MESOZOIC ARAUCARIACEAE - MORPHOLOGY AND SYSTEMATIC RELATIONSHIPS

The Southern Hemisphere conifer family Araucariaceae has a very restri cted present day distribution, but was more widespread in the past The genus Araucaria is represented by good fossil material in both hemisp heres as early as the Jurassic, while Agathis is only known from the S outhern Hemisphere beginning in the Cretaceous. Cuticle studies of ext ant araucarians have enabled accurate comparisons of fossil leaves to living taxa. Araucaria Section Bunya is represented by cones of severa l types in the Jurassic. In addition to these remains, a suite of arau carian cones showing affinities to several sections of the genus Arauc aria have been described from England, Japan and North America. Eviden ce that fossil araucarian cones may have produced seeds with hypogeal germination is discussed in light of recent work on germination of ext ant bunya seedlings and the discovery of new fossil shoots from the Ju rassic Morrison Formation of Utah.