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

Fossil wood specimen is described from the Late Pleistocene Arroyo Feliciano Formation, Entre Ríos, Argentina. The 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 (2?4 cells) and tangential multiples (2?7 cells) and in clusters; simple perforation plates; alternate, bordered and non-vestured intervessel pits; axial parenchyma apotracheal diffuse and paratracheal, vasicentric complete and incomplete, lozenge aliform and confluent; strands of 2?4 cells; homocellular rays; mainly uniseriate and some biseriate rays; fibres septate and non-septate; prismatic crystals in chambered axial parenchyma cells; partially and irregularly storied in vessels, rays and/or parenchyma. Bignonioxylon americanum Moya & Brea gen. nov & sp. nov. is the first wood fossil evidence of the Bignoniaceae family in America and exhibit anatomical features similar to extant Handroanthus Mattos, Parmentiera DC., Tabebuia Gomes ex DC. and Tecoma Juss. emend. Seem., genera currently include in Tabebuia alliance (Neotropical clade) and Tecomeae. This new fossil species has the potential synapomorphy (storied structure) of the Tabebuia alliance. The eco-anatomical features would indicate warmer and humid climatic conditions, and reconfirm the presence of tropical and subtropical forests during the Late Pleistocene. This is consistent with the sedimentological and microfossil data. Moreover, adds a new component to the paleoflora of the Arroyo Feliciano Formation. Also, this fossil extends the biochron of Bignoniaceae in South America, especially Argentina, by c. 5 Ma, from Miocene to Late Pleistocene.