Morphology and Affinities of Ampelocissites Seeds (Vitaceae: Ampelopsis clade) from the Paleogene of Texas, USA

Abstract—The type material on which the fossil genus name Ampelocissites was established in 1929 has been reexamined with the aid of X-ray micro-computed tomography (μ-CT) scanning and compared with seeds of extant taxa to assess the relationships of these fossils within the grape family, Vitaceae. The specimens were collected from a sandstone of late Paleocene or early Eocene age. Although originally inferred by Berry to be intermediate in morphology between Ampelocissus and Vitis, the newly revealed details of seed morphology indicate that these seeds represent instead the Ampelopsis clade. Digital cross sections show that the seed coat maintains its thickness over the external surfaces, but diminishes quickly in the ventral infolds. This feature, along with the elliptical chalaza and lack of an apical groove, indicate that Ampelocissites lytlensis Berry probably represents Ampelopsis or Nekemias (rather than Ampelocissus or Vitis) and that the generic name Ampelocissites may be useful for fossil seeds with morphology consistent with the Ampelopsis clade that lack sufficient characters to specify placement within one of these extant genera.

Fossil seeds from the La Cantera Formation, Early Cretaceous, San Luis Province, Argentina

In a study of fossil seeds recovered from the La Cantera Formation, Early Cretaceous, San Luis Basin, we establish a new species, Carpolithus volantus, and describe other specimens attributed to Carpolithus spp. and Ephedra canterata. The botanical affinity of winged seeds assigned to Carpolithus volantus is discussed in relation to the fossil flora recovered from this formation. Based on the abundance of Gnetales in the San Luis Basin (pollen grains, reproductive and vegetative structures assigned to Ephedra), we propose that Carpolithus volantus is affiliated with Gnetales (Weltwitschia). We suggest that Carpolithus spp. seeds may be angiospermous, because this group, represented by leaves and flowers, dominates the fossil macroflora of the La Cantera Formation. Micro- and macrofloral analyses of the La Cantera Formation and an assessment of available dispersal vectors suggests that wind (anemochory) and water (hydrochory) may have been the most important dispersal strategies for these seeds. The abundance and small size of seeds recovered from the La Cantera Formation, together with their morphological characters, such as the presence of wings in Carpolithus volantus, also favour abiotic mechanisms of dispersal such as anemochory or hydrochory.

Extinct Taxa of Exotestal Seeds Close to Austrobaileyales and Nymphaeales From the Early Cretaceous of Portugal

Early Cretaceous mesofossil floras from Portugal and North America include a surprising diversity of small, bitegmic angiosperm seeds with a hard exotestal seed coat. This study describes six different kinds of these seeds from three Portuguese mesofossil localities; Vale de Agua, Torres Vedras, and especially from Famalicão, which has yielded a flora exceptionally rich in exotestal seeds. All the seeds are almost smooth with a characteristic jigsaw puzzle-shaped surface pattern that is formed from the strongly undulate anticlinal walls of the sclerenchyma cells that comprise the exotesta. Several specimens have internal details preserved, including remains of a cellular nutritive tissue interpreted as endosperm, and a tiny embryo with two rudimentary cotyledons. Based on differences in details of the seed coat, and configuration of hilum and micropyle, the fossil seeds are assigned to six new genera, as six new species: Gastonispermum portugallicum gen. et sp. nov., Pazlia hilaris gen. et sp. nov., Pazliopsis reyi gen. et sp. nov., Reyispermum parvum gen. et sp. nov., Lusitanispermum choffatii gen. et sp. nov. and Silutanispermum kvacekiorum gen. et sp. nov. The characteristic exotestal cells with undulate anticlinal walls, details of the hilar and micropylar region, together with the tiny dicotyledonous embryos with rudimentary cotyledons, suggest close relationships to seeds of Nitaspermum and Tanispermum described previously from Early Cretaceous mesofossil floras from eastern North America. These exotestal seeds from Portugal and North America indicate the presence of diverse extinct early angiosperms close to the lineages that today include extant Austrobaileyales and Nymphaeales.

New names of Typha of Northern Eurasia (Typhaceae)

The nomenclature of some fossil and extant homonyms ofTypha(Typhaceae) is resolved. FossilTypha elongataP.I. Dorofeev 1982, being an illegitimate later homonym of extantTypha elongataPauquy 1834, is renamedT. asiaticanom. nov.Typha sibiricaKrasnova 1987 (extant) is replaced by a new name,T. krasnovaenom. nov., on account of the earlier homonym,T. sibiricaP.I. Dorofeev 1982 (fossil).T. transdnestrovicanom. nov. is proposed to replace the later homonymT. ellipticaNegru 1976 (fossil) nonT. ellipticaGmelin 1808 (extant). Fossil seeds from the Lower Oligocene (Rupelian) of Bembridge (Isle of Wight, U.K.), previously attributed to the fossil-speciesT. latissima, based on leaves, are described as a new fossil-species,T. latissimisperma sp. nov.Typha latissimais neotypified;Typha angustioris lectotypified for the first time.