Thalattosuchia (Early Jurassic to Early Cretaceous) and Dyrosauridea (Late Cretaceous to Early Eocene) are crocodylomorph archosaurs which diversified in fluvial and marine environments and endured extinction events (i.e. Jurassic–Cretaceous boundary for Thalattosuchia; Cretaceous–Palaeogene for Dyrosauridea). Their postcrania remain globally undervalued in anatomical descriptions and diagnoses, shrouding the locomotive adaptations that possibly underpinned their radiations and longevity. We thoroughly surveyed the postcranial morphology of Dyrosauridea and Thalattosuchia, recreated their girdles in three‐dimensions using tens of high‐precisions 3D scans, and analysed their shape using geometric morphometrics. Dyrosauridea and Thalattosuchia have clearly distinct postcrania, even when found within similar environments, suggesting the existence of clade‐specific features limiting the strength of evolutionary convergence. Moreover, the range of postcranial morphologies evolved by dyrosaurids and thalattosuchians is large compared to extant crocodylians, making the latter unsatisfactory functional analogues for every group of extinct crocodylomorphs. Our work reveals the previously unsuspected potential of postcranial anatomy as an abundant source of phylogenetic and taxonomic characters to assess the relationships within Crocodylomorpha. Incorporation of postcranial anatomy therefore appears crucial to fully assess the ecology, disparity, and relationships of crocodylomorphs.
{"title":"Limited convergence in the postcranium of aquatic Crocodylomorpha","authors":"Isaure Scavezzoni, Valentin Fischer","doi":"10.1111/pala.12678","DOIUrl":"https://doi.org/10.1111/pala.12678","url":null,"abstract":"Thalattosuchia (Early Jurassic to Early Cretaceous) and Dyrosauridea (Late Cretaceous to Early Eocene) are crocodylomorph archosaurs which diversified in fluvial and marine environments and endured extinction events (i.e. Jurassic–Cretaceous boundary for Thalattosuchia; Cretaceous–Palaeogene for Dyrosauridea). Their postcrania remain globally undervalued in anatomical descriptions and diagnoses, shrouding the locomotive adaptations that possibly underpinned their radiations and longevity. We thoroughly surveyed the postcranial morphology of Dyrosauridea and Thalattosuchia, recreated their girdles in three‐dimensions using tens of high‐precisions 3D scans, and analysed their shape using geometric morphometrics. Dyrosauridea and Thalattosuchia have clearly distinct postcrania, even when found within similar environments, suggesting the existence of clade‐specific features limiting the strength of evolutionary convergence. Moreover, the range of postcranial morphologies evolved by dyrosaurids and thalattosuchians is large compared to extant crocodylians, making the latter unsatisfactory functional analogues for every group of extinct crocodylomorphs. Our work reveals the previously unsuspected potential of postcranial anatomy as an abundant source of phylogenetic and taxonomic characters to assess the relationships within Crocodylomorpha. Incorporation of postcranial anatomy therefore appears crucial to fully assess the ecology, disparity, and relationships of crocodylomorphs.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":"87 3-4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135715487","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}
Joëlle Barido‐Sottani, Alexander Pohle, Kenneth De Baets, Duncan Murdock, Rachel C. M. Warnock
Abstract The fossilized birth–death (FBD) process provides an ideal model for inferring phylogenies from both extant and fossil taxa. Using this approach, fossils are directly integrated into the tree, leading to a statistically coherent prior on divergence times. Since fossils are typically not associated with molecular sequences, additional information is required to place fossils in the tree. We use simulations to evaluate two different approaches to handling fossil placement in FBD analyses: using topological constraints, where the user specifies monophyletic clades based on established taxonomy, or using total‐evidence analyses, which use a morphological data matrix in addition to the molecular alignment. We also explore how rate variation in fossil recovery or diversification rates impacts these approaches. We find that the extant topology is well recovered under all methods of fossil placement. Divergence times are similarly well recovered across all methods, with the exception of constraints which contain errors. We see similar patterns in datasets which include rate variation, however, relative errors in extant divergence times increase when more variation is included in the dataset, for all approaches using topological constraints, and particularly for constraints with errors. Finally, we show that trees recovered under the FBD model are more accurate than those estimated using non‐time calibrated inference. Overall, we show that both fossil placement approaches are reliable even when including uncertainty. Our results underscore the importance of core taxonomic research, including morphological data collection and species descriptions, irrespective of the approach to handling phylogenetic uncertainty using the FBD process.
