Abstract

SAINZ-RESENDIZ, B. Alejandra; ESTRADA-RUIZ, Emilio; MATEO-CID, L. Elena  and  PORRAS-MUZQUIZ, Héctor. First record of a palm trunk Coryphoideae: Palmoxylon kikaapoa from the Olmos Formation of the Upper Cretaceous, Coahuila, Mexico. Rev. Mex. Biodiv. [online]. 2015, vol.86, n.4, pp.872-881. ISSN 2007-8706.  https://doi.org/10.1016/j.rmb.2015.09.009.

In sediments of the Olmos Formation from the Late Cretaceous (upper Campanian) a diverse flora represented by flowers, fruits, leaves and wood of angiosperms, gymnosperms and polypodiales has been collected, these records document the presence of a flora with paratropical affinities. Here we describe a new fossil palm species, Palmoxylon kikaapoa. The permineralized palm trunk is characterized by an atactostele with fibro-vascular bundles simple with reniform shape; with 1-4 vessels of metaxylem with scalariform and oblique perforation plates; 1-5 protoxylem elements with simple perforation plates; paravascular parenchyma developed; phloem in one phloem strad; tabular parenchyma with 2-8 layers of elongated cells; ground tissue consisting of thin-walled cells forming a not compact tissue with intercellular spaces, type A; numerous fibrous bundles in the fundamental tissue; spherical stegmata occur in discontinuous files next to fibro-vascular bundles or fibrous bundles. These anatomical characters allowed us to taxonomically relate the fossil to the family Arecaceae, subfamily Coryphoideae, and tribe Trachycarpeae. Taking into account paleobotanical and botanical evidence, we propose a tropical affinity and an arboreal habit for this fossil species.

Keywords : Anatomy; Arecaceae; Upper Campanian; Subfamily Coryphoideae; Trachycarpeae.