scholarly journals Climatic influence on the growth pattern of Panthasaurus maleriensis from the Late Triassic of India deduced from paleohistology

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9868
Author(s):  
Elżbieta M. Teschner ◽  
Sanjukta Chakravorti ◽  
Dhurjati P. Sengupta ◽  
Dorota Konietzko-Meier

Metoposaurids are representatives of the extinct amphibian clade Temnospondyli, found on almost every continent exclusively in the Late Triassic deposits. Osteohistologically, it is one of the best-known temnospondyl groups, analyzed with a wide spectrum of methods, such as morphology, morphometry, bone histology or computed modelling. The least known member of Metoposauridae is Panthasaurus maleriensis from the Pranhita-Godavari basin in Central India, being geographically the most southern record of this family. For the first time the bone histology of this taxon was studied with a focus on the intraspecific variability of the histological framework and the relationship between the observed growth pattern and climatic and/or environmental conditions. The studied material includes thin-sections of five long bones, a rib, an ilium and an intercentrum belonging most likely to eight individuals ranging from different ontogenetic stages. All bones have a large medullary region with progressively increasing remodeling, surrounded by a lamellar-zonal tissue type. The primary cortex consists of parallel-fibered matrix showing various degrees of organization, less organized collagen fibers in the zones and higher organized in the annuli. Growth marks occur in the form of alternating zones and annuli in every bone except the ilium and the intercentrum. The vascularity becomes less dense towards the outermost cortex in all sampled limb bones. Towards the outermost cortex the zone thickness is decreasing, in contrast to the avascular annuli, that become thicker or are of the same thickness. The growth pattern of P. maleriensis is uniform and represents changes in ontogenetic development. Multiple resting lines are prominent in the outer annuli of the limb bones and the rib and they presumably indicate climatic and environmental influence on the growth pattern. Therefore, a prolonged phase of slowed-down growth occurred during the unfavorable phase, but a complete cessation of growth indicated by Lines of Arrested Growth (LAGs) is not recorded in the studied samples. Based on the histological framework we conclude that the climate had an impact on the growth pattern. As we do not see any LAGs in the Indian metoposaurid, we assume that the local climate was relatively mild in India during the Late Triassic. A similar prolonged phase of slowed down growth without the occurrence of LAGs was observed in Metoposaurus krasiejowensis from the Late Triassic of Krasiejów (Poland). This is in contrast to Moroccan metoposaurid Dutuitosaurus ouazzoui from the Late Triassic of Argana Basin, where LAGs are regularly deposited throughout ontogeny indicating most likely harsher climatic conditions.

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5216 ◽  
Author(s):  
Lucas J. Legendre ◽  
Jennifer Botha-Brink

Bone microstructure has long been known as a powerful tool to investigate lifestyle-related biomechanical constraints, and many studies have focused on identifying such constraints in the limb bones of aquatic or arboreal mammals in recent years. The limb bone microstructure of fossorial mammals, however, has not been extensively described. Furthermore, so far, studies on this subject have always focused on the bone histology of small burrowers, such as subterranean rodents or true moles. Physiological constraints associated with digging, however, are known to be strongly influenced by body size, and larger burrowers are likely to exhibit a histological profile more conspicuously influenced by fossorial activity. Here, we describe for the first time the limb bone histology of the aardvark (Orycteropus afer), the largest extant burrowing mammal. The general pattern is very similar for all six sampled limb bones (i.e., humerus, radius, ulna, femur, tibia, and fibula). Most of the cortex at midshaft is comprised of compacted coarse cancellous bone (CCCB), an endosteal tissue formed in the metaphyses through the compaction of bony trabeculae. Conversely, the periosteal bone is highly resorbed in all sections, and is reduced to a thin outer layer, suggesting a pattern of strong cortical drift. This pattern contrasts with that of most large mammals, in which cortical bone is of mostly periosteal origin, and CCCB, being a very compliant bone tissue type, is usually resorbed or remodeled during ontogeny. The link between histology and muscle attachment sites, as well as the influence of the semi-arid environment and ant-eating habits of the aardvark on its bone microstructure, are discussed. We hypothesize that the unusual histological profile of the aardvark is likely the outcome of physiological constraints due to both extensive digging behavior and strong metabolic restrictions. Adaptations to fossoriality are thus the result of a physiological compromise between limited food availability, an environment with high temperature variability, and the need for biomechanical resistance during digging. These results highlight the difficulties of deciphering all factors potentially involved in bone formation in fossorial mammals. Even though the formation and maintaining of CCCB through ontogeny in the aardvark cannot be unambiguously linked with its fossorial habits, a high amount of CCCB has been observed in the limb bones of other large burrowing mammals. The inclusion of such large burrowers in future histological studies is thus likely to improve our understanding of the functional link between bone growth and fossorial lifestyle in an evolutionary context.