{"title":"Putting the F into <scp>FBD</scp> analysis: tree constraints or morphological data?","authors":"Joëlle Barido‐Sottani, Alexander Pohle, Kenneth De Baets, Duncan Murdock, Rachel C. M. Warnock","doi":"10.1111/pala.12679","DOIUrl":"https://doi.org/10.1111/pala.12679","url":null,"abstract":"Abstract The fossilized birth–death (FBD) process provides an ideal model for inferring phylogenies from both extant and fossil taxa. Using this approach, fossils are directly integrated into the tree, leading to a statistically coherent prior on divergence times. Since fossils are typically not associated with molecular sequences, additional information is required to place fossils in the tree. We use simulations to evaluate two different approaches to handling fossil placement in FBD analyses: using topological constraints, where the user specifies monophyletic clades based on established taxonomy, or using total‐evidence analyses, which use a morphological data matrix in addition to the molecular alignment. We also explore how rate variation in fossil recovery or diversification rates impacts these approaches. We find that the extant topology is well recovered under all methods of fossil placement. Divergence times are similarly well recovered across all methods, with the exception of constraints which contain errors. We see similar patterns in datasets which include rate variation, however, relative errors in extant divergence times increase when more variation is included in the dataset, for all approaches using topological constraints, and particularly for constraints with errors. Finally, we show that trees recovered under the FBD model are more accurate than those estimated using non‐time calibrated inference. Overall, we show that both fossil placement approaches are reliable even when including uncertainty. Our results underscore the importance of core taxonomic research, including morphological data collection and species descriptions, irrespective of the approach to handling phylogenetic uncertainty using the FBD process.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":"33 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135715161","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}
Alessio Fabbrini, Mattia Greco, Francesco Iacoviello, Michal Kucera, Thomas H.G. Ezard, Bridget S. Wade
Abstract We conducted a morphometric study and wall texture analysis on extant and fossil specimens of the planktonic foraminifera Globigerina falconensis plexus. Our global data reveal morphological inconsistencies between fossil and extant populations. Our results are significant as G. falconensis is widely used in palaeoceanographic studies in conjunction with its sister taxon G. bulloides . Morphologically these two species are similar, with the main difference being the distinctive apertural lip present in G . falconensis . We selected cores covering the entire stratigraphic range of G . falconensis , from the early Miocene to current day, spanning sites from high latitudes in the North Atlantic Ocean and the southern Indian Ocean to sites in equatorial regions. The morphology found in the modern ocean is not consistent with the Miocene holotype of Globigerina falconensis Blow described from lower Miocene sediments in Venezuela. A more lobate morphology evolved in the late Miocene, thus, a new name is required for this morphotype, coexisting in the modern oceans with G . falconensis s.s . We thus describe the new morphospecies, G . neofalconensis for the more lobate forms which evolved in the late Miocene and inhabit the modern oceans. Additionally, we report a pseudocancellate wall texture present in the G . falconensis plexus. We use the molecular sequences from the PR 2 database to explore the generic attribution of the G . falconensis lineage, confirming its close relationship with G . bulloides and its retention in the genus Globigerina .
