Arthropleura

A giant millipede, the largest arthropod known.

Up to 2.63 m long and 55 cm wide, estimated from the Northumberland fossil. Beside a person 1.75 m tall; ticks every metre.Body shape drawn for this site

When: Early Carboniferous to Early Permian
Where: Found in Britain at Howick Bay, Northumberland, and elsewhere
Size: Up to 2.63 m long and 55 cm wide, estimated from the Northumberland fossil

Grey scanned images of a segmented Arthropleura fossil, with rows of ridged body plates. — A small, young Arthropleura from France, in the collections of the Muséum national d’Histoire naturelle, Paris. Adults grew far bigger.Arthropleura sp. MNHN.F.SOT002122 by Mickaël Lhéritier, Gregory D. Edgecombe, Russell J. Garwood, Adrien Buisson, Alexis Gerbe, Nicolás Mongiardino Koch, Jean Vannier, Gilles Escarguel, Jérome Adrien, Vincent Fernandez, Aude Bergeret-Medina, and Vincent Perrier, CC BY 4.0, via Wikimedia Commons. Resized.

Arthropleura was a giant relative of millipedes that lived from the early Carboniferous to the Early Permian. A piece of one found on a beach in Northumberland, 76 by 36 cm, is part of a shed skin. The animal that left it is estimated to have been up to 2.63 metres long and 55 cm wide.

By that estimate it is the largest arthropod known from the whole of Earth’s history, a little longer than the biggest sea scorpions.

Arthropleura: 331 to 273 million years ago. That is 7% of the way back to the Earth’s birth.Periods from the ICS chart

Found in Britain. See where Britain was at the time in Britain’s journey.

Also in onto the land

Cooksonia One of the first plants with pipes for water
Tiktaalik roseae A fish on the way to becoming a four-legged animal

Sources

N. S. Davies and others, Journal of the Geological Society 179, The largest arthropod in Earth history: newly discovered Arthropleura remains, Northumberland (2021)