Cycadodendron galtieri: Cycad wood from the Permian of Saxony, central-eastern Germany.

Cycads are a thought to have been among the earliest Gymnosperm Plants to have appeared, with molecular clock estimates suggesting that they diverged from other Gymnosperms in the Late Carboniferous or Early Permian. The group underwent a major evolutionary radiation in the Early Triassic, and fossils are abundant in Mesozoic and Cainozoic deposits. These fossils tend to closely resemble modern Cycads, despite these sharing a fairly recent common ancestor, suggesting a high degree of morphological conservatism within the group. Palaeozoic fossils are much less common, and can be more difficult to interpret. These comprise possible Cycad megasporophylls (leaves) from the Late Carboniferous and Early Permian, although it is difficult to be confident about the affinities of these.

In a paper published in the International Journal of Plant Sciences on 11 October 2023, Ludwig Luthardt of the Museum für Naturkunde at the Leibniz Institute for Evolution and Biodiversity Research, Ronny Rößler of the Museum für Naturkunde Chemnitz and the Department of Palaeontology at the Technische Universität Bergakademie Freiberg, and Dennis Stevenson of the New York Botanical Garden and the School of Integrative Plant Science at Cornell University, describe a new species of Cycad based upon a piece of stem wood from the Holocene gravel deposits of the Zwickauer Mulde river, which are known to produce silicified woods derived from the Permian Chemnitz Fossil Lagerstätte.

Geography and geology of the source area of the fossil Cycad stem, combining the catchment area of the Zwickauer Mulde River/Chemnitz River with the most important localities of mainly in situ found petrified wood and their stratigraphic affiliation. Abbreviations: NSVC, North SaxonyVolcanite Complex; ZVC, Zeisigwald Volcanic Complex. Luthardt et al. (2023).

The new species is named Cycadodendron galtieri, where 'Cycadodendron' means 'Cycad-tree' (the suffix '-dendron' is commonly used for fossil woods, on the basis that chunks of wood of any size must have come from a tree), and 'galtieri' honours Jean Galtier, a renowned palaeobotanist from Montpellier, France, for his significant contributions to the knowledge of the evolution and anatomy of Palaeozoic fossil Plants. It is described from a single piece of polished wood, K9883, roughly 69 mm by 56 mm, thought to have derived from a larger stem, as the outer parts, including the cortex and vestiges of leaf bases, are not preserved.

Overview of polished sections of Cycadodendron galtieri (K9883, holotype). (A) General view of the specimen in transverse section. K9883a. (B) Counterpart of the specimen, additionally cut in radial sections. K9883b, K9883c. (C), (D), Radial sections of the specimen; successivevascular cylinders are indicated by arrows and X1–X9 in (D). K9883b, K9883c. All specimens are at the same scale. Luthardt et al. (2023).

While foliage can be difficult to ascribe to a particular plant group, due to convergent evolution among plants living in similar environments, the wood of Cycads is highly distinctive, with vascular stands arranged in medullary bundles within a wide inner pith, surrounded by consecutive vascular segments each producing centripetal secondary xylem and centrifugal phloem. The presence of these features within Cycadodendron galtieri marks the specimen as an unequivocable Cycad, and therefore the oldest known fossil which can be confidently assigned to the group.

Anatomical sketches of Cycadodendron galtieri with the overall arrangement of stem tissues. (A) Transverse section showing the pith with medullary bundles and pith-peripheral bundles, successive vascular segments, and traversing medullary bundles. K9883a. (B) Radial section exhibiting vertical arrangement of stem tissues and indicating the number of successive vascular segments and phloem-parenchyma zones. K9883b. Luthardt et al. (2023).

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Evidence of a late Palaeozoic land connection between Appalachia and Iberia.

Over the past 30 years, a broad consensus has emerged that repeated cycles of supercontinent amalgamation and dispersal have occurred since the end of the Archean, and these cycles have profoundly affected the Earth’s evolution. Less clear is whether the supercontinent changes its configuration during its existence due to internal stresses. Although the classical 'Wegenerian' configuration of Pangaea immediately prior to its Early Mesozoic breakup is well constrained, there remains uncertainty about its late Palaeozoic configuration. Two end member models have emerged; Pangaea-A, which is essentially the 'Wegenerian' fit, and Pangaea-B, based on palaeomagnetic data, in which Gondwana was located about 3000 km farther east relative to Laurasia, compared to the Pangaea-A configuration. A late Palaeozoic Pangaea-B configuration would require substantial lateral (dextral) shear along major faults, inferred by Edward Irving to have occurred between the middle Carboniferous and Late Triassic, in order to obtain the Wegenerian configuration before Pangaea breakup. More recent palaeomagnetic data have been used to support the transition from a Pangaea-B to a Pangaea-A configuration during the Permian, and in the most recent model, the transition occurred between 275 and 260 million years ago. However, geologic evidence that would distinguish between these hypotheses is lacking. Moreover, the validity of the palaeomagnetic data purported to support the Pangaea-B configuration has recently been challenged.

