Mesozoic Araucariaceae: Morphology and systematic relationships

The Southern Hemisphere conifer family Araucariaceae has a very restricted present day distribution, but was more widespread in the past. The genusAraucaria is represented by good fossil material in both hemispheres as early as the Jurassic, whileAgathis is only known from the Southern Hemisphere beginning in the Cretaceous. Cuticle studies of extant araucarians have enabled accurate comparisons of fossil leaves to living taxa.Araucaria SectionBunya is represented by cones of several types in the Jurassic. In addition to these remains, a suite of araucarian cones showing affinities to several sections of the genusAraucaria have been described from England, Japan and North America. Evidence that fossil araucarian cones may have produced seeds with hypogeal germination is discussed in light of recent work on germination of extant bunya seedlings and the discovery of new fossil shoots from the Jurassic Morrison Formation of Utah.