Papers by Leyla Seyfullah
Fossil Imprint, 2021
Here we present LM and SEM data of pollen of extant Sciadopitys verticillata, fossil Cerebropolle... more 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 t...
Fossil Record, Jul 17, 2015
Cretaceous Research, 2022
Abstract Despite that there are only three morphologically isolated genera of Gnetales (gymnosper... more Abstract Despite that there are only three morphologically isolated genera of Gnetales (gymnosperm) plants surviving today, they are thought to have had a major peak in diversity during the Early Cretaceous, with the Crato Formation being one of the richest sources for these plants. The reinvestigation of a Crato Formation palynoflora sample with LM and SEM here gives further insights in to the wider diversity of fossil gnetaleans present, and their pollination types, which is not preserved in the corresponding macroflora. Here we present 21 different pollen types of gnetaleans from a single sample of Prof. David J. Batten’s legacy: 11 Ephedripites and seven Gnetaceaepollenites taxa, one Welwitchiapites taxon and Regalipollenites amphoriformis. We suggest that this sample, originating from the lowermost Crato Formation, corresponds to Lima’s palynozone 1a. The high resolution scanning electron microscopy reveals several types of conspicuous ornamentation of the pollen wall, i.e., implying a more insect-pollinated rather than wind-pollinated (i.e., mixed-ambophilous) pollination syndrome for many of these gnetalean plants. The ornamentation also provides clear indications for harmomegathic (shrinking and deshrinking) behaviour of many of the pollen grains as a likely adaptation to drier climate conditions. The pollen described here shows a far greater diversity of species and morphologies than seen today and in the gnetalean macroremains present in the Crato Formation flora, re-emphasising the importance of the Crato Formation as a source for both the macro-, and importantly, the micro-fossil diversity of gnetalean plants, not matched elsewhere.
New Phytologist
Summary The determinants of biodiversity patterns can be understood using macroevolutionary analy... more Summary The determinants of biodiversity patterns can be understood using macroevolutionary analyses. The integration of fossils into phylogenies offers a deeper understanding of processes underlying biodiversity patterns in deep time. Cycadales are considered a relict of a once more diverse and globally distributed group but are restricted to low latitudes today. We still know little about their origin and geographic range evolution. Combining molecular data for extant species and leaf morphological data for extant and fossil species, we study the origin of cycad global biodiversity patterns through Bayesian total‐evidence dating analyses. We assess the ancestral geographic origin and trace the historical biogeography of cycads with a time‐stratified process‐based model. Cycads originated in the Carboniferous on the Laurasian landmass and expanded in Gondwana in the Jurassic. Through now‐vanished continental connections, Antarctica and Greenland were crucial biogeographic crossroad...
Frontiers in Ecology and Evolution
The Gnetales are one of the most fascinating groups within seed plants. Although the advent of mo... more The Gnetales are one of the most fascinating groups within seed plants. Although the advent of molecular phylogenetics has generated some confidence in their phylogenetic placement of Gnetales within seed plants, their macroevolutionary history still presents many unknowns. Here, we review the reasons for such unknowns, and we focus the discussion on the presence of “long branches” both in their molecular and morphological history. The increased rate of molecular evolution and genome instability as well as the numerous unique traits (both reproductive and vegetative) in the Gnetales have been obstacles to a better understanding of their evolution. Moreover, the fossil record of the Gnetales, though relatively rich, has not yet been properly reviewed and investigated using a phylogenetic framework. Despite these apparent blocks to progress we identify new avenues to enable us to move forward. We suggest that a consilience approach, involving different disciplines such as developmenta...
Review of Palaeobotany and Palynology
Proceedings of the National Academy of Sciences, 2021
Significance There were two heterosporous lignophyte lineages of which only one, the seed plants,... more Significance There were two heterosporous lignophyte lineages of which only one, the seed plants, survived the Permian–Triassic mass extinction. Based on exceptionally complete fossil trees from a 300-My-old volcanic ash, the enigmatic Noeggerathiales are now recognized as belonging to the other lineage. They diversified alongside the primary seed plant radiation and constitute seed plants’ closest relatives. Noeggerathiales are reconstructed as members of a plexus of free-sporing woody plants called progymnosperms, extending their age range by 60 My. Following the origin of seed plants, progymnosperms were previously thought to have become gradually less abundant before dying out in Carboniferous. We show they diversified and evolved complex morphologies including cone-like structures from modified leaves before going extinct at the Permian–Triassic extinction.
Review of Palaeobotany and Palynology, Jul 1, 2022
Frontiers in Earth Science
The Carnian Pluvial Episode (CPE) has been recognized as a time of plant radiations and originati... more The Carnian Pluvial Episode (CPE) has been recognized as a time of plant radiations and originations, likely related to observed swift changes from xerophytic to more hygrophytic floras. This suggests that the increasing humidity causally resulting from LIP volcanism was the trigger for these changes in the terrestrial realm. Understanding the cause and effects of the CPE on the plant realm, requires study of well-preserved floras that are precisely aligned with the CPE. We therefore focus on the best age-constrained section within the CPE for the terrestrial to marginal marine environment to understand the floristic composition at the early CPE. This is found in the Dolomites, Italy, and is remarkable for the preservation of the oldest fossiliferous amber found in the rock record. An integrated study of palynomorphs and macro-remains related to the conifer families of the fossil resin bearing level brings together the floral components from this section. This observed mixture of di...