{"title":"Bridging the extant and fossil record of planktonic foraminifera: implications for the <i>Globigerina</i> lineage","authors":"Alessio Fabbrini, Mattia Greco, Francesco Iacoviello, Michal Kucera, Thomas H.G. Ezard, Bridget S. Wade","doi":"10.1111/pala.12676","DOIUrl":"https://doi.org/10.1111/pala.12676","url":null,"abstract":"Abstract We conducted a morphometric study and wall texture analysis on extant and fossil specimens of the planktonic foraminifera Globigerina falconensis plexus. Our global data reveal morphological inconsistencies between fossil and extant populations. Our results are significant as G. falconensis is widely used in palaeoceanographic studies in conjunction with its sister taxon G. bulloides . Morphologically these two species are similar, with the main difference being the distinctive apertural lip present in G . falconensis . We selected cores covering the entire stratigraphic range of G . falconensis , from the early Miocene to current day, spanning sites from high latitudes in the North Atlantic Ocean and the southern Indian Ocean to sites in equatorial regions. The morphology found in the modern ocean is not consistent with the Miocene holotype of Globigerina falconensis Blow described from lower Miocene sediments in Venezuela. A more lobate morphology evolved in the late Miocene, thus, a new name is required for this morphotype, coexisting in the modern oceans with G . falconensis s.s . We thus describe the new morphospecies, G . neofalconensis for the more lobate forms which evolved in the late Miocene and inhabit the modern oceans. Additionally, we report a pseudocancellate wall texture present in the G . falconensis plexus. We use the molecular sequences from the PR 2 database to explore the generic attribution of the G . falconensis lineage, confirming its close relationship with G . bulloides and its retention in the genus Globigerina .","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":"46 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135564547","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}
Valentin Bault, C. Crônier, C. Monnet, Diego Balseiro, Fernanda Serra, B. Waisfeld, Arnaud Bignon, J. Rustán
Phacopidae were a successful family of the Silurian–Devonian period. Although their diversity trends are well identified, their shape evolution is unknown; their morphology often considered to be conservative. We have quantified these morphologies using geometric morphometrics (landmarks) and investigated their evolution using morphological disparity indices. Results identified morphological variations between the genera, and through time. Phacopids differ from each other by the position of the facial suture linked to the size of the visual complex, the shape of the genal angle and the elongation of both cephalon and pygidium. The morphological disparity of cephala was high from the Silurian, contrary to that of pygidia. Subsequently, the morphological disparity increased in the Early Devonian with the development of narrow cephala and triangular pygidia. Morphological disparity was greater in the Emsian for both cephala and pygidia, more than 50 myr after the origination of phacopids. It constituted a perfect example illustrating that a peak of biodiversity does not necessarily happen in the early history of a clade. Subsequently, a strong decrease of morphological disparity occurred in the Middle Devonian, in conjunction with sea‐level changes and anoxic events. Taxonomic richness and morphological disparity declined strongly in the Givetian, in a non‐random extinction affecting particularly blind genera. The morphological disparity remained low in the Frasnian despite progressive eye reduction influenced by environmental changes. An extensive recovery occurred in the Famennian with an important increase of both taxonomic and morphological diversity. The Hangenberg event caused the final extinction of phacopids.
{"title":"Rise and fall of the phacopids: the morphological history of a successful trilobite family","authors":"Valentin Bault, C. Crônier, C. Monnet, Diego Balseiro, Fernanda Serra, B. Waisfeld, Arnaud Bignon, J. Rustán","doi":"10.1111/pala.12673","DOIUrl":"https://doi.org/10.1111/pala.12673","url":null,"abstract":"Phacopidae were a successful family of the Silurian–Devonian period. Although their diversity trends are well identified, their shape evolution is unknown; their morphology often considered to be conservative. We have quantified these morphologies using geometric morphometrics (landmarks) and investigated their evolution using morphological disparity indices. Results identified morphological variations between the genera, and through time. Phacopids differ from each other by the position of the facial suture linked to the size of the visual complex, the shape of the genal angle and the elongation of both cephalon and pygidium. The morphological disparity of cephala was high from the Silurian, contrary to that of pygidia. Subsequently, the morphological disparity increased in the Early Devonian with the development of narrow cephala and triangular pygidia. Morphological disparity was greater in the Emsian for both cephala and pygidia, more than 50 myr after the origination of phacopids. It constituted a perfect example illustrating that a peak of biodiversity does not necessarily happen in the early history of a clade. Subsequently, a strong decrease of morphological disparity occurred in the Middle Devonian, in conjunction with sea‐level changes and anoxic events. Taxonomic richness and morphological disparity declined strongly in the Givetian, in a non‐random extinction affecting particularly blind genera. The morphological disparity remained low in the Frasnian despite progressive eye reduction influenced by environmental changes. An extensive recovery occurred in the Famennian with an important increase of both taxonomic and morphological diversity. The Hangenberg event caused the final extinction of phacopids.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":"1 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48540804","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}
Edna Rodríguez‐Sánchez, Jesús Alvarado‐Ortega, Bruno A. Than‐Marchese
Abstract Evolutionary radiation is a problematic concept whose definition and classification have recently changed. Radiations can be defined as the pattern of abrupt increase in diversity of a lineage. It is relevant to evaluate the presence and interaction of different types of radiation in extant and fossil organisms to adequately delimitate the radiation types and to know the diversity in the context of Earth's history. Here, we employed the superorder Clupeomorpha at the Early–Late Cretaceous boundary as a study case to investigate radiation types and their interactions, using both taxic and morphological approaches. Clupeomorpha is an extensively studied, diverse and ancient teleostean superorder with wide geographical and ecological distributions. We propose a model for calculating rates of origination in order to analyse the taxic diversification and employ geometric morphometrics to analyse the morphological diversification that occurred at the temporal boundary. The results suggest the absence of taxic radiation due to a constant increase in taxon origination. However, the expansion of the phylomorphospace occupation and the disparity increase suggest the presence of a ‘climatic–geographical’ or ‘broad diversification‐like’ disparity, according to current classifications. This illustrates the incompatibility of current radiation classifications with this case study.
