Interpretation of the locomotion of biostratigraphically important graptolite taxa is rare, and rendered problematic due to a lack of close modern analogues and soft tissues. In this study, based on well‐preserved specimens of the early Silurian low‐helical spiral Demirastrites Eisel, we reconstructed three‐dimensional Demirastrites models and simulated their locomotion using computational fluid dynamics. Hydrodynamic properties (outer‐wall pressure fields and velocity fields) were obtained and used to test the prevailing hypothesis that the Silurian low helical spiral graptolite Demirastrites could rotate in seawater. The Demirastrites models kept rotating at different velocities in the simulation field, which helped to counteract the impact of the water current and achieve stability. During rotation, higher velocity fields could be observed near the thecal apertures, which meant better access to more nutrient particles in the sea water. Our simulation thus confirmed the rotating locomotory pattern of the Silurian low conical graptolite Demirastrites for the purpose of better feeding efficiency and tubarium stability. Moreover, we analysed how the evolution of structural innovations, such as the density and width of thecae and angle of proximal curvature of the tubarium within the recovered geological lineages of Demirastrites, were influenced and selected by hydrodynamics. The results showed that Demirastrites lineages evolved towards increased stability and higher rotation velocity. Our study highlights the importance of hydrodynamic constraints serving as hidden abiotic factors shaping the evolution of planktonic graptolites.
{"title":"Locomotory and morphological evolution of the earliest Silurian graptolite Demirastrites selected by hydrodynamics","authors":"Gao Shijia, Jingqiang Tan, Wenhui Wang","doi":"10.1111/pala.12716","DOIUrl":"https://doi.org/10.1111/pala.12716","url":null,"abstract":"Interpretation of the locomotion of biostratigraphically important graptolite taxa is rare, and rendered problematic due to a lack of close modern analogues and soft tissues. In this study, based on well‐preserved specimens of the early Silurian low‐helical spiral <jats:italic>Demirastrites</jats:italic> Eisel, we reconstructed three‐dimensional <jats:italic>Demirastrites</jats:italic> models and simulated their locomotion using computational fluid dynamics. Hydrodynamic properties (outer‐wall pressure fields and velocity fields) were obtained and used to test the prevailing hypothesis that the Silurian low helical spiral graptolite <jats:italic>Demirastrites</jats:italic> could rotate in seawater. The <jats:italic>Demirastrites</jats:italic> models kept rotating at different velocities in the simulation field, which helped to counteract the impact of the water current and achieve stability. During rotation, higher velocity fields could be observed near the thecal apertures, which meant better access to more nutrient particles in the sea water. Our simulation thus confirmed the rotating locomotory pattern of the Silurian low conical graptolite <jats:italic>Demirastrites</jats:italic> for the purpose of better feeding efficiency and tubarium stability. Moreover, we analysed how the evolution of structural innovations, such as the density and width of thecae and angle of proximal curvature of the tubarium within the recovered geological lineages of <jats:italic>Demirastrites</jats:italic>, were influenced and selected by hydrodynamics. The results showed that <jats:italic>Demirastrites</jats:italic> lineages evolved towards increased stability and higher rotation velocity. Our study highlights the importance of hydrodynamic constraints serving as hidden abiotic factors shaping the evolution of planktonic graptolites.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":"44 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141509316","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}
Aleksandr S. Bakaev, Valery V. Bulanov, Ilja Kogan, Zerina Johanson, Alla V. Minikh
Eurynotoidiformes are a little‐known group of actinopterygian fishes from the Permian of European Russia, characterized by the possession of multicuspid marginal teeth arranged in a single row. Morphologically, the teeth resemble those of Recent Cichlidae, Acanthuridae, Siganidae or Serrasalmidae, suggesting similar trophic adaptations related to herbivory. Tooth histology is similar to the majority of basal actinopterygians (composed of dentine, acrodin and collar enamel). Teeth are ankylosed in their attachment, and labial pleurodont in implantation, strengthening the tooth. The multicuspid tooth crowns derive from conical teeth of predatory or omnivorous ancestors, analogous to the evolution of multicuspid teeth in cichlid fishes. Tooth replacement in eurynotoidiforms is most comparable to an alternating pattern, with a possible simultaneous, unilateral replacement occurring in the whole jaw, similar to characiform fishes. Replacement teeth were formed extraosseously. Teeth of the inner dental arcade were conical. Based on comparisons with the teeth of extant actinopterygians specialized for herbivory, along with functional morphological analysis and consideration of wear patterns, we hypothesize that eurynotoidiforms represent the oldest known actinopterygians specialized for herbivory. Several strategies of herbivory in Recent actinopterygians were already realized by eurynotoidiforms as early as the Late Palaeozoic (middle and late Permian): grazing/cutting filamentous algae (Lapkosubia spp., Isadia suchonensis), browsing/biting off macrophyte fragments (Isadia aristoviensis), scraping/harvesting periphyton from hard substrates (Isadia opokiensis, I. arefievi). However, notable morphological differences in the jaws (elongate) and tooth arrangement (homodont along the jaw, functional teeth separated) suggest that this Permian experiment in herbivory followed different pathways compared to extant taxa.
