Palaeontology最新文献_第9页

Deep origin of the crossed‐lamellar microstructure in early Cambrian molluscs 早寒武纪软体动物交叉板层微观结构的深层成因

IF 2.6 2区地球科学

Palaeontology Pub Date : 2022-07-01 DOI: 10.1111/pala.12620

Luoyang Li, C. Skovsted, T. Topper

{"title":"Deep origin of the crossed‐lamellar microstructure in early Cambrian molluscs","authors":"Luoyang Li, C. Skovsted, T. Topper","doi":"10.1111/pala.12620","DOIUrl":"https://doi.org/10.1111/pala.12620","url":null,"abstract":"Aragonitic crossed‐lamellar (CL) is one of the most commonly formed and extensively studied molluscan shell microstructures, yet its origin and early evolution within the Mollusca remains poorly understood. Here, a primitive CL microstructure from one of the oldest gastropods, Pelagiella madianensis, and the problematic hyolith Cupitheca sp. of the Cambrian Series 2 Xinji Formation on the North China Platform, was investigated. In P. madianensis, detailed characterization has revealed a typical four‐ordered hierarchical organization of aragonitic crystallites, and a thick layer of organic membranes surrounding its first‐order lamellae. A transitional fibrous microstructure was observed between the outer CL and inner foliated aragonite structural layers. In Cupitheca sp., only the first and second‐order lamellae were visible due to preservation limitations, and the first‐order lamellae were extremely irregular in shape and size, which is consistent with modern representatives. This study demonstrates that the capability to construct highly‐mineralized intricate shells was acquired in early Cambrian stem‐group gastropods. The CL microstructure first emerged in the early Cambrian and as a basal synapomorphic trait in total‐group molluscs. Moreover, presence of the CL microstructure in problematic lophotrochozoans (i.e. hyoliths) is confirmed. This study contributes to a more complete picture of the evolutionary origin and architectural diversity of biomineralized mollusc shells during the Cambrian explosion, and strengthens the phylogenetic links between hyoliths and molluscs.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47257202","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: 7

Palaeobiology of the early sauropodomorph Mussaurus patagonicus inferred from its long bone histology 从其长骨组织学推断早期龙脚型巴塔哥龙的古生物学

IF 2.6 2区地球科学

Palaeontology Pub Date : 2022-07-01 DOI: 10.1111/pala.12614

I. Cerda, D. Pol, A. Otero, A. Chinsamy

{"title":"Palaeobiology of the early sauropodomorph Mussaurus patagonicus inferred from its long bone histology","authors":"I. Cerda, D. Pol, A. Otero, A. Chinsamy","doi":"10.1111/pala.12614","DOIUrl":"https://doi.org/10.1111/pala.12614","url":null,"abstract":"We present a detailed histological study of long bones from an ontogenetic series of Mussaurus patagonicus, an early sauropodomorph from the Lower Jurassic of Argentina. Twenty long bones, including humeri, femora and fibulae, obtained from 13 individuals of different body sizes were sampled for histological analysis. In general terms, the cortical bone is formed by a well vascularized fibrolamellar and parallel fibred bone. Except for the smaller individuals, cyclical growth marks (CGMs) are well recorded in all the specimens but their number and relative position is highly variable. Mussaurus exhibits marked variation regarding relative growth rate, with some individuals growing much faster than others. Such variation affects the size of the adult individuals, which results in a poor correlation between the body size and the age/ontogenetic stage for this taxon. These discrepancies may be related to sexual dimorphism and/or developmental plasticity. Intraspecific variation is also recorded with regard to the growth strategies, which can vary from cyclical, as in other early sauropodomorphs, to continuous, as reported in sauropods. Sexual maturity appears to have been reached between 23 and 31 years, which is delayed in comparison to other early sauropodomorphs but more comparable with derived sauropods. The attainment of somatic maturity appears to have been reached at about 14 years after onset of sexual maturity. Mussaurus is a sauropodiform, phylogenetically closer to sauropods than most other Early Jurassic sauropodomorphs, and therefore provides critical information for understanding palaeobiological aspects of the origin of sauropods and the onset of gigantism in this lineage.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43784253","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: 8

Diversity dynamics of microfossils from the Cretaceous to the Neogene show mixed responses to events. 从白垩纪到新近纪的微化石多样性动态表现出对事件的混合响应。

IF 2.6 2区地球科学

Palaeontology Pub Date : 2022-07-01 Epub Date: 2022-07-15 DOI: 10.1111/pala.12615

