“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 ...

Nautilus vs. Ammonite Compared with the modern-day chambered nautilus, ammonites had thin shells with marginally located siphuncles (tubes that interconnect shell chambers).

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.

Opalized ammonite fossils are some of the most unique and spectacular paleontological specimens. They were formed through a ...

Small ammonites have become earrings in the hands of Gabriella Kiss and Margery Hirschey, both fine jewelry designers in the United States. “I just try to honor them as they are,” said Ms ...

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: ...

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 ...

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 half-cut shell of the modern Nautilus (right). 3D-printed half-cut ammonite shell (left). Chamber model from the current study, cut to show internal geometry (top).

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