BMC Evolutionary Biology, 2020
Background Amber has been reported from the Early Cretaceous Crato Formation, as isolated clasts ... more Background Amber has been reported from the Early Cretaceous Crato Formation, as isolated clasts or within plant tissues. Undescribed cones of uncertain gymnosperm affinity have also been recovered with amber preserved in situ. Here, we provide multiple lines of evidence to determine the botanical affinity of this enigmatic, conspicuous cone type, and to better understand the diversity of amber-source plants present in the Crato Formation and beyond. Results A new taxon of amber-bearing pollen cone Araripestrobus resinosus gen. nov. et sp. nov. is described here from complete cones and characteristic disarticulated portions. The best-preserved cone portion has both in situ amber infilling the resin canals inside the preserved microsporophyll tissues and pollen of the Eucommiidites-type. This places this genus within the Erdtmanithecales, an incompletely known gymnosperm group from the Mesozoic. FTIR analysis of the in situ amber indicates a potential araucariacean conifer affinity, ...
Cretaceous Research, 2020
Scientific Reports, 2020
Some liquid plant exudates (e.g. resin) can be found preserved in the fossil record. However, due... more Some liquid plant exudates (e.g. resin) can be found preserved in the fossil record. However, due to their high solubility, gums have been assumed to dissolve before fossilisation. The visual appearance of gums (water-soluble polysaccharides) is so similar to other plant exudates, particularly resin, that chemical testing is essential to differentiate them. Remarkably, Welwitschiophyllum leaves from Early Cretaceous, Brazil provide the first chemical confirmation of a preserved gum. This is despite the leaves being exposed to water twice during formation and subsequent weathering of the Crato Formation. The Welwitschiophyllum plant shares the presence of gum ducts inside leaves with its presumed extant relative the gnetalean Welwitschia. This fossil gum presents a chemical signature remarkably similar to the gum in extant Welwitschia and is distinct from those of fossil resins. We show for the first time that a water-soluble plant exudate has been preserved in the fossil record, pot...
European Journal of Taxonomy, 2019
Two new species of ants (Hymenoptera: Formicidae) collected from New Caledonia are described and ... more Two new species of ants (Hymenoptera: Formicidae) collected from New Caledonia are described and figured based on worker specimens: Leptogenys loarelae Ramage sp. nov. (Ponerinae, Ponerini) and Lioponera neocaledonica Jouault, Ramage & Perrichot sp. nov. (Dorylinae, Cerapachyini). All specimens were collected from the South Province of Grande Terre. These two new species are primarily distinguished from the other New Caledonian relatives by the size and shape of petiole for L. loarelae Ramage sp. nov. and by the presence of dorsolateral margins on the mesosoma for L. neocaledonica Jouault, Ramage & Perrichot sp. nov. Keys to New Caledonian Leptogenys and Lioponera are provided.
Geobios, 2019
Abstract Species belonging to the Carboniferous genera Lepidodendron and Lepidophloios are well k... more Abstract Species belonging to the Carboniferous genera Lepidodendron and Lepidophloios are well known from the coalfields of Pennsylvania (Lower Asturian (Westphalian D) substage of the Pennsylvanian) through the publications of Lesquereux and White. They believed that the lycophyte flora was rather distinct from other contemporaneous coal floras elsewhere due to its isolation. A full revision of the lepidodendroid lycophyte species is given here and this reassessment permitted comparisons with those floras known from the European and Canadian Maritimes coalfields. Differences in species distribution suggest there was a barrier (Arcadian Highlands) to species distribution to and from the coalfields of Pennsylvania. Several species are recognized only from the coalfields of Pennsylvania, although the number has been significantly reduced from the original publications.
Journal of the Geological Society, 2018
Amber (fossil resin) is not common throughout the fossil record, and previously the only globally... more Amber (fossil resin) is not common throughout the fossil record, and previously the only globally significant deposits were thought to occur during the Cretaceous, Eocene, Oligocene and Miocene periods. Recent finds of Late Triassic (Carnian) ambers highlight a significantly older set of deposits. Here we review these ambers that appear coincident with the Carnian Pluvial Episode, a time interval of major climate change and biotic turnover. Much of the amber is found in a palaeolatitudinal belt between 5° and 30° N, and covers Italian, Austrian, Swiss, Hungarian, Spanish and Arizona (USA) deposits, with one exception from Lesotho, Southern Africa (c. 40° S). Most deposits are small and allochthonous, with the major exception of the autochthonous–parautochthonous amber deposit found as droplets in a palaeosol from the Dolomites (Italy). In some of these deposits there is even direct evidence of the source plants that produced the preserved resin. The oldest confirmed organisms found preserved in amber are from Carnian droplets from the Dolomites in Italy and include arthropods and microorganisms. The occurrence of amber in different localities and within the same time interval suggests a widespread stressed flora, and major biological turnover in the terrestrial ecosystems during the Carnian Pluvial Episode.
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Papers by Leyla Seyfullah