Paleobiology最新文献_第9页

Morphometric analysis of Skiagia-plexus acritarchs from the early Cambrian of North Greenland: toward a meaningful evaluation of phenotypic plasticity 北格陵兰早寒武纪树丛树的形态计量学分析:对表型可塑性的有意义评价

IF 2.7 2区地球科学

Paleobiology Pub Date : 2022-05-19 DOI: 10.1017/pab.2022.12

Elise Wallet, S. Willman, Ben J. Slater

{"title":"Morphometric analysis of Skiagia-plexus acritarchs from the early Cambrian of North Greenland: toward a meaningful evaluation of phenotypic plasticity","authors":"Elise Wallet, S. Willman, Ben J. Slater","doi":"10.1017/pab.2022.12","DOIUrl":"https://doi.org/10.1017/pab.2022.12","url":null,"abstract":"Abstract.— The Cambrian evolutionary radiations are marked by spectacular biotic turnovers and the establishment of increasingly tiered food chains. At the base of these food chains are primary producers, which in the Cambrian fossil record are chiefly represented among organic-walled microfossils. The majority of these microfossil remains have traditionally been attributed to an informal category of incertae sedis called “acritarchs,” based entirely on form taxonomy. Acritarch form taxa have been intensely used for biostratigraphy and in large-scale studies of phytoplankton diversity. However, both prospects have been challenged by cases of taxonomic inconsistencies and oversplitting arising from the large phenotypic plasticity seen among these microfossils. The acritarch form genus Skiagia stands as an ideal case study to explore these taxonomic challenges, because it encompasses a number of form species widely used in lower Cambrian biostratigraphy. Moreover, subtle morphological differences among Skiagia species were suggested to underlie key evolutionary innovations toward complex reproductive strategies. Here we apply a multivariate morphometric approach to investigate the morphological variation of Skiagia-plexus acritarchs using an assemblage sourced from the Buen Formation (Cambrian Series 2, Stages 3–4) of North Greenland. Our analysis showed that the species-level classification of Skiagia discretizes a continuous spectrum of morphologies. While these findings bring important taxonomic and biostratigraphic hurdles to light, the unequal frequency distribution of life cycle stages among Skiagia species suggests that certain elements of phytoplankton paleobiology are nonetheless captured by Skiagia form taxonomy. These results demonstrate the value of using morphometric tools to explore acritarch phenotypic plasticity and its potential ontogenetic and paleoecological drivers in Cambrian ecosystems.","PeriodicalId":54646,"journal":{"name":"Paleobiology","volume":"48 1","pages":"576 - 600"},"PeriodicalIF":2.7,"publicationDate":"2022-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46508011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

The life and times of Pteridinium simplex 蕨类植物的生命与时代

IF 2.7 2区地球科学

Paleobiology Pub Date : 2022-05-17 DOI: 10.1017/pab.2022.2

S. Darroch, Brandt M. Gibson, Maggie L. Syversen, I. Rahman, R. Racicot, F. Dunn, Susana Gutarra, E. Schindler, A. Wehrmann, M. Laflamme

