Cartorhynchus

Yesterday I saw So Long, and Thanks for All the Fish sitting on the bookshelf by The Secret Diary of Adrian Mole, aged 13 1/4. Picking up both volumes I was intrigued by the seal* on the cover of the former. I read it and finished it (it's rather short) and it was lying on my desk when I suddenly starting thinking about Cartorhynchus; the obvious connexion was made and I drew a picture of Cartorhynchus based on the picture of the seal. 

*For clarity: a photograph of the aquatic mammal called a seal.