Canrightia sp.

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 : 183

Canrightia sp.

Text-fig. 18a–e

D e s c r i p t i o n a n d r e m a r k s. A single fruit of Canrightia containing several seeds has been studied using SEM and SRXTM. The fruit is closely similar to fruits of Canrightia resinifera . However, the specimen from Torres Vedras differs in several features, as well as details of the associated pollen, and cannot be assigned to the same species. The fruit is broadly elliptical in lateral view with rounded apex and base ( Text-fig. 18a ), about 1.25 mm long and 0.95 mm broad. It is lignitised and compressed laterally and internal features are poorly preserved. The fruit contains three or four seeds, but none clearly shows details of the seed coat. The hypanthium is broad with a distinct rim ( Text-fig. 18a ). Five radially arranged scars at the rim of the hypanthium almost certainly indicate the position of five stamens. The epidermis of the fruit wall is composed of polygonal and equiaxial cells, among which are scattered rounded cells, or openings of cells, that are thought to be oil cells ( Text-fig. 18b ).

Pollen grains concentrated on the probable stigmatic area of the fruit are circular in equatorial outline, about 20 µm in diameter, with a long colpus that extends for the full length of the grain ( Text-fig. 18c, d ). The grains are semitectatereticulate with a heterobrochate reticulum that has lumina up to about 1.25 µm in diameter ( Text-fig. 18d, e ). Muri are smooth with an angular profile, and are supported by long, scattered columellae that are typically compressed ( Text-fig. 18e ). The reticulum is only loosely attached to the foot layer, and several grains (not shown) are naked and have lost the reticulum entirely.

Canrightia sp. is distinguished from Canrightia elongata by its more rounded shape and broader hypanthium, and while Canrightia sp. is more similar to Canrightia resinifera it probably represents a new species of the genus based on differences in the associated pollen. Pollen grains of Canrightia resinifera are semitectate-reticulate and columellate, like those associated with Canrightia sp. , but the reticulum in C. resinifera is homobrochate and with lumina that are much larger, up to about 3 µm in diameter. Notwithstanding these differences poor preservation of the internal features of Canrightia sp. precludes establishing a new species.

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. Canrightia sp. occurs, together with C. elongata , only at the Torres Vedras locality. Like Canrightia resinifera and C. elongata , Canrightia sp. is closely related to the clade comprising extant Ascarina , Chloranthus and Sarcandra , among extant Chloranthaceae . The pollen grains show some resemblance to grains of Eckhartia longicolumella described here from the Torres Vedras mesofossil flora (p. 210 herein), but they differ in the angular profile of the muri.

Figures

Text-fig. 18. Scanning electron microscope (SEM) images of a fruit of Canrightia sp. with associated pollen; Torres Vedras locality, Portugal. a) Fruit in lateral view showing prominent cavities in the fruit wall formed by the scattered oil bodies and the broad hypanthium fused to the base of the fruit (arrowhead); b) Fruit surface showing epidermal cells and the scattered oil cells embedded in the fruit wall (arrowheads); c) Cluster of monocolpate pollen grains in the probable stigmatic region of the fruit; d) Pollen grains showing the long colpus and semitectate-reticulate pollen wall; e) Pollen wall showing the reticulum with large and small lumina, and scattered, compressed columellae supporting the smooth muri. Specimen, TV142-S170213. Scale bars 300 Μm (a), 100 Μm (b), 30 Μm (c), 6 Μm (d), 1 Μm (e).