Добірка наукової літератури з теми "Megafan evolution"

Abstract. Alluvial megafans are sensitive recorders of landscape evolution, controlled by both autogenic processes and allogenic forcing, and they are influenced by the coupled dynamics of the fan with its mountainous catchment. The Lannemezan megafan in the northern Pyrenean foreland was abandoned by its mountainous feeder stream during the Quaternary and subsequently incised, leaving a flight of alluvial terraces along the stream network. We use numerical models to explore the relative roles of autogenic processes and external forcing in the building, abandonment and incision of a foreland megafan, and we compare the results with the inferred evolution of the Lannemezan megafan. Autogenic processes are sufficient to explain the building of a megafan and the long-term entrenchment of its feeding river on time and space scales that match the Lannemezan setting. Climate, through temporal variations in precipitation rate, may have played a role in the episodic pattern of incision on a shorter timescale. In contrast, base-level changes, tectonic activity in the mountain range or tilting of the foreland through flexural isostatic rebound do not appear to have played a role in the abandonment of the megafan.

AbstractNhecolândia is a fossil lobe of the Taquari River megafan and a prominent geomorphic subunit of the Pantanal wetlands because of the presence of >10,000 small lakes. We investigated the stratigraphic records of three saline lakes from Nhecolândia to explore their potential as Quaternary hydroclimate archives. Radiocarbon data indicate that accumulation at two lakes was approximately continuous in the late Holocene, and chemostratigraphic variability suggests sensitivity to environmental change with multicentennial resolution. A basal sandy unit and an upper muddy unit comprise the shallow stratigraphy of each lake. A pronounced change in depositional environment from freshwater wetlands to saline lakes at ~3300–3200 cal yr BP best explains the lithofacies transition. Ephemeral freshwater wetlands formed on the abandoned megafan lobe, which was molded by deflation in the arid early Holocene. Wind-scouring of the megafan lobe generated topographically closed depressions with complex marginal sand ridges, which allowed permanent lakes to evolve when rainfall increased in the late Holocene. The lakes became highly saline and alkaline after ~910 cal yr BP, which influences biogeochemistry and aquatic ecology. The results hold implications for understanding the response of the southern Pantanal to climate change, as well as the development of pans in tropical megafan settings.

Abstract. River avulsions are an important mechanism by which sediment is routed and emplaced in foreland basins. However, because avulsions occur infrequently, we lack observational data that might inform where, when, and why avulsions occur and these issues are instead often investigated by rule-based numerical models. These models have historically simplified or neglected the effects of abandoned channels on avulsion dynamics, even though fluvial megafans in foreland basins are characteristically covered in abandoned channels. Here, we investigate the pervasiveness of abandoned channels on modern fluvial megafan surfaces. Then, we present a physically based cellular model that parameterizes interactions between a single avulsing river and abandoned channels in a foreland basin setting. We investigate how abandoned channels affect avulsion setup, pathfinding, and landscape evolution. We demonstrate and discuss how the processes of abandoned channel inheritance and transient knickpoint propagation post-avulsion serve to shortcut the time necessary to set up successive avulsions. Then, we address the idea that abandoned channels can both repel and attract future pathfinding flows under different conditions. By measuring the distance between the mountain front and each avulsion over long (106 to 107 years) timescales, we show that increasing abandoned channel repulsion serves to push avulsions farther from the mountain front, while increasing attraction pulls avulsions proximally. Abandoned channels do not persist forever, and we test possible channel healing scenarios (deposition-only, erosion-only, and far-field-directed) and show that only the final scenario achieves dynamic equilibrium without completely filling accommodation space. We also observe megafan growth occurring via ∼100 000-year cycles of lobe switching but only in our runs that employ deposition-only or erosion-only healing modes. Finally, we highlight opportunities for future field work and remote sensing efforts to inform our understanding of the role that floodplain topography, including abandoned channels, plays on avulsion dynamics.

