This article was originally published with the title “ Polydactyl Horses, Recent and Extinct ” in SA Supplements Vol. 8 No. 188supp (August 1879), p. 2983 doi:10.1038 ...

Almost 50 cats - about half polydactyl, external - live in the Key West home and museum. Guinness World Records says the current record holder, Jake, lives in Ontario, Canada. More on this story ...