Dejaxia brevicolpites 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 : 199-200

Dejaxia brevicolpites E.M.FRIIS, P.R.CRANE et K.R.PEDERSEN sp. nov.

Text-fig. 30a–h

H o l o t y p e. Designated here. S137909 (Torres Vedras sample 44; figured Text-fig. 30a–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.

PFN000466 (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: brevis for short, and colpus, referring to the short colpus.

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 m e n s i o n s. Equatorial diameter of pollen grains: about 16 µm.

D e s c r i p t i o n a n d r e m a r k s. Dejaxia brevicolpites is based on a pollen clump, probably an abraded pollen sac, containing many pollen grains of the same kind ( Text-fig. 30a ). The pollen grains are small, almost spherical with a circular equatorial outline, and monocolpate ( Text-fig. 30b, c–h ). The exine is tectate, psilate-punctate-foveolate with a slightly undulating/rugulate surface in which the rugulae are associated with depressions around the scattered perforations ( Text-fig. 30b, h ). The colpus is short, about 6 µm long and much shorter than the equatorial diameter. The colpus margin is distinct but slightly irregular. The colpus membrane is finely verrucate ( Text-fig. 30d–e ). Abundant small, spherical orbicules with an irregular surface occur abundantly on the surface of the pollen grains ( Text-fig. 30b–e, g, h ).

regions of the grain beyond the colpus margin; f, h) Pollen grains in proximal view showing poorly differentiated microechinae; g) Stamen fragment that yielded the pollen in (h–i); i) Broken pollen grain showing the granular infratectal layer. Specimens, TV44 - S137919 (holotype; a–f, k) , TV44 - S148011 (g–i) , TV44 - S136768 (j) , TV44 - S174557 (l) . Scale bars 120 Μm (a, g), 6 Μm (b, d–f, h, j–l), 3 Μm (i), 1.2 Μm (c).

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. Dejaxia brevicolpites is currently known only from the Torres Vedras mesofossil flora. Dejaxia brevicolpites , like Appomattoxia minuta , Appomattoxia ancistrophora , Appofructus nudus and Appofructus sp. , as well as the species of Goczania , is probably related to extant Piperales (see above).

Figures

Text-fig. 30. Scanning electron microscope (SEM) images of monocolpatepollen of Dejaxia brevicolpites gen. et sp. nov. from a pollen clump; Torres Vedras locality, Portugal. a) Holotype; pollen clump (possible single pollen sac) that yielded the pollen in this Textfigure; b, c) Group of almost spherical pollen grains showing the irregularly undulating psilate tectum and abundant orbicules; d–g) Pollen grains showing the short colpi with a granular aperture membrane (d, f) and the irregularly undulating psilate tectum with scattered small perforations; note abundant orbicules (g); h) Pollen grain in proximal view showing the irregularly undulating psilate tectum resulting from the depressions around the perforations in the pollen wall. Specimen, TV44-S137909 (holotype). Scale bars 300 Μm (a), 30 Μm (b), 12 Μm (c), 6 Μm (d–h).