1. pertaining to or resembling a tortoise or tortoise shell.
Once Mrs. Buckland found herself being shaken awake in the middle of the night, her husband crying in excitement: “My dear, I believe that Cheirotherium’s footsteps are undoubtedly testudinal.” … Mrs. Buckland made a flour paste, which she spread across the table, while the Reverend Buckland fetched the family tortoise.
-- Bill Bryson, A Short History of Nearly Everything, 2003
Origin of testudinal
Testudinal derives from the Latin word for "tortoise," testūdō. It entered English in the early 1800s.