First Pleistocene record of fossil wood of Bignoniaceae in the Americas and a comparison with the extant Tabebuia alliance and Tecomeae

MOYA, E.; BREA M.

BOTANICAL JOURNAL OF THE LINNEAN SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2018 vol. 187 p. 303 - 318

0024-4074

A fossil wood specimen is described from the Late Pleistocene Arroyo Feliciano Formation, Entre Ríos, Argentina.Wood anatomical characteristics indicate a close affinity with extant Bignoniaceae. The diagnostic features are:growth rings indistinct; diffuse-porous wood; vessels predominantly solitary, occasionally radial (two to four cells)and tangential multiples (two to seven cells) and in clusters; simple perforation plates; alternate, bordered andnon-vestured intervessel pits; axial parenchyma apotracheal diffuse and paratracheal, vasicentric complete andincomplete, lozenge aliform and confluent; strands of two to four cells; homocellular rays; mainly uniseriate andsome biseriate rays; fibres septate and non-septate; prismatic crystals in chambered axial parenchyma cells; andpartially and irregularly storied structure in vessels, rays and/or parenchyma. This is the first wood fossil evidenceof Bignoniaceae in the Americas; it exhibits anatomical features similar to extant Handroanthus, Parmentiera,Tabebuia and Tecoma, genera currently included in the Tabebuia alliance (Neotropical clade) and Tecomeae. Thisnew fossil species has the potential synapomorphy (storied structure) of the Tabebuia alliance. The eco-anatomicalfeatures indicate warmer and humid climatic conditions and reconfirm the presence of tropical and subtropicalforests during the Late Pleistocene. This is consistent with sedimentological and microfossil data and adds a newcomponent to the palaeoflora of the Arroyo Feliciano Formation. Also, this fossil extends the biochron of Bignoniaceaein South America, especially Argentina, by c. 5 My, from the Miocene to the Late Pleistocene.