{"title":"Early ray‐finned herbivores: the dental system of Eurynotoidiidae (Actinopterygii; middle–late Permian, European Russia) and implications for palaeobiology and palaeoecology","authors":"Aleksandr S. Bakaev, Valery V. Bulanov, Ilja Kogan, Zerina Johanson, Alla V. Minikh","doi":"10.1111/pala.12700","DOIUrl":"https://doi.org/10.1111/pala.12700","url":null,"abstract":"Eurynotoidiformes are a little‐known group of actinopterygian fishes from the Permian of European Russia, characterized by the possession of multicuspid marginal teeth arranged in a single row. Morphologically, the teeth resemble those of Recent Cichlidae, Acanthuridae, Siganidae or Serrasalmidae, suggesting similar trophic adaptations related to herbivory. Tooth histology is similar to the majority of basal actinopterygians (composed of dentine, acrodin and collar enamel). Teeth are ankylosed in their attachment, and labial pleurodont in implantation, strengthening the tooth. The multicuspid tooth crowns derive from conical teeth of predatory or omnivorous ancestors, analogous to the evolution of multicuspid teeth in cichlid fishes. Tooth replacement in eurynotoidiforms is most comparable to an alternating pattern, with a possible simultaneous, unilateral replacement occurring in the whole jaw, similar to characiform fishes. Replacement teeth were formed extraosseously. Teeth of the inner dental arcade were conical. Based on comparisons with the teeth of extant actinopterygians specialized for herbivory, along with functional morphological analysis and consideration of wear patterns, we hypothesize that eurynotoidiforms represent the oldest known actinopterygians specialized for herbivory. Several strategies of herbivory in Recent actinopterygians were already realized by eurynotoidiforms as early as the Late Palaeozoic (middle and late Permian): grazing/cutting filamentous algae (<jats:italic>Lapkosubia</jats:italic> spp., <jats:italic>Isadia suchonensis</jats:italic>), browsing/biting off macrophyte fragments (<jats:italic>Isadia aristoviensis</jats:italic>), scraping/harvesting periphyton from hard substrates (<jats:italic>Isadia opokiensis</jats:italic>, <jats:italic>I. arefievi</jats:italic>). However, notable morphological differences in the jaws (elongate) and tooth arrangement (homodont along the jaw, functional teeth separated) suggest that this Permian experiment in herbivory followed different pathways compared to extant taxa.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":"329 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141193974","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}
Bing‐Cai Liu, Kai Wang, Jiao Bai, Yao Wang, Bing Huang, Hong‐He Xu
Dispersal, whether active or passive, plays a crucial role in biogeography by facilitating the movement of propagules away from their original location. Botanical geographical zonation, resulting from the co‐evolution of plants and their environment, has been established since the remarkable plant diversification during the Devonian Period (c. 419–359 Ma). However, a significant knowledge gap exists in understanding plant dispersal between living and fossil organisms due to the rarity of opportunities for tracing plant dispersal in geological history. In this study, we present evidence of two plant dispersal routes and verify their occurrence through the examination of geographical zonation, changes in plant diversity, and latitudinal and longitudinal gradients during the Devonian. We analyse global occurrence data from widely‐distributed and extensively‐studied Devonian plants. The two dispersal routes, namely clockwise and anticlockwise, connect the South China and Euramerica–Siberia realms. These routes clearly demonstrate inland and inter‐land dispersal models, closely linked to Devonian sea–land topography and dispersal vectors such as wind and ocean currents. Moreover, these models probably apply to all Devonian plants. Our comprehensive synthesis of plant dispersal in deep time reveals that propagule diversity and dispersal vectors have progressively increased and become more complex over time, facilitating plant colonization and diversity changes. Importantly, our study unveils the dispersal models of fossil plants, demonstrating the equivalent models observed in extant plants that have been established since the Devonian Period.