Abstract. During the Last Glacial Maximum (LGM), most of the major glaciated basins of the European Southern Alps had piedmont lobes with large outwash plains; only a few glaciers remained within the valley. Piedmont glaciers have left well-preserved terminal moraines, which allow for investigations to be carried out and inferences to be made regarding their evolution and chronology. Valley glaciers' remnants, on the contrary, are often scantly preserved, and changes can only be detected through correlations with glaciofluvial deposits in downstream alluvial basins. The Brenta glacial system's dynamics in the glacier's terminal tract have been inferred through a wide range of sediment analysis techniques on an alluvial stratigraphic record of the Brenta megafan (northeast Italy), and via the mapping of in-valley glacial/glaciofluvial remnants. Glaciers flowing across narrow gorges could possibly be slowed/blocked by such morphology, and glacial/sediment fluxes may then be diverted to lateral valleys. Moreover, narrow valleys may induce glaciers to bulge and form icefalls at their front, preventing the formation of terminal moraines. The Brenta Glacier was probably slowed/blocked by the narrow Valsugana Gorge downstream of Primolano and was effectively diverted eastwards across a wind gap (Canal La Menor Valley), joining the Cismon/Piave glaciers near Rocca and ending ∼2 km downstream. The Cismon and Piave catchments started to contribute to the Brenta system just after 27 ka cal BP until at least ∼19.5 ka cal BP. After the glaciers collapsed, the Piave River once again flowed into its main valley, whilst the Cismon continued to merge with the Brenta. This investigation shows that glacial catchments may vary significantly over time during a single glaciation in rugged Alpine terrains. Sand petrography and the chemical/mineralogical composition of sediments are powerful proxies for tracing such variations, as they propagate through the glacial and glaciofluvial systems and can be recognized in the alluvial stratigraphic record far downstream from the glacier front.

Human activities currently play a dominant role in shaping and eroding Earth’s biodiversity, but the historical dynamics leading to this situation are poorly understood and contentious. Importantly, these dynamics are often studied and discussed without an emphasis on cultural evolution, despite its potential importance for past and present biodiversity dynamics. Here, we investigate whether cultural filtering, defined as the impact of cultural evolution on species presence, has driven the range dynamics of five historically widespread megafauna taxa (Asiatic elephant, rhinoceroses, tiger, Asiatic black bear, and brown bear) across China over the past 2 millennia. Data on megafauna and sociocultural history were compiled from Chinese administrative records. While faunal dynamics in China are often linked to climate change at these time scales, our results reveal cultural filtering as the dominant driver of range contractions in all five taxa. This finding suggests that the millennia-long spread of agricultural land and agricultural intensification, often accompanied by expansion of the Han culture, has been responsible for the extirpation of these megafauna species from much of China. Our results suggest that cultural filtering is important for understanding society’s role in the assembly of contemporary communities from historical regional species pools. Our study provides direct evidence that cultural evolution since ancient times has overshadowed climate change in shaping broadscale megafauna biodiversity patterns, reflecting the strong and increasing importance of sociocultural processes in the biosphere.

This thesis explored the evolutionary trajectory of marsupials, focusing primarily on the Australasian marsupial fauna, and used a phylogenetic inference approach that combines molecular, ecological and fossil data sets. A first study provided the most complete and accurate (to-date) species-level marsupial phylogeny by using the most taxonomically complete set of nuclear and mitochondrial loci. In a second study, DNA and fossils from extinct and modern taxa were used to infer the evolution of macropods. A third project inferred the most complete (to-date) time-calibrated phylogeny of Diprotodontia. By incorporating fossil data, this last project revealed apparent competitive displacement of Vombatiformes (koala and wombats) by Macropodiformes (kangaroos) from the Late Miocene onwards, and a long (~25 million year) lag in the evolution of herbivory among marsupials compared to placental mammal faunas.

