The Pterosauria

Dave Martill, David Unwin and Robert Loveridge are working on a definitive publication on the order Pterosauria. The text has a significant number of contributions from the leading workers in the field and has a forward by Peter Wellnhofer. It is planned for publication by Cambridge University Press in December 2010 and this looks like a significant "must have" for anyone who is serious about fossil pterosaurs. The pre-order UK price is £80 sterling, though this is projected to increase after publication.
There have been some significant discoveries since Peter Wellnhofer wrote The Illustrated Encyclopedia of Pterosaurs (published in 1991) and this new text should address the later developments in a clear and informed way. Its publication is eagerly awaited.

New Species Pages

Having been dissatisfied with the way The Pterosaur Database represented the families and species of pterosaurs, I have just completed a re-structuring of the web pages. This is a job in progress, but it should be a little easier to find things. Previously, the pterosaurs were arranged and listed by geological age. This format is still available, but now they are also listed by classification as family groups. This includes time lines for each family extent.
The taxonomic list is based loosely on David Unwins classification, with a few alterations to accommodate some of the more recent ideas. It is not possible to please everyone when a classification structure is produced, and that is why I did not do this before. In reality, the analysis of characteristics that leads to a taxonomic structure is quite fluid. Structures may change over time, or be interpreted differently by different researchers, so these pages need to be viewed as useful, but not exclusive.
The geological age listing is a little more helpful as I have included continental maps to give an idea of the land masses at different tectonic ages.

At a later date, I intend to update individual pterosaur species pages and endevour to obtain photographs of fossils to add to the text only pages. I would also like to add a world distribution map for each family, but that will take a little more time.

Criticism and recommendations are welcome. If anyone wants to send in photographs, they will be appreciated and credited accordingly.

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.

Teeth Revealed

Identifying pterosaur teeth is not easy, especially from photographic evidence. The five teeth below were extracted from my own fossil collection to illustrate the difficulty in knowing that you have a pterosaur fossil tooth. They are all authenticated specimens.

1. Resin cast of a tooth from Syroccopteryx moroccensis - pterosaur
2. Geosaurid Crocodile tooth from the Kem-Kem formation, Morocco - non-pterosaur
3. Steniosaurus tooth collected from the Oxford Clay, UK. - non-pterosaur
4. Fish tooth, Enchodus sp. from the USA - non-pterosaur
5. Plesiosaur tooth from the Oxford Clay, UK - non-pterosaur

Many fossil species show a variation in tooth structure throughout the jaw. In the case of 3 - the tooth from the crocodile Steniosaurus durobreviensis, most of the teeth show little resemblance to pterosaur teeth, but in this case, a few broken teeth from the mid jaw could easily be confused if seen in isolation. I used to live near to the quarry where this specimen was found.

Tooth Quiz

Following on from my last post, I thought it would be interesting to give readers a chance to look at some teeth pictures. This should test even the most experienced eye as it is always difficult to examine teeth from photographs. The photo below is of some of the teeth in my own collection of fossils. Tooth 1 is 3.5 cm long for scale.
Question:- which teeth are pterosaur and which teeth are non-pterosaur?

You may even like to suggest a family or species for each tooth. Answers will follow in a future post.

Pterosaur Teeth

I am frequently asked to identify pterosaur teeth. Sadly, in most cases, the teeth turn out to be non-pterosaur. Many are of fish like Enchodus sp., the sabre toothed herring. These teeth are common and can easily be passed off by dealers as pterosaur teeth to increase profit. Many dealers will also obtain pterosaur teeth from suppliers without knowing that they have been duped.

This is my identification check list - most pterosaur teeth will exhibit these features.

1. Evenly curved and consistently tapering tooth.
2. Wear bevel at the top smooth with no abrasions.
3. Enamel cap at the crown.
4. Fine striations may be present towards the base of the tooth.
5. Open root.

Some larger pterosaur teeth may also show an oval shaped wear patch half way down the tooth where it has rubbed on the side of the opposing tooth when the jaw was closed.
If the tooth does not conform to this type, then the only sure way to know that it is a pterosaur tooth is for it to be fixed within a fragment of fossil jaw bone where the bone structure can be determined.
Most pterosaur teeth are evenly oval in cross section and generally of smooth appearance. There are some exceptions, like the tricuspate teeth of the very early pterosaur species. Specialist feeders like Dsungeripterus and Pterosdaustro, but the shapes of these exceptional teeth are well documented.
The moral of this post is - if you are buying an isolated pterosaur tooth, expect it to be non-pterosaur unless it has provenance and an expert opinion attached. It is also unwise to buy a fossil unless you know the locality, sediment and age of the site that it came from.

Rhamphorhynchus Wings

In 1882 Carl Zittel described a fossil pterosaur wing with the membrane preserved. This remarkable find was the highlight of that year and the Zittel wing became a very famous fossil. Casts were distributed to all of the main national museums and by 1883 most researchers and interested students of fossils had seen the wing.
In 1880, a fine fossil of Rhamphorhynchus was found in the Solenhofen Shales. The work was published in 1882 and clearly showed the wing membranes and tail fin. This specimen was originally named Rhamphorhynchus phyllurus (now Rh. muensteri) and it was sold to the Yale Peabody Museum in New Haven, USA. As with the Zittel specimen, casts were taken and distributed to National Museums.
Since the original finds of pterosaurs with wing membranes preserved, There have been many examples from the Lithographic Shales in Bavaria. The specimen above is in the Humboldt University Museum in Berlin.
Perhaps the best specimen of a Rhamphorhynchus with wing membrane preserved is the 'Dark Wing' specimen which is sometimes called the 'Tischlinger' specimen. This is a reflection of the work of Helmut Tischlinger who produced an amazing set of ultra-violet photographic images of this fossil to enable more detail of the wing to be observed.

These and other fossils enabled the wing structure to be studied in detail, from the fibres that run across the cord of the wing to the different layers of tissue within the wing membrane. As a result, there is a high level of understanding about the wing membrane structure of these and other pterosaurs.

von Zittel, K. A. 1882 Über Flugsaurier aus dem lithographischen Schiefer Bayerns. Paläontographica 29, 47–80 & pls 10–13.

Padian K & Rayner J M V; 1993, Structural fibres of the pterosaur wing: anatomy and aerodynamics. Naturwissenschaften 80: 361-364.

Martill D M and Unwin D M; 1989, Exceptionally well preserved pterosaur wing membrane from the Cretaceous of Brazil, Nature, 340:138-140

Tischlinger, H. and Frey, E. 2002. Ein Rhamphorhynchus (Pterosauria, Reptilia) mit ungewöhnlicher Flughauterhaltung aus dem Solnhofener Plattenkalk. Archaeopteryx, 20, 1-20.