• Webster's Revised Unabridged Dictionary
    • a Testudinate Resembling a tortoise shell in appearance or structure; roofed; arched; vaulted.
    • ***
Century Dictionary and Cyclopedia
    • testudinate Resembling the carapace of a tortoise; arched; vaulted; fornicated. Also testudinated.
    • testudinate Of or pertaining to the Testudinata; chelonian.
    • n testudinate One of the Testudinata or Chelonia.
    • ***
Chambers's Twentieth Century Dictionary
    • adjs Testudinate arched, vaulted, resembling the carapace of a tortoise
    • ***


Webster's Revised Unabridged Dictionary
L. testudinatus, fr. testudo, -inis, a tortoise, an arch or vault
Chambers's Twentieth Century Dictionary
L. testudo, -inis, the tortoise.


In literature:

O Tortoise, 'tis a happy, happy dream, My glorious testudinous regime!
"The Devil's Dictionary" by Ambrose Bierce
What need I mention towers, vineae, and testudines, and the other apparatus used in attacking towns?
"The History of Rome, Books 01 to 08" by Titus Livius
Testudinate -us: resembling the shell of a tortoise.
"Explanation of Terms Used in Entomology" by John. B. Smith
Notes on diseases and mortality in Testudines.
"Natural History of the Ornate Box Turtle, Terrapene ornata ornata Agassiz" by John M. Legler

In news:

So this isn't the first time a member of the order Testudines has proven it has the Right Stuff.