Early flowers of primuloid Ericales from the Late Cretaceous of Portugal and their ecological and phytogeographic implications
Abstract
A distinctive feature of the major eudicot diversification that occurred through the Late Cretaceous is the unequivocal presence of Cornales and diverse Ericales. Here we describe well-preserved fossil flowers from the Mira locality in western Portugal, of Campanian-Maastrichtian age, that we assign to a new extinct genus of Ericales with two new species; Miranthus elegans gen. et sp. nov. and Miranthus kvacekii sp. nov. The fossil flowers are pedicellate, structurally bisexual, actinomorphic, pentamerous and isomerous, with five narrowly triangular persistent calyx lobes, a five-lobed corolla, five antepetalous stamens, five staminodes alternating with the petals and a semi-inferior, unilocular ovary. The ovary consists of five carpels and has a raised nectariferous ring with stomata-like openings above the insertion of the perianth, and a long five-angled style. A key feature, which confirms a relationship with Primulaceae s. l., is the free, central dome-shaped placenta that bears numerous, densely spaced ovules. The ovary matures into a capsule containing many, minute, reticulate seeds. Flowers of Miranthus are especially similar to those of extant Samolus, a genus of about twelve species that is sister group to other genera of subfamily Theophrastoideae and that has a disjunct distribution mainly in the Southern Hemisphere. Miranthus also appears to have grown in environments influenced by marine conditions, an ecological preference also seen in Samolus. Miranthus expands the diversity of Ericales known from the Late Cretaceous, and together with previously described fossils provides further evidence that the diversification of Ericales was already underway by the Campanian-Maastrichtian stages of the Late Cretaceous.
Key words
Campanian, Ericales, fossil flowers, Maastrichtian, Primulaceae s. l., SRXTM, synchrotron radiation X-ray tomographic microscopyAngiosperm diversification in the Early Cretaceous of Primorye, Far East of Russia
Abstract
The Partizansk and Razdolnaya coal basins of Primorye, Far East of Russia, contain diverse early angiosperm fossils (pollen, leaves, and fruits). In this paper, we revise the previous data on early angiosperms of this region and summarize the results of our latest research. Age of the plant-bearing deposits was clarified using isotopic U-Th-Pb LA-ICP-MS and U-Pb ID-TIMS methods. Age of the upper part of the Lipovtsy Formation is 118 ± 1.4 Ma, which corresponds to the late Aptian. The early Albian age (109 ± 1 Ma) is assigned to the upper part of the Frentsevka Formation. The diversification of angiosperms in the Early Cretaceous of Primorye region and their systematic affinity are analyzed. Early representatives of Laurales, Ranunculales, Platanaceae, and probable Cercidiphyllaceae are revealed. New combination Pandanites ahnertii (Krysht.) Golovn., comb. nov. is created, and new species Araliaephyllum vittenburgii Golovn. et Volynets, sp. nov. is described. Reconstructions of herbaceous angiosperms from autochthonous locality Bolshoy Kuvshin are proposed.
Key words
early angiosperms, Early Cretaceous, Far East, Primorye, RussiaPlant mesofossils from the Late Cretaceous Klikov Formation, the Czech Republic
Abstract
Late Cretaceous mesofossils are described from the Zliv-Řídká Blana locality in the South Bohemian Basins, the Czech Republic. Angiosperm remains dominate the fossil assemblage both in terms of taxonomic diversity and quantitatively, with about 65 different species based on about 1,000 specimens of flowers, fruits and seeds. There are surprisingly few nonangiosperm species in the flora, with only four specimens assigned to bryophytes, ferns and conifers. There are no megaspores of Selaginellales or Salviniales, which are otherwise common in many Cretaceous mesofossil floras. Among angiosperms, flowers and fruits assigned to the Normapolles group (Fagales) and to the Ericales are particularly prominent. In systematic composition as well as general organization and size of the angiosperm reproductive organs, the Zliv-Řídká Blana mesofossil flora is comparable to other Late Cretaceous mesofossil floras collected from various regions of Laurasia. In addition to the plant remains, the fossil assemblage also includes insect eggs and coprolites.