Science ◽  
2018 ◽  
Vol 363 (6422) ◽  
pp. 78-80 ◽  
Author(s):  
Tomasz Sulej ◽  
Grzegorz Niedźwiedzki

Here, we describe the dicynodontLisowicia bojani, from the Late Triassic of Poland, a gigantic synapsid with seemingly upright subcursorial limbs that reached an estimated length of more than 4.5 meters, height of 2.6 meters, and body mass of 9 tons.Lisowiciais the youngest undisputed dicynodont and the largest nondinosaurian terrestrial tetrapod from the Triassic. The lack of lines of arrested growth and the highly remodeled cortex of its limb bones suggest permanently rapid growth and recalls that of dinosaurs and mammals. The discovery ofLisowiciaoverturns the established picture of the Triassic megaherbivore radiation as a phenomenon restricted to dinosaurs and shows that stem-group mammals were capable of reaching body sizes that were not attained again in mammalian evolution until the latest Eocene.


Author(s):  
Gunārs Lācis ◽  
Irita Kota-Dombrovska ◽  
Sarmīte Strautiņa

Abstract The structure of raspberry cultivars and genetic resources in the Baltic countries have been influenced by the historical political situation in the 20th century and climatic conditions, especially winterhardiness. The genetic resources consist of some old European and American cultivars, but mostly of cultivars and hybrids bred in Russia. Currently, targeted breeding programmes are active only in Estonia and Latvia, which aim to develop winterhardy, disease-resistant cultivars, well adapted to the local climate. Therefore, parent material for hybridisation has been chosen from local advanced hybrids and introduced cultivars suitable to the regional climatic conditions. The aim of the study was to estimate the level of genetic diversity of Rubus germplasm and assess inter-specific and intra-specific relationships using phenotypical characterisation and molecular markers. Forty one Rubus genotypes were evaluated by 41 phenotypical traits and 15 previously described SSR markers. Both characterisation approaches discovered high correspondence with pedigree and a low level of diversity. A limited amount of the diversity of raspberry genetic material has been used in various breeding programmes, despite their broad geographical origin. The obtained results indicate the need for including local wild R. idaeus plant material into breeding programmes.


2018 ◽  
Vol 22 (7) ◽  
pp. 4015-4032 ◽  
Author(s):  
Milad Aminzadeh ◽  
Peter Lehmann ◽  
Dani Or

Abstract. The growing pressure on natural freshwater resources and the projected climate variability are expected to increase the need for water storage during rainy periods. Evaporative losses present a challenge for the efficiency of water storage in reservoirs, especially in arid regions with chronic water shortages. Among the available methods for suppressing evaporative losses, self-assembling floating elements offer a simple and scalable solution, especially for small reservoirs. The use of floating elements has often been empirically based; we thus seek a framework for systematic consideration of floating element properties, local climate and reservoir conditions to better predict evaporative loss, energy balance and heat fluxes from covered water reservoirs. We linked the energy balance of the water column with energy considerations of the floating elements. Results suggest significant suppression of evaporative losses from covered reservoirs in which incoming radiative energy is partitioned to sensible and long wave fluxes that reduce latent heat flux and thus increase the Bowen ratio over covered water reservoirs. Model findings were consistent with laboratory-scale observations using an uncovered and covered small basin. The study offers a physically based framework for testing design scenarios in terms of evaporation suppression efficiency for various climatic conditions; it hence strengthens the science in the basis of this important water resource conservation strategy.


2021 ◽  
Author(s):  
Victoria S. Engelschiøn ◽  
Øyvind Hammer ◽  
Fredrik Wesenlund ◽  
Jørn H. Hurum ◽  
Atle Mørk

