Ginkgo Species Research Articles

A new Ginkgo from the Lower Cretaceous of Liaoning, Northeast China and its evolutionary implications

A new species of Ginkgo L., G. pediculata sp. nov., is described from the Lower Cretaceous of Liaoning Province, Northeast China, on the basis of a well-preserved ovule-bearing organ. The cuticles of the integument and peduncle are generally similar to those of the lamina and petiole of the associated Ginkgoites manchurica (Yabe et Ôishi) Cao, which is among the most widely distributed Ginkgo-like leaves in the Lower Cretaceous of Northeast China. The new species is close to the Jurassic Ginkgo yimaensis Zhou et Zhang and clearly distinguished from the Paleogene species Ginkgo cranei Zhou et al. and the extant Ginkgo biloba. Although the coeval Ginkgo apodes Zheng et Zhou and G. neimengensis Xu et al. from Northeast China bear more ovules, they both have no pedicel when matured as the living species. The associated Ginkgoites-type leaves morphologically also resemble those of the Jurassic species. Therefore, Ginkgo pediculata sp. nov. appears to be closely related to the Jurassic species and is the latest representative of the group with primitive type ovulate organs and vegetative leaves so far known of Ginkgo. Since there co-exist two different types of ginkgoes, one with primitive characters (Ginkgo pediculata) and the other such as Ginkgo apodes and G. neimengensis which resemble the extent species G. biloba, the Lower Cretaceous is a critical time in the morphological evolution of the genus Ginkgo, roughly corresponding to the major global floristic transformation marked by the rapid decline of gymnosperms and drastic rise of flowering plants.

Revisiting the Late Cretaceous Parataxodium wigginsii flora from the North Slope of Alaska, a high-latitude temperate forest

Reinvestigation of a Late Cretaceous plant assemblage from along the Colville River on the North Slope of Alaska reveals both that the flora is far more diverse than previously suspected, and that many specimens are anatomically preserved. The flora includes one moss, an osmundaceous fern, one species of Ginkgo, the putative conifer leaf Pityophyllum, five species of cupressaceous conifers, five dicot leaf morphotypes, and one monocot. The cupressaceous remains heretofore have been interpreted as a single taxodioid/sequoioid conifer species, Parataxodium wigginsii Arnold and Lowther. However, reexamination of the fossils reveals five different morphologies of cupressaceous ovuliferous cones, and a wide range of intergrading leafy shoot morphologies. Peel sections show excellent internal anatomy for many of the cupressaceous conifer organs, as well the moss. These fossils characterize a high-latitude deciduous flora dominated by cupressoid conifer trees, with less common dicot and Ginkgo trees, and with ground cover that includes osmundaceous ferns, monocots, and dicranalean mosses. The increased diversity of disarticulated plant parts in the assemblage demonstrates that Parataxodium wigginsii is not nearly as well understood as widely believed, and that the genus and species concepts as currently defined may be based on organs from several cupressaceous conifers. This assemblage is an outstanding example of an unusual Late Cretaceous, high-latitude, Northern Hemisphere, mixed dicot-coniferous, cool temperate, deciduous forest that existed in total darkness for a significant period each year.

An inter-comparison study of three stomatal-proxy methods for CO2 reconstruction applied to early Jurassic Ginkgoales plants

The inverse relationship between concentrations of CO2 in the atmosphere (pCO2) and the stomatal index of vascular plant has been widely used to estimate ancient levels of atmospheric CO2. However, some atmospheric concentration of CO2 in the geological past (paleo-CO2) estimates show little congruence because they are derived using different correlative methods, or from different fossil plant species with different calibration approaches. Here we apply three methods, including (1) the empirical method of McElwain (1998), (2) the empirical method of Barclay and Wing (2016) and (3) the mechanistic method of Franks et al., (2014) to a single fossil Ginkgo species (Ginkgoites marginatus) to track and assess their consistency of pCO2 estimates for the Early Jurassic. By using an inter-comparison of three methods, a high degree of consistency in pCO2 estimates and trends has been observed in two empirical proxy methods. In addition, the mechanistic method and both the empirical methods also show generally good consistent paleo-CO2 estimates at the bed-level. To test the congruence of paleo-CO2 estimates, we also apply all three methods to one additional Ginkgoalean fossil species (Sphenobaiera huangii). All three methods show species-dependent uncertainty in paleo-CO2 estimates when applied to different Ginkgalean fossil species collected from the same fossiliferous bed. Moreover, considering the potential effect of guard cell size to the mechanistic method, the genome size of fossil and living Ginkgo taxa was analyzed based on the significant positive relationship between genome size and guard cell size. The result demonstrates that a likely occurrence of polyploidy in Sphenobaiera huangii may result in underestimated paleo-CO2 when applying mechanistic method due to an increase in the size of the stomatal complex.

