It is most prominently exposed at its type locality in cliff section between Lyme Regis and Charmouth (alongside the underlying Blue Lias) but onshore it extends northwards to Market Weighton, Yorkshire, and in the subsurface of the East Midlands Shelf and Wessex Basin.

The formation played a prominent role in the history of early paleontology, with its Lyme Regis-Charmouth exposure being frequented by fossil collectors including Mary Anning.

Archaeonectrus[6] A. rostratus Charmouth Arnioceras semicostatum-Echioceras raricostatum ammonoid zone BMNH 38525 (holotype skeleton) A marine sauropterygian, member of the family Rhomaleosauridae Attenborosaurus[7] A. conybeari Asteroceras obtusum, Arnioceras semicostatum-Echioceras raricostatum ammonoid zones A marine sauropterygian, early member of the family Pliosauridae.

Prodactylioceras davoei ammonoid zone A marine sauropterygian, type member of the family Plesiosauroidea inside Plesiosauria.

Plesiosaurus[9] P. dolichodeirus Echioceras raricostatum ammonoid zone A marine sauropterygian, type member of the family Plesiosauroidea inside Plesiosauria.

West of Westhay Water, Stonebarrow Stonebarrow Marls Member NHMUK R15907, partial skeleton[12] Considered to belong to I. communis by Bennett et al. 2012, considered indeterminate within Ichthyosaurus by Lomax and Massare 2015 Leptonectes L. moorei[13] Seatown Belemnite Marls Member BMNH R14370 partial anterior skeleton with most complete skull A leptonectid ichthyosaur L. solei[14] Seatown Acanthopleuroceras valdani Subzone, Tragophylloceras ibex Zone, lower Pliensbachian NMW 91.296.2.2 "a large, isolated and incomplete forefin" Turnersuchus[17] T. hingleyae Belemnite Marl Member LRM 2021/45, a partial skeleton including cranial material, cervical, dorsal, and caudal vertebrae, ribs, right pectoral girdle, partial limb bones, and an osteoderm An early diverging thalattosuchian.

The relatively deep rostrum and extreme size dimorphism in the dentition show clear similarities to Dimorphodon, also from the Lias of Dorset.

[23] Dornraptor[25] D. normani Lower cliff face, Charmouth Black Ven Marl Member (Likely) An Averostran theropod, possible Ceratosaur or Tetanuran.

[27] NHMUK PV R36855 differs from those of all other Early Jurassic-Late Triassic, theropods in its combination of features, but bears no discernible autapomorphies.

One of the best known armored dinosaurs of the lower Jurassic, also the most complete found to date, with specimens preserving even the skin and dermal armour.

Foot of Black Ven, Charmouth Asteroceras obtusum ammonoid zone, Black Ven Marl Member Numerous fish species are known from the Charmouth Mudstone and underlying Blue Lias, from such horizons as the "Fish Bed" of the Shales With Beef Member.