<p>Several carbon isotope curves were recently published for the Early and Middle Triassic in Tethys. Recent work has also been done on the Early Triassic of Svalbard, but not yet for the Middle Triassic. This work is the first to measure δ<sup>13</sup>C for different Middle Triassic localities on Svalbard, which was then part of the Boreal Ocean on northern Pangea. Our aim is to understand the controls on the Svalbard carbon isotope curve and to place them in a global setting.</p><p>Correlating Triassic rocks around the world is interesting for several reasons. The Triassic Period was a tumultuous time for life, and the Arctic archipelago of Svalbard has shown to be an important locality to understand the early radiation of marine vertebrates in the Triassic. Much effort is also made to understand the development of the Barents Sea through Svalbard’s geology.</p><p>Carbon isotope curves are controlled by depositional environment and global fluctuations. Global factors such as the carbon cycle control the long-term carbon isotopic compositions, while short-term fluctuations may reflect the origin of organic materials in the sediment (e.g. algal or terrestrial matter), stratification of the water column, and/or surface water productivity. Carbon isotopes can therefore be useful to understand the depositional environment and to correlate time-equivalent rocks globally.</p><p>The dataset was collected through three seasons of fieldwork in Svalbard with localities from the islands Spitsbergen, Edgeøya and Bjørnøya. Detailed stratigraphic sampling has resulted in high-resolution δ<sup>13</sup>C curves. These show three strong transitions; 1) on the boundary between the Early and Middle Triassic, 2) in the middle of the formation and 3) at the Middle and Late Triassic boundary. Several Tethyan localities show a possibly similar Early-Middle Triassic signal. Current work in progress is sedimentological analysis by thin sections and X-ray fluorescence spectroscopy (XRF) to further understand the sedimentary environment.</p>


Author(s):  
P. А. Ageeva ◽  
М. V. Matyukhina ◽  
N. А. Pochutina ◽  
O. M. Gromova

The narrow-leafed lupin (Lupinus angustifolius L.) is a valuable legumes crop used as forage and green manure which is adapted to wide spectrum of soil-and climatic conditions; the crop has short domestication history. The protein content in its seeds and in dry matter of green mass varies from 30.0 to 37.0% and from 16.0 to 22.0 % respectively and depends on ecotype and soil-and-climatic conditions. This lupin specie can accumulate to 300 kg/ha symbiotic nitrogen in biomass and assimilates phosphorus and potassium of heavy available soil layers. It is very technological suitable for common used machinery systems. The State List of breeding achievements of Russia recommends the following regions for lupin cultivation: the North, the North-West, the Central, the Volga-Vyatka, the Middle-Volga, the Central Chernozem, the Ural, the West Siberia and the East Siberia. The tests were carried out in 2017-2020 in the All-Russian Lupin Scientific Research Institute which is located in the South-West of the Central region. Ten varieties and breeding lines bred in the Institute are tested. The samples differ by early ripeness and anthracnose tolerance. The average experimental variety grain yield was 2.38 t/ha. The vars. Uzkolistny 53-02, USN 53-236, Bryanskiy kormovoy and SBS 56-15 have the highest yield and adaptivity (103-113 %). The index of year conditions was revealed; 2017 with the index 0.56 was the most favorable for implementation of grain productivity of the tested narrow-leafed lupin varieties. In the ecological varieties testing the soil-and-climatic conditions of Shatilovskaya experimental station (Orel region) were the most favorable for implementation of variety grain productivity (4.0-4.5 t/ha). Grain yield was 3.0-4.0 t/ha in ecological locations which differ in soil-and-climatic conditions: there are Kaliningrad region, Mordovia Republic, Krasnoyarsk region etc.


Previous accounts of the dentition of the Carboniferous dipnoan Uronemus have stressed the significance of the scattered small denticles. These, together with the marginal teeth and ridges, have been interpreted as primitive characters of the dipnoan dentition shared with three other genera: the Devonian Uranolophus and Griphognathus and the Carboniferous to Permian Conchopoma . Genera with tooth plates have been considered to be a monophyletic group in which tooth plates are a derived character; Uronemus has been excluded from this group in all previous investigations dealing with the significance of the dentition for determining relationships among dipnoans. The macromorphology of the dentition of Uronemus has been re-examined and correlated with the histology of all the dental tissues. Optical study of thin sections and scanning electron microscope study of the adjacent cut surfaces has shown that the hard, wear-resistant dentine of the teeth and ridges is petrodentine. The arrangement, growth, wear and histology of the dental tissues have been compared with those of denticulated and tooth-plated genera. The arrangement of new teeth relative to the tooth ridge, the pattern of wear along the ridge, and the type of dentine and its growth indicate that the dentition of Uronemus is best interpreted as a tooth plate with one long lingual tooth ridge and reduced lateral tooth rows. Therefore the marginal tooth ridges are not considered to be homologous with those of denticulate dipnoans such as Uranolophus . The presence of petrodentine, a tissue type only found in forms with tooth plates, is consistent with the view that the dentition is derived by modification of a radiate tooth plate. The denticles covering restricted regions of the palate and lower jaw are considered to have been a secondary acquisition. The suggestion that Conchopoma is a close relative of Uronemus is not accepted, and possible new relationships have been proposed. New data on Scaumenacia and Phaneropleuron , two other genera previously compared with Uronemus , are presented. Rhinodipterus , a form with elongate lingual ridges, is also discussed. Phaneropleuron is shown to have radiate tooth plates and not a marginal row of conical teeth as previously described. It is proposed that the tooth plate of Uronemus is derived from a dipterid type of plate. A discussion of some of the other factors involved in determining the relationships of the genus is given. From an examination of the use of the tongue for respiration and feeding by the extant Lepidosiren paradoxa , it is concluded that many features of dipnoan evolution in the tooth-plated lineage result from the adoption of air breathing after an early evolutionary phase of gill respiration, and that Uronemus was adapted for air breathing. The ‘denticulated’ lineage, which included genera such as Uranolophus and Griphognathus , shows none of the skeletal features associated with the presence of a tongue, and presumably did not become air breathing.


