Sunday, 4 February 2018

A Red Crag whale

A fossil whale vertebra can be a beautiful thing. I was delighted when a friend gave me one he'd found on Landguard beach, near Felixstowe, south-east Suffolk.




The front (anterior) side of the specimen still has its flat articular surface, but the back (posterior) side has been worn away by the sea. There are two projections on either side. These are the eroded bases of the bony projections supporting the neural arch.

Thoracic vertebrae of Greenland right whale, showing
centrum and bones of the neural arch.
Image courtesy Eschricht & Reinhardt (1866)
Given its findspot, a Red Crag origin for the specimen is likely. It must have been washed out of the Red Crag strata which outcrop in the Felixstowe area. The town is founded on these reddish-yellow, sandy, fossiliferous sediments of Pliocene age about 2.5 million years old. They also outcrop to the north at Bawdsey and to the south at Walton-on-the-Naze, Essex.

My first exposure to whale fossils was when I was working on the geological collections at Ipswich Museum in 2004/05. There were racks and boxes full of Crag specimens like this, but very few of them had any firm identification. Spencer (1970) recounts everything known about the Crag cetaceans in Ipswich Museum.


I contacted the Natural History Museum in London to see whether I could find out more. Dr Travis Park, a fossil cetacean specialist, gave helpful replies to my questions.
It is a partial thoracic vertebra from either a small baleen whale or a big toothed whale... it's likely [to be] either an anterior or mid-thoracic. ... 
In terms of size, it’s probably closer to something in the 5-10 metre range. That’s a very rough estimate given the degree of wear of the specimen. So it could be a small sperm whale or one of the beaked whales which easily get that size and even bigger. If it’s a baleen whale then a minke whale would be a good proxy although there was quite possibly other small baleen whale lineages around at that time too
It's unfortunate that the specimen is so worn as to make it impossible to narrow down to Order level (mysticete or odontocete), let alone Family. Still, it's an attractive thing to have on my shelf, and it prompts me to find out more about the cetaceans of our beautiful 'Blue Planet' as they were in the Pliocene.




References
  • Eschricht, DF & Reinhardt, J. 'On the Greenland Right Whale Balaena Mysticetus. In: Flower, WH (ed). Recent Memoirs of the Cetacea. Ray Society, London, 1866.
  • Spencer, HEP (1970). A Contribution to the Geological History of Suffolk. Part 5. The Early Pleistocene. The Crag Epochs and their Mammals. Transactions of the Suffolk Naturalists’ Society, vol.15, pt. 4.
For further information about the geology of the Suffolk coast see my booklet 'Tides of Change' (2015).