Anatomically Preserved Early Cretaceous Bennettitalean Leaves: Nilssoniopteris corrugata n. sp. from Vancouver Island, Canada

2014 ◽  
Vol 88 (5) ◽  
pp. 1085-1093 ◽  
Author(s):  
M. Madeleine Ray ◽  
Gar W. Rothwell ◽  
Ruth A. Stockey

Early Cretaceous fossilized leaves assignable to the extinct seed plant order Bennettitales occur within an exceptionally diverse Early Cretaceous (Valanginian) flora of anatomically preserved plant fossils at Apple Bay on Vancouver Island, British Columbia, Canada. One of the bennettitalean leaf types has an entire margin, with laminae that are attached near the adaxial surface of the midvein. Leaves are 10–15 mm wide with an adaxial surface that shows distinct corrugations, and a midrib that is exposed adaxially. The vascular system of the midrib consists of a crescent-shaped ring of collateral bundles. Lateral veins diverge from midrib at ∼90°, are typically simple but occasionally branch at base of the lamina. Vein density is 12–15 per cm. Leaves are hypostomatic with syndetocheilic stomata that are randomly oriented between veins. Internal anatomy consists of an adaxial hypodermis of closely-spaced isodiametric cells, mesophyll that is differentiated into adaxial palisade and abaxial spongy zones, and collateral bundles that show a distinct bundle sheath with bundle sheath extensions. This novel combination of characters represents the diverse bennettitalean genus Nilssoniopteris. Nilssoniopteris corrugata new species is only the second species of the genus for which internal anatomy is preserved. This species increases the known variation of bennettitalean leaf anatomy, and reinforces our appreciation for the global distribution of bennettitalean seed plants during the Mesozoic.

1992 ◽  
Vol 6 ◽  
pp. 286-286
Author(s):  
David W. Taylor ◽  
J. Michael Moldowan ◽  
Leo J. Hickey

Oleanane is a triterpane that is commonly found in Late Cretaceous (Campanian) through Cenozoic marine and deltaic rocks and related oils. Based on its affinity to the β-Amyrin group of natural products and its abundance in Tertiary deltaic sediments and oils, such as in the Niger Delta, oleanane is thought to be a geochemical fossil of terrestrial flowering plants. The β-Amyrin group forms the basis of many angiosperm triterpenoids and triterpenoid saponins. These compounds appear in moderately advanced flowering plant lineages and are often used as a defense against herbivores. This group of compounds has not been reported from any other seed plant group, including conifers.We examined a suite of middle to early Cretaceous terrestrial sediments and plant fossils for the presence of oleanane. The existence of oleanane was documented by Gas Chromatography - Mass Spectrometry (GC-MS) and confirmed with Metastable Reaction Monitoring (MRM) GC-MS.Oleanane was identified from fossil bennettitaleans, an extinct group of seed plants. Cycadeoidea paynei and C. superba are permineralized fossil stems and are from the Early Cretaceous Inyan Kara Group of the Black Hills, SD. Oleanane was also found in carbonaceous compressed leaf fossils of Dioonites from the Barremian - early Aptian (Zone I) of the Potomac Group from Richmond, VA. This increases the number of seed plant groups known to have oleanane, and is of additional interest as the bennettitaleans are thought to be closely related to angiosperms.Oleanane was not found in contemporaneous fossil conifers. Our sample consisted of fossil conifer wood collected from the Campanian Magothy Beds of Martha's Vineyard, MA; the Cenomanian Raritan Formation of Sayreville, NJ; and the Barremian - early Aptian Patuxent Formation of Greenbelt, MD.Confirmed reports of oleanane have been from Late Cretaceous and younger marine sediments. We now report oleanane from Early Cretaceous terrestrial strata of the Inyan Kara Group. In addition we systematically sampled the sequence of Cretaceous terrestrial sediments of the coastal plain of the eastern U.S.A, and found oleanane in the Barremian - early Aptian (Zone I) Potomac Group. Preliminary data indicate variation in the occurrence of oleanane in contemporaneous Early Cretaceous sites from the Potomac Group. The localities accumulated in different depositional environments and the occurrence may be controlled by lithofacies.