{"title":"The life and times of Pteridinium simplex","authors":"S. Darroch, Brandt M. Gibson, Maggie L. Syversen, I. Rahman, R. Racicot, F. Dunn, Susana Gutarra, E. Schindler, A. Wehrmann, M. Laflamme","doi":"10.1017/pab.2022.2","DOIUrl":"https://doi.org/10.1017/pab.2022.2","url":null,"abstract":"Abstract.— Pteridinium simplex is an iconic erniettomorph taxon best known from late Ediacaran successions in South Australia, Russia, and Namibia. Despite nearly 100 years of study, there remain fundamental questions surrounding the paleobiology and paleoecology of this organism, including its life position relative to the sediment–water interface, and how it fed and functioned within benthic communities. Here, we combine a redescription of specimens housed at the Senckenberg Forschungsinstitut und Naturmuseum Frankfurt with field observations of fossiliferous surfaces, to constrain the life habit of Pteridinium and gain insights into the character of benthic ecosystems shortly before the beginning of the Cambrian. We present paleontological and sedimentological evidence suggesting that Pteridinium was semi-infaunal and lived gregariously in aggregated communities, preferentially adopting an orientation with the long axis perpendicular to the prevailing current direction. Using computational fluid dynamics simulations, we demonstrate that this life habit could plausibly have led to suspended food particles settling within the organism's central cavity. This supports interpretation of Pteridinium as a macroscopic suspension feeder that functioned similarly to the coeval erniettomorph Ernietta, emblematic of a broader paleoecological shift toward benthic suspension-feeding strategies over the course of the latest Ediacaran. Finally, we discuss how this new reconstruction of Pteridinium provides information concerning its potential relationships with extant animal groups and state a case for reconstructing Pteridinium as a colonial metazoan.","PeriodicalId":54646,"journal":{"name":"Paleobiology","volume":"48 1","pages":"527 - 556"},"PeriodicalIF":2.7,"publicationDate":"2022-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46097629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Understanding the ecology of host plant–insect herbivore interactions in the fossil record through bipartite networks—Corrigendum 通过二分网络了解化石记录中寄主植物-昆虫-食草动物相互作用的生态学——勘误表

IF 2.7 2区地球科学

Paleobiology Pub Date : 2022-05-01 DOI: 10.1017/pab.2022.4

A. Swain, S. Maccracken, W. Fagan, C. Labandeira

引用次数: 1

PAB volume 48 issue 2 Cover and Front matter PAB第48卷第2期封面和封面

IF 2.7 2区地球科学

Paleobiology Pub Date : 2022-05-01 DOI: 10.1017/pab.2022.20

引用次数: 0

Why the long teeth? Morphometric analysis suggests different selective pressures on functional occlusal traits in Plio-Pleistocene African suids 为什么长牙？形态计量学分析表明，不同的选择压力对上更新世非洲suids的功能性咬合特征产生影响

IF 2.7 2区地球科学

Paleobiology Pub Date : 2022-04-21 DOI: 10.1017/pab.2022.11

Deming Yang, Asli Pisano, Joan Kolasa, T. Jashashvili, J. Kibii, Ana R. Gómez Cano, L. Viriot, F. Grine, Antoine Souron

{"title":"Why the long teeth? Morphometric analysis suggests different selective pressures on functional occlusal traits in Plio-Pleistocene African suids","authors":"Deming Yang, Asli Pisano, Joan Kolasa, T. Jashashvili, J. Kibii, Ana R. Gómez Cano, L. Viriot, F. Grine, Antoine Souron","doi":"10.1017/pab.2022.11","DOIUrl":"https://doi.org/10.1017/pab.2022.11","url":null,"abstract":"Abstract. Neogene and Pleistocene African suids displayed convergent evolutionary trends in the third molar (M3) morphology, with increasingly elongated and higher crowns through time. While these features can prevent premature loss of masticatory functionality and potentially increase long-term reproductive success, changes in dental occlusal traits such as enamel complexity and thickness can also improve chewing efficiency and increase short-term energetic return. While both long-term and short-term benefits can contribute to the thriving of a lineage, the selective pressures associated with each category can be different. To examine how crown elongation correlates with these functional occlusal traits, we selected M3s of Kolpochoerus, Notochoerus, and Metridiochoerus from Kenya and South Africa, dated between 3.0 Ma and 0.4 Ma. To account for dental wear, we used micro-computed tomography imaging of unworn/slightly worn M3s to simulate wear progression within each tooth. We compared morphometric representatives of occlusal enamel complexity and thickness among the specimens following their respective wear trajectories. We found that M3 elongation correlates with higher occlusal complexity and thinner enamel in Notochoerus and Metridiochoerus lineages through time. In Kolpochoerus, enamel complexity and thickness were generally maintained through time, despite M3 elongation. The differences in M3 morphometric trends suggest that Kolpochoerus likely experienced a different set of selective pressures on functional occlusal traits compared with Notochoerus and Metridiochoerus. The shared evolutionary trends of M3 specialization among Notochoerus and Metridiochoerus suggest similar selective pressures on their chewing efficiency and the possibility of a dietary niche overlap in more xeric habitats.","PeriodicalId":54646,"journal":{"name":"Paleobiology","volume":"48 1","pages":"655 - 676"},"PeriodicalIF":2.7,"publicationDate":"2022-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47207110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Fossilized pollen malformations as indicators of past environmental stress and meiotic disruption: insights from modern conifers 化石花粉畸形作为过去环境压力和减数分裂破坏的指标:来自现代针叶树的见解