{"title":"Plant dispersal in the Devonian world (c. 419–359 Ma)","authors":"Bing‐Cai Liu, Kai Wang, Jiao Bai, Yao Wang, Bing Huang, Hong‐He Xu","doi":"10.1111/pala.12699","DOIUrl":"https://doi.org/10.1111/pala.12699","url":null,"abstract":"Dispersal, whether active or passive, plays a crucial role in biogeography by facilitating the movement of propagules away from their original location. Botanical geographical zonation, resulting from the co‐evolution of plants and their environment, has been established since the remarkable plant diversification during the Devonian Period (<jats:italic>c</jats:italic>. 419–359 Ma). However, a significant knowledge gap exists in understanding plant dispersal between living and fossil organisms due to the rarity of opportunities for tracing plant dispersal in geological history. In this study, we present evidence of two plant dispersal routes and verify their occurrence through the examination of geographical zonation, changes in plant diversity, and latitudinal and longitudinal gradients during the Devonian. We analyse global occurrence data from widely‐distributed and extensively‐studied Devonian plants. The two dispersal routes, namely clockwise and anticlockwise, connect the South China and Euramerica–Siberia realms. These routes clearly demonstrate inland and inter‐land dispersal models, closely linked to Devonian sea–land topography and dispersal vectors such as wind and ocean currents. Moreover, these models probably apply to all Devonian plants. Our comprehensive synthesis of plant dispersal in deep time reveals that propagule diversity and dispersal vectors have progressively increased and become more complex over time, facilitating plant colonization and diversity changes. Importantly, our study unveils the dispersal models of fossil plants, demonstrating the equivalent models observed in extant plants that have been established since the Devonian Period.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":"114 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140938178","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}
Maggie R. Limbeck, Jennifer E. Bauer, Bradley Deline, Colin D. Sumrall
Great strides have been made in understanding the phylogeny of the five extant echinoderm classes, however, many Palaeozoic groups have yet to be examined in a rigorous, quantitative framework. The aberrant morphologies of Paracrinoidea, an unusual group of Palaeozoic echinoderms, have hindered their inclusion in large‐scale phylogenetic and morphologic studies. This study uses a combined approach of phylogenetic analysis and morphological disparity to elucidate species relationships within the clade. Findings from this study suggest that Paracrinoidea is a monophyletic group and that respiratory structures, oral plate arrangement, and ambulacral morphologies are important for defining subclades within Paracrinoidea. Examination of paracrinoids in a quantitative framework, facilitates their inclusion in larger projects examining Palaeozoic echinoderm evolution, ecology and biogeography.
{"title":"Initial quantitative assessment of the enigmatic clade Paracrinoidea (Echinodermata)","authors":"Maggie R. Limbeck, Jennifer E. Bauer, Bradley Deline, Colin D. Sumrall","doi":"10.1111/pala.12695","DOIUrl":"https://doi.org/10.1111/pala.12695","url":null,"abstract":"Great strides have been made in understanding the phylogeny of the five extant echinoderm classes, however, many Palaeozoic groups have yet to be examined in a rigorous, quantitative framework. The aberrant morphologies of Paracrinoidea, an unusual group of Palaeozoic echinoderms, have hindered their inclusion in large‐scale phylogenetic and morphologic studies. This study uses a combined approach of phylogenetic analysis and morphological disparity to elucidate species relationships within the clade. Findings from this study suggest that Paracrinoidea is a monophyletic group and that respiratory structures, oral plate arrangement, and ambulacral morphologies are important for defining subclades within Paracrinoidea. Examination of paracrinoids in a quantitative framework, facilitates their inclusion in larger projects examining Palaeozoic echinoderm evolution, ecology and biogeography.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":"31 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140829562","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}
Benjamin F. Dattilo, Rebecca L. Freeman, Kyle Hartshorn, David Peterman, Aaron Morse, David L. Meyer, Lindsay G. Dougan, James W. Hagadorn
Strophomenoid brachiopods had thin, concavo‐convex shells, were ubiquitous colonizers of Palaeozoic muddy seafloors, and are hypothesized to have filter‐fed in a concave‐upward orientation. This orientation would elevate their line of commissure out of potentially lethal lophophore‐clogging mud. The paradox is that epibiont distributions on strophomenoids support a convex‐upward life position, as do studies of strophomenoid stability and trace fossils formed by strophomenoid sediment‐clearing. A premise of the concave‐upward orientation hypothesis is a narrow gape, which causes narrow, high velocity inhalant currents, leaving strophomenoids vulnerable to sediment entrainment. Herein we investigate the gape angle of Rafinesquina using serial thin sections and peels, silicified specimens, computer modelling, SEM analysis, x‐ray microCT, and 3D printing. Hinge line structure suggests that, conservatively, Rafinesquina could gape 40–45°. Such a gape occurred when diductor muscle contraction could not cause any further rotation, hinge teeth and crenulations were disengaged, and interareas interlocked. In contrast, when closed, hinge teeth were locked in hinge sockets. This wide gape eliminates constraints on feeding orientation. In either convex‐up or concave‐up orientation, Rafinesquina could feed with slow, diffuse inhalant currents incapable of disturbing sediment, and could snap valves shut to forcefully expel enough water to clear sediment from the mantle cavity, explaining previously described moat‐shaped trace fossils associated with shells. Our findings demonstrate that Rafinesquina gaped at an angle approximately equal to the angle between the two interareas when the valves are closed. Our analyses hint that other strophomenoids with similar interarea angles also lived with their shells widely agape.
