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TXV24

Bouldnor Formation Winter Finds

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TXV24

Hi,

 

I thought I'd share some of my best finds from what has been a brilliant start to collecting in 2018! The Isle Of Wight has been hit by heavy storms, with torrential rain and gale force winds, numerous times over the last month or so. This has caused some serious erosion and slipping to the soft clay cliffs and foreshore of the Bouldnor Fm. and the coast has been highly productive. I've made some of the best finds of my fossil hunting "career" (if that's the right term for it), including some very nice large mammal finds that I have dreamed of coming across for a while now. 

 

1. The partial cranium of a mammal. This is without a doubt one of my best finds. I collected it ex-situ from the foreshore and at first thought I was looking at a large piece of fossil wood, which are common in some of the fluvial and freshwater horizons of the Lower Hamstead Member. Luckily I spotted the cancellous bone texture, and quickly realised it was a large piece of mammal skull. The cranium is essentially the left portion of the brain case with the parietal bone, part of the frontal bone, jaw articulation surfaces and saggital crest with scars from the temporalis muscle. The brain case is filled with sediment and Viviparus gastropods, which may be the culprits for the extensive mollusc bore marks on the parietal bone. There is also a Stratiotes seed in one of the gastropod shells indicating the skull was deposited in a shallow (less than 6.5m deep) freshwater pool, probably already broken. Skulls like this are incredibly rare, and I've heard that it looks like it was probably out on the shore for just a couple of hours! As usual with my big or unusual finds I took it straight in to Dinosaur Isle Museum where it's currently on loan for preparation and identification in case it's an important find. I believe it may be something like an Anoplotherium although I'm not sure. 

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2. Partial Bothriodon mandible. This is a really cool find that I've always wanted to come across! Bothriodon is an abundant part of the Post-Grande Coupure mammal fauna, arriving in Europe and Britain around 33.6 million years ago from Asia. This was facilitated by the Oi-1 glaciation event in Antartica lowering global sea levels and opening up several migration routes from Asia into Europe for a myriad of immigrant taxa. The habitat of the early Oligocene Hampshire Basin was ideal for the proposed lifestyles of anthracotheres (low lying coastal plain with wetlands, lakes, and open woodland), which along with a preservation bias, makes Bothriodon the most common large mammal encountered. I found this jaw in two pieces, 14 days apart and 5m from each other in a mudflat at low tide. The bone is heavily crushed and has P- Min-situ, although Pis missing (possibly pre-fossilisation) and I still haven't found the other jaw section with the M2  (fingers crossed it'll turn up one of these days!). I think the jaw washed out of the Upper Hamstead Member during this winter's storms and smashed into several pieces which were subsequently scattered over the immediate area. 

 

(Pto M1 section found 14 days after the M3)

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TXV24

(Msection)

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3. Bothriodon Astragalus 

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indominus rex

Wow those are some amazing finds, well done:dinothumb:

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TXV24

4. Elomeryx distal humerus. Elomeryx is probably the second most common large mammal alongside Bothriodon, mainly as the two were probably frequenting the same habitats in and around freshwater bodies and waterways and were thus more likely to be fossilised. This is my 4th specimen attributable to Elomeryx, including a couple of teeth and another distal humerus.

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5. Isoptychus cf. pseudosiderolithicus cheek tooth. This is a really recent find I made whilst screen washing matrix from the White Band in the Upper Hamstead Member. It's a cheek tooth from the theridomyid rodent Isoptychus (not sure which tooth although I think an upper molar?). Theridomyids are the most frequently encountered micro-mammal taxa throughout the entire Solent Group (Headon Hill Fm., Bembridge Limestone Fm. and Bouldnor Fm.) and seem to have spent time in the proximity of freshwater bodies. They closely resembled modern kangaroo rats and were semi-terrestrial, spending time foraging in low trees and on the ground. Water soldier seeds (Stratiotes sp.) have been found with gnaw marks attributed to Isoptychus suggesting they also fed on seeds from marginal aquatic plants. Studies on rodent teeth from the Solent Group have found that there was a high rate of predation on theridomyid rodents by amphicyonids (Cynodictis sp.). It's believed teeth like this accumulated in freshwater bodies following periods of heavy rainfall, when ephemeral streams on the coastal and flood plains washed micro-mammal remains into nearby ponds, lakes, and wetlands. I really enjoy collecting micro-mammals and vertebrates in general as it adds a whole new perspective and collective view of the ecosystem, and having acquired a new fine mesh sieve finds like this should hopefully start coming in fast! 

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Tidgy's Dad

Marvelous finds and informative and interesting posts as always. 

Thanks for sharing and congratulations. :yay-smiley-1: 

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Phevo

Awesome finds, thanks for sharing them with us ;)

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WhodamanHD

Awesome finds! What an incredible site, I can’t believe I had no idea it existed till a few months ago.

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Ludwigia

Great finds from a great site! It's at times like this that bad weather can have its advantages.

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TXV24

@Tidgy's Dad@Phevo@indominus rex@Ludwigia Thank you! 

 

@WhodamanHD It's a pretty poorly known site even locally on the Island, as most collectors focus on the Dinosaurs and Cretaceous marine groups which the Island's famous for (who can blame them), when in reality we have the largest continual paleogene sequence in NW Europe from the Palaeocene through to Oligocene.

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ynot

Looks like some good hunting going on over there.

Nice finds.

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