Key words
angiosperms, fossil fruits, fossil seeds, fossil flowers, Late Cretaceous, mesofossils, Klikov FormationThe occurrence of pollen of Sciadopityaceae Luerss. through time
Abstract
Here we present LM and SEM data of pollen of extant Sciadopitys verticillata, fossil Cerebropollenites from Aptian/Albian strata (Austria, Mongolia) and Sciadopityspollenites from Campanian/Maastrichtian and Oligocene/Miocene strata (Siberia, Germany). Measurements and image comparisons show that the investigated fossil pollen taxa range from somewhat comparable to very similar to extant Sciadopitys verticillata, and that a previous affiliation of Cerebropollenites taxa with Tsuga cannot be corroborated. Additionally, it can be speculated that either the Rhaetian to Lower Cretaceous Cerebropollenites taxa are the pollen equivalent of the Eurasian Miroviaceae macrofossils that have unresolved relationships with Sciadopityaceae, or that they might belong to a basal group in the Sciadopityaceae, which is quite recognizable due to the similarity of the pollen morphology of Cerebropollenites thiergartii and Sciadopitys verticillata. However, until in situ pollen within cones attributed to the Miroviaceae are found, we will not know for sure.
Key words
Sciadopityaceae, pollen, Cretaceous, Neogene, Cerebropollenites, SciadopityspollenitesA new specimen of Araucaria fricii from the early Coniacian of the Bohemian Massif, Central Europe
Abstract
A specimen of Araucaria fricii is described from the upper part of the Teplice Formation in the Bohemian Cretaceous Basin. It extends the first occurrence of A. fricii from the mid-Coniacian back to the early Coniacian. Found in the Radovesice locality near Kučlín in the northern part of the Czech Republic, it is characterised by a deltoid cone scale complex with a centrally placed seed. It is compared to the type material of A. fricii from the mid-Coniacian Březno Formation and other European Cretaceous species of Araucaria. The taphonomy and palaeoecology of A. fricii is briefly discussed.
Key words
conifers, Araucariaceae, Araucaria, Cretaceous, ConiacianFraxinus L. (Oleaceae) fruits from the early Oligocene of Southwest China and their biogeographic implications
Abstract
Two new fossil taxa of the ash tree, namely F. zlatkoi Meng-Xiao Wu et J.Huang sp. nov. and Fraxinus cf. honshuensis Tanai et Onoe were reported from the early Oligocene of the Lühe flora, Yunnan Province, Southwest China. The fruit traits were used to assign the proposed species to the genus Fraxinus. These traits were a flattened and symmetrical shape, a single seed located in the base of the fruit and veins parallel to the long axis of each fruit. The new species have low length to width ratio and an obovate seed. Our fossils represent the oldest records of Fraxinus in the low latitude region of the Northern Hemisphere. These fossils provide evidence that Section Dipetalae and Section Ornus had appeared in Southwest China by the early Oligocene.
Key words
Fraxinus, fruit, Oligocene, Yunnan, plant diversity, ash tree, biogeographyA diverse assemblage of Late Eocene woods from Oregon, western USA
Abstract
Well-preserved silicified woods from a site near the town of Post, Oregon, western USA, provide insights into the late Eocene vegetation and climate ca. 36 million years and data for comparing with both older and younger wood floras regionally and globally. The composition of this wood flora, taken into consideration along with taxa identified from silicified fruits and seeds of the same locality, provides a more complete picture of the former vegetation. We recognize woods belonging to the families Anacardiaceae (Pistacia terrazasae sp. nov.), Cannabaceae (Celtis popsii sp. nov.), Cercidiphyllaceae (Cercidiphyllum cf. alalongum R.A.Scott et E.A.Wheeler), Fagaceae (Fagus dodgeii sp. nov., Lithocarpoxylon ashwillii sp. nov., Lithocarpoxylon sp., Quercus sp.), Hamamelidaceae (Hamamelidoxylon crystalliferum sp. nov., H. cf. suzukii E.A.Wheeler et T.A.Dillhoff), Juglandaceae (Pterocaryoxylon sp.), Malvaceae (Wataria kvacekii n. sp.), Platanaceae (Platanoxylon cf. haydenii (Felix) Süss et Müll.-Stoll, Platanus sp.), Sapindaceae (Acer, 2 spp.), Trochodendraceae (Trochodendron beckii (Hergert et H.K.Phinney) R.A.Scott et E.A.Wheeler). This assemblage, which we refer to as the Post Hammer flora (UF 279), is comparable in age to the nearby Teater Road flora known mainly from fossil leaf impressions. Comparing the functional traits of the Hammer woods to the older Clarno Nut Beds woods attests to changing climate in the region, including an increase in seasonality.