• Webster's Revised Unabridged Dictionary
    • n Mastodonsaurus (Paleon) A large extinct genus of labyrinthodonts, found in the European Triassic rocks.
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Century Dictionary and Cyclopedia
    • n mastodonsaurus A genus of very large labyrinthodont amphibia having a skull one and one quarter meters in length, the outer surface of which is highly sculptured, the premaxillæ pierced for the passage of two tusks of the lower jaw, and the teeth of very complicated structure. The body skeleton is known only in part. It occurs in the Triassic of Europe and India.
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Webster's Revised Unabridged Dictionary
NL., fr. E. Mastodon, + Gr. say^ros a lizard


In literature:

One of them, the Mastodonsaurus, had a head three feet long and two feet wide.
"The Story of Evolution" by Joseph McCabe