What animal is Arthur from the educational TV series for children named 'Arthur'?

Arthur Timothy Read, and Dora Winifred 'D.W.' Read, and their family are aardvarks. Francine Alice Frensky is a monkey. Prunella Deegan, Rubella Deegan, and their family are poodles. Buster Baxter is a rabbit. Alan "The Brain" Powers is a bear, Binky Barnes is a bulldog, Muffy Crosswire is a monkey. George Lundgren is a moose, and Emil Nigel Ratburn III aka, Mr. Ratburn is a rat.