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

Plant Fossil Names Registry Number: PFN001963

Act LSID: urn:lsid:plantfossilnames.org:act:1963

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

Rank: genus

Reference: Friis, E. M., Pedersen, K. R. & Crane, P. R. (2013): New diversity among chlamydospermous seeds from the Early Cretaceous of Portugal and North America. – International Journal of Plant Sciences 174(3): 530–558.

Page of description: 531

Type

Original diagnosis/description

Seeds small and orthotropous. Integument extended apically into long micropylar tube that projects well above the seed envelope. Micropylar tube lined by an outer and inner epidermis; cells of outer epidermis smaller in transverse section than those of inner epidermis. Micropylar canal open apically and closed farther down by cells of the inner epidermis that expand radially toward the center of the canal. Seed envelope obovoid in lateral view; in transverse section distinctly four angled in the middle and almost circular apically and basally. Surface of seed envelope with weakly developed transverse ridges forming a rugulate pattern. Seed envelope expanded apically and laterally into a cup-shaped structure with four long and narrow, almost straight, bipartite projections. In micropylar region the seed envelope is extended into short, collar-like central projection that supports the protruding micropylar tube. Near the base of the collar, small, oblique, upward-directed papillae on its internal surface interlock with small pits in the outer surface of the micropylar tube. Inner epidermis of seed envelope composed of relatively large, longitudinally elongated polygonal cells with thin cell walls. Outer epidermis of seed envelope composed of narrow, longitudinally elongated cells with a thick cuticle. Seed envelope composed of inner zone of sclerenchyma cells and outer zone of nonlignified cells. Sclerenchyma zone with an inner layer of narrow, transversely elongated cells and an outer layer of slightly longitudinally elongated cells, one or two outer layers deep. Inner sclerenchyma cells not markedly enlarged or extended near apex. Outer zone with narrow, longitudinally elongated tubular cells that are especially pronounced near the base and apex but also over the middle of the seed. Apically, the tubular cells form the cup-shaped extension and its four bipartite projections.

Etymology

From the TOMCAT beam line at the Swiss Light Source, Paul Scherrer Institut, Villigen, Switzerland, where the PCXTM and SRXTM analyses were carried out.