The collision between Laurasia and Gondwana during the Late Devonian-early Permian was a key event in the amalgamation of Pangaea and resulted in the destruction of the Rheic Ocean and the formation of the Appalachian and Variscan (Hercynian) orogens in the interior of Pangaea. A key element in reconstructing palaeogeographic environments is to examine the first appearance of shared flora between continents. For example, the occurrence of the Permian Glossopteris flore has been crucial in understanding the configuration of Gondwana. The confinement of this flora to Gondwana and its absence from Laurasia has been attributed to the presence of physical barriers (e.g. distance, mountain ranges, climate/latitude) that may have restricted its migration. However, determination of the palaeogeography of Laurasia relative to Gondwana during the late Palaeozoic is hindered by the lack of palaeobiogeographic evidence linking both continents.

In a paper published in the journal Scientific Reports on 12 February 2020, Pedro Correia of the Institute of Earth Sciences at the University of the Porto, and Brendan Murphy of the Department of Earth Sciences at St. Francis Xavier University, draw on recent discoveries in Carboniferous successions in the Iberian Massif (Douro Basin, Portugal) that, for the first time, provide linkages between the ancient landmasses Laurentia and Iberia (located along the northern margin of Gondwana) along the palaeoequatorial belt during the Late Pennsylvanian (307–299 million years ago). In so doing, they provide palaeobotanical and biostratigraphic evidence that the Pangaea-A configuration was in place at that time, negating the possibility of Pangaea-B configuration in the late Palaeozoic.

 

Idealised Pangaea-A ('Wegenerian') configuration based on continental connection between eastern Laurentia (Laurasia) and Iberia (northwestern Gondwana) in the late Palaeozoic. Colour legend for the image: blue: Oceans; light brown: Gondwana; dark brown: Laurasia; grey: shallow seas and coastal/flooded areas. Correia & Murphy (2020).

Models for Variscan orogenesis and Pangaea amalgamation rely on approximately 420–320 million year ago continental reconstructions. At about 420 million years ago, reconstructions primarily influenced by palaeomagnetic data show Gondwanan terranes, including Iberia rifted from the northern Gondwanan margin thereby forming the Palaeotethys Ocean. Other reconstructions, however, based on a wealth of faunal, lithological, stratigraphic, detrital zircon and palaeoclimatic data, imply that these terranes remained along the Gondwanan margin for the entirety of the Palaeozoic. In the latter scenario, Rheic Ocean closure resulted from continental collision of Laurasia with the northern Gondwanan margin, which began about 380 million years ago. Iberia preserves a continuous Early Ordovician to Late Devonian passive margin sequence including typically Gondwanan Late Ordovician glaciomarine deposits, and lacks roughly 420 million-year-old rift-drift deposits predicted by the formation of the Palaeotethys Ocean. On the basis of this evidence, Corriea and Murphy adopt the second scenario and our reconstructions showing a unified Iberia and Gondwana throughout the Palaeozoic.

 

Late Palaeozoic Pangaea-B configuration in which Gondwana is located about 3000 km farther east relative to Laurasia. Correia & Murphy (2020).

Abundant Carboniferous-Permian floras and palaeoenvironmental/climatic distribution data have been identified in Laurasia. Detailed studies of flora that demonstrate significant affinities between the Pennsylvanian (late Moscovian and Gzhelian) floras of North America and Iberian Massif are interpreted to reflect a proximal palaeobiogeography between Laurentia and Iberia within the palaeoequatorial belt. Biostratigraphic studies identify the existence of a macrofloral biostratigraphic gap for the Kasimovian stage in the Appalachian region in West Virginia Basin (USA) correlated with the Upper Pennsylvanian of Portugal. This gap is documented in parts of the palaeoequatorial belt during the Kasimovian and is attributed to a lowstand reflecting a major glaciation event in southern Gondwana.

 

Biostratigraphic constraints between Laurentia and Iberia including a macrofloral biostratigraphic gap correlated between the Upper Pennsylvanian successions of Appalachian region in West Virginia and Iberia in Portugal. Correia & Murphy (2020).

Carboniferous-Permian floras, restricted to same type of palaeoenvironments shared by Laurentia and Iberia, are key elements to determine the palaeogeography of Pangaea as it amalgamated. Determination of land bridges linking Laurentia and Iberia for floral exchange attests to the importance of constraining the palaeoenvironmental and palaeoclimatic conditions between these continental lands in the interior of Pangaea. Such constraints are provided by the floras that were restricted to “dryland” environments located in the tropical regions of central Pangaea and lived in both Laurentia and Iberia. The Cycadopsid Lesleya, a rare Carboniferous-early Permian Seed-plant of the Euramerican realm, was a dry-climate adapted flora (known as 'dryland flora') restricted to tropical dryland environments of central Pangaea.