2020 ◽  
Vol 58 (1) ◽  
pp. 253-276 ◽  
Author(s):  
Dmitry Lapin ◽  
Deepak D. Bhandari ◽  
Jane E. Parker

The EDS1 family of structurally unique lipase-like proteins EDS1, SAG101, and PAD4 evolved in seed plants, on top of existing phytohormone and nucleotide-binding–leucine-rich-repeat (NLR) networks, to regulate immunity pathways against host-adapted biotrophic pathogens. Exclusive heterodimers between EDS1 and SAG101 or PAD4 create essential surfaces for resistance signaling. Phylogenomic information, together with functional studies in Arabidopsis and tobacco, identify a coevolved module between the EDS1–SAG101 heterodimer and coiled-coil (CC) HET-S and LOP-B (CCHELO) domain helper NLRs that is recruited by intracellular Toll-interleukin1-receptor (TIR) domain NLR receptors to confer host cell death and pathogen immunity. EDS1–PAD4 heterodimers have a different and broader activity in basal immunity that transcriptionally reinforces local and systemic defenses triggered by various NLRs. Here, we consider EDS1 family protein functions across seed plant lineages in the context of networking with receptor and helper NLRs and downstream resistance machineries. The different modes of action and pathway connectivities of EDS1 family members go some way to explaining their central role in biotic stress resilience.


2019 ◽  
Vol 93 (3) ◽  
pp. 543-584 ◽  
Author(s):  
Matthew C. Herne ◽  
Jay P. Nair ◽  
Alistair R. Evans ◽  
Alan M. Tait

AbstractThe Flat Rocks locality in the Wonthaggi Formation (Strzelecki Group) of the Gippsland Basin, southeastern Australia, hosts fossils of a late Barremian vertebrate fauna that inhabited the ancient rift between Australia and Antarctica. Known from its dentary,Qantassaurus intrepidusRich and Vickers-Rich, 1999 has been the only dinosaur named from this locality. However, the plethora of vertebrate fossils collected from Flat Rocks suggests that further dinosaurs await discovery. From this locality, we name a new small-bodied ornithopod,Galleonosaurus dorisaen. gen. n. sp. from craniodental remains. Five ornithopodan genera are now named from Victoria.Galleonosaurus dorisaen. gen. n. sp. is known from five maxillae, from which the first description of jaw growth in an Australian dinosaur is provided. The holotype ofGalleonosaurus dorisaen. gen. n. sp. is the most complete dinosaur maxilla known from Victoria. Micro-CT imagery of the holotype reveals the complex internal anatomy of the neurovascular tract and antorbital fossa. We confirm thatQ. intrepidusis uniquely characterized by a deep foreshortened dentary. Two dentaries originally referred toQ. intrepidusare reassigned toQ.?intrepidusand a further maxilla is referred to cf.Atlascopcosaurus loadsiRich and Rich, 1989. A further ornithopod dentary morphotype is identified, more elongate than those ofQ. intrepidusandQ.?intrepidusand with three more tooth positions. This dentary might pertain toGalleonosaurus dorisaen. gen. n. sp. Phylogenetic analysis recovered Cretaceous Victorian and Argentinian nonstyracosternan ornithopods within the exclusively Gondwanan clade Elasmaria. However, the large-bodied taxonMuttaburrasaurus langdoniBartholomai and Molnar, 1981 is hypothesised as a basal iguanodontian with closer affinities to dryomorphans than to rhabdodontids.UUID:http://zoobank.org/4af87bb4-b687-42f3-9622-aa806a6b4116


1982 ◽  
Vol 48 (4) ◽  
pp. 691-815 ◽  
Author(s):  
Charles B. Beck ◽  
Rudolf Schmid ◽  
Gar W. Rothwell

2019 ◽  
Author(s):  
Xin Zhang

AbstractIn the ovule evolution, the integument is the most attention point in discussion as a morphologic character of the seed plants. There are several theories and hypotheses about the origin of the integument were presented in the history. However, the development and function of the ovule envelopes are not so clear until now. The development of thehe basal gymnosperms Cycas and Zamia were to investigated, especially of the integument to complement the existing knowledge in seed plants. The development of ovules of seed plant is documented with morphological and anatomical using LM and SEM.The nucellar beak found in Zamia is a structure that has not been recorded previously. It protrudes from the micropyle at pollination and may be the primary acceptor for pollen. There are striking similarities to the lagenostom or salpinx in Lyginopteridatae. There may be an evolutionary way to interpret the pollination drop existing in the Lyginopteridatae. Probably the nucellar beak of Cycads, even Ginkgoales have the same function with the lagenostom or salpinx of the Lyginopteridatea. Unfortunately, pollen and transport inside the pollination chambers have not been observed. Further analysis of this unusual structure seems to be very important.