Plant fossils from the Wealden facies (Lower Cretaceous, Berriasian) of Tecklenburg, Westphalia, Germany

While the Early Cretaceous flora of the English Wealden has been extensively revised in the last decades, the flora from the German Wealden is still in need of thorough revision. One major account on a flora from Duingen in the eastern Lower Saxony Basin (Niedersächsisches Becken) has been published a couple of years ago, but was covering freshly collected fossil material only. Here, a small flora from the southern margin of the Lower Saxony Basin is reported coming from Brochter-beck, a district of Tecklenburg, at the northern slopes of the Teutoburger Wald mountain range in Westphalia, Germany. The flora shows a slightly different composition compared to those of the 'classical' German Wealden: it is also characterised by remains of several delicate filmy ferns and cupressoid (taxodiaceous) conifers, but it is dominated by the presence of leaves of Nilssonia schaumburgensis, while other cycadophytes such as cycads and bennettites are entirely absent. One leaf reminiscent of a Ginkgo species was found as well. The relatively fine-grained sandstones of the rocks comprising the flora at Brochterbeck reflect a terrestrial deposit of the Wealden facies, which was deposited under deltaic freshwater conditions in brackish–limnic conditions in a humid, subtropical climate.

Ecologically conditioned imprinting of miRNA-based profiles of Ginkgo biloba L. growing in Slovakia

Abstract Ginkgo biloba L. is characterized by its high level of resistance to climatic conditions, diseases, and pests. In Slovakia, there is a rich collection of genetic resources of ginkgo consisting of 288 trees growing in 103 locations and providing valuable biological material for scientific research. There have been documented 45 trees of ginkgo older than 100 years (ranging from 112 to 242 years of age). Their dendrometrical parameters were recorded. For genomic imprinting, three types of microRNA-based markers were selected; highly conserved gb-miR160, moderately conserved gb-miR482 and the species-specific gb-miR75. The most efficient one can be considered the marker gb-miR482 with its genotype-unique miRNA profiles probably related to this marker functioning in the defence mechanisms of the ginkgo species. Unique miRNA loci were recorded in genomes of young ginkgo trees. We found that, by selecting the appropriate microRNA-based markers, it is possible to characterize the ginkgo genome in the context of microclimatic conditions.

Middle Jurassic Ginkgo leaves from the Daohugou area, Inner Mongolia, China and their implication for palaeo-CO2 reconstruction

Well-preserved Ginkgo leaves with cuticle were collected from the Middle Jurassic Jiulongshan Formation in the Daohugou area, Inner Mongolia, China, which form the common elements in the Daohugou flora. Three new species of Ginkgo are recognized and their leaf morphology and cuticular structure are described for the first time. Two different pCO2 proxy models were applied to reconstruct palaeo-atmospheric CO2 concentration by using these new Ginkgo material. NLE (nearest living equivalent) suggests a semi-quantitative pCO2 estimate as 839±99ppmv with Carboniferous standardization and 419±49ppmv with Recent standardization. While Barclay’s revised SI-pCO2 regression suggests the estimates as 405±71ppmv. The results show that the pCO2 estimate is higher than today’s atmospheric CO2 concentration but lower than most of the other results on the Jurassic Period. Combined with the floristic composition, the climate at 165Ma in the Daohugou area is inferred to be warm temperate.

A New Species ofGinkgowith Male Cones and Pollen Grains in situ from the Middle Jurassic of Eastern Xinjiang, China

Well-preserved Ginkgo pollen organs are analyzed from the Middle Jurassic Xishanyao Formation of the Turpan-Hami Basin, Xinjiang Uygur Autonomous Region, northwestern China, and are described as a new species, Ginkgo hamiensis Z.X. Wang et B.N. Sun sp. nov. The immature male cones are cylindrical and catkin-like, with two longitudinal stripes on the stalk. The pollen sacs are shaped like a long oval with two pollen sacs fused together for each microsporophyll, and the microsporophyll tip is a triangular cystidium. The pollen grains are oblong or fusiform and monocolpate; both ends are blunt or sharp. By comparison with previously reported fossil records of Ginkgo plants, we determined that the current fossils are different from all other reported species; thus, the present fossil is referred to as a new species of Ginkgo. The reproductive organs of the Ginkgo fossils described herein can provide valuable information for the study of Ginkgo plants. Further, there are two probable evolutionary trends in the Ginkgo pollen cones. One trend is that the number of pollen sacs changed from three or four during the Jurassic and Cretaceous to two at the present day; the other is that the number of pollen sacs has remained two from the Middle Jurassic to the present day. In addition, the pollen cones described herein are similar to the pollen cones of the extant Ginkgo, which strongly indicates that the morphology of Ginkgo plants may have remained highly conserved over millions of years.