 

Palaeoenvironmental and palaeoclimatic constraints and floral migration between Laurentia and Iberia within Pangaea-A. Enlarged view of central Pangaea (white rectangular box area in top image) showing the emergence of 'dryland' environments at varying spatial and temporal scales and diachronous migration of dryclimate adapted flora like Lesleya between the Laurentian and Iberian landmasses. Lesleya-fossil record data for the floral migration route are from. Correia & Murphy (2020).

Pangaean tropical regions experienced major cyclic environmental changes during the Pennsylvanian-early Permian interval, with significant modifications to ecosystems and biotic communities (biotic stress) resulting from alternation of wetland and dryland floras. Such changes were a result of glacial and interglacial cycles, and their effects were especially felt in the tropical regions of central Pangaea during this interval. The dryland environments occupied part of the tropical landscapes of central Pangaea during the Pennsylvanian. The emergence of these environments is intricately linked to a warmer or drier climate during interglacial periods. These interglacial periods led to significant changes in climate and therefore the overall composition of resident floral assemblages in the tropical regions of central Pangaea in the late Palaeozoic.

Fossils of Lesleya have been widely documented in Early-Middle Pennsylvanian-age dryland basins of North America. Recent discoveries in the Upper Pennsylvanian of Portugal have documented the first occurrence of Lesleya in Iberian Massif. The Portuguese Lesleya specimens were found in lower Gzhelian strata of the Douro Basin and occur in intramontane deposits that preserve evidence of dry climate. Dry climate is characterised by the moisture-deficient (dryness) and well-drained conditions. The appearance of Lesleya in Iberia coincided with the onset of an interglacial interval in the Kasimovian-Gzhelian (304 million years) after the waning of a major glaciation in southern Gondwana. As a result, parts of palaeoequatorial belt especially of central Pangaea, where eastern Laurentia and Iberia were located, became drier and less humid during the Gzhelian (Late Pennsylvanian, 304–299 million years ago).

Other typical dryland floras such as the Walchian Conifers, Walchia and Ernestiodendron, Cordaitalean Cordaites, Callipterid Peltasperms, Autunia conferta and Rhachiphyllum, and the Dicranophyllalean, Dicranophyllum, also flourished at various places in Laurentia (e.g. West Virginia) and Iberia. Such dryland biomes were more abundant during periods of warm or dry climate in the Late Pennsylvanian and early Permian. These palaeobotanical data provide palaeogeographic constraints on the proximity of Laurentia and Iberia and are key to distinguishing between the competing Pangaea configurations.

The Pangaea-A versus Pangaea-B controversy underscores large uncertainties about the palaeogeographic position of Gondwana relative to Laurasia in the Late Devonian-early Permian interval. Recent palaeobotanical and biostratigraphic studies indicate a proximal Iberian-Appalachian palaeogeography in the Late Pennsylvanian. Such evidence provides significant constraints in the palaeogeography, palaeoclimate and palaeotopography in both the Appalachian and Iberian (Variscan) orogens.

 

Palaeogeographic and palaeotopographic constraints within Pangaea-A showing the continental linkage between eastern Laurentia and Iberia and uplift of the Appalachian and Variscan orogens in the late Gzhelian-early Permian. Abbreviations: WV, West Virginia; IM, Iberian Massif; Aq, Aquitaine; AM: Armorican Massif; MC: French Central Massif; RH: Rheno-Hercynian terrane; ST, Saxo-Thuringian terrane; BM, Bohemian Massif; Sd, Sardinia (Italian island); Co, Corsica (French Mediterranean island); NI, Variscan basement of northern Italy. Correia & Murphy (2020).

Because they are indicators for climatic and environmental conditions, the occurrence of dryland floras typical from North America such as Lesleya in the Upper Pennsylvanian strata of Portugal is evidence of migration of dry-climate adapted floras between the Laurasian and Gondwanan continents. This floral migration suggests that eastern Laurentia and Iberia were connected or geographically very close, sharing the same tropical dryland environment within central Pangaea in the Late Pennsylvanian. Moreover, the appearance of Lesleya in the early Gzhelian (Late Pennsylvanian, 304–301 million years ago) of Iberia, immediately after a transition from glacial to interglacial conditions in the Kasimovian-Gzhelian interval (304 million years ago), indicates that this flora migrated from Laurentia to Iberia, possibly when new dryland habitats appeared. In this proximal configuration, Iberia probably acted as a migratory option or refuge to the many dry-climate adapted floras of Laurentia, perhaps because conditions of greater dryness had prevailed in Iberia in the early Gzhelian. During that time interval, new dryland species such as Lesleya iberiensis emerged in the Iberia in well-drained, moisture-deficient environments.

