Anaspermum operculatum 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 : 176-179

Anaspermum operculatum E.M.FRIIS, P.R.CRANE et K.R.PEDERSEN sp. nov.

Text-fig. 15d–j

H o l o t y p e. Designated here. S136740 (Torres Vedras sample 43; figured Text-fig. 15d ).

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.

PFN000455 (for new species).

P a r a t y p e s. Designated here. S174608 (Torres Vedras sample 38); S136739, S136742, S136743, S136746, S170071, S170082-S170084, S170093, S174990 (Torres Vedras sample 43).

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: operculum referring to the presence of an operculum at the micropyle region.

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 seed: 0.7–8.4 mm; width of seeds: 0.42–0.6 mm

D e s c r i p t i o n a n d r e m a r k s. The seeds occur singly and isolated, and there is no information on the fruit or other parts of the plant. The seeds were illustrated earlier, but not formally described or named ( Friis et al. 2010a). They are small, elliptical to ovate in lateral view and elliptical in transverse section ( Text-fig. 15d–f, h, i ). They are anatropous with the hilar scar and micropyle close together on an apical cap-like structure ( Text-fig. 15d, e ) that is sometimes shed ( Text-fig. 15h ). The course of the raphe is seen as a slightly raised rib extending from hilum to the chalazal end of the seed ( Text-fig. 15d, e, i ). The seeds have an almost smooth surface with a faint jigsaw puzzle-like pattern formed from the slightly raised anticlinal walls of the exotesta sclerenchyma that are stellate-undulate folded near the surface of the seed ( Text-fig. 15g ).

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. The cap-like structure with micropyle and hilar scar resembles the germination lid seen in seeds of extant and fossil Nymphaeales . Together with the undulate outline of the exotestal cells this feature strongly suggests a nymphaealean affinity for Anaspermum operculatum . Small seeds, very similar to Anaspermum operculatum , are also known from the Buarcos locality, but details of the micropylar area are not known for these seeds.

Figures

Text-fig. 15. Scanning electron microscope (SEM) images of seeds of Pazliopsis reyi (a–c) and Anaspermum operculatum gen. et sp. nov. (d–j). a) Seed in lateral view showing poorly preserved remains of fruit wall and rough surface of the exotesta; b) Section through the wall of a broken seed showing palisade cells of the exotesta; c) Seed surface showing sunken very deeply sinuous outlines of the exotesta cells; d–f, h, i) Seeds in lateral view (holotype figured in d) showing the pointed micropylar-hilar area, the rounded chalazal end, the smooth surface of the exotesta composed of cells with sinuous cell outlines, and the distinct course of the raphe; g) Surface of the exotesta showing the distinctive cell outlines formed by the sinuous anticlinal walls of the palisade cells; j) Apical view of seed showing the prominent operculum. Specimens, TV43-S171534 (a), TV44-S136683 (b), TV43-S136745 (c), TV43-S136740 (holotype; d), TV43-S136746 (e), TV43-S136739 (f), TV43-S170083 (g), TV S136743 (h), TV43-S136742 (i), TV38-S174608 (j). Scale bars 300 Μm (a, b, d–f, h, i), 50 Μm (j), 30 Μm (c, g).