New Specimen of CF. Asiatosuchus (Crocodyloidea) from the Middle Eocene Drazinda Formation of the Sulaiman Range, Punjab (Pakistan)

163-189http://deepblue.lib.umich.edu/bitstream/2027.42/48655/2/ID522.pd

The earliest bird-line archosaurs and the assembly of the dinosaur body plan

© 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.The relationship between dinosaurs and other reptiles is well established, but the sequence of acquisition of dinosaurian features has been obscured by the scarcity of fossils with transitional morphologies. The closest extinct relatives of dinosaurs either have highly derived morphologies or are known from poorly preserved or incomplete material. Here we describe one of the stratigraphically lowest and phylogenetically earliest members of the avian stem lineage (Avemetatarsalia), Teleocrater rhadinus gen. et sp. nov., from the Middle Triassic epoch. The anatomy of T. rhadinus provides key information that unites several enigmatic taxa from across Pangaea into a previously unrecognized clade, Aphanosauria. This clade is the sister taxon of Ornithodira (pterosaurs and birds) and shortens the ghost lineage inferred at the base of Avemetatarsalia. We demonstrate that several anatomical features long thought to characterize Dinosauria and dinosauriforms evolved much earlier, soon after the bird-crocodylian split, and that the earliest avemetatarsalians retained the crocodylian-like ankle morphology and hindlimb proportions of stem archosaurs and early pseudosuchians. Early avemetatarsalians were substantially more species-rich, widely geographically distributed and morphologically diverse than previously recognized. Moreover, several early dinosauromorphs that were previously used as models to understand dinosaur origins may represent specialized forms rather than the ancestral avemetatarsalian morphology

Antiquity of forelimb ecomorphological diversity in the mammalian stem lineage (Synapsida)

Mammals and their closest fossil relatives are unique among tetrapods in expressing a high degree of pectoral girdle and forelimb functional diversity associated with fully pelagic, cursorial, subterranean, volant, and other lifestyles. However, the earliest members of the mammalian stem lineage, the “pelycosaur”-grade synapsids, present a far more limited range of morphologies and inferred functions. The more crownward nonmammaliaform therapsids display novel forelimb morphologies that have been linked to expanded functional diversity, suggesting that the roots of this quintessentially mammalian phenotype can be traced to the pelycosaur–therapsid transition in the Permian period. We quantified morphological disparity of the humerus in pelycosaur-grade synapsids and therapsids using geometric morphometrics. We found that disparity begins to increase concurrently with the emergence of Therapsida, and that it continues to rise until the Permo-Triassic mass extinction. Further, therapsid exploration of new regions of morphospace is correlated with the evolution of novel ecomorphologies, some of which are characterized by changes to overall limb morphology. This evolutionary pattern confirms that nonmammaliaform therapsid forelimbs underwent ecomorphological diversification throughout the Permian, with functional elaboration initially being more strongly expressed in the proximal end of the humerus than the distal end. The role of the forelimbs in the functional diversification of therapsids foreshadows the deployment of forelimb morphofunctional diversity in the evolutionary radiation of mammals

Redescription of Digalodon rubidgei, an emydopoid dicynodont (Therapsida, Anomodontia) from the Late Permian of South Africa

The Late Permian dicynodont Digalodon rubidgei Broom and Robinson, 1948, is redescribed based on reanalysis of the holotype and newly recognized referable specimens. Digalodon can be diagnosed by the presence of a long "beak" sharply demarcated from the caniniform process; an extremely tall zygomatic ramus of the squamosal, with a thickened, "folded-over" dorsal margin; raised parietal "lips" along the lateral edges of the pineal foramen; and a broad posterolateral expansion of the parietal, excluding the postorbital from the back of the skull roof. Inclusion of Digalodon in a recent analysis of anomodont phylogeny recovers it as a kistecephalian emydopoid, specifically as the sister taxon to the clade containing the remaining kistecephalians. Four definite specimens of Digalodon are known, but several additional specimens lacking tusks, the swollen pineal "lips", and a thickened zygoma may represent sexually dimorphic females or juveniles. Specimens of Digalodon are restricted to the central portion of the Karoo Basin, in the area around Graaff-Reinet, and are part of a characteristic fauna probably representing a limited time span

Zakładanie plantacji turówki leśnej z sadzonek pędowych uzyskanych przez podział roślin matecznych