{"title":"Paradox lost: wide gape in the Ordovician brachiopod Rafinesquina explains how unattached filter‐feeding strophomenoids thrived on muddy substrates","authors":"Benjamin F. Dattilo, Rebecca L. Freeman, Kyle Hartshorn, David Peterman, Aaron Morse, David L. Meyer, Lindsay G. Dougan, James W. Hagadorn","doi":"10.1111/pala.12697","DOIUrl":"https://doi.org/10.1111/pala.12697","url":null,"abstract":"Strophomenoid brachiopods had thin, concavo‐convex shells, were ubiquitous colonizers of Palaeozoic muddy seafloors, and are hypothesized to have filter‐fed in a concave‐upward orientation. This orientation would elevate their line of commissure out of potentially lethal lophophore‐clogging mud. The paradox is that epibiont distributions on strophomenoids support a convex‐upward life position, as do studies of strophomenoid stability and trace fossils formed by strophomenoid sediment‐clearing. A premise of the concave‐upward orientation hypothesis is a narrow gape, which causes narrow, high velocity inhalant currents, leaving strophomenoids vulnerable to sediment entrainment. Herein we investigate the gape angle of <jats:italic>Rafinesquina</jats:italic> using serial thin sections and peels, silicified specimens, computer modelling, SEM analysis, x‐ray microCT, and 3D printing. Hinge line structure suggests that, conservatively, <jats:italic>Rafinesquina</jats:italic> could gape 40–45°. Such a gape occurred when diductor muscle contraction could not cause any further rotation, hinge teeth and crenulations were disengaged, and interareas interlocked. In contrast, when closed, hinge teeth were locked in hinge sockets. This wide gape eliminates constraints on feeding orientation. In either convex‐up or concave‐up orientation, <jats:italic>Rafinesquina</jats:italic> could feed with slow, diffuse inhalant currents incapable of disturbing sediment, and could snap valves shut to forcefully expel enough water to clear sediment from the mantle cavity, explaining previously described moat‐shaped trace fossils associated with shells. Our findings demonstrate that <jats:italic>Rafinesquina</jats:italic> gaped at an angle approximately equal to the angle between the two interareas when the valves are closed. Our analyses hint that other strophomenoids with similar interarea angles also lived with their shells widely agape.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":"9 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140800584","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}
This research explores the significance of rapid burial in preserving fossils, with a particular focus on free‐living echinoderms. Experiments were based on ophiuroids to simulate burial under different turbiditic flows. The results showed that a bed thickness of around 10 cm is a limit for the preservation of whole skeletons in most cases. The type of sediment can affect the integrity of the buried skeletons, with sand deposition resulting in higher rates of autotomy. However, mud deposition did not show any numbing effect, as previously believed for echinoderms. In contrast, freshwater‐rich sediments can play a critical role, paralysing specimens and preventing escape postures through rapid changes in salinity. From this, the study highlights the importance of extrabasinal turbidites, generated outside the marine basin, in the fossilization of marine invertebrates. Such sediments are rich in fresh water and can be more efficient burial traps compared to other intrabasinal deposits generated by storm waves or submarine landslides.
