Sunday, 21 March 2010

The Stonesfield Slate

The Stonesfield Slate is an interesting deposit which contains quite a lot of fragmentary pterosaur remains. It is one of the few Middle Jurassic deposits in the UK that has yielded pterosaur remains. The pterosaurs of the Middle Jurassic are poorly represented worldwide, so this is an important source of information on the species that were around at that time. It is clear that this age had a very rich pterosaur fauna, as a large number of species are represented by bone fragments, some of which are specific to this time.

One such genus is Rhamphocephalus, which is known from a few jaw, tooth and wing bone remains. It is uncertain that the jaws and wing bones are from the same species, so they are assigned differently.
Rhamphocephalus depresirostris is known from a distal lower jaw fragment and a few isolated teeth. The jaw is unlike any other pterosaur. Two dissociated wing bones are also assigned to this species. Another few wing bones are assigned to Rhamphocephalus bucklandi along with another different jaw fragment.
A further specimen of an upper skull bone is assigned as Rhamphocephalus prestwichi.
There are many remains from the Stonesfield Slate, including individual bones from Dimorphodon, Anurognathus, Pterodactylus and other species.

Huxley T. H., 1859, On Rhamphorhynchus bucklandi, a Pterosaurian from the Stonesfield Slate, Quarterly Journal of the Geological Society, 15: 658, London.

Seeley H.G. 1879, On Rhamphocephalus prestwichi, Seeley, an Ornithosaurian from the Stonesfield Slate of Kineton. Quart. J. Geol. Soc. 36: 27-30

Lydekker R., 1888, Catalogue of the fossil Reptilia and Amphibia in the British Museum (Natural History). I. London, pp. 2–42.

Whalley G., 2000, Pterosaurs of the English Middle Jurassic, Thesis submission, School of Earth, Environmental and Physical Sciences, Portsmouth University, BSc (Hons) in Palaeobiology and Evolution.


  1. oh good timing! I was just looking into the stonefield slate pterosaur fauna and especially what was the diversity like there. Whalley documented an interesting variety of humeri from there. too bad that most of that stuff is still unfigured and the photos in Whalleys dissertation are unfortunately too small to draw any conclusions.

    By the way, is that R. depressirostris photo taken by you? If so would you happen to ha a bigger photo of that and if so could you send me a copy at This is the first time I have seen that specimen. Huxley did figure atleast two mandibles but I don't think this was among them.