This study attempts to revive T.J. Dunbabin's multi-dimensional approach to the history of Early Iron Age Sicily in The Western Greeks (Oxford 1948). Dunbabin recognised that archaic Sicily had no real history, and that any historical account involved combining the very scant documentary record with the fuller and ever-growing body of archaeological evidence to produce a framework for writing social and economic history. These innovative methods ended with Dunbabin, however: today the field is dominated by scholars impeded artificially by disciplinary boundaries, which discourage the productive combination of historical and archaeological sources, leaving a number of important questions in a sort of academic no man's land. In the introduction an overview of the study of Sicily since Dunbabin is given, and Dunbabin's own weaknesses are explored: Dunbabin modelled Greek colonisation in Sicily on modern British colonisation; such a decision strait-jacketed his image of the past, causing him to draw conclusions unacceptable today. The increase in the quantity of archaeological evidence since Dunbabin means that it is no longer possible to make an in-depth study of the whole of Sicily in a single volume. Consequently, the focus has to be considerably more restricted than Dunbabin's; specific questions need to be selected. Megara Hyblaia and Selinous offer two particular advantages for studying the evolution of Greek settlement in Sicily: besides being Megarian, both are sufficiently well explored archaeologically to make historical investigation profitable, but they were founded a century apart on different sides of the island, in different environmental and socio-political contexts. The study itself is divided into two main parts, the first focusing on Megara Hyblaia and the second on Selinous; each of these two parts consists of five chapters, in which the same questions are asked of the evidence from the two sites, for comparative purposes. Chapters I and VI explore the background to settlement, with such subjects as the native world encountered by the settlers at the time of colonisation, pre- and proto-colonial activity, and the respective foundations of the colonies examined. Settlement development is the subject of chapters II and VII; the emphasis here is to monitor the successive stages of the physical growth of the colonies, and also to study the size and nature of the settlement itself. Chapters III and VIII deal with demography (particularly population size). The following chapters (IV and IX) use archaeological and written evidence to reconstruct socio-political history. Chapters V and X investigate environment and economy. In the closing chapter, after a review of the conclusions reached, the question of why Selinous evolved so differently from it mother-city is addressed. The thesis ends with brief consideration of the (Megarian) Sicilian contribution to the study of the polis.

This project used a variety of genetic markers to investigate the evolution and population genetics of hydrothermal vent fauna that were recovered from the Scotia Sea, in the Atlantic sector of the Southern Ocean. The origins of one of these species, an undescribed species of Kiwa sp. found on the East Scotia Ridge (ESR) and its constituent family Kiwaidae, a group of vent and seep-associated decapod squat lobsters (infraorder Anomura) was investigated using a concatenated nine-gene dataset and key divergences were dated using fossil calibrations. These results confirm earlier research showing Kiwaidae reside in the superfamily Chirostyloidea, but form a monophyletic clade with the non-chemosynthetic family Chirostylidae and not Eumunididae. Chirostyloid families diverged in the Cretaceous, although extant Kiwaidae radiated in the Eocene, consistent with many other chemosynthetic taxa that appear recently derived. The basal tree position of Pacific species (and the Alaska location of a likely stem-lineage kiwaid fossil) suggests kiwaids originated in the East Pacific. Within a Southern Hemisphere clade, the divergence between the southeastern Pacific K. hirsuta and a non-Pacific lineage (Kiwa sp. ESR and Southwest Indian Ridge kiwaids) is no earlier than 25.9 Ma, consistent with a spread from the Pacific into the Scotia Sea and beyond via now-extinct active ridge connections or mediated by a Miocene onset of the Antarctic Circumpolar Current (ACC) through a newly-opened Drake Passage. This project also investigated the population genetics of three undescribed species found at two vent fields ~ 440 km apart at either end of the ESR: Kiwa sp., a peltospirid gastropod and Lepetodrilus sp. limpets. Lepetodrilus sp. was also found at the Kemp Caldera, a submerged part of the South Sandwich Islands (SSI). Analyses of cytochrome c oxidase subunit 1 (COI) as well as microsatellite loci developed from Roche 454 sequence libraries revealed no differentiation along the ESR for all three species consistent with panmixia, or the dominance of non-equilibrium processes between vent field colonies within a metapopulation, possibly enhanced further by cold-induced arrested larval development. Despite apparent connectivity along the ESR, both COI and microsatellites revealed differentiation between ESR limpets and Kemp Caldera limpets ~ 95 km to the east, possibly owing to the hydrographic isolation of the caldera. Both COI and microsatellite diversity patterns were consistent with recent (< 1 Ma) demographic expansions for all three species (although the influence of selection sweeps on COI cannot be discounted); a pattern observed worldwide at vent communities and may reflect demographic instability over time as a consequence of the stochastic birth and death of vent colonies within a metapopulation. Different COI bottleneck ages between the three species (excluding the influence of possible selection) as well as the absence of kiwaids and peltospirids at Kemp, have been attributed to differences in life history, in particular larval morphology and presumed dispersal strategy. These results highlight the role of larval dispersal of vent fauna along active spreading ridges, both in maintaining vent metapopulations across vent colonies prone to stochastic birth and extinction in the short term, but also in the spread of taxa globally and the formation of biogeographic provinces. The likelihood that the three species presented here exist at vents east of the ESR and SSI, prompts further exploration along ridges in the South Atlantic, in order to investigate the effect of the ACC in enhancing gene flow and delineating biogeographic provinces.