{"title":"Taxic and morphological diversification during the early radiation of Clupeomorpha (Actinopterygii, Teleostei)","authors":"Edna Rodríguez‐Sánchez, Jesús Alvarado‐Ortega, Bruno A. Than‐Marchese","doi":"10.1111/pala.12675","DOIUrl":"https://doi.org/10.1111/pala.12675","url":null,"abstract":"Abstract Evolutionary radiation is a problematic concept whose definition and classification have recently changed. Radiations can be defined as the pattern of abrupt increase in diversity of a lineage. It is relevant to evaluate the presence and interaction of different types of radiation in extant and fossil organisms to adequately delimitate the radiation types and to know the diversity in the context of Earth's history. Here, we employed the superorder Clupeomorpha at the Early–Late Cretaceous boundary as a study case to investigate radiation types and their interactions, using both taxic and morphological approaches. Clupeomorpha is an extensively studied, diverse and ancient teleostean superorder with wide geographical and ecological distributions. We propose a model for calculating rates of origination in order to analyse the taxic diversification and employ geometric morphometrics to analyse the morphological diversification that occurred at the temporal boundary. The results suggest the absence of taxic radiation due to a constant increase in taxon origination. However, the expansion of the phylomorphospace occupation and the disparity increase suggest the presence of a ‘climatic–geographical’ or ‘broad diversification‐like’ disparity, according to current classifications. This illustrates the incompatibility of current radiation classifications with this case study.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135691385","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}
Shumin Liu, Zhiheng Li, Di Liu, Jingmai K. O'Connor
Abstract Some birds intentionally ingest stones to facilitate digestion of hard foodstuffs, a behaviour inherited from non‐avian dinosaurs and present in some of the earliest birds, as evidenced by clusters of gastroliths preserved within the abdominal cavity of a wide range of dinosaurs and Cretaceous birds. For the first time, high‐resolution computed laminographic and computed tomographic scans were used to reconstruct the gastral mass in two species of non‐neornithine ornithuromorph birds from the Lower Cretaceous Jehol Group. Four specimens of each taxon were analysed. Preservation of the gastral mass in most of these specimens is in situ and regarded as complete or nearly so. The number of gastroliths, their total volume, and their total mass relative to the estimated body mass were calculated for each specimen. The resultant gastral mass to body mass ratios fall within the range observed in extant birds, supporting previous inferences that the digestive system in non‐neornithine ornithuromorphs was comparable to that of extant taxa. Compared to available data for non‐volant non‐avian theropods, the gastral mass is proportionately smaller in birds suggesting that the evolution of flight constrained gastral mass size in the theropod lineage. Currently available data on gastral mass characteristics suggests that Iteravis ate larger food particles compared to Archaeorhynchus but cannot be used to determine diet more precisely. Better understanding of the relationship between gastral mass characteristics and food items across a broader range of extant taxa may provide an indirect but important method through which to infer diet and digestive function in archosaurs.
