Araucariaceae is a very ancient family of conifers. It achieved its maximum diversity in the Jurassic and Cretaceous periods, when it was distributed almost worldwide. At the end of the Cretaceous, when dinosaurs became extinct, so too did the Araucariaceae in the northern hemisphere.
Fossils widely believed to belong to Araucariaceae include the genera Araucarioxylon (wood), Brachyphyllum (leaves), and Protodammara (cones). In Arizona, the petrified woods of the famous petrified forest in Petrified Forest National Park belong to several species of Araucarioxylon, the most common of them being Araucarioxylon arizonicum. During the Upper (Late) Triassic, the region was moist and mild. The trees washed from where they grew in seasonal flooding and accumulated on sandy delta mudflats, where they were buried by silt and periodically by layers of volcanic ash which mineralized the wood. Some of the segments of trunk represent giant trees that are estimated to have been over 50 meters tall when they were alive.
Cookson, I. C. and Duigan, S. L. (1951) "Tertiary Araucariaceae from South-eastern Australia, with notes on living species" Australian Journal of Scientific Research Series B (Biological Sciences) 4: pp. 415–449
Kendall, Mabel W. (1949) "A Jurassic member of the Araucariaceae" Annals of Botany, New Series 13(50): pp. 151–161
Kershaw, Peter and Wagstaff, Barbara (2001) "The Southern Conifer Family Araucariaceae: History, Status, and Value for Paleoenvironmental Reconstruction" Annual Review of Ecology and Systematics 32: pp. 397–414, doi: 10.1146/annurev.ecolsys.32.081501.114059
Krasilov, Valentin A. (1978) "Araucariaceae as indicators of climate and paleolatitudes" Review of Palaeobotany and Palynology 26: pp. 113–124
Pye, Matthew G.; Henwood, Murray J. and Gadek, Paul A. (2009) "Differential levels of genetic diversity and divergence among populations of an ancient Australian rainforest conifer, Araucaria cunninghamii" Plant Systematics and Evolution 277(3/4): pp. 173–185, doi: 10.1007/s00606-008-0120-1
Usually dioecious, rarely monoecious, evergreen trees. Branches whorled. Leaves awl-shaped or broadly ovate and flattened. Male flowers: large and cone-like, axillary or terminal; stamens numerous. Female flowers: in terminal heads, maturing to a woody cone; each scale with 1 seed, without distinct bracts.
Barcode of Life Data Systems (BOLD) Stats Specimen Records:232 Specimens with Sequences:221 Specimens with Barcodes:214 Species:41 Species With Barcodes:41 Public Records:190 Public Species:40 Public BINs:0