“Some of their morphology was closer to that of the coleoid group,” says Zoë. “We think it’s more likely that ammonites would have had eight arms rather than lots of tentacles like a nautilus, though ...

They’re much more complex than the suture lines of ammonites’ nearest extant cousin, the nautilus. 3D-printed ammonite shell (left) and nautilus shell (right) show their respective ...

The modern nautilus has a similar design, but ammonites are far older, having lived around 340 to 65 million years ago, at which point these marine invertebrates went extinct along with the dinosaurs.

However, this study highlights that ammonites and Nautilus may not be as similar as previously thought. The study’s lead author Dr Lesley Cherns of Cardiff University said: ...

First ever 3D visualisation of an ammonite's muscles show how it swam and evaded predators before going extinct with the ... 'We found evidence for muscles that are not present in Nautilus, ...

However, this study highlights that ammonites and Nautilus may not be as similar as previously thought. The study's lead author Dr Lesley Cherns of Cardiff University said: ...

The ammonite fossil used in the Geology study was discovered in 1998 at the Claydon Pike pit site in Gloucestershire, England, which mostly comprises poorly cemented sands, sandstone, and limestone.

LAST MEAL The teeth (yellow) of an ammonite, ... In contrast, the related cephalopod known as the nautilus survived the extinction, ...

And although the modern nautilus looks superficially like an ammonite, it is in fact a more distant cousin. Indeed, the nautilus has far more robust mouth parts; and can scavenge a wide variety of ...

Left: 3D reconstruction. Right: Labelled internal organs. Credit: Cherns et al. For the first time, researchers have revealed the soft tissues of a 165-million-year-old ammonite fossil using 3D ...