Southern sweet-grass (Hierochloë australis /Schrad./ Roem. & Schult.) is a perennial, wild growing tuft grass occurring in North-East Poland, Belarus and Finland. In Poland the species is under the partial legal protection. The raw material harvested from this plant are leaves rich in coumarins, mainly in coumarin responsible for specific sweet aroma of leaves. They are used mostly for the aromatization of alcohol and tobacco products. Due to high demand for the raw material and decrease in the natural resources of the species, it is advisable to introduce the plant into cultivation. In the presented study vegetative planting stock (1-, 2-, and 4-stem cuttings) were used to set the plantation of southern sweet-grass. The influence of the planting stock type on the mass of leaves and their quality in the first and second year of plant vegetation as well as the mass of seeds from two-year-old plants were investigated. The highest number of well rooted plants was obtained from 4-stem cuttings (74.07%) and the least – from 1-stem cuttings (47.53%). Both, on one- and two-year-old plantations the plants from 4-stem cuttings were characterized by the highest mass of leaves (7.73 and 24.65 g × plant-1, respectively). The plants were also characterized by the highest number of generative shoots (40.71 pcs. × plant-1) and mass of seeds (4.62 g × plant-1). The total contents of coumarins and phenolic acids did not depend on the type of planting stock. The contents of these compounds was higher in two-year-old plants than in one-year-old ones, whereas the content of flavonoids was higher in one-year-old plants.Turówka leśna (Hierochloë australis /Schrad./ Roem. & Schult.) jest wieloletnią, dziko rosnącą trawą kępkową występującą na terenie północno-wschodniej Polski, na Białorusi i w Finlandii. W Polsce jest to gatunek objęty częściową ochroną prawną. Częścią użytkową u tej rośliny są liście bogate w związki kumarynowe, a przede wszystkim w kumarynę, odpowiedzialną za słodki, specyficzny zapach surowca. Liście turówki leśnej wykorzystywane są głównie do aromatyzowania alkoholi i tytoniu. Ze względu na duże zapotrzebowanie na surowiec oraz na kurczące się zasoby naturalne tej rośliny celowe jest wprowadzenie jej do uprawy. W niniejszej pracy oceniono przydatność sadzonek wegetatywnych (jedno, dwu i czteropędowych) do zakładania plantacji turówki leśnej. Określono wpływ tych sadzonek na przyrost masy liści i ich jakość w pierwszym i drugim roku wegetacji roślin oraz masę nasion uzyskanych z roślin dwuletnich. Najwięcej ukorzenionych roślin uzyskano z sadzonek czteropędowych (74,07%), a najmniej z sadzonek jednopędowych (47,53%). Zarówno na plantacji jedno- jak i dwuletniej rośliny uzyskane z sadzonek czteropędowych wytworzyły najwyższą masę liści (odpowiednio: 7,73 i 24,65 g × roślina-1). Rośliny te charakteryzowały się także najwyższą liczbą pędów generatywnych (40,71 szt. × roślina-1) i najwyższą masą nasion (4,62 g × roślina-1). Ogólna zawartość kumaryn i kwasów polifenolowych nie zależała od użytego materiału sadzonkowego. Zawartość tych grup związków była wyższa u roślin dwuletnich niż jednorocznych, natomiast ogólna zawartość flawonoidów była wyższa u roślin jednorocznych

Modeling The Role Of Primary Productivity Disruption In End-Permian Extinctions, Karoo Basin, South Africa

The end-Permian mass extinction is well-known as the most severe mass extinction of the Phanerozoic. Terrestrial communities appear to have been strongly affected by the event, but the cause of the extinction remains enigmatic. Here we explore whether primary producer disruption (e.g., extinction of terrestrial plants) could have led to a collapse of end-Permian terrestrial ecosystems, using models of probabilistic trophic networks. Based on a trophic network reconstructed for the Dicynodon Assemblage Zone community of the Karoo Basin, we show that late Permian terrestrial communities were vulnerable to collapse brought about by the disruption of primary producers. However, relatively high levels of primary producer loss are needed to account for observed levels of extinction among consumers in the Dicynodon zone fauna. Depending on network parameters, we predict that a shutdown of 69% to 87% of primary producers would be needed to generate observed extinction levels. A disruption of this magnitude is not unreasonable, given that terrestrial floras underwent a major turnover at the end of the Permian, and our predictions can be tested by further scrutiny of floras from this time

Wpływ zacieniania na plon i jakość surowca turówki lesnej (Hierochloe australes (Schrad.) Roem. and Schult)