Fossil Record ◽  
2002 ◽  
Vol 5 (1) ◽  
pp. 19-44 ◽  
Author(s):  
M. Aberhan ◽  
R. Bussert ◽  
W.-D. Heinrich ◽  
E. Schrank ◽  
S. Schultka ◽  
...  

The Late Jurassic to Early Cretaceous Tendaguru Beds (Tanzania, East Africa) have been well known for nearly a century for their diverse dinosaur assemblages. Here, we present sedimentological and palaeontological data collected by the German-Tanzanian Tendaguru Expedition 2000 in an attempt to reconstruct the palaeo-ecosystems of the Tendaguru Beds at their type locality. Our reconstructions are based on sedimentological data and on a palaeoecological analysis of macroinvertebrates, microvertebrates, plant fossils and microfossils (ostracods, foraminifera, charophytes, palynomorphs). In addition, we included data from previous expeditions, particularly those on the dinosaur assemblages. <br><br> The environmental model of the Tendaguru Beds presented herein comprises three broad palaeoenvironmental units in a marginal marine setting: (1) Lagoon-like, shallow marine environments above fair weather wave base and with evidence of tides and storms. These formed behind barriers such as ooid bar and siliciclastic sand bar complexes and were generally subject to minor salinity fluctuations. (2) Extended tidal flats and low-relief coastal plains. These include low-energy, brackish coastal lakes and ponds as well as pools and small fluvial channels of coastal plains in which the large dinosaurs were buried. Since these environments apparently were, at best, poorly vegetated, the main feeding grounds of giant sauropods must have been elsewhere. Presumably, tidal flats and coastal plains were visited by dinosaurs primarily during periods of drought. (3) Vegetated hinterland. Vegetation of this environment can only be inferred indirectly from plant material transported into the other depositional environments. Vegetation was dominated by a diverse conifer flora, which apparently formed part of the food source of large herbivorous sauropods. Evidence from various sources suggests a subtropical to tropical palaeoclimate, characterised by seasonal rainfall alternating with a pronounced dry season during the Late Jurassic. In Early Cretaceous times, sedimentological and palaeontological proxies suggest a climatic shift towards more humid conditions. <br><br> Die Tendaguru-Schichten von Tansania in Ostafrika (Oberjura bis Unterkreide) sind als Lagerstätte oberjurassischer Dinosaurier seit nahezu einem Jahrhundert weltweit bekannt. Anhand von sedimentologischen und paläontologischen Daten, die während der Deutsch-Tansanischen Tendaguru Expedition 2000 im Typus-Gebiet der Tendaguru-Schichten gewonnen wurden, werden Paläo-Ökosysteme rekonstruiert. Grundlage der Rekonstruktionen sind die Auswertung sedimentologischer Daten sowie die paläo-ökologische Analyse von Makroinvertebraten, Mikrovertebraten, pflanzlichen Fossilien und Mikrofossilien (Ostrakoden, Foraminiferen, Charophyten, Palynomorphen). Darüber hinaus werden Informationen über Dinosaurier berücksichtigt, die bei früheren Expeditionen gewonnen wurden. <br><br> Das hier vorgestellte Ablagerungsmodell der Tendaguru-Schichten umfaßt drei Teilbereiche eines randlich marinen Sedimentationsraumes, die wie folgt gekennzeichnet werden können: (1) Lagunen-artige, marine Flachwasserbereiche, die oberhalb der Schönwetter-Wellenbasis lagen und unter deutlichem Einfluß von Gezeiten und Stürmen standen. Sie waren vom offenen Meer durch Barrieren, wie Ooidbarren und siliziklastischen Sandbarrenkomplexen, getrennt und wiesen einen leicht schwankenden Salzgehalt auf. (2) Ausgedehnte Wattgebiete und flache Küstenebenen. Dort befanden sich niedrig-energetische, brackische Strandseen und Teiche sowie Tümpel und kleinere Flußrinnen, in denen die großen Dinosaurier eingebettet wurden. Da diese Lebensräume bestenfalls dürftig bewachsen waren, müssen die Nahrungsquellen und der eigentliche Lebensraum der riesigen Sauropoden anderswo gelegen haben. Vermutlich wurden die Wattgebiete und Flachküsten von Dinosauriern vorrangig in den Trockenzeiten aufgesucht. (3) Bewachsenes Hinterland. Die Vegetation dieses Lebensraumes kann nur indirekt aus Pflanzenresten erschlossen werden, die in die anderen Ablagerungsraume transportiert wurden. Die Vegetation wurde von einer diversen Koniferenflora dominiert, die zumindest teilweise die Nahrungsgrundlage der großen, herbivoren Sauropoden bildete. Sedimentologische und paläontologische Indikatoren sprechen für ein subtropisches bis tropisches Klima wahrend der späten Jurazeit mit einem jahreszeitlichen Wechsel von Regenfällen und ausgeprägten Trockenzeiten. In der frühen Kreidezeit deutet sich ein Wechsel zu starker humiden Bedingungen an. <br><br> doi:<a href="http://dx.doi.org/10.1002/mmng.20020050103" target="_blank">10.1002/mmng.20020050103</a>