A presença de depósitos fossilíferos na antepraia e plataforma continental interna foi atribuída às oscilações do nível do mar durante o Quaternário. Hoje em dia, esses depósitos estão sendo erodidos por ondas e correntes e transportados para a praia. O presente trabalho teve como objetivo comparar o setor central e sul da Planície Costeira do Rio Grande do Sul, quantificando e qualificando quanto sua tafonomia, taxonomia e representatividade dos restos esqueletais. Foi coletado um total de 2.820 fósseis, dentre os quais 95% foram coletados no setor sul e apenas 5% foram coletados no setor central. A principal hipótese para essa diferença é a disponibilidade de fósseis na antepraia e plataforma interna. A presença de vários parceis e elevações e depressões submersas na antepraia e plataforma interna do setor sul indica, provavelmente as áreas-fonte de onde os fósseis são erodidos. Em ambos os setores foram identificados duas populações de bioclastos: fósseis nãoidentificados (85%) e fósseis identificados (15%), indicando maior e menor retrabalhamento pelas ondas, respectivamente. As mesmas ordens e restos esqueletais foram identificados em ambos os setores, com exceção de alguns que foram encontrados somente no setor sul. Na fauna marinha, a ordem mais comum foi a Perciformes representada principalmente por tumores ósseos da espécie Pogonias cromis. Dentes de tubarões (Lamniformes e Carcharhiniformes) e raias (Myliobatiformes) foram encontrados apenas no setor sul, devido à presença da espessa konzentrat-lagerstätte de conchas marinhas fósseis, chamada de "Concheiros". Na fauna terrestre, a ordem mais comum foi a Cingulata (principalmente gliptodontídeos do gênero Glyptodon). Os elementos acessórios representados por osteoderms de cingulados foram os restos esqueletais mais abundantes, devido ao grande número de osteodermos que cobre o esqueleto de cingulates e ao pequeno tamanho e forma compacta das osteodermos que favorecem o transporte. Elementos de tamanho pequeno (32-64 mm) e de forma compacta, como osteoderms, dentes e vértebras, são encontrados em maior quantidade e são facilmente transportados. Elementos de tamanho grande (maior que 128 mm) e de forma de lâmina/disco, como ossos longos e elementos cranianos, são encontrados em menor quantidade e são dificilmente transportados.
The presence of fossiliferous deposits in the shoreface and inner continental shelf was attributed to the sea-level oscillations during the Quaternary. Nowadays, these deposits are being eroded by waves and currents and transported onto the beach. The present work aimed to compare the central and southern sectors of the Coastal Plain of Rio Grande do Sul, quantifying and qualifying as its taphonomy, taxonomy and skeletal remains representativeness. A total of 2.820 fossils was collected, among which 95% were collected in the southern sector and only 5% were collected in the central sector. The hypothesis for this difference is the availability of fossils in the shoreface and inner continental shelf. The presence of several sedimentary submerged rocks and submerged elevations and depressions in the shoreface and inner continental shelf of the southern sector indicates probably the source-areas where the fossils are eroded from. In both sectors were identified two populations of bioclasts: non-identified fossils (85%) and identified fossils (15%), indicating greater and less waves reworking, respectively. The same orders and skeletal remains were identified in both sectors, except for some that were only found in the southern sector. In the marine fauna, the most common order was the Perciformes represented mainly by bone tumors of the species Pogonias cromis. Teeth of sharks (Lamniformes and Carcharhiniformes) and rays (Myliobatiformes) were only found in the southern sector due to the presence of the thick konzentrat-lagerstätte of fossil marine shells, called “Concheiros”. In the terrestrial fauna, the most common order was the Cingulata (mostly glyptodontids especially the genre Glyptodon). The accessory elements represented by osteoderms of cingulates were the most abundant skeletal remains, due to the large number of osteoderms that covers the skeleton of cingulates and the small size and compact shape of the osteoderms which favour the transport. Small-size (32-64 mm) and compact-shape elements such as osteoderms, teeth and vertebrae are found in greater quantity and are easily transported. Bigger-sizes (exceeding 128 mm) and blade/disc-shape elements such as long bones and cranial elements are found in less quantity and are hardly transported.