2019 ◽  
Vol 116 ◽  
pp. 00039 ◽  
Author(s):  
Piotr Kowalski ◽  
Paweł Szałański

The article discusses the problem of determining for air heat pumps the seasonal efficiency of energy production necessary to determine the energy performance of a building. On the example of selected Polish cities (Suwalki, Bialystok, Warsaw, Wroclaw, Zielona Gora, Resko, Szczecinek, Koszalin) the influence of climatic conditions on the SCOP of an exemplary air-to-air heat pump and on the result of building energy performance calculations was analysed. SCOPs for each location were determined according to the method of EN 14825. The difference between SCOP for average (A) and colder (C) climates according to EN 14825 was 35.6%. It has been shown that the climate of Polish cities may be similar to both the average climate (A) and the colder climate (C), or they significantly differ from both climates. The most significant difference in SCOP between the analysed cities was obtained for Suwalki and Szczecinek. It was 31.9% and 31.4% for the assumed heating season length as for climate (A) and (C) respectively. For the exemplary building in Suwalki, taking SCOP for the average climate (A) and not based on climatic data of Suwalki gives an error of 39.3% in the calculation of primary energy for heating. For the same locations, the differences in SCOP and EP resulting from the assumption of the heating season length as for the average climate (A) or as for the colder climate (C) were respectively from 2.4% to 3.3% and from -3.4% to -2.2%. In diversified Polish climate, assuming the same SCOP values of air heat pumps regardless of location does not allow for their full comparison with devices whose efficiency does not depend on climatic conditions. The authors suggest that when calculating the energy performance of the building, the SCOP should be always determined on the basis of the local climate and the length of the heating season.


1979 ◽  
Vol 36 (11) ◽  
pp. 1395-1400 ◽  
Author(s):  
Richard J. Beamish

A comparison of ages determined from surfaces of otoliths and from sections of otoliths showed that ages were similar up to a section age of 22–24 yr. The growth pattern observed on thin sections of otoliths and from broken and burned otoliths from the region of the nucleus was interpreted to indicate that Pacific ocean perch probably live much longer than previously thought. Because the criteria used to identify annuli from otoliths sections appeared valid for younger fish, there was no justification to reject the application of these criteria for estimating ages of older fish and thus no reason to reject the possibility that Pacific ocean perch might live to be older than 70 yr. Ages determined from sections of otoliths from other rockfish species found off the west coast of Canada such as Sebastes fiavidus and Sebastes brevispinis have ranged from 30 to 60 yr indicating that many species of rockfish may live longer than previously thought. Key words: age determination, otolith, maximum age, age determination errors, Pacific ocean perch, otolith sections


2007 ◽  
Vol 274 (1620) ◽  
pp. 1885-1893 ◽  
Author(s):  
Torsten M Scheyer ◽  
P.Martin Sander

The palaeoecology of basal turtles from the Late Triassic was classically viewed as being semi-aquatic, similar to the lifestyle of modern snapping turtles. Lately, this view was questioned based on limb bone proportions, and a terrestrial palaeoecology was suggested for the turtle stem. Here, we present independent shell bone microstructural evidence for a terrestrial habitat of the oldest and basal most well-known turtles, i.e. the Upper Triassic Proterochersis robusta and Proganochelys quenstedti . Comparison of their shell bone histology with that of extant turtles preferring either aquatic habitats or terrestrial habitats clearly reveals congruence with terrestrial turtle taxa. Similarities in the shell bones of these turtles are a diploe structure with well-developed external and internal cortices, weak vascularization of the compact bone layers and a dense nature of the interior cancellous bone with overall short trabeculae. On the other hand, ‘aquatic’ turtles tend to reduce cortical bone layers, while increasing overall vascularization of the bone tissue. In contrast to the study of limb bone proportions, the present study is independent from the uncommon preservation of appendicular skeletal elements in fossil turtles, enabling the palaeoecological study of a much broader range of incompletely known turtle taxa in the fossil record.


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