 Description:
This incredibly beautiful specimen is an example of the seed cone
from Auraucaria mirabilis. This  silicified
cone has been sectioned and polished to show the wonderful interior
(the species name says it all). It differs from pinecones in having
only a single ovule (seed) in the cone scale, rather than a pair.
The genus derives its name from the Arauco Province of Chile. Its
closest relatives today are the Monkey Puzzle Tree of South America
(I’ve included a photo of a branch section) and the Norfolk
Island Pine.
The
genus today enjoys a disjunct distribution due to continental drift,
being found in South America  (Argentina,
Brazil, and Chile) as well as New Caledonia, Australia, and New
Guinea. The Araucariaceae had their maximum distribution during
the Mesozoic, becoming extinct in North America with the passing
of the dinosaurs at the end of the Cretaceous. These trees stood
some 100 meters tall, and were felled by a series of volcanic eruptions,
covered by ash, and preserved. Over time, water seeped into the
deposits, digesting the ash, and depositing minerals that resulted
in the panoply of colors seen today.
The
bottom right picture above shows a branch of the extant Araucaria
columnaris.
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