I am once again delighted to be invited to write a guest blog for UCL’s Grant Museum of Zoology, and this one is about the extraordinarily large ammonites encountered in Portland Limestone. As avid readers of former Grant Musuem Curator Mark Carnall’s ‘cephalopod column’ in The Guardian will already be aware, cephalopods are a group of marine molluscs and amongst them live and lived the giants of the invertebrate world. Represented today by octopuses, squids, cuttlefishes and nautiluses, and extinct taxa represented by ammonoids and belemnoids, cephalopods have been a dominant invertebrate species in our seas since the Ordovician, 480 million years ago.

A giant ammonite (Titanites giganteus) in the Grant Museum. LDUCZ-R205

We have all heard of the giant squid, the somewhat shadowy and rarely observed Architeuthis dux which can reach lengths of up to 13 m, but this is not the only example of gigantism in cephalopods. Indeed, it is something that occurs regularly in this group throughout the fossil record. Although evidence exists for fossilised giant squid, these are rare as the soft-bodied animals do not preserve well. However nautiloids, ammonoids and belemnoids with their hard shells do preserve very well. (more…)

In both sad and happy news, I’m off to pastures new at the end of August, leaving the Grant Museum after what will be ten years and off to the Oxford University Museum of Natural History. Although that’s still a while away yet, the schedule for the specimen of the week writing mean that this will be my last specimen of the week.

LDUCZ-R16 A clue to this week’s specimen of the week

One question I get a lot working at the Grant Museum is “What is your favourite specimen?”. My normal answer is that it changes from week to week depending on what I’ve recently been working on or the specimens I’ve become familiarised with which have been requested for use by researchers. However, I do have a soft spot for this week’s specimen of the week which has been used in teaching and research and hundreds, if not thousands of people have got hands on with this specimen in family and school handling activities. I was pleasantly surprised to find that it hadn’t already been featured in this blog series either.

This week’s (and my final) specimen of the week is… (more…)