Canrightia resinifera E.M.FRIIS et K.R.PEDERSEN, 2011

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 : 345-347

Canrightia resinifera E.M.FRIIS et K.R.PEDERSEN, 2011

Text-fig. 2c–g

Description and remarks. Fruits and seeds of Canrightia resinifera are the most common angiosperm fossils in the Catefica mesofossil flora with several hundred specimens recorded so far including the type material on which the genus was established ( Friis and Pedersen 2011). The fruits are elliptical to spherical in outline, contain two to five seeds, and have abundant resin-bodies in the fruit wall. The fruits are interpreted as berries ( Text-fig. 2c, d ). The fruits develop from bisexual flowers with a semi-inferior ovary and about four staminal scars in a radially symmetrical arrangement on the rim of the hypanthium ( Text-fig. 2c ). The many resin bodies in the fruit wall, combined with the often-wrinkled fruit surface, sometimes make the precise position of the hypanthium and the staminal scars difficult to distinguish. The stigma at the apex of the fruit is lobed. The seeds are orthotropous, pendent and endotestal, with a distinct, finely crystalliferous, endotesta ( Text-fig. 2d, e ) and with the inner epidermis of the tegmen developed as a distinct endothelium ( Text-fig. 2g ).

Pollen grains are common in the stigmatic region. They are monocolpate, 15.8–21.0 μm with a long extended colpus, and a coarsely reticulate tectum. Muri are smooth, with a high and sharp profile, and are supported by long and scattered columellae ( Text-fig. 2f ). The grains are similar to pollen assigned to the extinct genus Piercipollis E.M.FRIIS, P.R.CRANE et K.R.PEDERSEN ( Friis et al. 2019a). Dispersed pollen of this type has traditionally been assigned to the extinct genus Retimonocolpites R.L.PIERCE , but in the type species, Retimonocolpites dividuus R.L.PIERCE , the colpus extends from the distal surface over to the proximal surface of the grain dividing the grain in two halves ( Pierce 1961). In contrast, in Piercipollis the colpus is restricted to the distal half of the grain ( Friis et al. 2019a).

A second species of Canrightia , Canrightia foveolata sp. nov., is formally described below from the Catefica mesofossil flora. It is distinguished from C. resinifera by its finely pitted endotesta. Canrightia elongata E.M.FRIIS, P.R.CRANE et K.R.PEDERSEN described from the Torres Vedras mesofossil flora ( Friis et al. 2019a) is distinguished from both of the Catefica species by its more elongated fruits that have a shorter hypanthium.

Affinity and other occurrences. The original phylogenetic analysis of Canrightia placed the genus close to the base of the Chloranthaceae ( Friis and Pedersen 2011) , a position that has been corroborated by several subsequent analyses ( Doyle and Endress 2014, Friis et al. 2015a).

Canrightia resinifera is one of the most common angiosperm fossils in the Early Cretaceous floras of Portugal with numerous specimens recorded from the Arazede, Buarcos, Catefica, Famalicão and Vale de Água mesofossil floras ( Friis and Pedersen 2011), as well as from the Chicalhão and Nossa Senhora da Luz mesofossil floras ( Mendes et al. 2014, Mendes and Friis 2018). In the Catefica mesofossil flora Canrightia resinifera is recorded from all samples.

Pollen similar to that associated with Canrightia resinifera has not been observed in situ in any of the dispersed stamens from the Catefica mesofossil flora ( Tab. 1 ). Pollen grains similar to those observed on the Canrightia fruits are present, however, in palynological samples analyzed from the Catefica locality and in other palynofloras from the Early Cretaceous of Lusitanian Basin in western Portugal.

Figures

Text-fig. 2. Scanning electron microscope (SEM, a, c–f) and synchrotron radiation X-ray tomographic microscopy (SRXTM, b, g) images of the flower of Mugideiriflora portugallica (a, b) and fruits, seeds and pollen of Canrightia resinifera (c–g); Catefica locality, Portugal. a) Oblique, apical view of flower showing multiparted organization with numerous laminar tepals, stamens that are rhomboidal and flattened in transverse section and carpels that are borne on the short conical apex of the receptacle; b) Transverse section (orthoslice xy0800) through basal part of flower showing the elongate bases of the laminar tepals and the flattened rhomboidal bases of the stamens; c) Fruit in lateral view showing irregular surface resulting from the abundant resin bodies in the fruit and hypanthium wall, scars from stamens on the rim of the hypanthium (arrowheads) and the lobed apical stigmatic region (st); d) Broken fruit with one or two seeds missing but showing three pendant, orthotropous seeds with pointed micropylar regions (mi) and a finely pitted crystalliferous endotesta; note the remains of the apical vascular bundles (vb); e) Single seed isolated from a fruit showing two distinct bundles (vb) still attached apically to the chalazal region of the seed, the pointed micropyle (mi) and the finely pitted surface of the crystalliferous endotesta; f) Monocolpate pollen from stigmatic region of fruit showing the long colpus and coarse reticulum; g) Transverse section (orthoslice xy0705) through a fruit showing four seeds all with radially elongated endothelium cells formed from the inner epidermis of the tegmen (asterisks). Specimens, Catefica 150-S174254 (a, b), Catefica 49-S170377 (c), Catefica 49-S170372 (d), Catefica 50-S170401 (e), Catefica 50-S170404 (f), Catefica 50-S174906 (g). Scale bars = 300 Μm (a–e, g), 6 Μm (f).