the sewerage system or shared lavatory facilities. He told the paper: Strange things like this happened with Spanish Flu. In 1918, around 30 per cent of the population of Western Samoa died of Spanish Flu and they hadnt had any communication with the outside world. Meatpacking plants are often at 4°C, which is the ideal temperature for the coronavirus to be stabledDr Tom Jefferson, University of Oxford The explanation could only be that these agents dont come or go anywhere. They are always here and something ignites them, maybe human density or environmental conditions, and this is what we should look for, said Jefferson. There is quite a lot of evidence of huge amounts of the virus in sewage all over the place, and an increasing amount of evidence there is faecal transmission. There is a high concentration where sewage is 4°C, which is the ideal temperature for it to be stabled and presumably activated. And meatpacking plants are often at 4°C. These outbreaks need to be investigated properly. Reader Q&A: Why dont viruses like the flu die off when no one is ill? Asked by: Andrew Cirel, via email Strictly speaking, viruses cant die off as theyre just inanimate strips of genetic material plus other molecules. But the reason that they keep coming back is because theyre always infecting someone somewhere; its just that at certain times of the year, theyre less able to infect enough people to trigger a full-blown epidemic. Many viruses flare up during the winter because people spend more time indoors in poorly-ventilated spaces, breathing in virus-laden air and touching contaminated surfaces. The shorter days also lead to lower levels of vitamin D, and this weakens our disease-fighting immune system. Experiments also suggest that the flu virus in particular remains infectious for longer in low temperatures. But even when conditions arent ideal, viruses will find enough people to infect to ensure their survival, until they can come roaring back in an epidemic. Read more: