Ammonites are a tale of two textures. The prehistoric cephalopods were composed of fleshy soft tissue (the living bit of the animals) and hard external shells, which, according to a paper published ...

The ammonoids, an extinct subclass of cephalopods, offer a remarkable window into the evolutionary innovations of marine life. Their coiled, chambered shells and intricate suture patterns record a ...

Many constructional and taphonomic incongruencies dissolve if ammonites are modeled as active Cartesian divers, whose last septum remained a rubber-like, uncalcified membrane until the next chamber ...