Abstract

GNAEDINGER, Silvia  and  HERBST, Rafael. First Record Of Gymnosperm Woods From The Roca Blanca Formation (Lower Jurassic), Santa Cruz Province, Argentina. Ameghiniana [online]. 2009, vol.46, n.1, pp.59-71. ISSN 1851-8044.

Three fossil wood species are recognised from the Liassic (Sinemurian- Toarcian) Roca Blanca Formation: Agathoxylon protoaraucana (Brea) Gnaedinger and Herbst nov. comb., Prototaxoxylon pintadense Gnaedinger and Baieroxylon sp. cf. B. chilensis Torres and Philippe. For their secondary anatomical structures these species have close affinities with the Coniferales (Araucariaceae), Taxales and Ginkgoales? respectively. Also, comparisons of Agathoxylon protoaraucana (Brea) Gnaedinger and Herbst and extant Araucaria araucana (Molina) K. Koch showed that both have identical anatomical characters, which suggests a very conservative group.

Keywords : Fossil wood; Anatomy; Roca Blanca Formation; Liassic; Patagonia.