Katie M Jamson, Benjamin C Moon, Andrew J Fraass

{"title":"Diversity dynamics of microfossils from the Cretaceous to the Neogene show mixed responses to events.","authors":"Katie M Jamson, Benjamin C Moon, Andrew J Fraass","doi":"10.1111/pala.12615","DOIUrl":"https://doi.org/10.1111/pala.12615","url":null,"abstract":"Microfossils have a ubiquitous and well-studied fossil record with temporally and spatially fluctuating diversity, but how this arises and how major events affect speciation and extinction is uncertain. We present one of the first applications of PyRate to a micropalaeontological global occurrence dataset, reconstructing diversification rates within a Bayesian framework from the Mesozoic to the Neogene in four microfossil groups: planktic foraminiferans, calcareous nannofossils, radiolarians and diatoms. Calcareous and siliceous groups demonstrate opposed but inconsistent responses in diversification. Radiolarian origination increases from c. 104 Ma, maintaining high rates into the Cenozoic. Calcareous microfossil diversification rates significantly declines across the Cretaceous-Palaeogene boundary, while rates in siliceous microfossil groups remain stable until the Paleocene-Eocene transition. Diversification rates in the Cenozoic are largely stable in calcareous groups, whereas the Palaeogene is a turbulent time for diatoms. Diversification fluctuations are driven by climate change and fluctuations in sea surface temperatures, leading to different responses in the groups generating calcareous or siliceous microfossils. Extinctions are apparently induced by changes in anoxia, acidification and stratification; speciation tends to be associated with upwelling, productivity and ocean circulation. These results invite further micropalaeontological quantitative analysis and study of the effects of major transitions in the fossil record. Despite extensive occurrence data, regional diversification events were not recovered; neither were some global events. These unexpected results show the need to consider multiple spatiotemporal levels of diversity and diversification analyses and imply that occurrence datasets of different clades may be more appropriate for testing some hypotheses than others.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9540813/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33515269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Osteohistology and taphonomy support social aggregation in the early ornithischian dinosaur Lesothosaurus diagnosticus 骨组织学和解剖学支持早期鸟臀目恐龙Lesothosaurus diagnosticus的社会聚集

IF 2.6 2区地球科学

Palaeontology Pub Date : 2022-07-01 DOI: 10.1111/pala.12619

J. Botha, J. Choiniere, P. Barrett

{"title":"Osteohistology and taphonomy support social aggregation in the early ornithischian dinosaur Lesothosaurus diagnosticus","authors":"J. Botha, J. Choiniere, P. Barrett","doi":"10.1111/pala.12619","DOIUrl":"https://doi.org/10.1111/pala.12619","url":null,"abstract":"Lesothosaurus diagnosticus is a small ornithischian dinosaur from the Lower Jurassic Massospondylus Assemblage Zone of the upper Elliot Formation of the Karoo Basin of South Africa and Lesotho. The Early Jurassic age, comparatively large sample size, and multiple growth stages of Lesothosaurus make it an excellent taxon for investigating the plesiomorphic condition of ornithischian growth. Here, we examine the osteohistology of an ontogenetic series of Lesothosaurus diagnosticus using multiple limb elements to assess the maximum body size, life history, growth dynamics and potential for sociality in one of the earliest‐branching ornithischian dinosaurs. We found that Lesothosaurus grew rapidly during early and mid‐ontogeny (as shown by its highly vascularized woven‐parallel complex) with its growth rate decreasing between 2–4 years of age, possibly indicating the onset of reproductive maturity. However, an external fundamental system, indicating a cessation in growth, could not be confirmed in any of the individuals studied, suggesting that at 6 years of age, this taxon was still not fully grown. The presence of multiple individuals of varying ontogenetic stages in a monodominant bone bed strongly suggests that it lived in multigenerational herds, indicating that, along with the Venezuelan Laquintasaura venezuelae, social behaviour developed very early in ornithischian evolutionary history.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42044371","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

Skeletal and soft tissue completeness of the acanthodian fossil record 棘蜥化石记录的骨骼和软组织完整性

