Such uncoiled ammonites, which tend to appear sporadically in evolutionary records, once were viewed as evolutionary dead-ends, serving only as a fountainhead for their more symmetrical descendants.

The fossils are actually from a grouping of straight, or uncoiled, ammonites known as Baculites, external but the implications should hold across a great swathe of species.

The Role of Ammonites in the Mesozoic Marine Food Web Revealed by Jaw Preservation. Science , 2011; 331 (6013): 70-72 DOI: 10.1126/science.1198793 Kazushige Tanabe.

New research published in Science shows ammonite "teeth" for the first time, suggesting that these invertebrates were filter feeders. Knowing that ammonites probably ate plankton provides insight ...

Ammonites, which evolved about 416 million years ago, were once the most abundant animals of the ancient seas. Scientists have identified more than 10,000 ammonite species, such as ...

Opalized ammonite fossils are some of the most unique and spectacular paleontological specimens. They were formed through a geological process known as opalization, wherein organic material from ...

Artefacts include the world's largest uncoiled ammonite, an entire ichthyosaur skeleton, ... to the time that ammonites died out with the dinosaurs 66 million years ago.

Ammonites are extinct relatives of the squid and octopus. The Nautilus, a present-day marine invertebrate, is similar in appearance to many ammonites but is a more distant relative.

Scientists use X-rays to establish the feeding habits of everyone's favourite fossils - the ammonites.