Eckhartiopsis parva E.M.FRIIS, P.R.CRANE et K.R.PEDERSEN, 2019

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 : 215

Eckhartiopsis parva E.M.FRIIS, P.R.CRANE et K.R.PEDERSEN sp. nov.

Text-fig. 40a–h

H o l o t y p e. Designated here. S170217 (Torres Vedras sample 39; figured Text-fig. 40a–h ).

P l a n t F o s s i l N a m e s R e g i s t r y N u m b e r.

PFN000476 (for new species).

R e p o s i t o r y. Palaeobotanical Collections , Department of Palaeobiology, the Swedish Museum of Natural History, Stockholm, Sweden .

E t y m o l o g y. From Latin: parvus for small referring to small size of the pollen grains.

T y p e l o c a l i t y. Torres Vedras (NE of Forte de

Forca; 39°06′13″ N, 9°14′47″ W).

T y p e s t r a t u m a n d a g e. Lower member of the Almargem Formation; Early Cretaceous (late Barremianearly Aptian).

D i a g n o s i s. As for the genus.

D i s t i n g u i s h i n g f e a t u r e s. Eckhartiopsis parva is distinguished from Eckhartia as represented in the Torres Vedras mesofossil flora ( Eckhartia brevicolumella , Eckhartia longicolumella , Eckhartia sp. ) by the broader anthers and the heteropolarity of the reticulum, in which the reticulum on the proximal surface is coarser than the reticulum on distal surface. Pollen grains of Eckhartiopsis also lack the distinct psilate region at the ends of the colpi that is characteristic of Eckhartia pollen. Nevertheless, Eckhartia and Eckhartiopsis have similar tooth-shaped orbicules and it is possible that they are systematically closely related.

D i m e n s i o n s. Length of anthers: about 0.53 mm; width of anthers: 0.25 mm. Length of pollen grains: 14– 15 µm.

D e s c r i p t i o n a n d r e m a r k s.Thespeciesisbased on a single well-preserved anther. The anther is dithecate and tetrasporangiate, about 0.53 mm long and 0.25 mm wide ( Text-fig. 40a ).

Pollen grains are about 14–15 µm in equatorial diameter and monocolpate. The exine is semitectate-reticulate, heterobrochate and columellate ( Text-fig. 40b–g ). The reticulum is coarser on the proximal face than on the distal face ( Text-fig. 40c–e ). Larger lumina on the proximal face are up to about 1.5 µm in diameter ( Text-fig. 40c ). Lumina on the distal face are smaller, and only slightly smaller along the colpus margin ( Text-fig. 40e, f ). Muri are about 0.2 µm wide with a rounded or flattened profile. Columellae are long, about 0.5 µm tall and typically widely spaced (Textfig. 40c, h). The foot layer is about 0.4 µm thick ( Text-fig. 40h ). The endexine is granular, apparently very restricted, and developed only under the aperture ( Text-fig. 40h ). The reticulum loosens easily from the foot layer sometimes leaving the main body of the grain naked ( Text-fig. 40g ). Orbicules are densely scattered on the inner surface of the anther wall and over the surface of the pollen grains (Textfig. 40b, e). They are tooth-like with pointed protrusions.

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. Eckhartiopsis parva is currently not known from any other mesofossil flora in Portugal.

Figures

Text-fig. 40. Scanning electron microscope (SEM) images of monocolpate pollen of Eckhartiopsis parva gen. et sp. nov. from an anther; Torres Vedras locality, Portugal. a) Holotype; elongated anther that yielded the pollen in this Text-figure; b–e) Pollen grains showing dense reticulate tectum supported by short columellae that are only loosely attached to the smooth surface of the foot layer: note dentate orbicules on inner surface of anther wall (b, arrowhead); f) Reticulate tectum showing smooth muri with small adhering orbicules (arrowhead); g) Pollen grains showing one in which the reticulum has been lost exposing the smooth surface of the foot layer; h) Fractured pollen wall showing reticulum, short columellae and thick foot layer; note granules on the inner surface of the apertural region (arrow). Specimen, TV39-S170217 (holotype). Scale bars 300 Μm (a), 6 Μm (b–e, g), 3 Μm (f, h).