The migration routes of dryland flora between Laurentia and Iberia provide insights into the location and timing of uplift of the Appalachian and Variscan orogens during continental collision between Laurasia and Gondwana during the amalgamation of Pangaea. These migration routes were influenced by climate and tectonically-induced topographic changes. As mountain ranges acted as physical barriers to the floral exchanges between Laurentia and Iberia within central Pangaea, this migration occurred before uplift of the Appalachian and Variscan orogens, i.e. during the early Gzhelian (Late Pennsylvanian, 304–301 million years ago). This palaeobiogeographic connection records early stages of uplift during the assembly and amalgamation of Pangaea and implies a connection along the palaeoequatorial belt between the Appalachian orogen and the Variscan orogen in Iberia. A macrofloral biostratigraphic gap correlated between the Upper Pennsylvanian successions of Appalachian region in West Virginia and Portugal supports an Iberian-Appalachian connection at that time. The timing of this connection implies that uplift of the Appalachian and Variscan orogens occurred during the late Gzhelian (Late Pennsylvanian) to Asselian (early Permian) (301–295 million years ago).

OurCorreia and Murphy's data provide the ‘missing link’ between Gondwana and Laurasia during the final amalgamation of the supercontinent Pangaea in the Late Pennsylvanian and confirms a Pangaea-A ('Wegenerian') configuration at that time. Consequently, these results indicate that the palaeomagnetic data used to support a Pangaea-B configuration in the late Palaezoic5 represent an artifact of data quality, geometrical fits used to restore the Atlantic-bordering continents to one another, and processes such as inclination shallowing in clastic rocks.

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First discovery of the Horsetail Neocalamites in the West Qinling Orogenic Belt of China.

The fossil Neocalamites is a Horsetail, Sphenopsida , known from Permian-Jurassic deposits around the world. In China Neocalamites has been reported from the Late Triassic of Xinjiang and Qinghai in the northwest of the country and Hubei Province in Central China, plus the Early Jurassic of North China.

In a paper published in the journal Acta Geologica Sinica on 11 March 2019, Li Zuochen of the Key Laboratory of Western China’s Mineral Resources and Geological Engineering at Chang’an University, and the Department of Geosciences at Eberhard Karls University Tübingen, Pei Xianzhi, also of the Key Laboratory of Western China’s Mineral Resources and Geological Engineering at Chang’an University, Wei Liyong of the No. 5 Gold Geological Party of China Armed Police Force, Guo Junfeng, Xiao Liang, Li Ruibao, and Pei Lei, also of the Key Laboratory of Western China’s Mineral Resources and Geological Engineering at Chang’an University, Zhao Wenchuan, also of the No. 5 Gold Geological Party of China Armed Police Force, Wang Meng, Chen Youxin, Liu Chengjun, Zhao Shaowei, Gao Feng, Shao Jiakun, and Qin Li, again of the Key Laboratory of Western China’s Mineral Resources and Geological Engineering at Chang’an University, and Zhao Changcun and Zhang Zhen, again of the No. 5 Gold Geological Party of China Armed Police Force, describe the first known occurence of Neocalamites from the West Qinling Orogenic Belt of Central China.

Li et al. report the discovery of numerous Neocalamites fossils from the Late Triassic Daheba Formation in Lintan County of Gansu Province, part of the West Qinling Orogenic Belt, which separates the North and South China Blocks. The specimens comprise trucks from 5 to 12.5 cm in length and from 0. 8 to 1.5 cm in diameter, with an internode length (length between the nodes from which leaves or stems arise of 6.2 to 10.5 cm.

Neocalamites Fossils from the Upper Triassic Daheba Formation in the Lintan Area, Western Section of the West Qinling Orogenic Belt. (a) Field photograph; (b) Samples photograph; (c)–(d) Micrographs. Li et al. (2019).

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Nothodichocarpum lingyuanensis: A new species of Angiosperm from the Jehol Biota.

The Early Cretaceous Yixian Formation of Lioaning Province, China, has produced a wide range of well preserved animals and plants, including many Vertebrates and Insects, collectively known as the Jehol Biota. The plants from these deposits include the earliest known diverse community of Angiosperms (Flowering Plants), providing a valuable insight into the earliest members and initial diversification of this group.

In a paper published in the journal Acta Geologica Sinica on 1 February 2017, Han Gang of the Hainan Tropical Ocean University and the Palaeontological Center at Bohai University, Liu Zhongjiang, also of the Palaeontological Center at Bohai University, and of the Shenzhen Key Laboratory for Orchid Conservation and Utilization at the National Orchid Conservation Center of China and Orchid Conservation & Research Center of Shenzhen, and Wang Xin of the State Key Laboratory of Palaeobiology and Stratigraphy at the Nanjing Institute of Geology and Palaeontology, describe a new species of Angiosperm from the Jehol Biota.

The new species is named Nothodichocarpum lingyuanensis, where 'Nothodichocarpum' means 'false-Dichocarpum', in reference to a modern genus of herbaceous Flowering Plants in the Ranunculaceae (Buttercup Family) that it superficially resembles, and 'lingyuanensis' means 'from Lingyuan', the locality where the fossils were discovered. 