IF 2.7 2区地球科学

Paleobiology Pub Date : 2022-04-20 DOI: 10.1017/pab.2022.3

Jeffrey P. Benca, I. Duijnstee, C. Looy

{"title":"Fossilized pollen malformations as indicators of past environmental stress and meiotic disruption: insights from modern conifers","authors":"Jeffrey P. Benca, I. Duijnstee, C. Looy","doi":"10.1017/pab.2022.3","DOIUrl":"https://doi.org/10.1017/pab.2022.3","url":null,"abstract":"Abstract. Pollen malformations have been proposed as a paleoenvironmental stress proxy. However, the frequency and variability of pollen malformations under near-optimal conditions and environmental stress, as well as their developmental origins, remain unclear. To bridge these gaps, we compared pollen malformation frequencies and assemblages of 14 extant conifer genera of Pinaceae and Podocarpaceae producing saccate (winged) grains grown under near-optimal conditions. These baseline pollen yields were compared with those produced by Pinus mugo ‘Columnaris’ cultured under an abiotic stress—three experimentally heightened ultraviolet-B radiation (UV-B) regimes proposed for the end-Permian crisis. We additionally reviewed previous cytological literature of abnormal microsporogenesis in conifers. Under near-optimal conditions, malformations comprise <3% of pollen yields in 12 out of 13 bisaccate genera and >10% of yields in the naturally trisaccate Dacrycarpus dacrydioides. We detected no phylogenetic pattern in malformation assemblages of the baseline comparisons. UV-B–irradiated P. mugo produced significantly higher malformation frequencies and different assemblage compositions when compared with baseline bisaccate lineages. We propose that pollen malformations originate during the meiotic and tetrad stages of microsporogenesis and present a framework for the ontogeny of different malformation types seen in the fossil record. Malformations comprising >3% of bisaccate pollen yields can be used as a paleoenvironmental stress proxy, but rare, naturally trisaccate lineages are not suitable for such assessments. Furthermore, heightened UV-B not only increases pollen malformation production, but also alters the types of abnormalities trees produce. Different environmental stresses may therefore leave behind distinct fingerprints in the fossil record.","PeriodicalId":54646,"journal":{"name":"Paleobiology","volume":"48 1","pages":"677 - 710"},"PeriodicalIF":2.7,"publicationDate":"2022-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42216598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

The chondrichthyan fossil record of the Florida Platform (Eocene–Pleistocene) 佛罗里达地台的球粒陨石化石记录（始新世-更新世）