{"title":"How does rapid burial work? New insights from experiments with echinoderms","authors":"Malton Carvalho Fraga, Cristina Silveira Vega","doi":"10.1111/pala.12698","DOIUrl":"https://doi.org/10.1111/pala.12698","url":null,"abstract":"This research explores the significance of rapid burial in preserving fossils, with a particular focus on free‐living echinoderms. Experiments were based on ophiuroids to simulate burial under different turbiditic flows. The results showed that a bed thickness of around 10 cm is a limit for the preservation of whole skeletons in most cases. The type of sediment can affect the integrity of the buried skeletons, with sand deposition resulting in higher rates of autotomy. However, mud deposition did not show any numbing effect, as previously believed for echinoderms. In contrast, freshwater‐rich sediments can play a critical role, paralysing specimens and preventing escape postures through rapid changes in salinity. From this, the study highlights the importance of extrabasinal turbidites, generated outside the marine basin, in the fossilization of marine invertebrates. Such sediments are rich in fresh water and can be more efficient burial traps compared to other intrabasinal deposits generated by storm waves or submarine landslides.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":"36 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140609591","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}
The Mediterranean Sea is recognized as a hotspot of marine biodiversity. Analysing its past biodiversity can help in understanding species' response to climate change. We built a species-level dataset of bivalve occurrences across the Zanclean–Calabrian interval, a time characterized by significant changes in climate, and by bivalve extinctions. The dataset includes more than 400 species distributed from the eastern to the western Mediterranean Sea. We measured changes in richness and turnover through time, for the entire dataset, and for different palaeoenvironments and combinations of tiering and feeding categories to test if specific environmental conditions and different lifestyles were correlated to species extinction or survival through time. We also compared niche breadth, geographical range size, and species abundance of extinct and extant species, to test which of these parameters potentially affected extinction risk. Our results confirm a loss of biodiversity between 3 Ma and the Early Pleistocene, although this loss was less intense and more gradual than previously estimated. We also found significant differences in niche breadth and geographical range size between extinct and extant species. Suspension feeders lost a higher proportion of species and suffered a higher reduction of geographical range compared to infaunal deposit feeders. Species loss was more protracted and higher on the shoreface than on the shelf, which is probably related to the reduction of shallow-water vegetated environments and to the disaggregation of heterozoan carbonate ramp habitats with cooling and sea-level drop at the onset of the northern hemisphere glaciation.
{"title":"Response of Mediterranean Sea bivalves to Pliocene–Pleistocene environmental changes","authors":"Alessandro Mondanaro, Stefano Dominici, Silvia Danise","doi":"10.1111/pala.12696","DOIUrl":"https://doi.org/10.1111/pala.12696","url":null,"abstract":"The Mediterranean Sea is recognized as a hotspot of marine biodiversity. Analysing its past biodiversity can help in understanding species' response to climate change. We built a species-level dataset of bivalve occurrences across the Zanclean–Calabrian interval, a time characterized by significant changes in climate, and by bivalve extinctions. The dataset includes more than 400 species distributed from the eastern to the western Mediterranean Sea. We measured changes in richness and turnover through time, for the entire dataset, and for different palaeoenvironments and combinations of tiering and feeding categories to test if specific environmental conditions and different lifestyles were correlated to species extinction or survival through time. We also compared niche breadth, geographical range size, and species abundance of extinct and extant species, to test which of these parameters potentially affected extinction risk. Our results confirm a loss of biodiversity between 3 Ma and the Early Pleistocene, although this loss was less intense and more gradual than previously estimated. We also found significant differences in niche breadth and geographical range size between extinct and extant species. Suspension feeders lost a higher proportion of species and suffered a higher reduction of geographical range compared to infaunal deposit feeders. Species loss was more protracted and higher on the shoreface than on the shelf, which is probably related to the reduction of shallow-water vegetated environments and to the disaggregation of heterozoan carbonate ramp habitats with cooling and sea-level drop at the onset of the northern hemisphere glaciation.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":"89 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140167007","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}
To reconstruct a fossil forest in three dimensions, an accurate estimation of tree height is crucial. However, modelling the height–diameter relationship of ancient trees is difficult, because the trunks of fossil trees are usually fragmentary, making direct height measurements impossible. One practical approach for reconstructing ancient tree height is to use growth models based on the height–diameter relationships of the nearest living relatives of fossil taxa. Here we apply 19 models to describe height–diameter relationships of living Araucaria trees for establishing appropriate models for ancient Araucariaceae trees. Data come from four living populations of Araucaria: A. bidwillii and A. cunninghamii in Queensland, Australia, and A. cunninghamii and A. hunsteinii in New Guinea. According to an AIC-based model selection, a power function with an exponent of 0.67 (termed here the modified Mosbrugger model) is found to be the most appropriate for each population and for the entire dataset (157 trees), but normalization constants differ across populations. To find the most appropriate models for the genus Araucaria, 100 random samples (each population generating 25 random samples) from the entire dataset are used. Based on 100 curve fitting results on each model and multiple performance criteria, three median models are generated from the medians of their parameter estimates. Of these, the median 2pPower model works best for Araucaria, but the modified Mosbrugger and Curtis models perform nearly as well. In a case study, we revise tree heights of Upper Jurassic araucariaceous logs in Utah, USA, by applying these three models.