Morphology and epidermal characters of Ginkgo pilifera Samyl. leaves and distribution of this species in the Late Cretaceous of Northern Asia

In the result of investigation of new findings, the variability of leaf shape and epidermal characters of Ginkgo pilifera Samyl. were studied. Geographical and stratigraphic ranges of this species were analyzed on the base of new material and earlier published data. This species was described by Samylina (1967) from the upper part of the Timmerdyakh Formation exposed in the Lena-Vilyui depression in Eastern Siberia. After that many new occurrences of this species were reported. G. pilifera was widely distributed from late Albian to Maastrichtian in Asian part of the Siberian-Canadian paleogeographical region. The earliest occurrence was documented from the late Albian-lower Turonian deposits of the Krivorechenskaya Formation, Grebenka River basin, Northeastern Russia. Approximately in the same time (in the Cenomanian) remains of G. pilifera appeared in the lower part of the Timmerdyakh Formation in the Lena-Vilyui depression. In Western Siberia in the late Albian and Cenomanian other species of Ginkgo were found: G. sertensis N. Nosova et Golovn. and G. chlonoviae N. Nosova et Golovn. were described from the Kiya Formation and G. ragosinii N. Nosova et Golovn. and G. tjukansis Kiritch. were described from the Simonovo Formation. In the Turonian and Coniacian G. pilifera was discovered in the upper part of the Timmerdyakh Formation, in the Valizhgen Formation of Yelistratov peninsula in Penzhina Bay area, in volcanogenic deposits of the Kolyma River basin and in the Derevyannye Gory Formation of New Siberia Island. In the Santonian-Campanian this species was reported from the Arkagala Formation of the Kolyma River basin and from two localities in the Amur River basin: from upper part of the Kundur Formation in Russia and from the Taipinglinchang Formation in China. The last occurrence is the most southern finding of this species. In Maastrichtian G. pilifera penetrated in Western Siberia, that significantly increased its area in western direction. The most variable character in G. pilifera morphology is the leaf shape. Leaves change from entire to deep-dissected into several wide lobes with rounded or truncate apices. Dissected forms occured from late Albian to Coniacian and predominated in the Krivorechenskaya (late Albian-lower Turonian) and the Valizhgen (Turonian-Coniacian) Formations Northeastern Russia.During Santonian-Maastrichtian only entire forms were distributed. The variability of epidermal characters is insignificant. The most variable characters are degree of undulation of the anticlinal cell walls, degree of development of cuticular thickenings and number of stomata on adaxial epidermises and number of trichomes on of abaxial and adaxial epidermises. The specific diagnosis of this species was emended. Remains of G. pilifera occur in allochtonous taphocenosis together with other plants characteristic to riparian habitats. Probably, this species was confined to river valleys and was not connected with swamp environments.Paleoecological implication of great number of papillae and trichomes is steel unclear. Emended diagnosis. Leaves broadly fan-shaped, entire with undulate upper margin with several shallow incisions, or, more rarely, dissected into several wide lobes with rounded or truncate apices. Leaves amphistomatic. Anticlinal cell walls of adaxial epidermis sinuous with amplitude up to 2–3 μm; in costal zones sometimes slightly sinuous or straight. Periclinal walls with cuticular dome-shaped thickenings and rare trichomes. Number and development of cuticular thickenings vary in different areas of leaf lamina and in different leaves. Weak development of thickenings usually correlates with increased number of trichomes. Stomata at abaxial epidermis rare; the papillae of subsidiary cells do not cover the stoma completely. Anticlinal cell walls of abaxial epidermis slightly sinuous or straight. Periclinal walls usually with papillae (12-20 μm long), more rarely, smooth. Trichomes (up to 60–100 μm long) occur rather often. Big trichomes usually consist of 2-3 cells. Stomata at adaxial epidermis orientated irregularly, without formation of regular rows, surrounded by five to seven subsidiary cells. Each subsidiary cell bears a proximal papilla up to 15–25 μm long. These papillae completely cover the stoma.

