Written by Emily Meredith (Year 12)
On holiday this summer in the Isle of Man, I found an object I now puzzle over: a Siphonodendron fossil. I found it while walking the Northwest coast of the Isle of Man, a windswept stretch of stony beach lined for much of it by towering sandy cliffs that edge the Northern plains. This is the main area of coastal erosion on the island as the cliffs battle with strong prevailing winds and destructive waves that begin in the Atlantic. Waves plough through the North channel, a narrow strait between Northern Ireland and Scotland that connects the Atlantic Ocean and the Irish sea. Across the water, the closest land, 37 km away, is the tip of the Mull of Galloway which, on a clear day, shimmers on the horizon. The shore feels remote, bleak even, with few landmarks – some sea armour at the Killane, a look out post at Jurby. Sea spray slaps your face, walking into a wind that turns you inside out, breathless and exhilarated, absorbing the forces and noise of the sea into your core.
My eyes skit rapidly, scanning the stones for the ancient coral fossils that can be found here. The pebbles here are varied – flint and sandstone, quartz and grey limestone – but prettiest are the stones embedded with Siphonodendron. I spot a great example at the sea edge: relatively large, 20 cm across with the clear speckled markings of fossilised coral. Siphonodendron is an extinct genus of rugose corals which were abundant during the carboniferous period. Fossilised, the rugose coral appears as white spaghetti-like threads preserved within the limestone. Corals are a soft-bodied aquatic animal, with a calcium shell and extensive tentacles. Rugose are in the subclass Hexacorallia which means there are six fold radial symmetry of the structure of the coral in cross section. The rugose corals were abundant in the Paleozoic period but became extinct at the end of the Permian period when over 90% of all invertebrates died out a mind-blowing 252 million years ago. The reason is thought to be a catastrophic loss of their environment niche when the supercontinent Pangaea formed. With more competition for less space on the continental shelf the rugose were displaced. Florida and Indonesia are the main sites where fossilised rugose corals have been reported but also at select areas along the rocky coasts of the British Isles.
Rewarded by my find, we turn and return to the car. The wind now behind us, sheltered by our backs, we can breathe again. Humbled by the timelessness of this wild landscape we watch the Stena Line Stranraer-Larne ferry creep along the horizon, the only reminder that we are about to return to the 21st Century.
The Sixth Form Review 