{"title":"Quantifying the gastral mass in Early Cretaceous ornithuromorphs (Aves, Ornithothoraces) from the Jehol avifauna","authors":"Shumin Liu, Zhiheng Li, Di Liu, Jingmai K. O'Connor","doi":"10.1111/pala.12677","DOIUrl":"https://doi.org/10.1111/pala.12677","url":null,"abstract":"Abstract Some birds intentionally ingest stones to facilitate digestion of hard foodstuffs, a behaviour inherited from non‐avian dinosaurs and present in some of the earliest birds, as evidenced by clusters of gastroliths preserved within the abdominal cavity of a wide range of dinosaurs and Cretaceous birds. For the first time, high‐resolution computed laminographic and computed tomographic scans were used to reconstruct the gastral mass in two species of non‐neornithine ornithuromorph birds from the Lower Cretaceous Jehol Group. Four specimens of each taxon were analysed. Preservation of the gastral mass in most of these specimens is in situ and regarded as complete or nearly so. The number of gastroliths, their total volume, and their total mass relative to the estimated body mass were calculated for each specimen. The resultant gastral mass to body mass ratios fall within the range observed in extant birds, supporting previous inferences that the digestive system in non‐neornithine ornithuromorphs was comparable to that of extant taxa. Compared to available data for non‐volant non‐avian theropods, the gastral mass is proportionately smaller in birds suggesting that the evolution of flight constrained gastral mass size in the theropod lineage. Currently available data on gastral mass characteristics suggests that Iteravis ate larger food particles compared to Archaeorhynchus but cannot be used to determine diet more precisely. Better understanding of the relationship between gastral mass characteristics and food items across a broader range of extant taxa may provide an indirect but important method through which to infer diet and digestive function in archosaurs.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135735457","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}
D. Fredrik K. Söderblom, Alejandro Blanco, Albert Prieto‐Márquez, Nicolás E. Campione
Abstract The near‐global distribution of hadrosaurid dinosaurs during the Cretaceous has been attributed to mastication, a behaviour commonly recognized as a mammalian adaptation. Its occurrence in a non‐mammalian lineage should be accompanied by the evolution of several morphological modifications associated with food acquisition and processing. This study investigated morphological variation in the dentary, a major element of the hadrosauroid lower jaw. Eighty‐four hadrosauroid dentaries were subjected to geometric morphometric and statistical analyses to investigate their taxonomic, ontogenetic, and individual variation. Results suggest increased food acquisition and processing efficiency in saurolophids through a complex pattern of evolutionary and growth‐related changes. The edentulous region grew longer relative to dentary length, allowing for food acquisition specialization anteriorly and processing posteriorly, and became ventrally directed, possibly associated with foraging low‐growing vegetation, especially in younger individuals. The saurolophid coronoid process became anteriorly directed and relatively more elongate, with an expanded apex, increasing moment arm length, with muscles pulling the jaw more posteriorly, increasing mechanical advantage. During growth, all hadrosauroids underwent anteroposterior dental battery elongation by the addition of teeth, and edentulous region ventralization decreased. The dental battery became deeper in saurolophids by increasing the number of teeth per tooth family. The increased coronoid process anterior inclination and relative edentulous region elongation in saurolophids are hypothesized to have evolved through hypermorphosis and/or acceleration, peramorphic heterochronic processes; the development of an anteroposteriorly shorter but dorsoventrally taller saurolophid dentary, is probably due to post‐displacement in dental battery elongation and edentulous region decreased ventral orientation, a paedomorphic heterochronic process.