Southern sweet-grass (Poaceae) rarely occurs in Polish coniferous or mixed forests. Leaves of this plant, rich in coumarin compounds, are mainly used as a flavouring raw material in alcohol, tobacco and cosmetic industry. The aim of the study was to investigate the influence of shading on the yield and quality of southern sweet-grass. The experiment was established at the certificated organic field of Department of Vegetable and Medicinal Plants. The sunlight was reduced up to 50 and 70% by using shading nets. The object of experiment was two-year-old plants grown on the alluvial soil. Leaves were harvested two times: in mid-May and in the last week of August (regrowth). The highest yield of leaves was observed at 50% of shading. The shaded plants were characterized by higher content of coumarin and 3,4-dihydrocoumarin and lower content of bergapten in comparison to non-shaded ones. In the leaves five phenolic acids and two flavonoids were identified.Turówka leśna (Poaceae) występuje rzadko na terenie Polski. Rośnie głównie w lasach iglastych i mieszanych. Liście tej rośliny, bogate w kumaryny, stosowane są przede wszystkim jako surowiec aromatyzujący w przemyśle alkoholowym, tytoniowym i kosmetycznym. Celem niniejszej pracy było określenie wpływu cieniowania na plon i jakość liści tej rośliny. Doświadczenie założono na certyfikowanym, ekologicznym Polu Doświadczalnym Katedry Roślin Warzywnych i Leczniczych. Dostępność światła słonecznego modyfikowano poprzez cieniowanie roślin siatką raszlową (50 i 70% zacienienia). Obiektem badań były rośliny dwuletnie rosnące na podłożu składającym się z mieszanki mady rzecznej, kompostu z obornika i torfu wysokiego. Liście turówki ścinano dwukrotnie: w połowie maja oraz w ostatnim tygodniu sierpnia (odrost). Najwyższy plon liści wytworzyły rośliny rosnące przy pięćdziesięcioprocentowym zacienieniu. Rośliny cieniowane charakteryzowały się również wyższą zawartością kumaryny i 3,4-dihydrokumaryny oraz niższą zawartością bergaptenu w porównaniu z roślinami nie cieniowanymi (kontrola). W liściach zidentyfikowano pięć kwasów polifenolowych i dwa flawonoidy

Trophic Network Models Explain Instability Of Early Triassic Terrestrial Communities

Studies of the end-Permian mass extinction have emphasized potential abiotic causes and their direct biotic effects. Less attention has been devoted to secondary extinctions resulting from ecological crises and the effect of community structure on such extinctions. Here we use a trophic network model that combines topological and dynamic approaches to simulate disruptions of primary productivity in palaeocommunities. We apply the model to Permian and Triassic communities of the Karoo Basin, South Africa, and show that while Permian communities bear no evidence of being especially susceptible to extinction, Early Triassic communities appear to have been inherently less stable. Much of the instability results from the faster post-extinction diversification of amphibian guilds relative to amniotes. The resulting communities differed fundamentally in structure from their Permian predecessors. Additionally, our results imply that changing community structures over time may explain long-term trends like declining rates of Phanerozoic background extinction

Abnormal development of paired enigmatic structures in the derived dicynodont Lystrosaurus murrayi (Therapsida, Anomodontia).

Derived dicynodonts, including Lystrosaurus murrayi, have edentulous lower jaws. As an interesting exception to this conventional wisdom, a well-preserved specimen of L. murrayi (MGGC- 8850/1RE13 F) has abnormal, paired mandibular structures similar in overall morphology to dental teeth. The specimen pertains to the historical collections of the Museo G. Capellini (Bologna, Italy) and was collected in 1929 by M. Gortani during prospecting activities near Harrismith, South Africa. The specimen is articulated and includes a nearly complete skull, the first eight vertebrae and the proximal end of the right scapula. Reconstruction based on a Dual-Beam CT revealed unusual, paired structures similar to mandibular teeth, encased within the lower jaw, lingual to maxillary tusks. Different interpretations are possible for the abnormal mandibular structures in MGGC-8850/1RE13 F: 1) the dental lamina in the lower jaw, which would normally degenerate in derived dicynodonts, remained active and potentiated the odontogenesis; 2) the dental lamina was potent in the lower jaw throughout the ontogeny across dicynodonts but activated differentially; or 3) the mandibular patterning in our specimen was dorsalized, which resulted in an ectopic formation of upper jaw dentition in the lower jaws. Supranumerary or ectopic teeth are a commonly screened phenotype in modern mammalian models. Such variation distributes in a continuum \u2013 rarely does an edentulous jaw develop fully functional teeth that are present in outgroups. The absence of mandibular dentition in other specimens of L. murrayi and in most other bidentalian dicynodonts suggests that MGGC- 8850/1RE13 F represents a rare developmental abnormality or a case of atavism