IF 2.6 2区地球科学

Palaeontology Pub Date : 2022-07-01 DOI: 10.1111/pala.12616

Lisa Schnetz, R. Butler, M. Coates, I. Sansom

{"title":"Skeletal and soft tissue completeness of the acanthodian fossil record","authors":"Lisa Schnetz, R. Butler, M. Coates, I. Sansom","doi":"10.1111/pala.12616","DOIUrl":"https://doi.org/10.1111/pala.12616","url":null,"abstract":"Acanthodians are a poorly understood paraphyletic grade of extinct Palaeozoic fishes. They play an increasingly prominent role in our understanding of vertebrate evolution as part of the chondrichthyan stem‐group even though their evolutionary history is scarce. The limited preservation of their mostly cartilaginous skeleton largely results in a bias towards isolated remains such as fin spines and scales. Here, we quantify the quality of the acanthodian fossil record by using a variation of the Skeletal Completeness Metric (SCM), an approach that calculates how complete the skeletons of individuals are compared to their theoretical complete skeleton. A novel Soft Tissue Completeness Metric (STCM) is introduced to estimate the percentage of soft body tissue preserved as an alternate measurement of completeness. Completeness scores for >1600 specimens comprising >300 taxa obtained from museum collection visits and literature surveys were assembled into a database. Acanthodian completeness peaks in the Lower–Middle Devonian, Pennsylvanian, and earliest Permian. There is no correlation between acanthodian taxonomic richness and completeness. Acanthodians show a significantly lower completeness distribution than many tetrapod groups, but a similarly low distribution to bats. Skeletons deposited in freshwater are significantly more complete than in marine environments where sea level significantly negatively correlates with observed completeness. Our assessment reveals only weak spatial biases influencing the acanthodian fossil record while environmental biases are much higher. This quantified evaluation of acanthodians provides a foundation for further assessments of the likely influence of character absences from morphological datasets on estimates of early chondrichthyan and, therefore, early gnathostome evolution.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42659421","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

Experimental analysis of organ decay and pH gradients within a carcass and the implications for phosphatization of soft tissues 胴体内器官腐烂和pH梯度的实验分析及其对软组织磷酸化的影响

IF 2.6 2区地球科学

Palaeontology Pub Date : 2022-07-01 DOI: 10.1111/pala.12617

Thomas Clements, M. Purnell, S. Gabbott

{"title":"Experimental analysis of organ decay and pH gradients within a carcass and the implications for phosphatization of soft tissues","authors":"Thomas Clements, M. Purnell, S. Gabbott","doi":"10.1111/pala.12617","DOIUrl":"https://doi.org/10.1111/pala.12617","url":null,"abstract":"Replacement of soft tissues by calcium phosphate can yield spectacular fossils. However, in the fossil record, the phosphatization of internal organs is highly selective; some internal organs, such as muscles, stomachs, and intestines, appear to preferentially phosphatize while other organs seldom phosphatize. The reasons for this are unclear but one hypothesis is that, during decay, organs create distinct chemical microenvironments and only some fall below the critical pH threshold for mineralization to occur (i.e. below the carbonic acid dissociation constant: pH 6.38). Here, we present a novel investigation using microelectrodes that record dynamic spatial and temporal pH gradients inside organs within a fish carcass in real time. Our experiments demonstrate that within a decaying fish carcass, organ‐specific microenvironments are not generated. Rather, a pervasive pH environment forms within the body cavity which persists until integumentary failure. With no evidence to support the development of organ‐specific microenvironments during decay our data suggest other factors must control differential organ phosphatization. We propose, that when conditions are amenable, it is tissue biochemistry that plays an important role in selective phosphatization. Tissues with high phosphate content (and those rich in collagen) are most likely to phosphatize. Internal organs that typically have lower tissue‐bound phosphate, including the integuments of the stomach and intestine, may require other sources of phosphate such as ingested phosphate‐rich organic matter. If tissue biochemistry is the driver behind selective phosphatization, this may provide insights into other highly selective modes of soft‐tissue preservation (e.g. pyritization).","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47115871","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

Planetary‐scale change to the biosphere signalled by global species translocations can be used to identify the Anthropocene 以全球物种迁移为标志的生物圈的行星尺度变化可用于确定人类世

IF 2.6 2区地球科学

Palaeontology Pub Date : 2022-07-01 DOI: 10.1111/pala.12618

Mark Williams, R. Leinfelder, A. Barnosky, M. Head, F. McCarthy, A. Cearreta, Stephen Himson, R. Holmes, C. Waters, J. Zalasiewicz, S. Turner, M. McGann, E. Hadly, M. Stegner, P. Pilkington, J. Kaiser, J. Berrío, I. Wilkinson, J. Zinke, K. Delong

{"title":"Planetary‐scale change to the biosphere signalled by global species translocations can be used to identify the Anthropocene","authors":"Mark Williams, R. Leinfelder, A. Barnosky, M. Head, F. McCarthy, A. Cearreta, Stephen Himson, R. Holmes, C. Waters, J. Zalasiewicz, S. Turner, M. McGann, E. Hadly, M. Stegner, P. Pilkington, J. Kaiser, J. Berrío, I. Wilkinson, J. Zinke, K. Delong","doi":"10.1111/pala.12618","DOIUrl":"https://doi.org/10.1111/pala.12618","url":null,"abstract":"We examine three distinctive biostratigraphic signatures of humans associated with hunting and gathering, landscape domestication and globalization. All three signatures have significant fossil records of regional importance that can be correlated inter‐regionally and help describe the developing pattern of human expansion and appropriation of resources. While none have individual first or last appearances that provide a globally isochronous marker, all three signatures overlap stratigraphically, in that they are part of a continuum of change, with complex regional patterns. Here we show that during the later stages of globalization, late nineteenth to twentieth century records of species translocations can be used to build an interconnected web of palaeontological correlation with decadal or sub‐decadal precision that dovetails with other stratigraphic markers for the Anthropocene. This palaeontological web is also a proxy for accelerating species extinction and of a state shift in the biosphere in the twentieth century.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42180439","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: 10