When rural settlements are examined in Anatolia, an evolution process from the prehistoric times could be observed rather than a radical change, about the building architecture and settlement pattern qualities. However, it is, in fact, a chronic discussion subject between the authorities that this case is a result of an inheritance of a building tradition from the predecessors to successors of the society or a reproduction of the similar spatial fiction after the same factors and inputs. The case of Fenaket rural settlement, which is situated at the western part of the Bozburun peninsula, maintains parallel characteristics, and stays within the limits of this discussion, by its vernacular architecture and spatial arrangement. The purpose of this research is to analyze and to document the vernacular dwellings and settlement pattern of abandoned Fenaket Village
to identify the evolution and the evaluation process of the megaroid houses of Fenaket
and to develop the means for sustaining this traditional example.

Ancient fluvial and deltaic systems are estimated to host a large proportion of the world’s remaining hydrocarbon reserves. Establishing links between processes and forms in similar modern analogue systems can improve our understanding of the architecture of such systems and thereby enhance hydrocarbon recovery from their ancient counterparts. Research attention has traditionally focused on fluvial-dominated river deltas. However, fluvial-dominated deltas constitute only 3% of the modern global coastline. Rather, the majority of the world’s coastal zone is mixed-influenced (waves, tides, fluvial energy), with waves and tides being the two most dominant processes. To address this knowledge gap, this project has investigated process-form links in the mixed-process Mitchell River Delta, which has the additional benefit of being fed by a megafan, a characteristic that is now recognised to be well represented in the rock record, though under-represented in the literature. The Holocene Mitchell River Delta and Quaternary Megafan is located in the shallow (less than 70 m deep), intracratonic basin of the Gulf of Carpentaria (GOC), in north-eastern Australia. The Holocene Delta was deposited in association with relative sea-level fall, the last of multiple cycles of sea-level fluctuation that have affected the greater Quaternary megafan system. The Mitchell River Delta and Megafan has been minimally disturbed by anthropogenic activity and provide a unique opportunity to examine the link between megafan channel avulsions and coeval deltaic evolution. Detailed mapping, field and chronologic investigations were used to characterise the palaeo-distributary channel belts on the megafan, and to reconstruct architectural changes on the megafan and delta related to internal and external forcing factors. The evolution of the Mitchell River Delta can be summarised into four depositional Phases: (I) Progradation was initiated during the maximum Holocene marine transgression, approximately 6 ka; (II) The fluvial-dominated Central Mitchell depocentre was deposited by avulsions on the upper delta plain during the peak of Holocene Effective Precipitation (EP); (III) The first major fan avulsion caused sediment supply to shift northwards, initiating the Main Mitchell Depocentre. Forced regression commenced approximately 3 ka, as evidenced by the first subtle downstepping of this Depocentre; (IV) A second episode of accelerated sea-level downstepping at approximately 2 ka was recorded in the Main Mitchell River Depocentre and the Nassau depocentre. A second major partial avulsion on the megafan during this episode also resulted in the ongoing splitting of catchment flows between these two major depocentres. Shifting of depositional loci is driven primarily by avulsion. Two types of avulsion have been described: (1) frequent (more than 16 per 1000 years; or an average of one avulsion every 60 years) backwater mediated avulsions on the delta plain, which have resulted in relatively small scale shifts in depositional loci in the order of 10 – 20 km alongshore. These are clustered at the backwater limit and define the megafan to delta boundary. Avulsion rate in the backwater zone also appears to be influenced by sea-level trajectory. Estimated avulsion rate has doubled from 11 per 1000 years in the Central Mitchell depocentre, (under highstand conditions) to 20 per 1000 years in the Main Mitchell depocentre (during sea-level fall) in spite of decreased EP following ~3.7 ka, and may be attributed to the relative sea-level fall causing the superelevation of the channels thus promoting avulsion conditions. (2) The second avulsion type are less frequent (approximately 3 per 1000 years; or an average of one