Ichthyosarus larkini preparation

In this blog are a series of images showing the preparation stages of a Ichthyosaur, which was found in a hard limestone nodule from Somerset UK. In the 3 months or so it has taken to prep I have documented the process and would like to share it on my website blog page.We recently discovered that it is part of a new species just described, now known as Ichthyosaurus larkini. The preparation has been mostly mechanical, but the later stages have also involved acid prep.


Image01 Above: This image shows one half of the nodule with the top part of the skull being exposed and the top part of the rostrum. I started to acid prep the nodule, but later decided to prep it by hand with air tools as the bone was hard and with good preservation.

Image02 Above: Gradually the recognizable shape of the Ichthyosaur skull starts to emerge. Part of the eye socket and the very delicate Sclerotic ring are carefully exposed.



Please click an image to enlarge

The next three images above show the partial 3D nature of the skull. A lot more rock has been removed than bone has been exposed, which is often the case when preparing a fossil in a nodule. The rostrum is also slightly displaced which is a common occurrence with Ichthyosaurs, often after plunging nose first into the sea floor. The back of the skull (temporal fenestra) are also gradually exposed. All the bones so far seem to be where they should be which helps the preparation process.


Please click an image to enlarge

Above images show the roughing out of the front part of the skull, now it is mostly exposed, I move on to the back of the skull. In doing so I realise that a couple of the bones are displaced a little and also the rock is becoming much harder closer to the center of the nodule. I decide to remove as much rock as I can mechanically, before continuing with acid preparation.



 During the two weeks of acid prep, several bones have emerged, this will make the mechanical prep easier.



Above: Now I start work on the back part of the nodule and  piece together the various parts to get a better idea of the preparation as a whole.  The back part of the nodule is much harder and the bone in comparison is much softer, this always creates a challenge for the preparitor. So I use a combination of acid and mechanical prep to locate the bones and discover that they are increasingly displaced and peter out. This may indicate the Ichthyosaur was another marine predators lunch, most likely before it landed on the sea floor as the front half is still well articulated.

The skull itself reminds me of a old plague doctors mask, very bird like.


Above: The various parts of the nodule have been glued together using a strong epoxy resin and reinforced with metal rods for added strength. Now it’s time to work on the detailing of the fossil and shape the edge of the nodule a little more.

Ichthyosarus larkini_01

 Detailing of the nodule is almost finished along with the making of the frame and stand to display the specimen. I have constructed a fiberglass jacket to support the fossil on the stand. This allows for the fossil to be removed from the metal frame and base. I now need to refine the shape of the resin jacket to create a snug fit for the fossil and undertake the last finishing touches to the fossil and surrounding nodule.

Ichthyosarus larkini_04

Ichthyosarus larkini_03Ichthyosarus larkini_02

The frame is finished and I’ve added an apple for scale!

Some last minute alterations have been made to allow the fossil to be removed simply if needed from the frame.

Overall I’m pleased with the result, it has been a tricky and time consuming job due to the nature of the preservation, but worth it.