In 1870 workmen who were excavating a cutting through the edge of Colborough Hill for a new railway line exposed a multitude of strange creatures that had not seen the light of day for more than 200m years.
The workmen clawed through loose clayey mudstones and unearthed millions of ammonites, from the size of a palm to a fingernail, bearing ribbed coils variously sculpted, with sharp dense parallel ribs or gentle ripples.
As the men went deeper the rocks would have got harder. Their blasting powder, hitting the limestone and ironstone, must have thrown out millions more fossils – dense concreted clumps of brachiopods, like grey china nuts, some smooth, others deeply and jaggedly grooved, mixed with scallops, oysters and the flinty rods and bullets of belemnites.
I wondered what the discoverers of these little treasures made of them just 19 years after Darwin published the Origin of Species. Did they puzzle over and debate the origin of these shells? Or did the ancient nature of their finds not occur to them?
By 1877 the site’s significance as a window on to planetary history was being recognised; a visit by the Geologists’ Association noted “several good fossils”. Since then a number of animals found in the cutting, including the ammonite Tiltoniceras acutum, have turned out to be new discoveries altogether.
In 1965 the railway line was closed by Beeching and in 1983 the site became a nature reserve run by the Leicestershire and Rutland Wildlife Trust. Today it is an area of shady, damp, tranquillity, overhung, now in autumn, with the yellowing foliage of ash and goat willow and browning leaves of oak.
Hart’s-tongue ferns sprout from crannies in the limestone cliffs, and wild strawberry plants trail long runners from the overhangs; little clumps of leaves sprout every few feet, but their roots find no tenure.
To get to the ammonite beds you have to tread a treacherous steep bank of clay and brambles. We disturb a fluffy ginger fox, who slinks lithely away up a near vertical section of the cutting wall and exits into the surrounding farmland. We happily retreat carrying our prizes, hands and legs scratched and caked with grey clay.