avulsion every 330 years) avulsions on the megafan (upstream of backwater influence), which have resulted in shifts in depositional loci in excess of 80 km alongshore and the initiation of new depocentres. Geomorphic investigation has resulted in a number of lateral relationships being determined between architectural units across both the megafan and delta. Channel belt distribution, morphology and sedimentary fill, are a product of the complex interplay of waves, tides and backwater dynamics. Backwater dynamics have an overriding influence on the position of avulsion nodes, hence exerting a major control on channel belt distribution. Channel belt spacing and channel belt segment length is reduced in the backwater zone compared to the purely alluvial portion of the megafan. Channel belt width and depth is also less in the backwater zone compared to upstream as a result of flow partitioning from partial avulsions. Although a general decrease in sediment calibre can be observed in a downstream direction from the apex of the megafan through the backwater zone, channel fill consists of predominantly gravel and sand. Silt and clay is typically confined to the top 1.5 m of the channel fills. On the lower delta plain, channels are affected by waves and tides. Waves suppress mouth bar development thereby reducing the number of smaller scale distributary channels. As a result, power-law distribution of decreasing channel length and width typical of fluvial-dominated deltas is not observed on the Mitchell River Delta. Conversely, channel belt widths on the lower delta plain are similar to those observed on the upper delta plain, and the channel segment length is typically greater on the lower delta plain than the upper delta plain as both avulsion and bifurcation is reduced in this zone. The degree of tidal influence (process category) is intimately related to delta evolution. Fluvial-dominated, tide-influenced (Ft) channel belts can transition to tide-dominated fluvial-influenced (Tf) and tide-dominated (T) channel Elements and belts. Such a change can occur bothlongitudinally (i.e. along channel length) and laterally, as channel belts become progressively abandoned with time. Channel fill on the lower delta plain has a distinct marine signature with the presence of shell material, marine bioturbation and inclined heterolithic stratification. The degree of tidal influence is the primary control on the ratio of sand to mud fill. Depositional units on the Mitchell River Delta have been mapped and presented within the framework of the WAVE process and architectural classification. Element Complex (EC) units (equivalent to sedimentary facies associations) have been presented as a facies atlas. Sedimentary facies data are directly related to process category. Parent-child and neighbour statistics have also been generated for EC units. These statistics have predictive power in analogous subsurface settings. Geometric attribute data has also been presented for Element Complex Set (ECS) and Element Complex Assemblage (ECA) units, which represent depositional environments associated with pulses of shoreline migration. These data are presented in terms of their process category, shape, and in the context of delta evolution. Non megafan-fed delta lobes are typically driven by backwater mediated avulsions. Results from this study depocentres in linked megafan shoreline systems are controlled by both backwater avulsions (ECS and ECA) and to larger scale avulsions that occur upstream of the backwater zone below the megafan apex (depocentre development). Detailed mapping of the megafan and delta, combined with geometric analysis of ECS and ECA units has led to a generalised linked megafan-delta model for the prediction of the autogenic evolution of a deltaic depocentre. Depocentre development is initiated with an avulsion on the megafan and the progradation of a fluvial-dominated, tide-influenced, wave-affected (Ftw) or a Twf unit. Changes in shoreline orientation cause ECS development and are related to backwater mediated avulsions on the lower delta plain. ECS within an ECA increase in volume as flow capture increases. A second (partial) avulsion on the megafan causes the reduction of sediment supply to the active depocentre. The ECS in the active depocentre decrease in area and show a relative increase in tide or wave to fluvial influence thus defining an ECA boundary. The completion of flow capture on the megafan causes the abandonment of the depocentre and there is net erosion of the seaward ECS units. The depocentre terminates in wave-dominated ECA, whereby sediment is sourced primarily by longshore transported sand.
Thesis (Ph.D.) -- University of Adelaide, Australian School of Petroleum, 2016.