IF 2.7 2区地球科学

Paleobiology Pub Date : 2022-04-18 DOI: 10.1017/pab.2021.47

Victor J. Perez

{"title":"The chondrichthyan fossil record of the Florida Platform (Eocene–Pleistocene)","authors":"Victor J. Perez","doi":"10.1017/pab.2021.47","DOIUrl":"https://doi.org/10.1017/pab.2021.47","url":null,"abstract":"Abstract.— As of September 2019, the Florida Museum of Natural History (FLMNH) had a curated collection of 117,449 chondrichthyan specimens from Florida, spanning the Eocene through the Pleistocene. Herein, I evaluate the completeness of the chondrichthyan fossil record from Florida based on the FLMNH collection, while analyzing patterns in taxonomic and ecomorphological diversity. At least 70 chondrichthyan taxa were recognized, representing 10 orders, 26 families, and 42 genera; of which, 20 taxa represent first occurrences from Florida. A sample of 107,698 specimens was organized into 12 time bins to analyze taxonomic and ecomorphological diversity, with an expectation that diversity patterns would correspond with global climate events (e.g., the Eocene–Oligocene transition and the middle Miocene climatic optimum). However, diversity patterns were obscured by pervasive sampling bias, attributable to variable collection methods, research prioritizations, and regional lithologic controls. Sampling is particularly poor for smaller specimens and older geologic units (e.g., the Paleogene). Despite incomplete sampling of the Florida chondrichthyan fossil record, there was an apparent turnover along the Atlantic and Gulf Coastal Plains from a lamniform- to carcharhiniform-dominated chondrichthyan fauna that occurred during the Eocene. This turnover corresponded with the extinction of many lamniform taxa with grasping-dominated dentition types (e.g., Brachycarcharias, Jaekelotodus, and Macrorhizodus). Selachian taxa that survived the late Eocene extinctions were predominantly represented by cutting-dominant dentition types. As cutting aids in the dismemberment of prey, this may reflect a macroevolutionary trend toward active predation and scavenging on larger prey, such as marine mammals, teleost fish, and other sharks.","PeriodicalId":54646,"journal":{"name":"Paleobiology","volume":"48 1","pages":"622 - 654"},"PeriodicalIF":2.7,"publicationDate":"2022-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46279668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Paleodiet of Lamini camelids (Mammalia: Artiodactyla) from the Pleistocene of southern Brazil: insights from stable isotope analysis (δ13C, δ18O) 巴西南部更新世Lamini camelids(哺乳纲:偶蹄目)的古饮食:稳定同位素分析(δ13C， δ18O)的启示

IF 2.7 2区地球科学

Paleobiology Pub Date : 2022-04-12 DOI: 10.1017/pab.2022.10

Thayara S. Carrasco, C. Scherer, A. M. Ribeiro, F. S. Buchmann

{"title":"Paleodiet of Lamini camelids (Mammalia: Artiodactyla) from the Pleistocene of southern Brazil: insights from stable isotope analysis (δ13C, δ18O)","authors":"Thayara S. Carrasco, C. Scherer, A. M. Ribeiro, F. S. Buchmann","doi":"10.1017/pab.2022.10","DOIUrl":"https://doi.org/10.1017/pab.2022.10","url":null,"abstract":"Abstract. Camelids (Camelidae) were a diverse and widely distributed group in South America during the Pleistocene. According to the fossil record, three species inhabited southern Brazil in the recent past: Hemiauchenia paradoxa, Lama guanicoe, and Vicugna vicugna. The analysis of carbon and oxygen stable isotope ratios in bioapatite provides insight into the paleobiology of nonliving animals and the environment they used to inhabit. We applied this tool to investigate the diet of camelids from two geological localities in southern Brazil: Touro Passo and Santa Vitória Formations (H. paradoxa, n = 7; L. guanicoe, n = 6; V. vicugna, n = 4). Carbon stable isotopes from enamel, dentin, and bone indicated that H. paradoxa and L. guanicoe had diets comprising mostly C3 grasses, but the latter showed a broader diet due to one individual with a mixed diet, whereas V. vicugna had a mixed C3–C4 diet. These different foraging behaviors may have minimized interspecific competition and favored niche partitioning and the coexistence of related species. Combined oxygen and carbon isotope data showed a consistent diet according to climate, probably due to the greater availability in glacial periods of cool-season grasses, which mainly use the C3 photosynthetic pathway. Given their adaptations to grazing, the climate amelioration, followed by the loss of grasslands, likely had a great impact on camelid populations, leading to their extinction in southern Brazil. These results, therefore, contribute to the understanding of the dynamics of paleocommunities in this region.","PeriodicalId":54646,"journal":{"name":"Paleobiology","volume":"48 1","pages":"513 - 526"},"PeriodicalIF":2.7,"publicationDate":"2022-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45355718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Sr/Ca and Ba/Ca ratios support trophic partitioning within a Silurian conodont community from Gotland, Sweden Sr/Ca和Ba/Ca比值支持瑞典哥特兰志留系牙形石群落的营养分配