Новые виды Ginkgo L. из сертинской флоры, поздний альб, Западная Сибирь

Two new species of Ginkgo with dissected leaves, Ginkgo sertensis N. Nosova et Golovn., sp. nov. and G. chlonoviae N. Nosova et Golovn., sp. nov., from the upper Albian deposits of the Kiya Formation of Western Siberia are described. These species expand the taxonomic composition of the Serta flora and supplement our understanding of the systematic diversity and distribution of Ginkgo in the Cretaceous of Russian Asia.

Jurassic mimicry between a hangingfly and a ginkgo from China

A near-perfect mimetic association between a mecopteran insect species and a ginkgoalean plant species from the late Middle Jurassic of northeastern China recently has been discovered. The association stems from a case of mixed identity between a particular plant and an insect in the laboratory and the field. This confusion is explained as a case of leaf mimesis, wherein the appearance of the multilobed leaf of Yimaia capituliformis (the ginkgoalean model) was accurately replicated by the wings and abdomen of the cimbrophlebiid Juracimbrophlebia ginkgofolia (the hangingfly mimic). Our results suggest that hangingflies developed leaf mimesis either as an antipredator avoidance device or possibly as a predatory strategy to provide an antiherbivore function for its plant hosts, thus gaining mutual benefit for both the hangingfly and the ginkgo species. This documentation of mimesis is a rare occasion whereby exquisitely preserved, co-occurring fossils occupy a narrow spatiotemporal window that reveal likely reciprocal mechanisms which plants and insects provide mutual defensive support during their preangiospermous evolutionary histories.

Ginkgo Huolinhensis sp. nov. from the Lower Cretaceous of Huolinhe Coal Field, Inner Mongolia, China

Abstract:A new species, Ginkgo huolinhensis sp. nov., with well‐preserved cuticle from the Lower Cretaceous, Huolinhe Formation of Huolinhe Coal Field in Inner Mongolia, China, was studied morphologically and anatomically. The main characters of the new species are found in the leaves which are deeply dissected with narrow lobes, trichomes developed on both upper and lower epidermal cells, a media papilla developed on the periclinal walls for each cell in upper cuticle, and no trichomes on the cuticle of the petioles. These characters of G. huolinhensis sp. nov. distinguish from the known species of Ginkgo previously reported. This study of the new species is beneficial for the taxonomic research of fossil Ginkgo, and should be helpful for a better understanding the paleoenvironment of Ginkgo living in northeastern China during the Early Cretaceous.

Variability in epidermal characters of Ginkgo tzagajanica Samylina (Ginkgoales) from the Paleocene of the Tsagayan formation (Amur Region) and the taxonomy of tertiary species of Ginkgo

The study of new material on Ginkgo tzagajanica Samylina and earlier published data has shown that the epidermal morphology of the species in highly variable; several new characters were found. Occurrence of different states of characters was analyzed, their frequency distribution was revealed, and typical and rare states of characters within variation rows were determined. The specific diagnosis of G. tzagajanica was emended. The most variable characters are degree of undulation of the anticlinal walls of cells of abaxial and adaxial epidermises (the latter is more variable) and degree of development and number of papillae on ordinary epidermal cells. Less variable characters are degree of development of papillae on subsidiary cells of stomata and how the papillae cover the stomatal apertures. These are characters that bear maximal diagnostic significance for Cenozoic Ginkgo.

Quantitative Analysis of Paleoatmospheric CO2 Level Based on Stomatal Characters of Fossil Ginkgo from Jurassic to Cretaceous in China

Abstract: A better theoretical and practical understanding of the linkage between paleo‐CO2 and climate during geological history is important to enhance the sustainable development of modern human society. Development in plant physiology since the 1980s has led to the realization that fossil plants can serve as a proxy for paleoatmosphere and paleobiosphere. As a relict gymnosperm with evolutionary stasis, Ginkgo is well suited for paleoenvironmental reconstruction. This paper analyzes fossil Ginkgo species from integrated strata in the north of China using anatomic data of plant physiology. Using stomatal parameters, a trend for the paleo‐CO2 level during the Early‐Middle Jurassic and the Early Cretaceous was obtained, which is consistent with the estimates by GEOCARB. The trend is also similar to that of Mean Global Surface Temperature in geological time. Compared with three other atmospheric CO2 concentration parameters, the trend of paleo‐CO2 level based on the stomatal parameter of the fossil Ginkgo specimens from three contiguous strata is more exact.

