Psephophorus is an extinct genus of sea turtle that lived from the Oligocene to the Pliocene. Its remains have been found in Europe, Africa, North America, and New Zealand. It was first named by Hermann von Meyer in 1847, and contains seven species, P. polygonus, P. calvertensis, P. eocaenus, P. oregonesis, P. californiensis, P. rupeliensis, P. scaldii, and a species discovered in 1995, P. terrypratchetti.

Sir Terence David John Pratchett was an English author, humorist, and satirist, best known for his 41 comic fantasy novels set on the Discworld, and for the apocalyptic comedy novel Good Omens (1990) which he wrote with Neil Gaiman.