Eckhartianthus lusitanicus 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 : 207-208

Eckhartianthus lusitanicus E.M.FRIIS, P.R.CRANE et K.R.PEDERSEN sp. nov.

Text-fig. 36a–e

H o l o t y p e. Designated here. S101306 (Torres Vedras sample 39; figured Text-fig. 36a–e ).

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.

PFN000470 (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: Lusitania for Portugal where the fossil was discovered.

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. Length of: 1 mm; width of: 0.55 mm.

Diameter of pollen grains: 12–13 µm.

D e s c r i p t i o n a n d r e m a r k s. Eckhartianthus lusitanicus is based on a single flower with perianth, stamens and carpels partly preserved. The base of the flower is missing and there is no information on how the flower was borne on the plant. The flower is bisexual and trimerous with three long tepals apparently in a single whorl, nine stamens and three carpels ( Text-fig. 36a ). The ovary is superior and the stigma apparently sessile. Details of the arrangement of floral organ are uncertain.

The stamens have long broad filaments and dithecate and tetrasporangiate anthers. The anthers are elongate, apparently with longitudinal dehiscent slits. Anthers are indehisced, and full of pollen. Small, irregular rounded orbicules line the inner wall of the anthers. Pollen grains are monocolpate, semitectate-reticulate, with heterobrochate reticulum, rounded muri and short, densely spaced columellae (Textfig. 36b–e). The colpus is long extending almost to the equator and the colpus margin is distinct and psilate (Textfig. 36c). The flower was described and figured in earlier publications ( Friis et al. 1994b, 2006, 2010a, 2011), but not formally named until now.

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. Eckhartianthus lusitanicus is only known from the Torres Vedras locality. The trimerous organization may suggest affinity with monocotyledons (Friis et al. 2011), but critical features needed for a definitive systematic placement are currently lacking.

Figures

Text-fig. 36. Scanning electron microscope (SEM) images of flower of Eckhartianthus lusitanicus gen. et sp. nov.; Torres Vedras locality, Portugal. a) Holotype; oblique lateral view of hypogynous flower showing perianth surrounding the stamens and protruding gynoecium; b–d) Pollen from the flower in (a) showing single distal aperture and reticulate exine with thick muri, small lumina and short, densely spaced columellae; e) Reticulum showing thick, smooth muri supported by numerous short columellae firmly attached to the smooth surface of the foot layer. Specimen, TV39-S101306 (holotype). Scale bars 300 Μm (a), 6 Μm (b–d), 3 Μm (e).