 Nothodichocarpum and its details. (a) Holotype including branches, leaves, and flowers. Scale bar is 1 cm. (b) One of the leaves with a midrib (arrow). Scale bar is 1 mm. (c) Another narrow obovate leaf with attenuated tip and several teeth (black arrows), overlapped by a young flower including two carpels (1, 2) and at least one male part (white arrow). Scale bar is 1 mm. (d) Pinnate venation in one of the leaves. Scale bar is 0.5 mm. (e) Opposite branching. Note the main branch (2), axillary branch (1), subtending leaf (3), and leaves (l). Scale bar is 1 mm. (f) Three flowers (1-3) of different stages overlapping leaves. Note several male parts (arrows) beside carpels. Scale bar is 1 mm. (g) Two divergent, basally coalescent follicles and two male parts (arrows). Note the spatial relationship between the follicles and male parts. Scale bar is 2 mm. (h), Two young basally coalescent carpels (1-2). Scale bar is 1 mm. (i) Detailed view of the right male part in (g). Scale bar is 0.5 mm. (j) The right fruit in (g) showing abutting seeds (black arrows) inserted along the dorsal vein (white arrow). Scale bar is 1 mm. (k) Four abutting seeds (1-4) in the fruit shown in (g). Note seed 4 is apparently connected to the dorsal of the fruit (black arrow). Scale bar is 1 mm. Han et al. (2017).

Nothodichocarpum lingyuanensis shows a number of unusual features, including the arrangement of the leaves, and the structure of the flower. 

The leaves of Nothodichocarpum are opposite, that is to say arranged in pairs which are opposite one-another on the stem. This is a very common arrangement in modern Flowering Plants, and is also found in a variety of other, non-flowering, Plants, but has not previously been recorded in an early Angiosperm. However re-examination of Archaefructus, another Flowering Plant from the Jehol Biota, and a candidate for the most primitive Angiosperm known, suggests that this plant may also have had an opposite arrangement of leaves, suggesting that this may have been the condition in the very first Flowering Plants.

Sketches of Nothodichocarpum. (a) Sketch showing the physical connection among various parts. Green: leaf; gray: leaf vein; red: follicle/carpel; black: branch; blue: male part. Scale bar is 10 mm. (b) The fruit shown in (g) and (j) above. Note the seeds inserted onto the dorsal vein (right) and male part (blue). Scale bar is 1 mm. (c), Semi-idealised sketch of the leaf shown in (c) above. Han et al. (2017).

Nothodichocarpum lingyuanensis is preserved with both fruit and flowers, enabling examination of both these structures, an unusual opportunity in such an early Plant. The seeds are enclosed within an ovule, which considered to be one of the defining features of an Angiosperm, but the 'flowers' are arranged in a way quite unlike that seen in modern Plant, suggesting that Nothodichocarpum lingyuanensis represents an early stage in the development of the Angiosperms, with a floral structure on the way to developing into a flower, but which we would not necessarily recognise as such.

Details of the flowers of Nothodichocarpum under Scanning Electron Microscope. (a) Basal portion of the fruit shown in top (g). Note the scars left by fallen off male parts (arrows), and their spatial relationship with the carpel (c) and filament (f). Scale bar is 1 mm. (b) A filament (f, white arrow) subtended by a bract (b, black arrow). This male part corresponds to the one marked by left white arrow in above (a). Scale bar is 0.1 mm. (c) Detailed view of rectangle in (a) above. Note spatial relationship among the bract (b) filament (f) in its axil, and carpel (c). Scale bar is 0.1 mm. (d) Detailed view of the right follicle of fruit 2 in top (f). Note the relationship between the carpel (c, white arrow) and male part (black arrows). Scale bar is 1 mm. Han et al. (2017).

The flower of Nothodichocarpum lingyuanensis appears to have had four male parts, two of which were opposite the female folicles and two located between; this is represented by two surviving parts, one in each of these positions and two scars, where the remaining two would be predicted to be. Each of these has a bract beneath which appears to support it. This places the male and female reproductive parts of the plant together at the end of a stem, but does not integrate them into a single flower; forming a structure different to that seen in any living or fossil plant (though a number of early fossil Angiosperms are identified as such from preserved fruiting bodies, without the flowers being known, so they could presumably have supported structures similar to those seen in Nothodichocarpum.

 Reconstruction of Nothodichocarpum in its flower (a) and fruit (b) stages. Note the dorsal vascular bundle connected with seeds in an opened fruit (b). Han et al. (2017).

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Notonuphar antarctica: A new species of Water Lily from the Eocene of Seymour Island, Antarctica.

Water Lilies, Nymphaeales, are herbaceous aquatic plants found on all continents except Antarctica, but most diverse in the tropics. They are thought to have been one of the earliest groups of Flowering Plants to appear, splitting away from other members of the Angiosperms early in the history of the group, and have a fossil record dating back to the Early Cretaceous.

