Caithness CWS - A - Z Caithness - Achanarras


Achanarras fish beds can be found in the layers that were laid down in Lake Orcadie during the Devonian period - 380 million years ago. This was a considerable period before the dinosaurs. Caithness has a great many sites where fish fossils can be found but Achanarras has the most variety of different types. Dipterus valenciennesi a lung fish is the most common fossil at Achanarras The tiny Palaespondylus was a completely new discovery at Achanarras. 14 types of fish have been found at Achanarrras.		The land that became Scotland lay 20 degrees south of the equator 380 million years ago. and appears to have had a warm and dry climate. The climate changed between wetter and dryer periods from 10's to 100's of thousands of years. In wet periods the lake of Orcadie was deep and fish killed by natural events sank and were covered by layers of mud. then in dry times the mud left on the surface was left high and dried out in the sun with layers of sand and sediment becoming eventually 2km thick. The layers were compressed into rock and the many fish were trapped in the layers formed.
Events	Geological Period		Million Years Ago
Present Day The Ice Age	Quaternary		0 - 2
	Tertiary		2 - 65
Extinction of Dinosaurs	Cretacious		65 - 135
First Birds First Mammals	Jurassic		135 - 205
First Dinosaurs	Triassic		205 - 250
	Permian		250 - 290
First Reptiles First Amphibians	Carboniferous		290 - 355
The Achanarras Site	DEVONIAN		355 - 417
	Silurian		417 - 435
First Plants	Ordovician		435 - 510
First Fish	Cambrian		570 - 700
	Pre-Cambrian Eras		700 - 4600
Oldest Rocks In Britain			2800
First Bacteria			3400
Beginning Of Earth			4600