Werkgroep Fossielen regio Wageningen

Plesiosaurs ate shells from the water, but were unable to digest them or grind them down with their teeth. They therefore swam to the shore to regurgitate the indigestible shells. This is what palaeontologist Dirk Knaust writes in the *Geological Magazine*. Just as owls still do today with their pellets. Photo by Akshit Jhanwar.

American palaeontologists have discovered small fossils that may show that the assumption that the first land animals came ashore as tadpoles is incorrect. The fossils come from Mazon Creek, in the US state of Illinois. 

An almost perfectly preserved pterosaur has been found in Brazil. Its bone structure was examined using an electron microscope and appears to be similar to that of modern birds. Because it was encased in limestone, even organic molecules have been preserved – steroids!

The ammonites became extinct during the mass extinction 65 million years ago, following the asteroid impact. The nautilus, however, did not. An attempt has been made to explain this by referring to the size of the eggs they laid, but this hypothesis has been shown to be incorrect. The reason for their extinction therefore remains unknown for the time being.