Relic proves existence of coastal crocodiles

Fossilised Steneosaurus bone.
Fossilised Steneosaurus bone.

It’s hard to believe, but large crocodiles were once a fairly common sight along this part of the Yorkshire coast. We’re talking, of course, about the Jurassic period, about 160 million years ago – but relics of their existence around here can still be found.

On a stormy Boxing Day afternoon in 1982, a local family found a piece of that evidence. They were walking on the beach at Robin Hood’s Bay when they spotted some ammonites on the cliff face.

Many fossilised marine reptiles were found along this coast in the 18th and 19th centuries.

Further investigation revealed that the ammonites were attached to what appeared to be a bone. The family managed to release the fossil from its home, and took it to what was then the Natural History Museum at Woodend on Scarborough’s Crescent, where it was photographed, and the picture sent to the University Museum at Oxford.

The photograph was examined by the museum’s Curator of Geological Collections Mr HP Powell, and leading vertebrate palaeontologists Michael Benton and Michael Taylor, now both senior members of the Department of Earth Sciences at the University of Bristol.

The latter wrote a charming letter to Don Waterman, then Director of Tourism and Amenities at Scarborough Borough Council.

“It is difficult to be sure from the photo alone, especially as we are not sure what if any has been worn away by wave action, but we don’t think it’s plesiosaurauian. The nearest we can think of at the moment is that is the posterior portion of the skull roof of a gavial-like marine crocodile, such as Steneosaurus and Pelagosaurus (Upper Lias of the Yorkshire Coast).”

A hand-written note at the end of the letter further identifies the bone as “Upper Lias – 160 millions years ago. Probably Steneosaurus Bollensis, a marine crocodile about 2½ metres long.”

Dr Taylor also produced a rough sketch of the probable location of the bone at the back of the crocodile’s skull.

Steneosaurus was a fairly modern-looking crocodile. Later Jurassic forms reached up to 13 feet (four metres) in length. It had a long narrow snout, similar to modern garials from South East Asia, and long slender teeth for catching and eating fish.

Fossil specimens of Steneosaurus have been found in England, France, Germany, Switzerland and Morocco. The largest species, Steneosaurus heberti, could grow to a mighty 5m (16-and-a-half feet) long, although a fully-grown size of 2.5–3.5m was much more common.

If you’d like to see a spectacular complete crocodile skeleton, then pay a visit to the Whitby Museum, whose most treasured fossil is that of a Teleosaurus chapmani. This three-metre-long marine crocodile was found in Whitby in 1824. A local carpenter, Brown Marshall, had spotted the beast’s snout sticking out of the cliff, and excavated the skeleton by hanging perilously from the cliff top on ropes. He sold it to the museum for the princely sum of £7 – the equivalent of around £685 today.

Many fossilised marine reptiles were found along this coast in the 18th and 19th centuries when vast quantities of alum shale were moved in order to extract the alum, which was used in the textile industry as a fixative for dyes.

The fossilised bone which is our exhibit of the week today was recently donated by the family who found it at Christmas over 30 years ago to the Scarborough Collections, the name given to all the museum objects and artwork acquired by the borough over the years, and now in the care of Scarborough Museums Trust. For further information, please contact Collections Manager Jennifer Dunne on or 01723 384510.

And you can find out much more about fossils at the second annual Yorkshire Fossil Festival, which will be held in and around the Rotunda Museum on Vernon Road between 18 and 20 September.

Events will include, on the Saturday at 4.30pm at Scarborough Library, a family-friendly talk by Dr Alexander Dunhill, Research Fellow at the University of Leeds, on the dinosaurs that once roamed the Yorkshire Coast.

For further information, please visit the Scarborough Museums Trust website:!fossil-festival/csj0