Written by Alex Peaker, Assistant Community Learning Officer, Dinosaur Isle Museum.
This past year has been the weirdest I have experienced in my lifetime but one thing the uncertainty of COVID hasn’t affected is the steady flow of spectacular specimens found on the Isle of Wight.
Over the last nine months a small area of the Isle of Wight has produced the remains of at least four partial turtle skeletons, including one of the most complete Palaeogene turtle skeletons to have been found in England.
The initial find dates back to April 2020 when we received an enquiry through Facebook. We see some lovely finds through this method but not often do we get sent a photo of a pyritic block containing a large portion of turtle carapace along with the skull and some articulated cervical vertebrae.
This is an amazing find, skulls of any animal are quite rare, but to find a skull, partially articulated neck and part of the carapace of the animal all together is unbelievably unlikely.
At the time of the enquiry we were in the height of the first lockdown and the finder very kindly offered to donate the specimen to the Museum, but due to the COVID regulations at the time we held back and met with him in May 2020 when the regulations had started to ease off. Unfortunately none of us at the Museum live near the site and so visiting it would have likely broken the laws at the time. It wasn’t until May that any of us managed to visit where the skull had been found in order to narrow down the geology of the specimen and to prospect for more.
Later in April however, another gentleman got in touch with the Museum for an identification as he suspected he had found bone. This time we were shown another pyritic block containing a portion of turtle carapace along with a humerus, ulna, radius and other bones.
In amongst the pyrite and bones of both blocks are numerous mollusc remains that allowed us to recognise the bed that the turtles had come from. Unfortunately, although we re-visited the site on numerous occasions, the bed was always covered with sand and seaweed so we never managed to find more.
Late in August 2020, we received a call from a member of the public who believed she had found a turtle in clays close to where the skull and arm had been found. What she had spotted turned out to be one of the most spectacular fossils I have excavated; exposed in dark blue clays at the base of the cliff was the carapace, scapulae and a vertebra. Over the next two days with help from the finder and volunteers we collected loose material on the foreshore nearby and excavated further into the clays to expose and jacket the turtle. Whilst digging it became apparent we had most of a turtle; the majority of the carapace and plastron, articulated limbs and vertebrae.
Over the last months both turtles have been conserved and prepared. The excavated turtle has shown to be complete from the shoulders to the tail, missing only a small amount of the carapace, the neck and the skull. The finding of the skull on the same beach turns out to be co-incidental; the carapace preserved with the skull shows costals (the middle ‘ribs’ of the carapace) and the more complete individual is only missing part of the nuchal (the forward-most part of the carapace).
During conservation of the specimens it became apparent that whilst a reasonable amount of what we found loose on the foreshore was associated with the excavated skeleton, a good amount is from a completely different animal, the shape and size of the ornamentation on the carapace show it to be a different, smaller individual. Unfortunately, although we have found a good number of fragments of the individual, partial remains like this are quite common on the North Coast of the Isle of Wight and as of yet it hasn’t shown to be any more than fragments of carapace.
Since August 2020, staff and volunteers have visited the site on numerous occasions and more fragments associated with each of the three individuals were found. This went on until the end of November when one of our volunteers found the remains of a fourth turtle. From the same locality (although a slightly different lithology) we excavated what appears to be the majority of a slightly dis-articulated carapace, a partial pes/manus, a cervical vertebra and part of the plastron (a hypoplastron).The latest specimen was excavated at the beginning of December and the preparation and conservation of it is ongoing work.
All four turtles show a distinctive rippled pattern on the outward facing surface of the plastron and carapace, a feature that in the British Paleogene is specific to Trionyx, an extant genus of soft-shelled turtle.
Unfortunately, due to our third lockdown – field and lab work slowed down again but things have still progressed. Loose material found on the foreshore has been attributed to the four different animals, the conservation and preparation of the most complete individual and the skull has nearly finished and the most recent specimen has been partly stabilised and readied for further conservation and preparation.
In the future it is likely the specimens will be displayed at the Museum and will be used in on-going research into the Paleogene turtles of the Isle of Wight. Aside from a Master’s thesis describing the partial remains held at the Museum (1995), few studies have looked at these fossils since Richard Owen’s descriptions of Paleogene turtles (1849). Since then the seven species of Trionyx created by Owen have been moved into one, T. henrici, and a publication has made the British Trionyx synonymous with Rafetoides, so in theory the four turtles are examples of Rafetoides henrici but this will eventually be decided by people with more knowledge of turtles than me.
I (and Dinosaur Isle Museum) owe a huge thanks to the numerous members of public and volunteers who found, donated, and assisted with the excavation of these turtles. Thank you to:
Juliet Dettmer, Sandra Garbett, Anne Hornett, Martyn Hornett, Colin Lamplough, Jeremy Lockwood, Steve Simmonds and Trudie Wilson.