Eckhartia longicolumella 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 : 210-213

Eckhartia longicolumella E.M.FRIIS, P.R.CRANE et K.R.PEDERSEN sp. nov.

Text-fig. 38a–i

H o l o t y p e. Designated here. S136754 (Torres Vedras sample 44; figured Text-fig. 38b–i ).

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.

PFN000473 (for new species).

P a r a t y p e s. Designated here. S136673, S137901

(Torre Vedras sample 44).

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:longus for long and columella referring to the long columellae supporting the muri.

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 with the following additions: Anthers long and narrow. Reticulum fine. Columellae long, scattered.

D i s t i n g u i s h i n g f e a t u r e s. See comments for

Eckhartia brevicolumella and E. intermedia .

D i m e n s i o n s. Length of anthers: about 0.55 mm; width of anthers: 0.15 mm. Length of pollen grains: 16–19 µm.

D e s c r i p t i o n a n d r e m a r k s. Eckhartia longicolumella is based on a single well-preserved anther and several anther fragments. It was first illustrated by Friis et al. (2010a), but not formally described or named. The anthers are about 0.55 mm long, 0.15 mm wide and are dithecate and tetrasporangiate ( Text-fig. 38a, b ).

Pollen grains are about 16–19 µm in equatorial diameter and monocolpate. The exine is semitectate-reticulate, heterobrochate and columellate ( Text-fig. 38c–i ). The reticulum over most of the pollen grain is relatively fine compared to the reticulum of Eckhartia brevicolumella . Lumina are of two sizes; larger lumina are up to about 1.35 µm in diameter ( Text-fig. 38g ). Towards the colpus margin, and particularly around the end of the colpi, the lumina become very small and the colpus margin is psilate ( Text-fig. 38c, e, f ). Muri are about 0.2 µm wide with a rounded or flattened profile. Columellae are long, about 0.45 µm long, typically widely spaced ( Text-fig. 38g, i ). The reticulum is only loosely attached and easily separates from the foot layer, leaving the foot layer naked or with only columellae attached ( Text-fig. 38 h, i ). Orbicules are densely distributed on the inner surface of the anther wall and scattered among the pollen grains ( Text-fig. 38f ). The orbicules are closely similar to the tooth-like orbicules of E. brevicolumella ( Text-fig. 38f ).

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. Like Eckhartia brevicolumella , E. longicolumella has not been observed in any other mesofossil flora from Portugal. The grains of E. longicolumella resemble the grains found on the stigmatic surface of Canrightia sp. described here (p. 183 herein), but differ in the shape of the muri and details of the reticulum.

Figures

Text-fig. 38. Scanning electron microscope (SEM) images of anthers and monocolpate pollen of Eckhartia longicolumella sp. nov. from stamen fragment; Torres Vedras locality, Portugal. a) Dithecate, tetrasporangiate anther that yielded the same kind of pollen as the holotype (b); b) Holotype; stamen fragment that yielded the pollen shown in this Text-figure; c–e) Pollen grains showing the elongated colpi, reticulum with large and small luminae and continuous muri along the aperture margins; f, g) Pollen grains in