Salamander ate a frog for its final meal

The fossil of an extinct salamander is so exquisitely preserved that the remains of its last meal – a frog – can be seen in its gut.

The fossil comes from the site of the Quercy phosphorites in south-west France, which has thrown up many vertebrate fossils over the years. This is despite a large number of specimens probably being destroyed by phosphate mining in the 19th and 20th centuries.

The salamander fossil had remained largely forgotten in the French National Museum of Natural History for decades, until Jérémy Tissier of the JURASSICA Museum in Porrentruy, Switzerland, and his colleagues took a closer look.

They scanned the fossil using advanced imaging techniques, and named it Phosphotriton sigei after the phosphorus-rich sediments of Quercy. It is the only known fossil of this species, with a search in museums and sediment deposits coming up empty.

The salamander died 34 to 40 million years ago, yet aside from its skeleton, many of its soft tissues are preserved: an initial examination identified skin and a lung. These were protected by a process called permineralisation, sometimes loosely known as “mummification”. Under this mechanism, minerals from groundwater seep into a buried animal and fill any empty pockets, or even individual cells…

Read the whole story published in New Scientist here.

Photo credit: Jérémy Tissier

Eye shape reveals whether animal is predator or prey

A link between pupil shape and the feeding behaviour of animals has been made by studying the eyes of 214 species. By modelling how differently shaped pupils collect light, researchers in the UK and US have argued that the shape of an animal’s pupil – the aperture through which light enters the eye – is related to whether that animal is predator or prey.

The study reveals that herbivorous prey animals such as deer and zebras are likely to have horizontal pupils, while predators actively hunting during the day – like cheetahs and coyotes – usually have circular pupils. Furthermore, animals that hunt at night, or both day and night, tend to have vertical pupils. This vertical group includes some foxes, cats and snakes…

Read the full story at Physics World.

Photo credit: David Corby