Vera Ezequiel I, Césari Silvia N
CONICET- Museo Argentino de Ciencias Naturales, Buenos Aires, Argentina.
An Acad Bras Cienc. 2012 Sep;84(3):617-26. doi: 10.1590/s0001-37652012005000047. Epub 2012 Jul 17.
Two new conifer morphospecies represented by a secondary xylem are reported for the Lower Cretaceous Baqueró Group (Santa Cruz Province, Argentina). Agathoxylon sp. is characterized by poorly defined growth rings, predominantly uniseriate pitting in the radial wall of the tracheids, cross fields with 1-6 pits and uniseriate rays. These features are shared with the leafy branches described for the unit as Araucaria grandifolia Feruglio emend. Del Fueyo and Archangelsky. The second taxon, Brachyoxylon sp. cf. B. boureaui, possesses poorly defined growth rings, mixed wood with predominantly uniseriate radial pitting, cross fields with 8-26 pits and uniseriate rays. These taxa represent the first fossil woods described for Baqueroan strata.
据报道，在阿根廷圣克鲁斯省的下白垩统巴克罗组发现了两种以次生木质部为代表的新针叶树形态种。Agathoxylon sp. 的特征是生长轮不明显，管胞径向壁上主要为单列纹孔，交叉场有1 - 6个纹孔，以及单列射线。这些特征与该单元中描述为大叶南洋杉（Araucaria grandifolia Feruglio emend. Del Fueyo and Archangelsky）的叶枝相同。第二个分类群，Brachyoxylon sp. cf. B. boureaui，生长轮不明显，木材混合，主要为单列径向纹孔，交叉场有8 - 26个纹孔，以及单列射线。这些分类群代表了巴克罗阶地层中首次描述的化石木材。