{"title":"Modelling height–diameter relationships in living Araucaria (Araucariaceae) trees to reconstruct ancient araucarian conifer height","authors":"Aowei Xie, Carole T. Gee, Eva M. Griebeler","doi":"10.1111/pala.12693","DOIUrl":"https://doi.org/10.1111/pala.12693","url":null,"abstract":"To reconstruct a fossil forest in three dimensions, an accurate estimation of tree height is crucial. However, modelling the height–diameter relationship of ancient trees is difficult, because the trunks of fossil trees are usually fragmentary, making direct height measurements impossible. One practical approach for reconstructing ancient tree height is to use growth models based on the height–diameter relationships of the nearest living relatives of fossil taxa. Here we apply 19 models to describe height–diameter relationships of living <i>Araucaria</i> trees for establishing appropriate models for ancient Araucariaceae trees. Data come from four living populations of <i>Araucaria</i>: <i>A. bidwillii</i> and <i>A</i>. <i>cunninghamii</i> in Queensland, Australia, and <i>A</i>. <i>cunninghamii</i> and <i>A</i>. <i>hunsteinii</i> in New Guinea. According to an AIC-based model selection, a power function with an exponent of 0.67 (termed here the modified Mosbrugger model) is found to be the most appropriate for each population and for the entire dataset (157 trees), but normalization constants differ across populations. To find the most appropriate models for the genus <i>Araucaria</i>, 100 random samples (each population generating 25 random samples) from the entire dataset are used. Based on 100 curve fitting results on each model and multiple performance criteria, three median models are generated from the medians of their parameter estimates. Of these, the median 2pPower model works best for <i>Araucaria</i>, but the modified Mosbrugger and Curtis models perform nearly as well. In a case study, we revise tree heights of Upper Jurassic araucariaceous logs in Utah, USA, by applying these three models.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":"45 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140107389","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}
E.J. Huang, Jacob D. Wilson, Bhart‐Anjan S. Bhullar, Gabriel S. Bever
Body mass is a pivotal quantity in palaeobiology but must be inferred from an imperfect fossil record. We analyse the performance of regression models derived from various dentoskeletal predictors in mammals to inform fossils from the early, Mesozoic history of this radiation. Our focus is on the critical small end of the size spectrum; critical because the earliest mammals were small, because small size persisted onto the stems of the major extant radiations, and because small mammals compose a large proportion of crown diversity. The sampling strategy is diverse in terms of both phylogeny and skeletal predictors: the former allows a general application, while the latter enables comparison of various models. Linear regressions based on extant small mammals indicate a universal correlation of body mass with observed measurements, but with clear differences in precision. Postcranial predictors outperform jaw and dental metrics, with certain femoral joint dimensions providing surprisingly precise predictions. Our results indicate complex patterns of size evolution within the small‐bodied category, including the possibility that multiple Mesozoic species approached the theoretical lower limit of mammalian body size. The ability to study such dynamics only becomes possible when predicting body mass within a strict, highly focused phylogenetic context. The heuristic value of the models we provide here is not limited to the Mesozoic but is applicable to small‐bodied mammals of any geologic age.
