Samylinaea punctata 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 : 233-236

Samylinaea punctata E.M.FRIIS, P.R.CRANE et K.R.PEDERSEN sp. nov.

Text-fig. 52a–h

H o l o t y p e. Designated here. S174565 (Torres Vedras sample 44; figured Text-fig. 52a–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.

PFN000496 (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: punctatus referring to fine perforations of the tectum.

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 pollen grains: about 29 µm; width of pollen grains: about 21 µm.

D e s c r i p t i o n a n d r e m a r k s. Samylinaea punctata is based on a single pollen clump comprising only one kind of pollen. It is probably a fragment of a stamen ( Text-fig. 52a ). The pollen is of medium size, prolate, with polar axis about 29 µm long and about 21 µm wide at the equator ( Text-fig. 52b, e, g ). The basic arrangement of the apertures is tricolpate, but their arrangement exhibits unusual variation. The colpi are long, reaching almost to the poles ( Text-fig. 52b, g ) and are often irregular and appear branched ( Text-fig. 52e, f, h ). The exine is tectate-punctate, and columellate with short columellae ( Text-fig. 52d ). The tectum and the infratectal columellate layer are of almost equal thickness, each about 0.3–0.4 µm thick, while the foot layer is slightly thinner. The colpus margin is distinct and the colpus membrane coarsely verrucate ( Text-fig. 52b, e, g, h ). Small, spherical orbicules with a finely granular surface occur abundantly on the surface of the pollen grains ( Text-fig. 52c, h ).

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. Currently Samylinaea punctata is known only from the Torres Vedras site. The triaperturate pollen grains clearly indicate a relationship to eudicots. Pollen of Samylinaea punctata shows some similarity with pollen found in situ in the ranunculalean flower Teixeiraea lusitanica BALTHAZAR, K.R.PEDERSEN et E.M.FRIIS from the Vale de Água locality (von Balthazar et al. 2005), but the pollen grains in Teixeiraea lusitanica flowers are smaller, lack the irregular folds, and have larger perforations in the tectum and orbicules that are smaller with a central depression. Tricolpate pollen with tectate-perforate pollen wall and very long colpi resembling the pollen of Samylinaea punctata was described from the mid-Aptian-mid-Albian of Egypt as Punctitri-Fineret ( Penny 1991), but this pollen type is distinguished by its smaller size and larger perforations (foveolate-microreticulate).

Figures

Text-fig. 52. Scanning electron microscope (SEM) images of tricolpate pollen of Samylinaea punctata gen. et sp. nov from a pollen clump; Torres Vedras locality, Portugal. a) Pollen clump (probable stamen fragment) that yielded the pollen in this Text-figure; b) Polar view of pollen grain showing two colpi, granular aperture membrane, and punctate tectum; c) Orbicule showing very finely granular surface; d) Pollen wall showing short columellae, well-developed punctate tectum and slightly thinner foot layer; e–h) Pollen grains showing punctate tectum and the folds associated with the irregular development of the colpi. Specimen, TV44-S174565 (holotype; a–h). Scale bars 300 Μm (a), 6 Μm (b, e–h), 3 Μm (c, d).