Albian Flora Research Articles

Albian flora from Archingeay-Les Nouillers (Charente-Maritime): comparison and synthesis of Cretaceous meso- and macro-remains from the Aquitaine Basin (southwestern France)

Over recent decades, diverse structures ascribed to angiosperms, bennettitaleans, conifers, cycads, ginkgophytes and pteridosperms have been reported from the Cretaceous deposits of the Aquitaine Basin (southwestern France). However, Albian macrofloras remain uncommon in Aquitania as well as in France. The clay from the Archingeay-Les Nouillers quarries is one of the rare deposits of the Aquitaine Basin to yield Albian plant meso- and macro-remains. Although Albian plant-bearing beds are not accessible any more in these quarries, samples collected from excavations conducted at the end of the XXth century were deposited in the collections of the University of Rennes 1. This paper provides a synthesis of the meso- and macro-remains contained in these collections, including angiosperm leaves and leafy conifer axes, dated as Late Albian. Providing here an inventory of the Cretaceous meso- and macro-remains from the Aquitaine Basin, we compare the Albian flora from Archingeay-Les Nouillers with pre-Albian, Albian, Cenomanian, and Turono-Coniacian floras from other localities in southwestern France.

A new uppermost Albian flora from Teruel province, northeastern Spain

ABSTRACT This paper reports a new Early Cretaceous flora discovered recently near the village of Estercuel (Teruel province, northeastern Spain). The plant bearing beds belong to the uppermost part of the Early Cretaceous succession, at the top of the fluvial deposits of the Utrillas Formation. The site has yielded a diverse assemblage of plant compressions including lycopods and ferns, various gymnosperms as well as terrestrial and aquatic angiosperms. Leaves of aquatic lycopods (Isoetites sp.) constitute a minor component of the palaeobotanical assemblage. Filicales are not very common, with Dicksoniales (Onychiopsis sp.) and a few specimens of Cladophlebis type fronds. The gymnosperms are represented by fragmented remains of long parallel veined Desmiophyllum leaves as well as a great abundance of conifer axis corresponding to the form-genus Pagiophyllum and female cones. Terrestrial angiosperms include pinnately lobed leaves of the genus Myricompia, simple leaves with spatulate lamina and some petiola...

Mid-Cretaceous floras and climate of the Russian high Arctic (Novosibirsk Islands, Northern Yakutiya)

Two mid-Cretaceous floras collected in terrigenous and volcaniclastic deposits of the Novosibirsk Islands in the Russian high Arctic were studied. These floras are the most poleward mid-Cretaceous floras known and existed at palaeolatitudes up to 82–85° N. These represent our best insight into polar conditions at one of the warmest intervals in Earth history. An Albian flora from the Balyktakh Formation of the Kotel'nyi Island comprises 40 species of ferns, bennettites, cycadophytes, ginkgoaleans, czekanowskialeans, conifers and gymnosperms incertae sedis. This flora is most similar to the Albian Buor-kemuss Flora widespread in the Arctic Siberia and Alaska and, to a lesser extent, to the Aptian Silyap Flora of Siberia. A Turonian flora from the Derevyannye Gory Formation on the Novaya Sibir' Island includes approximately 50 taxa of ferns, ginkgoaleans, conifers and angiosperms. This flora exhibits plants common for the early Cretaceous as well as taxa typical for Cenomanian–Senonian, which implies that the age of the plant-bearing deposits is likely to be Turonian. The Cretaceous climate has often been described as ‘warm’ with a higher degree of equability than today with the near-polar regions in particular being much warmer than today. Our estimates using CLAMP and a new global gridded climate calibration demonstrate that for the Turonian Novaya Sibir' Flora plant physiognomy reflects a humid climate with warm summers and mild frost-free winters: the mean annual temperature is estimated to have been + 9.2 ± 2.2 °C, the warm month mean temperature + 17.2 ± 2.8 °C, the cold month mean temperature + 1.1 ± 3.8 °C and the mean growing season precipitation 537 ± 392 mm. These temperature parameters indicate that within 900 km of the Turonian North Pole the climate was similar to that of modern temperate, or even warm-temperate, zones but must have differed considerably in having pronounced high-latitude sunlight seasonality. The ecology of the late Cretaceous Arctic plants reflects their adaptation to this climate. Synchronous shedding of foliage (deciduousness) was by far the most common strategy and retention of leaves year round (evergreenness) was also viable for a small number of taxa. Large deciduous leaves typical for the Cretaceous Arctic dicots probably reflect the combination of a warm and humid climate with high-latitude light regime: long days in summer and predominance of relatively weak and mostly diffuse sunlight. The large range of leaf size in a given plant species of Arctic angiosperms was most probably linked to the seasonal character of annual shoot development.