{"title":"The dentary of hadrosauroid dinosaurs: evolution through heterochrony","authors":"D. Fredrik K. Söderblom, Alejandro Blanco, Albert Prieto‐Márquez, Nicolás E. Campione","doi":"10.1111/pala.12674","DOIUrl":"https://doi.org/10.1111/pala.12674","url":null,"abstract":"Abstract The near‐global distribution of hadrosaurid dinosaurs during the Cretaceous has been attributed to mastication, a behaviour commonly recognized as a mammalian adaptation. Its occurrence in a non‐mammalian lineage should be accompanied by the evolution of several morphological modifications associated with food acquisition and processing. This study investigated morphological variation in the dentary, a major element of the hadrosauroid lower jaw. Eighty‐four hadrosauroid dentaries were subjected to geometric morphometric and statistical analyses to investigate their taxonomic, ontogenetic, and individual variation. Results suggest increased food acquisition and processing efficiency in saurolophids through a complex pattern of evolutionary and growth‐related changes. The edentulous region grew longer relative to dentary length, allowing for food acquisition specialization anteriorly and processing posteriorly, and became ventrally directed, possibly associated with foraging low‐growing vegetation, especially in younger individuals. The saurolophid coronoid process became anteriorly directed and relatively more elongate, with an expanded apex, increasing moment arm length, with muscles pulling the jaw more posteriorly, increasing mechanical advantage. During growth, all hadrosauroids underwent anteroposterior dental battery elongation by the addition of teeth, and edentulous region ventralization decreased. The dental battery became deeper in saurolophids by increasing the number of teeth per tooth family. The increased coronoid process anterior inclination and relative edentulous region elongation in saurolophids are hypothesized to have evolved through hypermorphosis and/or acceleration, peramorphic heterochronic processes; the development of an anteroposteriorly shorter but dorsoventrally taller saurolophid dentary, is probably due to post‐displacement in dental battery elongation and edentulous region decreased ventral orientation, a paedomorphic heterochronic process.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135736735","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}
Pub Date : 2023-07-26eCollection Date: 2023-07-01DOI: 10.1111/pala.12669
Giuseppe Marramà, Eduardo Villalobos-Segura, Roberto Zorzin, Jürgen Kriwet, Giorgio Carnevale
Studies of the origin of evolutionary novelties (novel traits, feeding modes, behaviours, ecological niches, etc.) have considered a number of taxa experimenting with new body plans, allowing them to occupy new habitats and exploit new trophic resources. In the marine realm, colonization of pelagic environments by marine fishes occurred recurrently through time. Stingrays (Myliobatiformes) are a diverse clade of batoid fishes commonly known to possess venomous tail stings. Current hypotheses suggest that stingrays experimented with a transition from a benthic to a pelagic/benthopelagic habitat coupled with a transition from a non-durophagous diet to extreme durophagy. However, there is no study detailing macroevolutionary patterns to understand how and when habitat shift and feeding specialization arose along their evolutionary history. A new exquisitely preserved fossil stingray from the Eocene Konservat-Lagerstätte of Bolca (Italy) exhibits a unique mosaic of plesiomorphic features of the rajobenthic ecomorph, and derived traits of aquilopelagic taxa, that helps to clarify the evolutionary origin of durophagy and pelagic lifestyle in stingrays. A scenario of early evolution of the aquilopelagic ecomorph is proposed based on new data, and the possible adaptive meaning of the observed evolutionary changes is discussed. The body plan of †Dasyomyliobatis thomyorkei gen. et sp. nov. is intermediate between the rajobenthic and more derived aquilopelagic stingrays, supporting its stem phylogenetic position and the hypothesis that the aquilopelagic body plan arose in association with the evolution of durophagy and pelagic lifestyle from a benthic, soft-prey feeder ancestor.
