Friday, September 18, 2015

Fossil Hedgehogs


A slightly different #fossilfriday this week ( I missed last week as I was busy hiking and looking for fossils on the American Prairie Reserve). Back in 2000 I found a very productive seam of microvertebrates in the Oligocene Hamstead beds of Boldnor on the Isle of Wight. We retrieved something like 300 mammal teeth from only about 1-2 kilos of sediment. Jerry Hooker (Natural History Museum, London) came over to Bristol University to see the fossils and told me that among our cache were the best preserved oldest hedgehog teeth in the world. I gather that there are older hedgehog remains, but these teeth are the best preserved. Anyway, everyone likes hedgehogs, so I was very pleased.

Fossil Hedgehog teeth. Adapted from Hooker (2010).


The specimens were donated to the NHM to be studied by Jerry. The above image is a figure from his 2010 paper and shows Scanning Electron Microscope photos of hedgehog teeth from Hamstead. I do not know if the teeth shown here are the ones I found, but I suspect they are.

The hedgehog teeth are part of the fossil fauna from immediately after the Grande Coupure extinction event that occurred in the northern hemisphere in the earliest Oligocene, about 34 million years ago.

This image is a bit plain though, so here's a photo to remind you of how cute hedgehogs are:

(image from pinlovely.com)

Reference

Hooker, J. J. "The ‘Grande Coupure’ in the Hampshire Basin, UK: taxonomy and stratigraphy of the mammals on either side of this major Palaeogene faunal turnover." Micropalaeontology, Sedimentary Environments and Stratigraphy: A Tribute to Dennis Curry (1912–2001) (2010): 147-215.

Friday, September 4, 2015

Baby Iguanodons!

Here are a couple of pictures of baby Iguanodon fossils that I have posted to Facebook for #FossilFriday.

This week: baby aff. Iguanodon tooth 

 A very small (~9mm) crown of a juvenile aff. Iguanodon from Chilton Chine, Wessex Formation, (Barremian, Lower Cretaceous, ~130 Ma), Isle of Wight, UK.


Aff. Iguanodon juvenile dentary tooth.
Scalebar in mm. Photo: Steve Sweetman.

Iguanodontid material is common in the UK Wealden, but juvenile material is always nice to find. This looks to be a dentary tooth, based on the broad diamond shape. For comparison, here's a photo of a medium-sized adult dentary tooth from Iguanodon bernissartensis:
 
Iguanodon bernissartensis tooth.
Photo from dinowight.org.uk

A few weeks ago: The best Iguanodon fossil

A few weeks ago (on my Facebook page), I posted this photo of another juvenile Iguanodon bone. It's a tiny thumb spike! The spike is a little bit worn as it has been rolling around the beach for a while, but you can see the "nail groove" running down the side.

When I found this back in the 1990's, I was not particularly experienced in identifying bones, so for a while I thought it was a crocodile tooth, but it is clearly bone.

Juvenile aff. Iguanodon thumb spike.