Palaeophis toliapicus (Owen, 1841)

Palaeophis toliapicus is one of the two types of sea snake which have been found in the London clay. Snake fossils are quite rare and usually found as individual vertebrae in the shingle patches of the beach and extremely rarely found as articulated nodules. 

Studies on the Palaeophis (the genus of Palaeophis toliapicus) vertebrae show a high degree of vascularisation, suggesting that it had a considerably faster metabolism and growth rate than modern snakes. This may suggest that palaeophiids, like other marine reptiles such as mosasaurs, might have developed towards endothermy*.

*Endothermy is the ability of an organism to maintain a constant body temperature through metabolic processes. Endothermic organisms are also known as warm-blooded. 

Examples can be seen below:

Acknowledgments:

Thank you very much Tony Mitchell and Martin Rayner for allowing usage of the images on this page. 

References:

https://www.biodiversitylibrary.org/item/99824#page/12/mode/1up 

https://www.gbif.org/species/4968179 

https://en.wikipedia.org/wiki/Palaeophis 

Further reading:

http://www.sheppeyfossils.com/pages/snake_2.htm