Exposures of Cambridge Greensand can be found in both Cambridgeshire and neighbouring Hertfordshire. It is famous for pterosaur fossils. Over two hundred pterosaur fossil bones have been found, although they are fragmentary.  These fossils represent pterosaurs (mostly ornithocheirids) that died out at sea.  Their bones were buried on the seafloor only to be exhumed again by ancient storms and redeposited as part of geologically much younger strata.  Despite their poor condition and highly fragmentary nature, 19th century scientists erected numerous pterosaur taxa.

To read an article about research into toothless pterosaurs from the Cambridge Greensand: Sinking our Teeth into Toothless Pterosaurs.

An example of a dubious Cambridge Greensand ornithocheirid is Criorhynchus.

Many genera of pterosaur have been erected from highly fragmentary remains associated with Cambridge Greensand material. An example is the ornithocheirid “Criorhynchus”. There is much debate whether this is a valid genus or a nomen dubium. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

Criorhynchus and the Cambridge Greensand

Team members at Everything Dinosaur were given the opportunity to view Cambridge Greensand pterosaur fossils whilst visiting the Sedgwick Museum of Earth Sciences (Cambridge).  Many of the labels associated with the fossilised bones refer to Criorhynchus.  The validity of this taxon has been questioned.  It is an example of a taxon being erected based on poorly preserved and scrappy fossil remains.  More than half a dozen Criorhynchus species were named, all based on Cambridge Greensand material. The controversy over the validity of the pterosaur genera erected based on fossils from this geological unit continues.

The Ornithocheiridae were geographically widespread. Their fossils have been found in Asia, Australia, Europe and the Americas. However, establishing the taxonomy of the Ornithocheiridae as a result of the 19th century research continues to remain problematic.  It is still interesting to visit museums that have these fossils in their collections.  Whilst most researchers disregard a lot of the Cambridge Greensand pterosaur fossils, they represent an important chapter in the study of the remarkable Pterosauria.

Visit the award-wining Everything Dinosaur website for pterosaur and other prehistoric animal models: Pterosaur and Dinosaur Models.