Eocene Ginkgo leaf fossils from the Pacific Northwest

Middle Eocene lacustrine deposits in south-central British Columbia and north-central Washington state preserve two types of Ginkgo leaves. A morphotype characterized by deeply divided multiple lobes is herein described as Ginkgo dissecta sp.nov. Leaves that are either undivided or shallowly divided into bilobate symmetry are indistinguishable from foliage of extant Ginkgo biloba Linnaeus. These fossils contradict the widely held belief that only a single Ginkgo species, Ginkgo adiantoides (Unger) Heer, inhabited Cenozoic forests.Key words: British Columbia, Eocene, fossil, Ginkgo adiantoides, Ginkgo biloba, Ginkgo dissecta, McAbee, Republic, Tertiary, Washington.

First evidence of epidermal structures of Ginkgo from the Mediterranean Tertiary

Tertiary leaf compressions of a Ginkgo plant with cuticle displaying all taxonomically important epidermal features are reported for the first time from Greece, and for the Mediterranean area as a whole. The fossils are from Upper Miocene sediments of Vegora, north-western Greece, and assigned to Ginkgo adiantoides (Unger) Heer. The most conspicuous cuticle characteristics are prominent papillae on the subsidiary cells that sometimes completely cover the stomatal apertures. Such papillae also occur in leaves of G. adiantoides from the Pliocene of eastern Central Europe, but are absent in leaves from the Pliocene of Germany also assigned to this species. We observed a high variability in the degree of papillosity of subsidiary cells of stomata in leaves of living Ginkgo biloba that exhibited prominent papillae in mature sun leaves and a total lack of papillae in shade leaves of a potted plant. This may suggest that differences in epidermal characters between the fossil leaves from Greece and Germany are due to ecotypical/intraspecific variability and not to genetically fixed specific differences. It also suggests that a number of Tertiary Ginkgo species from Eurasia that were distinguished from G. adiantoides by having papillate epidermis cells and subsidiary cells of the abaxial cuticle should be included within G. adiantoides. Two lineages of Ginkgo can be distinguished for the Tertiary of the Northern Hemisphere. From the Palaeogene high latitudes leaves were reported that exhibit upper epidermis cells with prominent papillae similar to those of older Mesozoic Ginkgo, whereas G. adiantoides lacks the papillae of the upper epidermis, a feature which is shared with the living G. biloba. In general, the size of stomata is larger in extant Ginkgo leaves than in those of the fossils.

A Method To Distinguish Between Woods Produced By Evergreen And Deciduous Coniferopsids On The Basis Of Growth Ring Anatomy: A New Palaeoecological Tool

A method is outlined in which woods produced by deciduous and evergreen coniferopsids may be distinguished from one another on the basis of a quantitative analysis of growth ring anatomy. In this method the diameter of successive tracheid cells was measured across growth rings in modern coniferopsid woods, viewed using standard transverse anatomical sections. The cumulative algebraic sum of each cell's deviation from the mean was then calculated for each growth ring increment and plotted as a zero‐trending curve (CSDM curve). Deciduous conifer and ginkgo species dominantly possess symmetrical or left‐skewed CSDM curves whilst evergreen conifer species dominantly possess right‐skewed CSDM curves. These data suggest that in most cases it may be possible to distinguish between evergreen and deciduous fossil coniferopsid species using wood anatomical characteristics, thus providing important insight into coniferopsid palaeoecology. key words: growth rings, conifer wood, palaeoclimate, evergreen, deciduous.

Bennettitales, Cycadales and Ginkgoales from the mid Cretaceous of the Eromanga Basin, Queensland, Australia

Cycadophytes and ginkgophytes are frequent components of maceration residues in mid Cretaceous (Late Albian–Cenomanian) samples derived from bore cores within the Eromanga Basin, central Queensland, Australia. The material, from the Winton, Mackunda, and Allaru Formations, is in dispersed, fragmentary form, although some nearly intact leaves occur. Coniferous leaves dominate most samples. Bennettitaleans are represented by at least two species of Ptilophyllum, including P. boolensis and P. fasciatum. The Bennettitales documented are close to the end of their range in Australia. There is also one species of Pterostoma (Cycadales), P. hirsutus. Bennettitales were much more numerically important than Cycadales. Three species of Ginkgo are present: G. cf. G. wintonensis (as abundant fragments), G. cf. G. australis, and G. cf. G. multiloba. A further cuticle type is suggested to belong to the Caytoniales or Cycadales. Chi-squared tests of association did not suggest any mutual exclusiveness amongst the taxa, but the Bennettitales showed a correlation with the presence of charcoal (suggesting fire-tolerance or pioneers after burning).