ABSTRACT The current study documents the findings from immunohistochemical examination of the brains of microbats and megabats (Chiroptera) using antibodies for cholineacetyltransferase (cholinergic neurons), tyrosine hydroxylase (dopaminergic, adrenergic and noradrenergic neurons), and serotonin (serotonergic neurons). The objective of the study was firstly to describe the anatomical organization and morphology of the neuromodulatory systems (nuclear complement) in both microbats and megabats, as there is no literature on these systems in the brains of chiropterans. Secondly, we aimed to investigate whether or not there are differences in these systems between the two suborders of chiroptera in hopes to shed some light on the phylogeny of the two, which is a controversial subject. The two groups were found to possess clear differences in their respective neuromodulatory nuclear complements. The differences observed between the two groups include a dorsal division of the locus coeruleus (A6d), which was absent in microbats but present in megabats, also the absence of an A4 in microbats but clear presence in megabats, and the parabigeminal (PBg) nucleus that was absent in microbats but clearly visible in megabats. The microbats were found to possess a complement that appeared similar to that of insectivores; whereas megabats had a complement resembling that of primates, carnivores and rodents. The differences found between the two groups suggest a diphyletic origin for the two groups.

The aim of the article is to investigate the historical development of the architectural form of the megaron and identify the factors that contributed to the rethinking of its functional features: from a purely utilitarian to a cult purpose. The research methodology is based on an integrated approach and relies on the analytical (when analyzing art history and cultural literature on the subject of research), historical (when clarifying the stages of the formation of the megaron as a form of cult architecture) and conceptual (when analyzing the influence of the processes of aestheticization, ethization and sacralization on the formation of the megaron). The scientific novelty of the article is to identify the factors that contributed to the rethinking of its functional features: from a purely utilitarian to a cult purpose. The results. The evolution of the architectural form of the megaron – from adobe houses with a place for a fire and an overnight stay in the stone building itself, certifying the fact of aestheticization (I invoke this form in the historical development of mankind). In particular, the example of the Temple of Hera in Olympia shows the imitation of wooden structures in stone architecture. This fact historically testifies to the peculiarities of the formation of the Dorian architectural order in Greek culture. Reconsideration of the megaron as a residential building, and as a result of a monumental temple, an altar, is a process of etization and sacralization. This also applies to the columns, in particular, which are first erected out of technological necessity, and over time serve as a necessary aesthetic attribute of the architectural form of the megaron. If clay and wooden buildings were erected mainly for the life of people, then the stone megaron, according to the technology of processing raw materials and the principles of construction, were many times more complicated – they became a kind of monuments and temples, often of a purely religious purpose. The reason for this is not only an understanding of the strength and endurance of raw materials, because if people created structures of stone only so that the latter would withstand as long as possible, then these amazing artifacts would not be so exquisitely and filigree decorated. The practical significance. Key points and the research results can be useful for studies of the processes of cultural development of mankind, in particular, consideration of the history of architecture and sculpture, the processes of aesthetization, ethization and sacralization. Moreover, the article can be used for educational disciplines of culturological and art history in Ukraine and abroad.