Feeding habits of the Middle Triassic pseudosuchian Batrachotomus kupferzellensis from Germany and palaeoecological implications for archosaurs 德国中三叠世kupferzellbatrachotomus的食性及其古生态学意义

IF 2.6 2区地球科学

Palaeontology Pub Date : 2022-05-01 DOI: 10.1111/pala.12597

E. Mujal, C. Foth, E. Maxwell, Dieter Seegis, R. Schoch

{"title":"Feeding habits of the Middle Triassic pseudosuchian Batrachotomus kupferzellensis from Germany and palaeoecological implications for archosaurs","authors":"E. Mujal, C. Foth, E. Maxwell, Dieter Seegis, R. Schoch","doi":"10.1111/pala.12597","DOIUrl":"https://doi.org/10.1111/pala.12597","url":null,"abstract":"Bite traces on fossil bones are key to deciphering feeding ecology and trophic interactions of vertebrate past ecosystems. However, similarities between traces produced by different carnivorous taxa with similar dentitions, and misidentifications due to equifinality, hinder confident identifications of the bite makers. Here, we correlate bite traces with macroscopic wear and microanatomy of the teeth of the pseudosuchian archosaur Batrachotomus kupferzellensis from the Triassic Lower Keuper fossil lagerstätten (southern Germany), untangling its feeding habits and shedding light on the bite traces generated by ziphodont teeth (teeth with serrated carinae). Individually, bite traces reflect tooth morphology, whereas composite bite traces and their frequency are related to feeding behaviour and explain tooth macroscopic wear and microanatomy. Therefore the identification of the bite maker is possible by analysing composite bite traces, their location on bones, and their relative abundance. In addition, tooth macroscopic wear and microanatomy are proven as independent lines of evidence of feeding ecology. Comparing bite traces on fossil and present‐day bone assemblages, we observe that bone modifications by the crocodylomorph lineage (from Triassic pseudosuchian archosaurs to extinct and extant crocodylians) are strikingly similar, including taxa with and without ziphodont teeth. Such a set of features differs from bone modification assemblages produced by taxa with similar ziphodont teeth outside the pseudosuchian lineage, such as theropod dinosaurs and the Komodo monitor, suggesting phylogeny is a better predictor of feeding ecology among saurian reptiles than tooth morphology.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2022-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42234052","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

When less is more and more is less: the impact of sampling effort on species delineation 当少即是多，多即是少：采样工作对物种划分的影响

IF 2.6 2区地球科学

Palaeontology Pub Date : 2022-05-01 DOI: 10.1111/pala.12598

P. Guenser, S. Ginot, G. Escarguel, N. Goudemand

{"title":"When less is more and more is less: the impact of sampling effort on species delineation","authors":"P. Guenser, S. Ginot, G. Escarguel, N. Goudemand","doi":"10.1111/pala.12598","DOIUrl":"https://doi.org/10.1111/pala.12598","url":null,"abstract":"Taxonomy is the very first step of most biodiversity studies, but how confident can we be in the taxa delineation? One may hypothesize that the more abundant the material, the more accurate the description of morphological variability and hence the better the taxonomic delineation. Yet, as we shall see, in the case of numerous transitional forms, this hypothesis may prove wrong. Similarly to rarefaction curves that assess the degree of knowledge on taxonomic diversity through sampling effort, we aim to test the impact of sampling effort on species delineation by subsampling a given assemblage. To do so, we use an abundant and morphologically diverse conodont fossil assemblage from the Smithian of Oman. We first recognize four well established morphospecies but about 80% of the specimens are transitional forms. We quantify the diagnostic characters in a sample of 159 P1 elements using geometric morphometrics and assess, via gradually subsampling the assemblage, the number of morphometric groups (i.e. morphospecies) using ordination and clustering analyses. Four morphospecies were detected when less than 20% of the specimens were considered. The number of detected clusters dropped to two when including more than 30% of the specimens. Such influence of sampling effort on species delineation highlights the complexity of taxonomic work, especially when transitional forms are more abundant than typical specimens. These results should encourage researchers to extensively illustrate, measure and quantitatively compare their material to better constrain the morphological variability and delineation of taxa.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2022-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46439869","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

Issue Information 问题信息

IF 2.6 2区地球科学

Palaeontology Pub Date : 2022-05-01 DOI: 10.1111/pala.12554

引用次数: 0