(CNN) Drawings of an Australasian cockatoo found in a 13th century manuscript in the Vatican library suggest that trade routes around Australia were thriving during medieval times, according to a study published in the journal Parergon.

The four drawings were found in the "De Arte Venandi cum Avibus" (The Art of Hunting with Birds), a book of ornithology and falconry written by the Holy Roman Emperor Fredrick II.

The latest drawings come 250 years before what was previously considered the oldest European depiction of a cockatoo -- found in Italian renaissance painting "Madonna della Vittoria" -- according to Heather Dalton, one of the authors of the study.

This finding suggests that trade off of Australia's northern coast -- an area referred to as Australasia -- was occurring much earlier than previously thought.

"Although our part of the world is still considered the very last to have been discovered, this Eurocentric view is increasingly being challenged by finds such as this," Dalton said in a press statement from Melbourne University

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