Resumo

CEVALLOS-FERRIZ, Sergio, R.S.; RIOS-SANTOS, César  e  LOZANO-GARCIA, Socorro. Abies cuitlahuacii sp. nov. a mummified Late Quaternary fossil wood from Chalco, Mexico. Bol. Soc. Geol. Mex [online]. 2019, vol.71, n.1, pp.193-206. ISSN 1405-3322.  https://doi.org/10.18268/bsgm2019v71n1a10.

A fragment of mummified wood collected from a Quaternary sedimentary sequence of Lake Chalco, Central Mexico, in the depocenter of the Basin (19°15ʹ26ʺN, 98°58ʹ32ʺW), has anatomical characteristics of Abies. Identification is based on the presence of a warty layer in the walls of the tracheids, prismatic crystals in ray cells, taxodioid pits in the cross-fields, and lack of ray tracheids and normal intercellular canals, among other well-preserved characteristics. This specimen represents the first macrofossil evidence of the genus in this region and suggests that by the Late Quaternary it was already established in the surroundings of Lake Chalco, and most probably in what is now central Mexico. Unfortunately, as with morphological and genetic characteristics, the anatomical attributes of the wood of the genus have not been useful for the delimitation of species. Most wood characteristics have been considered of little diagnostic value. However, comparison of available anatomical descriptions of fossil and living species highlight differences among them, even with Abies religiosa wood, which is the closest species to Lake Chalco. Other characteristics or plant organs are needed to assemble a whole plant that can be used to establish phylogenetic relationships and clarify the evolutionary history of the genus. Meanwhile this wood is assigned to a new fossil taxon, Abies cuitlahuacii Cevallos-Ferriz, Ríos-Santos & Lozano-García.

Palavras-chave : wood; Lake Chalco; anatomical characteristics; Late Quaternary; Abies cuitlahuacii.

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