{"title":"High‐precision body mass predictors for small mammals: a case study in the Mesozoic","authors":"E.J. Huang, Jacob D. Wilson, Bhart‐Anjan S. Bhullar, Gabriel S. Bever","doi":"10.1111/pala.12692","DOIUrl":"https://doi.org/10.1111/pala.12692","url":null,"abstract":"Body mass is a pivotal quantity in palaeobiology but must be inferred from an imperfect fossil record. We analyse the performance of regression models derived from various dentoskeletal predictors in mammals to inform fossils from the early, Mesozoic history of this radiation. Our focus is on the critical small end of the size spectrum; critical because the earliest mammals were small, because small size persisted onto the stems of the major extant radiations, and because small mammals compose a large proportion of crown diversity. The sampling strategy is diverse in terms of both phylogeny and skeletal predictors: the former allows a general application, while the latter enables comparison of various models. Linear regressions based on extant small mammals indicate a universal correlation of body mass with observed measurements, but with clear differences in precision. Postcranial predictors outperform jaw and dental metrics, with certain femoral joint dimensions providing surprisingly precise predictions. Our results indicate complex patterns of size evolution within the small‐bodied category, including the possibility that multiple Mesozoic species approached the theoretical lower limit of mammalian body size. The ability to study such dynamics only becomes possible when predicting body mass within a strict, highly focused phylogenetic context. The heuristic value of the models we provide here is not limited to the Mesozoic but is applicable to small‐bodied mammals of any geologic age.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":"103 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140043927","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}
<p>Novack-Gottshall, P. M., Purcell, J., Sultan, A., Ranjha, I., Deline, B. and Sumrall, C. D. 2024. <i>Palaeontology</i>, <b>67</b>, e12688.</p> <p>Figure 6 should illustrate echinoderm phyloecospace through the Cambrian and Ordovician periods using the time-scaled UEH phylogeny number 49 as an example, but instead shows the alternative representation using the EAT topology (and phylogeny no. 57; see Fig. S6). This is the correct Figure 6:</p> <figure><picture> <source media="(min-width: 1650px)" srcset="/cms/asset/badefd0a-96d6-4905-97b1-f3c05abeee19/pala12694-fig-0001-m.jpg"/><img alt="Details are in the caption following the image" data-lg-src="/cms/asset/badefd0a-96d6-4905-97b1-f3c05abeee19/pala12694-fig-0001-m.jpg" loading="lazy" src="/cms/asset/c44bab13-0db6-4b70-a3d0-68bd948b5a00/pala12694-fig-0001-m.png" title="Details are in the caption following the image"/></picture><figcaption> <div><strong>FIG. 6<span style="font-weight:normal"></span></strong><div>Open in figure viewer<i aria-hidden="true"></i><span>PowerPoint</span></div> </div> <div>Echinoderm phyloecospace through the Cambrian and Ordovician periods. Only the ecospace for the time-scaled UEH phylogeny number 49 is illustrated as one example; the remaining 49 time-scaled UEH phylogenies produce similar ordination structures. See Figure S6 for an alternative representation of ecospace using the EAT topology. Terreneuvian and Furongian epochs are plotted separately to the remaining Cambrian and Ordovician epochs to highlight changes occurring prior to diversification during the Cambrian and Ordovician radiations. First four principal coordinate (PCO) axes are illustrated, with each point representing some unique life habit, and colour-coded according to taxonomic class. The underlying time-scaled phylogeny represents the phylogenetic distribution of tip genera and ancestral nodes in the ecospace. The convex hull in each ordination is provided as a simple measure of overall ecospace occupied during each interval; the Terreneuvian and Furongian convex hulls are plotted as dashed lines in the subsequent temporal interval for comparison. Points are transparent to illustrate regions where multiple tips and ancestors overlap, with ancestral classes assigned when all descendants are assigned the same class, and with nodes illustrated as more transparent than tips. Taxonomic group ‘other’ includes the early blastoid <i>Macurdablastus</i>, coronate blastoid <i>Mespilocystites</i>, cyclocystoids, helicoplacoids, parablastoids, and taxa of uncertain class affiliation. The legend at bottom left illustrates the approximate positions of the four iconic ecological strategies mentioned in text. The first four axes account for 1.40, 0.40, 0.32, and 0.27% of explained relative eigenvalues in the 731-dimensional distance matrix. This figure is updated from Novack-Gottshall <i>et al</i>. (2022, fig. 2), which provides additional context.</div> </figcaption> </figure> <p>We apologize for this error.</p
