Abstract

CARIGLINO, Bárbara. Permian glossopterid scale leaves from the La Golondrina Formation (Santa Cruz, Argentina): the neglected members of Glossopteris floras. Rev. Mus. Argent. Cienc. Nat. [online]. 2013, vol.15, n.1, pp.61-70. ISSN 1853-0400.

Glossopterid scale leaves from the La Golondrina Formation are described and analyzed. Three different types are recognized based on their morphological differences and venation patterns. Type A scale leaves are triangular in shape, have central veins running straight to the apex, and lateral veins dichotomizing once or twice before reaching the margins. Type B scales have wide-ranging shapes, and a number of separate, central veins running straight upwards, dividing and anastomosing several times, while lateral veins arch towards the margin, forming meshes that become shorter and numerous closer to the margins. Last, Type C scale leaves are triangular to rhombic, sometimes subcircular, convex scales, furrowed by straight, sub-parallel veins that arise from the base and reach the distal margin, occasionally dichotomizing closer to the margins. The lower and middle parts of these scales are covered by rounded, small punctuations. The artificial classification here proposed is solely for the purpose of identification of these elements, and do not necessarily imply relationships. The different types of scales could have acted as protection of buds and/or fertile parts or as disperser of the latter once they were ripe.

Keywords : Argentina; Glossopteris; La Golondrina Formation; Permian; Scale leaves.

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