Samylinaea punctatus, E. M. FRIIS, K. R. PEDERSEN et MARONE, 2014

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 : 165-167

Arcellites punctatus E.M.FRIIS, K.R.PEDERSEN et MARONE, 2014

Text-fig. 6c, d

D e s c r i p t i o n a n d r e m a r k s. The species is common in the Torres Vedras mesofossil flora from which more than 100 specimens of megaspores, often with associated microspores ( Friis et al. 2014b) have been recovered. The megaspores are spherical, lack appendages on the spore wall and have a long, twisted acrolamella often with smooth microspores attached to its surface ( Text-fig. 6c, d ).

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. Arcellites punctatus is the only species of Arcellites currently recognized in the mesofossil floras from the Early Cretaceous of Portugal. In addition to the specimens from Torres Vedras, other (rare) specimens are known only from Buarcos and Catefica. The presence of an acrolamella, and the associated microspores, clearly indicate a relationship to extant Marsileaceae , with the fossil genus most likely on the stem group of the extant family.

Figures

Text-fig. 6. Scanning electron microscope (SEM) images of megaspores (a–c) and attached microspores (c, d) with possible affinities to Salviniales; Torres Vedras locality, Portugal. a) Lateral view of Molaspora sp. megaspore showing almost spherical body with a relatively long apical acrolamella; b) Apical view of Molaspora sp. megaspore showing almost spherical body with slightly twisted apical acrolamella; c, d) Lateral view of Arcellites punctatus megaspore showing coarsely rugulate body and apical acrolamella with attached microspores (d). Specimens, TV39-S174616 (a), TV38-S170224 (b), TV43-S170169 (c, d). Scale bars 100 Μm (a–c), 25 Μm (d).