Arctinurus was first reported during the construction of the Erie Canal through soft Silurian shales and mudstones in upstate New York.
It is well developed in the neighbourhood of Ludlow (it is sometimes called the Ludlow limestone) and occupies a similar position in the Ludlow shales at Woolhope, the Abberley Hills, May Hill and the Malvern Hills.
The Hastings Beds are divided into three formations: Tunbridge Wells Sand Formation 130–400 ft; Wadhurst Clay Formation 100–230 ft, shales with bands of sandstone and iron ore; and the Ashdown Formation 160–700 ft; sandstones.
Hopanoids, including 2-alpha-methylhopanes from photosynthetic bacteria (cyanobacteria), were discovered by Roger Summons and colleagues as molecular fossils preserved in 2.7 Gya shales from the Pilbara, Australia.
The Tarannon group is represented by the Rhayader Pale Shales in Powys; in the Moffat Silurian belt in south Scotland by a thick development, including the Hawick rocks and Ardwell Beds, and the Queensberry Group or Gala; in the Girvan area, by the Drumyork Flags, Bargany Group and Penkill Group; and in Ireland by the Treveshilly Shales of Strangford Lough, and the shales of Salterstown, Co.
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The Tarannon shales, grey and blue slates, designated by Adam Sedgwick the Paste Rock, is traceable from Conwy into Carmarthenshire; in Ceredigion, there are gritty beds; and in the neighbourhood of Builth, soft dark shales.