Top 5 – Phil’s Fossils

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Next up to share his favourite five specimens from the Museum’s collection is Philip Hadland. Phil joined us a few months ago as an Earth Collections assistant and has already discovered some fascinating fossils in the stores.

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5 – Fossil crab from Folkestone

Necrocarcinus labeschii (Deslongschamps, 1835) from the Gault Clay. Scale in mm.

Necrocarcinus labeschii (Deslongschamps, 1835) from the Gault Clay

These Cretaceous crabs are interesting because of their similarity to modern Bubbler Crabs. As you can see from the photo at the top of this post, Bubbler Crabs feed during low tides on microscopic creatures living between grains of sand, processing it into ‘sand balls’.

Natural cast of a footprint resembling the form of an ostrich foot from the Lower Greensand with ‘sand balls’. Approximately 250 mm long. Natural cast of a footprint resembling the form of an ostrich foot from the Lower Greensand with ‘sand balls’. Approximately 250 mm long.

Natural cast of a footprint resembling the form of an ostrich foot from the Lower Greensand with ‘sand balls’. Approximately 250 mm long.

In some cases, trace fossils very similar to the modern sand balls can also be found. Natural casts resembling ostrich footprints have been found alongside the ‘sand ball’ fossils.

Maybe the crabs were a food source for the mysterious animals that left the footprints?

4 – TV rock

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Ulexite (NaCaB5O6(OH)6•5(H2O)) (hydrated sodium calcium borate hydroxide), is a mineral with natural fibre optic properties. The fibres transmit light through internal reflection, which is the same way that fibre optics work. If a crystal of ulexite is cut correctly and placed on an image, that image will be projected to the other surface. For this reason it is also known as TV rock.

3 – Heteromorphic ammonites

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A tower shell shaped ammonite, Turrilites costatus (Lamarck, 1801)

Heteromorphic ammonites are extinct cephalopods, related to squid and cuttlefish. They are different from other ammonites with flat spirals; they coil in unusual ways. Some are shaped like paperclips and some resemble tower shells. They are a fascinating enigma and we can probably only guess how they lived. I suspect that at least some were mimicking other animals. Mimicry is often used by living animals to catch food or to avoid becoming prey themselves, so perhaps they sat motionless on the sea bed waiting to devour unsuspecting crustaceans, a popular prey of living cephalopods.

2 – Challenger Shark Tooth

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A fossil shark’s tooth collected on the Challenger expedition (1872-1876), dredged from the Pacific ocean, at a depth of 2350 fathoms, over 4 kilometers. The naturalist Henry Moseley (1844-1891) published notes on the expedition, describing numerous encounters with living sharks. The largest they encountered was Carcharodon rondelettii known today as as Carcharodon carcharias, the great white shark. In the notes he also states “The Challenger dredged in the Pacific Ocean in deep water numerous teeth of what must be an immensely large species of this genus”. In fact these were fossil teeth of the extinct giant shark Carcharocles megalodon. Awesome!

1 – Kirkdale Cave Mammal Fossils

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In 1821 labourers in a quarry at Kirkdale, Yorkshire, found a cave full of animal bones. Professor William Buckland of Oxford University visited the cave and recognised over 20 kinds of animal, including Elephant, Hippopotamus and Hyaena. These fossils were 120,000 years old! He thought that it was once a Hyaena den, as there were many hyaena bones in the cave. To prove his idea he gave an Ox bone to a Hyaena, which was travelling through Oxford in Mr Wombwell’s menagerie. The Hyaena produced gnaw marks identical to those on a comparable Bison shin bone from the cave. I think this was really clever. It may be the earliest example of experimental palaeontology.

Philip Hadland, Collections assistant (Earth)

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