Early Cretaceous Gleicheniaceae and Matoniaceae (Gleicheniales) from Alexander Island, Antarctica

The first Cretaceous representatives of Matoniaceae and Gleicheniaceae in the Antarctic are described from the Albian flora of Alexander Island. Two new species are recognized, one is assigned to Matonia, and another to the emended gleicheniaceous form-genus Gleicheniaceaephyllum. The taxonomy of fossil genera assigned to Gleicheniaceae is problematic, and as an alternative to the invalid genus Gleichenites, we propose that Microphyllopteris be utilised as a form-genus for species that have either an unknown branching pattern or pseudo-dichotomous branching without resting buds; Microphyllopteris is reserved for ferns that cannot be ascribed conclusively to Gleicheniaceae. Alternatively, Gleicheniaceaephyllum should be used for gleicheniaceous material that has a resting bud amongst two to four primary branches. Gleicheniaceaephyllum acutum sp. nov. is preserved as sterile and fertile fronds, pinnae and pinnules. The other new species, Matonia jeffersonii sp. nov., occurs as sterile and fertile pinnae and pinnules, and is aligned to Matoniaceae based on the presence of circular-oval sori with peltate indusia. The two taxa are inferred to have either a pedate or scrambling habit. These morphologies are relatively common at Alexander Island, compared to other high latitude fossil floras, and are interpreted as an adaptation to the high disturbance, polar conditions and unusual photoperiod experienced at Alexander Island during the Early Cretaceous. The theory that angiosperms caused the demise of ferns is discussed in relation to the Matoniaceae and Gleicheniaceae, and there does not appear to be association between angiosperm expansion and the decline of these two fern families.

Ferns from the Cretaceous of Alexander Island, Antarctica: Implications for Cretaceous phytogeography of the Southern Hemisphere

Six new records of ferns from the late Albian flora of Alexander Island, Antarctic Peninsula, provide further evidence for a widespread Cretaceous Austral flora. Phyllopteroides antarctica sp. nov. is the first record of this genus from Antarctica, extending its range from Australia, New Zealand, and India. It appears that Phyllopteroides forms an important component of eastern Gondwana mid-Cretaceous floras. Further floristic affinities with Australia are supported by the presence of Sphenopteris warragulensis, Microphyllopteris and Coniopteris sp. cf. C. frutiformis. Few southern South American forms can be recognized and these include Sphenopteris sanjuliensis. The Alexander Island flora comprises a mixture of endemic, eastern Gondwanan, and rare South American elements that reflect its position close to a major floristic boundary.

The Albian–Cenomanian flora of the Kukpowruk River, western North Slope, Alaska: stratigraphy, palaeofloristics, and plant communities

Cretaceous plant fossils were collected in the context of sedimentary facies at 34 localities along the Kukpowruk River, north-western Alaska. The river transects three mapped units: the predominantly marine Torok Formation, the transitional Kukpowruk Formation and the predominantly non-marine Corwin Formation. Fifty-seven taxa, mostly leaves but including several reproductive structures, were recognised and compared to similar aged fossil plants from north-eastern Russia and Alaska. Although divisible into upper and lower regional floral suites, most of the flora represents a single stage in floral evolution (we refer to these two plant suites together as the Kukpowruk flora). There are strong similarities to the very rich (more than 150 species) early–middle Albian flora of the Buor-kemuss floral type in north-eastern Russia. However, because several taxa are quite long-ranging those plants from the upper delta plain environments of the Corwin Formation are likely to be late Albian in age. A second, smaller, component of the flora (which we here refer to as the Corwin flora) contains angiosperms and is similar both to the Grebenka floral type of north-eastern Russia and the Upper Killik and Niakogon floras from the central and eastern North Slope of Alaska. From consistent associations between specific taxa and sedimentary facies distinct plant communities have been recognised: a marginal marine and early successional marsh/heath community dominated by Equisetites andBirisia ferns, shrubby to forested river margin communities dominated by Ginkgo, and mire forest communities dominated by Pityophyllum and Podozamites.

Early Cretaceous changes of vegetation and environment in East Asia

Early Cretaceous floras of the Razdolnensky (Suifun) and Partizansky (Suchan) basins, currently located close to each other in South Primorye, differ significantly. The pre-Albian flora assemblages of the Razdolnensky basin are similar to those of northeastern China, whereas the pre-Albian assemblages of the Partizansky basin are close to the Rioseki complex of the Outer Japan. Tectonic reconstructions using these data have showed that the Voznesenka terrane, underlying Cretaceous sediments of the Razdolnensky basin, as well as the terranes of Inner Japan were displaced northwards along faults of the Tan-Lu system for more than 5° by latitude. The Sergeevka terrane, forming the basement of Early Cretaceous sediments of the Partizansky basin, as well as the terranes of Outer Japan, were displaced in the same direction for a much larger distance (about 15° by latitude). The major movements occurred in the earliest Albian as is suggested by the same Albian flora assemblages in the two basins.