Arcellites punctatus E.M.Friis, K.R.Pedersen et Marone

Plant Fossil Names Registry Number: PFN002844

Act LSID: urn:lsid:plantfossilnames.org:act:2844

Authors: E. M. Friis, K. R. Pedersen & F. Marone

Rank: species

Genus: Arcellites E.L.Miner

Reference: Friis, E. M., Pedersen, K. R. & Marone, F. (2014): Arcellites punctatus sp. nov.: a new megaspore from the Early Cretaceous of Portugal studied using high resolution synchrotron radiation X-ray tomographic microscopy (SRXTM). – Grana 53(2): 91–102.

Page of description: 93

Illustrations or figures: figs 1–5

Types

Original diagnosis/description

Arcellites megaspore with prominent six-parted acrolamella. Megaspore trilete. Megaspore body spherical with an open, coarsely rugulate surface formed from broad, rounded ridges; outer megaspore wall smooth lacking body appendages. Segments of acrolamella laminar with membranous, crenulate or serrate outer margin. Megaspore wall over the megaspore body three-layered; inner layer thin, of even thickness; middle layer granular-fibrous of uneven thickness causing the rugose surface pattern; outer layer solid, of more or less even thickness, perforated by short, narrow canals that extend almost to the middle layer. Canals straight, of uneven length and distribution with most canals in the valleys between and along the flanks of the rounded ridges; canals absent or scattered over the ridges. Acrolamella extends from outer layer. Microspores adhering to the acrolamellae are trilete with raised proximal region, more or less circular outline, and a psilate-perforate, sometimes faintly rugulate surface.

Etymology

From the distinctive punctate, perforated wall ultrastructure.

Stratigraphy

Cretaceous, Lower Cretaceous
Fluviatile cross-bedded sands with intercalated clay beds and darker organic rich horizons (Almargem Formation); Late Barremian–Aptian

Locality

Portugal
Torres Vedras (39° 06′ 13″ N; 009° 06′ 44″ W)