IF 2.7 2区地球科学

Paleobiology Pub Date : 2022-04-08 DOI: 10.1017/pab.2022.9

D. Terrill, E. Jarochowska, C. Henderson, Bryan Shirley, Oskar Bremer

{"title":"Sr/Ca and Ba/Ca ratios support trophic partitioning within a Silurian conodont community from Gotland, Sweden","authors":"D. Terrill, E. Jarochowska, C. Henderson, Bryan Shirley, Oskar Bremer","doi":"10.1017/pab.2022.9","DOIUrl":"https://doi.org/10.1017/pab.2022.9","url":null,"abstract":"Abstract. Conodonts were a highly diverse and abundant vertebrate group whose fossils are found in marine Paleozoic and Triassic strata around the world. They inhabited environments ranging from lagoons to open oceans and are represented by a wide variety of dental morphologies. Conodonts may have filled many different ecological niches and represent a significant proportion of nekton before the Devonian. Despite this, very little is known about trophic ecology of conodonts. While morphological diversity suggests a complex trophic structure within conodont communities, there is little evidence to support dietary niche partitioning among conodonts. We tested the hypothesis that individual conodont taxa occupied different trophic niches, using Sr/Ca and Ba/Ca ratios preserved in the dental elements of assemblages from Silurian strata of Gotland, Sweden. Sr/Ca and Ba/Ca have been shown to vary in vertebrate skeletal tissues depending on trophic positioning, although biological and environmental conditions can affect these ratios. Environmental influences were minimized by examining entire conodont communities from a tropical epeiric sea and by measuring strontium isotope ratios using thermal ionization mass spectrometry in the most metropolitan taxon (Ozarkodina confluens). Composition of white matter, a tissue unique to conodonts, was also analyzed using microprobe analysis, revealing significantly lower Sr concentrations than in surrounding lamellar tissue, suggesting taxon-specific histology should be considered when analyzing conodonts for geochemical data. Excluding taxa with highly variable quantities of white matter, the results show that each taxon preserves different Sr/Ca and Ba/Ca ratios with limited overlap, indicating variation in trophic positioning.","PeriodicalId":54646,"journal":{"name":"Paleobiology","volume":"48 1","pages":"601 - 621"},"PeriodicalIF":2.7,"publicationDate":"2022-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45813697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Applying the Prigogine view of dissipative systems to the major transitions in evolution 将耗散系统的普里高津观点应用于进化中的主要转变

IF 2.7 2区地球科学

Paleobiology Pub Date : 2022-04-06 DOI: 10.1017/pab.2022.7

Carlos de Castro, D. McShea

{"title":"Applying the Prigogine view of dissipative systems to the major transitions in evolution","authors":"Carlos de Castro, D. McShea","doi":"10.1017/pab.2022.7","DOIUrl":"https://doi.org/10.1017/pab.2022.7","url":null,"abstract":"Abstract. Ilya Prigogine's trinomial concept is, he argued, applicable to many complex dissipative systems, from physics to biology and even to social systems. For Prigogine, this trinomial—functions, structure, fluctuations—was intended to capture the feedback-rich relations between upper and lower levels in these systems. The main novelty of his vision was his view of causation, in which the causal arrow runs downward from dissipative structures to their components or functions. Following this insight, some physicists and biophysicists are beginning to apply terms formerly used mainly in biology, such as evolution, adaptation, learning, and life-like behavior, to physical and chemical nonequilibrium systems. Here, instead, we apply Prigogine's view to biology, in particular to evolution, and especially the major transitions in evolution (MTE), arguing that at least the hierarchical transitions—the transitions in individuality—follow a trajectory anticipated by the trinomial. In this trajectory, formerly free-living organisms are transformed into “functions” within a larger organic “structure.” The Prigogine view also predicts that, consistent with available data, the increase in number of hierarchical levels in organisms should accelerate over time. Finally, it predicts that, on geological timescales, ecosystems and Gaia in particular will tend to “de-Darwinize” or “machinify” their component organisms.","PeriodicalId":54646,"journal":{"name":"Paleobiology","volume":"48 1","pages":"711 - 728"},"PeriodicalIF":2.7,"publicationDate":"2022-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46389687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3