In a paper published in the journal Plant Systematics and Evolution on 14 June 2017, Else Friis of the Department of Palaeobiology at the Swedish Museum of Natural History, Ari Iglesias of the Instituto de Investigaciones en Biodiversidad y Ambiente, Marcelo Reguero of the Divisio´n Paleontologı´a de Vertebrados at the Universidad Nacional de La Plata and the Instituto Antártico Argentino, and Thomas Mörs, also of the Department of Palaeobiology at the Swedish Museum of Natural History, describe a new species of Water Lily from the Early to Middle Eocene of Seymour Island, Antarctica.

The new species is named Notonuphar antarctica, where 'Notonuphar' means 'southern-Nuphar' (Nuphar being a modern genus from the Northern Hemisphere which the new genus resembles) and antarctica refers to the location where it was found. The species is described from a series of seeds and seed fragments extracted from sediments by dry sieving. These are coalified on the outside, with a calcified inner core comprised of the mesotesta, endotesta, tegmen and the inner seed tissues.

Notonuphar antarctica, from the Eocene of Seymour Island, Antarctica; synchrotron radiation-based X-ray tomographic microscopy volume renderings of seeds. (a) Holotype; lateral view of seed showing outer smooth surface of exotesta and germination; hilum (hi) and micropyle (mi) are close to each other on the germination cap. (b), (c) Lateral views of seed with exotesta partly broken off exposing the inner calcified core lined by mesotesta and tegmen; note the distinct raphe on the inner core. (d) Apical view of holotype showing germination cap with closely spaced hilum (hi) and micropyle (mi). (e) Apical view of seed with part of exotesta and germination cap preserved; note tall and thick-walled cells exotesta and the thin layer of mesotesta between exotesta and tegmen. (f), (g) Volume renderings cut through the micropylar (mi) and hilar (hi) area of seed shown in (e) in angles perpendicular to each other; mesotesta is thicker close to the micropyle. (h), (i) Volume renderings transversely cut through the micropylar (mi) and hilar (hi) area of seed shown in (e) at two different levels, (h) close to the apex and (i) further down; note narrow zone of exotestal cells (asterisk) between micropyle and hilum/raphe (h cut at orthoslice xy0300; i cut at orthoslice xy0510). Scale bars 1 mm (a–c), 0.5 mm (d–i). Friis et al. (2017).

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Euanthus panii: A flower from the Middle-Late Jurassic Jiulongshan Formation of Liaoning Province, China.

Flowering Plants, Angiosperms, are the dominant group of plants in almost all modern terrestrial ecosystems, but their origins remain somewhat obscure. The group rose to dominance early in the Cretaceous, and have only a pachy and debatable fossil record before this,  though molecular clock dating methods have suggested that Angiosperms are considerably older than Cretaceous in origin.

In a paper published in the journal Historical Biology on 16 March 2016, Zhong-Jian Liu of the Shenzhen Key Laboratory for Orchid Conservation and Utilization at the National Orchid Conservation Center of China and Orchid Conservation and Research Center of Shenzhen and Xin Wang of the State Key Laboratory of Palaeobiology and Stratigraphy at the Nanjing Institute of Geology and Palaeontology and the Palaeontological Center at Bohai University describe a well preserved flower from the Middle-Late Jurassic Jiulongshan Formation of Liaoning Province, China.

The specimen is described as Euanthus panii, where 'Euanthus' means 'real-flower' in Latin and 'panii' honours Kwang Pan, who collected the specimen and donated it to the Nanjing Institute of Geology and Palaeontology. Euanthus panii comprises a single flower on a split limestone block, with part and counterpart showing the adaxial and abaxial surfaces; the specimen is a compression with some coalified residue.

Euanthus panii and its details. Stereomicroscopy. (a, b) The flower in two facing parts, with sepals (S) and petals (P) radiating from the receptacle. The black arrows mark the distal of the style, and the blue arrow in (b) marks the stamen. (c) A sepal (S) is almost structureless between the two arrows, implying that it is attached to the receptacle (O) with its whole base. Enlarged from (a). Bar ¼ 1 mm. (d) Pentamerous receptacle with ovarian cavity (O) in its centre. Note the corners (arrows) of about 110 degrees. Bar = 0.5 mm. (e) Basal portion of the flower after degagement. Note spatial relationship among the ovary (O), style base, a possible filament stub (arrow), sepals (S) and petal (P). Bar = 1.0 mm. Liu & Wang (2016).

The flower is about 12mm long and 12.7mm wide, with pentamerous symmetry and short stout sepals alternating with longer petals. The androecium has dithecate anthers with in situ pollen grains, the gynoecium a long, slender hairy style and an unilocular ovary enclosing unitegmic ovules. Given past controversy about pre-Cretaceous Angiosperm fossils, Lui & Wang are cautious in their dating of the specimen, but are confident the rocks of the outcrop which produced it are at least 161.8 million years old.

