Giant Ammonites – Potentially Under Your Feet

Ammonites are closely related to extant squids and octopi (cephalopods).   Ammonite fossils can be collected from many sites around the world, including numerous locations in the UK. Often, an ammonite fossil shell is the first discovery of a young fossil hunter, a find that can lead to a lifetime of fossil collecting.

The Simple Pleasure of Finding an Ammonite Fossil

A beautiful ammonite fossil.

A beautiful pyritised ammonite fossil.

Picture Credit: Everything Dinosaur

Titanites giganteus

Whilst on a visit to the Grant Museum of Zoology and Comparative Anatomy (London), a team member of Everything Dinosaur took a photograph of a giant ammonite fossil (Titanites giganteus) in one of the glass display cases.

The Relatively Small – Titanites giganteus Specimen at the Museum

An enormous ammonite fossils photographed in the Grant Museum of Zoology (London).

A giant ammonite fossils photographed in the Grant Museum of Zoology.

Picture Credit: Everything Dinosaur

This is a relatively small specimen, measuring around forty centimetres in diameter.  The biggest specimens of this ammonite species have shells more than a metre across.  University College London is built from Portland Stone, a limestone formed in tropical seas in the Late Jurassic around 146 million years ago.  This stone is quarried from the Isle of Portland in Dorset and is used all over the world for building projects.  Some of the ammonite specimens that have been collected were huge, with shells much bigger than the one in the Grant Museum.  This one photographed by an Everything Dinosaur team member, could represent a relatively young animal or perhaps a male (female ammonites are believed to have been much larger than males).

The helpful information in the display case explains that visitors to London can see a rare example of a fossil Titanites ammonite in building stones outside the Slade School of Fine Art in the University’s Main Quad.  In the paving are slices of preserved whorls, each one is a slice through the same fossil.  Hundreds of people walk over this fossil every day, we wonder how many of them notice?

Stepping Over a Giant Ammonite

University College London Titanites cross section preserved in a paving stone.

University College London Titanites cross section.

Picture Credit: Ruth Siddal/University College London