Joseph Mahon

I enjoy looking for fossils. The most productive area somewhat close to me is the East/North Yorkshire coast. Some locations on this coastline are productive for Jurassic fossils like ammonites, belemnites (squid-like creatures) and bivalves (shells). You can also find marine reptile remains such as plesiosaur and ichthyosaur, and Whitby jet. There are also a few local areas, where plant fossils can be found on old colliery sites and spoil heaps.
Here are some of my favourite fossils that I have collected 🦴

• Ammonites
• Belemnites
• Plant Fossils
• Misc

Ammonites

Ammonites are relatively common on the North Yorkshire coast and are mostly Jurassic (180 million years old).
From left to right:
- Dactylioceras (positive/negative)
- Harpoceras (flattened in shale and preserved in pyrite)
- Eliganticeras

From left to right:
- Hildoceras fragment with suture pattern visible
- Large segment of unidentified ammonite. If whole, this ammonite may have been ~40cm diameter. This is a glacial erratic found on the East Yorkshire coast.
- Small unidentified ammonite, only ~1.5cm diameter

Back to top

Belemnites

Belemnites are also relatively common on the North Yorkshire coast. These are the remains of squid-like creatures and are often mistaken for teeth. Some of the smaller belemnites have been preserved in calcites which makes them translucent.
- The first image are some of the larger belemnites I have.
- The second image shows the different shapes that can differentiate species.
- The third image shows the translucency present in calcite-preserved belemnites.

Back to top

Plant Fossils

These fossil plants are carboniferous (~300-360 million years old). They have been collected from old collliery sites and spoil heaps.

Fossil Ferns

This These are fossil seed ferns, likely Neuropteris. There is still a large amount of leaf detail preserved.

Lepidodendron

These are fossil trees, growing up to 50m tall, with bark that looks like scales.
From left to right:
- Lepidodendron leaves
- Lepidodendron bark
- Lepidodendron bark detail
- Lepidodendron root cast

Sigillaria

These are trees related to Lepidodendron. It's trunk and bark are vertically aligned and smooth - Sigillaria bark
- Sigallaria bark (reverse pattern)

Back to top

Misc

Whitby Jet. This is fossilised Monkey Puzzle Tree and is often carved into jewellery. I have a few small pieces but this the largest piece

Marine reptile bone - This is a piece of marine reptile, most likely a paddle digit from an Ichthyosaur

Iron Pyrite - Also known as fools gold. It 'grows' into cubic structures.

Back to top