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Juraherba bodae: A herbaceous Angiosperm (Flowering Plant) from the Middle Jurassic of Inner Mongolia.                                  Angiosperms (Flowering Plants) are the dominant plants in almost all modern ecosystems, producing a wide variety of woody and herbaceous forms. The earliest Angiosperms are thought to have...

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Xenoxylon junggarensis: A new Gymnospermous fossil wood from the Late Triassic Huangshanjie Formation of Xinjiang.

Plant fossils are considered to be extremely important in the reconstruction of ancient environments, however, unlike animals, complete plants are extremely rare in the fossil record, with almost all plants known from dissarticulated material, such as wood leaves or pollen, so that these different parts of the plant are usually described as different species. Wood is the toughest material produced by plants (other than wind-blown pollen) and is extremely useful in reconstructing ancient climates, as growth patterns directly related to seasonality are preserved in the wood.

In a paper published in the journal Palaeogeography, Palaeoclimatology, Palaeoecology on 1 January 2016, Mingli Wan of the Department of Palaeobotany and Palynology and the State Key Laboratory of Palaeobiology and Stratigraphy at the Nanjing Institute of Geology and Palaeontology , Weiming Zhou of the School of Earth Sciences and Engineering at Nanjing University, Peng Tang, also of the Department of Palaeobotany and Palynology at the Nanjing Institute of Geology and Palaeontology, and Lujun Liu and Jun Wang, again of the Department of Palaeobotany and Palynology and the State Key Laboratory of Palaeobiology and Stratigraphy at the Nanjing Institute of Geology and Palaeontology, describe a new species of fossil wood from the Late Triassic Huangshanjie Formation of Jimsar County in Xinjiang Province in northwestern China.

The new species is placed in the widespread Mesozoic genus Xenoxylon, and given the specific name junggarensis, meaning 'from Junggar' in reference to the Junggar Basin, where the specimens were found. The species is described from five wood specimens, all of which were fragmented into smaller pieces by weathering. The specimens are interpreted as having come from branches or stems 3-10 cm in diameter, though only the secondary xylem has been preserved, all cortex and peridermal structures having been lost.

Xenoxylon junggarensis from the Norian (Late Triassic) Huangshanjie Formation in Dalongkou Section, Jimsar County, Xinjiang Uygur Autonomous Region, China. (A) Field photo showing the original position, and a small diameter and length (2 cm in diameter and 6 cm in length) of the fossil stem. The hammerhead is ~10 cm long. (B) Field photo showing the original position and a relatively larger size (10 cm × 7 cm) of the fossil stem. The hammer is ~21 cm long. (C) Photomicrograph of a transverse section showing an exceptional wide growth ring (white arrow) and a relatively narrow growth ring (black arrow). (D) Photomicrograph of a transverse section showing ring boundary and the tacheids collapsed into zigzag pattern (white arrow). Note large amount of earlywood and the smaller amount of latewood. Wan et al. (2016).

Members of the genus Xenoxylon have generally been interpreted as having lived in cool wet climates. The climate of the Junggar Basin in the Late Triassic is still the subject of some discussion; the area was located at a latitude of about 60° at the time, equivalent to southern Scandinavia or Siberia today, but the Triassic climate was much warmer, and most climatic interpretations of the Junggar Basin have suggested the area was at least seasonally warm and wet, and never prone to freezing.

The Xenoxylon junggarensis specimens preserve easily observed growth rings, generally taken as an indicator of a seasonal climate, but the pattern of this is somewhat different to that seen in most modern temperate trees, with an abrupt transition from earlywood (spring and summer growth) to latewood (darker autumn growth), unlike that seen in modern trees, where the transition is more gradual as late summer conditions slowly cool and/or dry until photosynthesis becomes impossible over the winter/dry season months. Wan et al. suggest that this indicates that conditions were sufficiently warm and wet for the trees to photosynthesise till the very end of their growth season, suggesting that some other factor may have restricted their growth in the non-growing season. They further suggest that this limiting factor may have been light, with the trees, which were growing at a high latitude having to survive an annual dark season in which they did not receive enough light to carry out photosynthesis.

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Diptocarp wood from the northwest of India. Diptocarps, Dipterocarpaceae, are the dominant trees of modern South and Southeast Asian rainforests, and are also found in South America, Africa and Madagascar. The group reach their maximum diversity today on the island of Bornea, where there are over 280 described species of Diptocarp, but the earliest...

Wood fossils from the Plio-Pleistocene of northwest India with African affinities.           India separated from Africa about 130 million years ago, and was effectively an island continent until its collision with Eurasia in the Middle Cenozoic. Nevertheless the modern flora and fauna of India show strong affinities with that of Africa, and while there...

Preserved wood from an Early Eocene kimberlite pipe in northwestern Canada’s Slave Province.                                       Kimberlite pipes are produced by rapid volcanic intrusions carrying magma from the Earth’s mantle rapidly to the surface, often...