2018 ◽  
pp. 18-24
Author(s):  
V. Doronin ◽  
Yu. Kravchenko ◽  
V. Dryga ◽  
M. Budovsky ◽  
V. Doronin

In the intensive arable farming the productivity of sugar beets depends on many factors: soil-climatic conditions, introduction of highly productive hybrids, quality pre-sowing seed treatment, use of updated machinery and technologies, fertilizers, reliable plant protection, high technological processing at sugar mills and others. All the mentioned factors can reduce the productivity of sugar beets considerably, but it is not possible to reach a maximum potential of crop productivity without the use of good-quality seeds of the latest hybrids. The quality of sugar beet seeds is formed during the growth, and it depends on several factors, and first of all on the quality of mother root crops – their mass, sizes, turgor, disease damage and others. Laboratory trials were carried out at the Institute of bio-energy crops and sugar beets of Ukraine’s NAAS, field trials were carried out in the conditions of Ivanivka research-breeding station in the years of 2016–2018. The trial scheme envisaged the planting of root crops, which were not damaged with root rot and damaged with root rot, a focal point of rot being removed before planting. During vegetation, seed plants were treated with fungicides at a bud stage (one–time treatment) and at a bud stage and the beginning of flowering (two–time treatment). Fungicides were not used in the control. Mother root crops, seed plants and seeds of a sugar beet hybrid, developed on the basis of cytoplasm male sterility Romul, were the object of the research. In the field trials the following was determined: viability of the root crops (the number of the emerged crops as to the number of the panted root crops) and the seed plant density at a full emergence stage and before harvesting. Agro-biological evaluation of the seed plant condition was made before harvesting – the number of non-productive seed plants (dried, infertile ones and others), the number of disease-damaged plants and the degree of their development. A record plot area of one replication was 20 m2 in field trials, a fourfold replication. The technology of seed plant cultivation is conventional, in accordance with the recommendations of the Institute of bio-energy crops and sugar beets of Ukraine’s NAAS. The paper covered some peculiarities of the yield formation and the quality of sugar beet seeds, depending on the quality of mother root crops. It was proved that the use of the root crops, partially damaged with rot during storage, and even when a focal point of rot was removed before harvesting, had an effect on the root crop viability (which was by 4.4 % lower), the formation of more non-productive plants – by 1.6–1.8 times – due to the increase of prematurely dried plants and infertile ones, which resulted in a serious yield decease – by 0.09-0.13 t/ha and seed quality – viability by 4 % and emergence by 6 %, as compared with the variants where health root crops were planted. Two-time spraying of the seed plants with fungicides resulted in the increase of the yield capacity and the seed quality in the variants where only partially rot-damaged root crops were planted. A tendency to the increase of the mentioned indicators, both in the variants with healthy root crops planted and with partially damaged root crops planted, was recorded under one-time spraying of the seed plants with fungicides. The research of the seeds gathered from the seed plants, which were grown from the root crops, disease-damaged and healthy ones, confirmed the results of the field trials. The viability of the seeds, received from the healthy (not disease-damaged) root crops was higher by 9 %, emergence – by 5 %, as compared with the root crops, partially rot-damaged, focal points of which were removed before planting. Key words: mother root crops, rot, productive seed plants, yield capacity, viability, germination.


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