Clavatipollenites sp. 2

Friis, Else Marie, Crane, Peter R. & Pedersen, Kaj Raunsgaard, 2019, The Early Cretaceous Mesofossil Flora Of Torres Vedras (Ne Of Forte Da Forca), Portugal: A Palaeofloristic Analysis Of An Early Angiosperm Community, Fossil Imprint 75 (2), pp. 153-257 : 189

Clavatipollenites sp. 2

Text-fig. 23a–c

D e s c r i p t i o n a n d r e m a r k s. The material comprises a single clump of many pollen grains (not shown) that are all of the same kind. Pollen grains are monocolpate, almost circular in equatorial outline, about 16 µm in diameter, and semitectate-reticulate with a homobrochate reticulum ( Text-fig. 23a–c ). Lumina are irregular and up to about 1.5 µm in diameter. Muri are ornamented with tiny verrucae arranged along the margins of the muri. Columellae are long and widely spaced ( Text-fig. 23c ). The aperture is narrow elongate without a distinct margin ( Text-fig. 23a ), but in most grains only the proximal surface is exposed ( Text-fig. 23b ).

A f f i n i t y a n d o t h e r o c c u r r e n c e s. In their general shape, the nature of the pollen wall and aperture configuration, the pollen grains are similar to various dispersed pollen grains that are generally assigned to the genus Clavatipollenites and that are thought to be of probable chloranthoid affinity (see above).

Figures

Text-fig. 23. Scanning electron microscope (SEM) images of Clavatipollenites sp. 2 (a–c) from a fragmentary stamen, and stamen fragments with in situ pollen of Clavatipollenites sp. 3 (d–j); Torres Vedras locality, Portugal. a, b) Distal (a) and proximal (b) view of pollen showing simple, elongate colpus on distal surface and semitectate-reticulate pollen wall; c) Detail of pollen wall showing muri with finely verrucate supratectal ornamentation and long scattered columellae; d) Fragment of tetrasporangiate stamen; e, f) Distal views of pollen from stamen fragment showing poorly defined aperture, coarse reticulum and long scattered columellae; g) Fragment of stamen; h) Distal view of pollen showing poorly defined aperture covered by irregular verrucae; i, j) Pollen wall showing rounded orbicules (i) and fractured pollen wall showing long scattered columellae (j). Specimens, TV43-S136728 (a–c), TV44-S149201 (d–f), TV44-S149220 (g–j). Scale bars 300 Μm (d, g), 6 Μm (a, b, e, f, h), 3 Μm (c), 1.5 Μm (i, j).