Novack-Gottshall, P. M., Purcell, J., Sultan, A., Ranjha, I., Deline, B. and Sumrall, C. D. 2024.图 6 应该以第 49 号 UEH 系统发生的时间尺度为例说明棘皮动物在寒武纪和奥陶纪的植物空间，但却显示了使用 EAT 拓扑（和第 57 号系统发生；见图 S6）的另一种表示方法。这才是正确的图 6：FIG. 6Open in figure viewerPowerPoint棘皮动物在寒武纪和奥陶纪的植物生态空间。仅以第 49 个时间标度的 UEH 系统发生的生态空间为例进行说明；其余 49 个时间标度的 UEH 系统发生也产生了类似的排序结构。使用 EAT 拓扑的另一种生态空间表示方法见图 S6。特雷努维纪和芙蓉纪与剩余的寒武纪和奥陶纪分开绘制，以突出寒武纪和奥陶纪辐射期间分化之前发生的变化。图中显示了前四个主坐标（PCO）轴，每个点都代表某种独特的生活习性，并根据分类学类别用不同颜色标注。底层的时间尺度系统发生代表了生态空间中尖端属和祖先节点的系统发生分布。每个排序中的凸壳是对每个时间间隔内整体生态空间占据情况的简单衡量；在随后的时间间隔内，特雷努维亚凸壳和芙蓉亚凸壳被绘制成虚线，以便比较。点是透明的，以说明多个顶端和祖先重叠的区域，当所有后代被分配到同一类别时，祖先类别也被分配到，节点比顶端更透明。其他 "分类群包括早期胀大藻类 Macurdablastus、冠状胀大藻类 Mespilocystites、环囊藻类、helicoplacoids、parablastoids 以及分类群归属不确定的类群。左下方的图例说明了文中提到的四种标志性生态策略的大致位置。前四条轴线分别占 731 维距离矩阵中相对特征值的 1.40%、0.40%、0.32% 和 0.27%。本图根据 Novack-Gottshall 等人（2022 年，图 2）更新。(2022，图 2）更新而来，它提供了更多的背景信息。我们对这一错误表示歉意。
{"title":"Correction to ‘Ecological novelty at the start of the Cambrian and Ordovician radiations of echinoderms’","authors":"","doi":"10.1111/pala.12694","DOIUrl":"https://doi.org/10.1111/pala.12694","url":null,"abstract":"<p>Novack-Gottshall, P. M., Purcell, J., Sultan, A., Ranjha, I., Deline, B. and Sumrall, C. D. 2024. <i>Palaeontology</i>, <b>67</b>, e12688.</p>\u0000<p>Figure 6 should illustrate echinoderm phyloecospace through the Cambrian and Ordovician periods using the time-scaled UEH phylogeny number 49 as an example, but instead shows the alternative representation using the EAT topology (and phylogeny no. 57; see Fig. S6). This is the correct Figure 6:</p>\u0000<figure><picture>\u0000<source media=\"(min-width: 1650px)\" srcset=\"/cms/asset/badefd0a-96d6-4905-97b1-f3c05abeee19/pala12694-fig-0001-m.jpg\"/><img alt=\"Details are in the caption following the image\" data-lg-src=\"/cms/asset/badefd0a-96d6-4905-97b1-f3c05abeee19/pala12694-fig-0001-m.jpg\" loading=\"lazy\" src=\"/cms/asset/c44bab13-0db6-4b70-a3d0-68bd948b5a00/pala12694-fig-0001-m.png\" title=\"Details are in the caption following the image\"/></picture><figcaption>\u0000<div><strong>FIG. 6<span style=\"font-weight:normal\"></span></strong><div>Open in figure viewer<i aria-hidden=\"true\"></i><span>PowerPoint</span></div>\u0000</div>\u0000<div>Echinoderm phyloecospace through the Cambrian and Ordovician periods. Only the ecospace for the time-scaled UEH phylogeny number 49 is illustrated as one example; the remaining 49 time-scaled UEH phylogenies produce similar ordination structures. See Figure S6 for an alternative representation of ecospace using the EAT topology. Terreneuvian and Furongian epochs are plotted separately to the remaining Cambrian and Ordovician epochs to highlight changes occurring prior to diversification during the Cambrian and Ordovician radiations. First four principal coordinate (PCO) axes are illustrated, with each point representing some unique life habit, and colour-coded according to taxonomic class. The underlying time-scaled phylogeny represents the phylogenetic distribution of tip genera and ancestral nodes in the ecospace. The convex hull in each ordination is provided as a simple measure of overall ecospace occupied during each interval; the Terreneuvian and Furongian convex hulls are plotted as dashed lines in the subsequent temporal interval for comparison. Points are transparent to illustrate regions where multiple tips and ancestors overlap, with ancestral classes assigned when all descendants are assigned the same class, and with nodes illustrated as more transparent than tips. Taxonomic group ‘other’ includes the early blastoid <i>Macurdablastus</i>, coronate blastoid <i>Mespilocystites</i>, cyclocystoids, helicoplacoids, parablastoids, and taxa of uncertain class affiliation. The legend at bottom left illustrates the approximate positions of the four iconic ecological strategies mentioned in text. The first four axes account for 1.40, 0.40, 0.32, and 0.27% of explained relative eigenvalues in the 731-dimensional distance matrix. This figure is updated from Novack-Gottshall <i>et al</i>. (2022, fig. 2), which provides additional context.</div>\u0000</figcaption>\u0000</figure>\u0000<p>We apologize for this error.</p","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":"49 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139948463","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}
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