Thodaya E.M.Friis, P.R.Crane et K.R.Pedersen

Plant Fossil Names Registry Number: PFN000213


Authors: E. M. Friis, P. R. Crane & K. R. Pedersen

Rank: genus

Reference: Friis, E. M., Crane, P. R. & Pedersen, K. R. (2019): Chlamydospermous seeds document the diversity and abundance of extinct gnetalean relatives in Early Cretaceous vegetation. – International Journal of Plant Sciences 180(7): 643–666.

Page of description: 657


Thodaya sykesiae E.M.Friis, P.R.Crane et K.R.Pedersen

Original diagnosis/description

Seeds borne three together in a linear arrangement. Seeds small and orthotropous. Integument free from seed envelope for its full length except at the base, where it is broadly attached. Apex of nucellus composed of thinwalled cells and a papillate depression (probable broad pollen chamber). Integument extended apically into a long micropylar tube formed by an inner and an outer epidermis. Micropylar canal open apically, closed farther down by the cells of the inner epidermis of the micropylar tube that are expanded radially toward the center of the micropylar canal. Seed envelope
broadly elliptical in lateral view, elliptical in transverse section, slightly pointed in the micropylar region. Outer surface of the seed envelope almost smooth; outer epidermis of narrow, longitudinally aligned cells covered by a thin cuticle. Inner surface of the seed envelope in the micropylar region
smooth, without papillae. Seed envelope with an inner layer of transversely elongate fibers, a middle layer of small, equiaxial, thin-walled cells, and an outer zone of large, thin-walled cells.


In honor of Mary G. Thoday (Sykes) for her pioneering studies of extant Gnetales.

Plant fossil remain

macro- and meso-fossils-embryophytes except wood

Names associated with genus

Thodaya sykesiae E.M.Friis, P.R.Crane et K.R.Pedersen 2019


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