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Juraherba bodae: A herbaceous Angiosperm (Flowering Plant) from the Middle Jurassic of Inner Mongolia.

Angiosperms (Flowering Plants) are the dominant plants in almost all modern ecosystems, producing a wide variety of woody and herbaceous forms. The earliest Angiosperms are thought to have been woody in nature, as the group they arose from, the Gymnosperms (Conifers, Cycads, Ginkos etc.) are exclusively woody today, and appear to have been so throughout their history (some putative herbaceous Conifers have been described from the Triassic of France, but these are disputed). The first Angiosperm pollen appears in the fossil record in the Triassic, with Angiosperm macrofossils appearing in the Jurassic and the group rising to dominance in the Early Cretaceous. However herbaceous plants lacking woody material have limited preservational material, so while herbaceous Angiosperms could potentially have been present since the Triassic, the origin of such plants is unclear.

In a paper published in the journal Acta Geologica Sinica on 18 February 2016, Han Gang of the Palaeontological Center at Bohai University, Liu Zhongjian of the Palaeontological Center at Bohai University and the Shenzhen Key Laboratory for Orchid Conservation and Utilization at the National Orchid Conservation Center of China and Orchid Conservation & Research Center of Shenzhen, Liu Xueling, also of the Palaeontological Center at Bohai University, Mao Limi of the State Key Laboratory of Palaeobiology and Stratigraphy at the Nanjing Institute of Geology and Palaeontology, Frédéric Jacques of the Key Laboratory of Tropical Forest Ecology at the Xishuangbanna Tropical Botanical Garden, and Wang Xin, also of the State Key Laboratory of Palaeobiology and Stratigraphy at the Nanjing Institute of Geology and Palaeontology, describe a herbaceous Angiosperm from the Middle Jurassic Jiulongshan Formation of Inner Mongolia.

The Daohugou Beds of the Jiulongshan Formation are a fossil Lagarstätte from Ningcheng County in Inner Mongolia, which have produced a large number of well preserved Middle Jurassic Vertebrates, Insects, Plants and other fossils. The  deposits comprise coarse conglomerates, sandstone, mudstone and thin coal layers laid down in a lake surrounded by a moist, warm-temperate forest, dominated by Conifers, Ginkos and Cycads.

The new Angiosperm is named Juraherba bodae, where 'Juraherba' implies 'Jurassic Herb' and 'bodae' is a Chinese diminutive of Bohol University. The species is described from a single specimen, a complete plant 38 mm in length, with a preserved root system, elongate, blade shaped leaves similar to those of modern Grasses and four fructifications, one of which is split open sufficiently to reveal an internal seed, clearly identifying the plant as an Angiosperm.

General morphology and details of Juraherba. (a) Whole plant with physically connected parts including roots (r), stem (s), leaves (f), and fructifications (1-4). Note an associated fossil insect (arrow) at the top. Scale bar is 10 mm. (b) Helically arranged leaves (1-6). Scale bar is 0.5 mm. (c) Coalified lower portion with scales (white arrows) and hairy roots (black arrows). Scale bar is 0.5 mm. (d) Fructification 3 in Fig. 2a, with longitudinal ridges (arrows) and some coalified remains. Scale bar is 1 mm. (e) Margin (arrows) of a leaf (l) with smooth surface, and the stem (s) with rough surface. Scale bar is 0.5 mm. (f) One of the leaves with an array of insect damages (arrows). Scale bar is 1 mm. (g) Detailed view of one (arrow) of insect damages. Scale bar is 0.1 mm. Han et al. (2016).

The root structure of Juraherba bodae is extremely limited, leading Han et al. to suggest that it lived in a still aquatic environment. All of the frutifications appear to have been held at the same level, which Han et al. suggest may have been the water surface. The frutifications are fleshy in nature, raising the possibility that like many modern Angiosperms, Juraherba bodae may have relied on an unknown animal to dispurse its seeds by consuming these fruit.

 Reconstruction of whole plant, fructification, and leaf of Juraherba. Not to scale. Han et al. (2016).

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Glenrosa carentonensis: A new species of Conifer from the Early Cretaceous of Charente-Maritime, France.                             Conifers of the genus Glenrosa were first recorded from the Early Cretaceous Glen Rosa Formation of Texas in 1984 (although specimens of the plant had been collected in the area since the 1890s)...

Pollen and Spores from the Early Cretaceous Damoguaihe formation in eastern Mongolia. The Damouguaihe formation is found in the Hailar Basin in Inner Mongolia, where it has been accessed from a number of coal mines (it never naturally outcrops at the surface). More recently it has also been found in the Tamutsag Basin of Mongolia, where it has been accessed by exploration wells sunk by oil...

Traces of Insect oviposition on Ginko leaves from the Middle Jurassic Daohugou Biota of Inner Mongolia.                                         Plants and Insects are the most abundant organisms in modern terrestrial ecosystems, and generally considered to be the most important. It is thought...

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