Endressistemon cateficensis E.M.FRIIS, P.R.CRANE, K.R.PEDERSEN, M.M.MENDES et J.KVAČEK, 2022

Friis, Else Marie, Crane, Peter R., Pedersen, Kaj Raunsgaard, Mendes, Mário Miguel & Kvaček, Jiří, 2022, The Early Cretaceous Mesofossil Flora Of Catefica, Portugal: Angiosperms, Fossil Imprint 78 (2), pp. 341-424 : 381

Endressistemon cateficensis E.M.FRIIS, P.R.CRANE, K.R.PEDERSEN, M.M.MENDES et J.KVAČEK sp. nov.

Text-fig. 28a–g

H o l o t y p e. S107778 (Catefica sample 49; figured Text-fig. 28a, b, e, f ).

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.

PFN002797 (for new species).

P a r a t y p e s. S107751, S107768, S107769, S266022 (Catefica sample 49).

R e p o s i t o r y. Palaeobotanical Collections, Department of Palaeobiology, Swedish Museum of Natural History, Stockholm, Sweden (S).

E t y m o l o g y. From the Catefica locality where the fossils were collected.

Ty p e l o c a l i t y. Catefica (39° 03ʹ30ʺ N; 09°14ʹ 30ʺ W), between the villages of Catefica and Mugideira, about 4 km south of Torres Vedras, Portugal .

T y p e s t r a t u m a n d a g e. Almargem Formation, Early Cretaceous (Aptian-early Albian).

S p e c i f i c d i a g n o s i s.As for the genus.

D i m e n s i o n s. Stamens up to about 0.9 mm long and 0.2 mm in broad.

D e s c r i p t i o n a n d r e m a r k s. The material includes isolated staminal structures each consisting of two lateral stamens and in some specimens a median axislike structure. The two stamens and axis-like structure are borne on a short, common stalk ( Text-fig. 28a–e ). The anthers are basifixed, tetrasporangiate and dithecate ( Text-fig. 28a, b ).

Figures

Text-fig. 28. Scanning electron microscope (SEM) images of stamens and pollen of Endressistemon cateficensis gen. et sp. nov.; Catefica locality, Portugal. a, b) Staminal structure with two lateral stamens and one median structure seen in ventral and dorsal view (orientation unknown) showing that each stamen has a prominent apical extension and two pairs of pollen sacs separated by a narrow connective; both stamens are borne on a common base together with the median structure and their anthers are sessile on the common stalk; note the apical projection of the median structure (asterisk) between the two stamens and the ribs over probable vascular bundles that extend from the common base into the apical projections of both stamens and the median structure (arrows); c) Staminal structure showing two stamens with prominent apical projections and median axis-like structure between the two stamens (arrow); d) Staminal structure showing two stamens with prominent apical projections borne on a common base; e) Staminal structure in (a) and (b), from the same orientation as (b), showing the ribs over probable vascular bundles (yellow) that extend into the apical projections; f) Detail of staminal structure in (a) and (b) showing the fused or strongly adhering apical projections of the two lateral stamens and the median structure (asterisk); g) Monocolpate, reticulate pollen grains from the pollen sacs of stamen in (d). Specimens, Catefica 49-S107778 (holotype, a, b, e, f), Catefica 49-S107769 (c), Catefica 49-S107751 (d, g). Scale bars = 600 Μm (a–d), 300 Μm (e), 100 Μm (f), 6 Μm (g).