对新物种（新性状、摄食模式、行为、生态位等）进化起源的研究考虑到了许多类群尝试新的身体结构，使它们能够占据新的栖息地和利用新的营养资源。在海洋领域，海洋鱼类在水层环境中的殖民活动随着时间的推移不断发生。黄貂鱼（Myliobatiformes）是种类繁多的蝙蝠科鱼类，通常拥有有毒的尾刺。目前的假说认为，黄貂鱼经历了从底栖过渡到中上层/底层栖息地的过程，同时也经历了从非嗜黑性食物过渡到极端嗜黑性食物的过程。然而，目前还没有详细的宏观进化模式研究来了解栖息地的转变和摄食的专业化是如何以及何时在其进化史上出现的。来自意大利博尔卡始新世Konservat-Lagerstätte的一个新的保存完好的黄貂鱼化石展示了独特的rajobenthic ecomorph的多形性特征，以及水层类群的衍生特征，有助于澄清黄貂鱼嗜黑和水层生活方式的进化起源。根据新的数据提出了水层拟态的早期进化方案，并讨论了观察到的进化变化可能具有的适应意义。†Dasyomyliobatis thomyorkei gen. et sp. nov.的体表介于底栖黄貂鱼和更进化的水层黄貂鱼之间，支持其系统发育干系位置，以及水层黄貂鱼的体表与底栖软食祖先的黑鳃和中上层生活方式的进化相关联的假说。
{"title":"The evolutionary origin of the durophagous pelagic stingray ecomorph.","authors":"Giuseppe Marramà, Eduardo Villalobos-Segura, Roberto Zorzin, Jürgen Kriwet, Giorgio Carnevale","doi":"10.1111/pala.12669","DOIUrl":"10.1111/pala.12669","url":null,"abstract":"<p><p>Studies of the origin of evolutionary novelties (novel traits, feeding modes, behaviours, ecological niches, etc.) have considered a number of taxa experimenting with new body plans, allowing them to occupy new habitats and exploit new trophic resources. In the marine realm, colonization of pelagic environments by marine fishes occurred recurrently through time. Stingrays (Myliobatiformes) are a diverse clade of batoid fishes commonly known to possess venomous tail stings. Current hypotheses suggest that stingrays experimented with a transition from a benthic to a pelagic/benthopelagic habitat coupled with a transition from a non-durophagous diet to extreme durophagy. However, there is no study detailing macroevolutionary patterns to understand how and when habitat shift and feeding specialization arose along their evolutionary history. A new exquisitely preserved fossil stingray from the Eocene Konservat-Lagerstätte of Bolca (Italy) exhibits a unique mosaic of plesiomorphic features of the rajobenthic ecomorph, and derived traits of aquilopelagic taxa, that helps to clarify the evolutionary origin of durophagy and pelagic lifestyle in stingrays. A scenario of early evolution of the aquilopelagic ecomorph is proposed based on new data, and the possible adaptive meaning of the observed evolutionary changes is discussed. The body plan of †<i>Dasyomyliobatis thomyorkei</i> gen. et sp. nov. is intermediate between the rajobenthic and more derived aquilopelagic stingrays, supporting its stem phylogenetic position and the hypothesis that the aquilopelagic body plan arose in association with the evolution of durophagy and pelagic lifestyle from a benthic, soft-prey feeder ancestor.</p>","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":"66 4","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7614867/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10307918","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}
P. Nätscher, Jana Gliwa, K. De Baets, A. Ghaderi, D. Korn
The body size of marine ectotherms is often negatively correlated with ambient water temperature, as seen in many clades during the hyperthermal crisis of the end‐Permian mass extinction (c. 252 Ma). However, in the case of ostracods, size changes during ancient hyperthermal events are rarely quantified. In this study, we evaluate the body size changes of ostracods in the Aras Valley section (northwest Iran) in response to the drastic warming during the end‐Permian mass extinction at three taxonomic levels: class, order, species. At the assemblage level, the warming triggers a complete species turnover in the Aras Valley section, with larger, newly emerging species dominating the immediate post‐extinction assemblage for a short time. Individual ostracod species and instars do not show dwarfing or a change in body size as an adaptation to the temperature stress during the end‐Permian crisis. This may indicate that the ostracods in the Aras Valley section might have been exceptions to the temperature–size rule (TSR), using an adaptation mechanism that does not involve a decrease in body size. This adaptation might be similar to the accelerated development despite constant instar body sizes that can be observed in some recent experimental studies of ostracod responses to thermal stress.
{"title":"Exceptions to the temperature–size rule: no Lilliput Effect in end‐Permian ostracods (Crustacea) from Aras Valley (northwest Iran)","authors":"P. Nätscher, Jana Gliwa, K. De Baets, A. Ghaderi, D. Korn","doi":"10.1111/pala.12667","DOIUrl":"https://doi.org/10.1111/pala.12667","url":null,"abstract":"The body size of marine ectotherms is often negatively correlated with ambient water temperature, as seen in many clades during the hyperthermal crisis of the end‐Permian mass extinction (c. 252 Ma). However, in the case of ostracods, size changes during ancient hyperthermal events are rarely quantified. In this study, we evaluate the body size changes of ostracods in the Aras Valley section (northwest Iran) in response to the drastic warming during the end‐Permian mass extinction at three taxonomic levels: class, order, species. At the assemblage level, the warming triggers a complete species turnover in the Aras Valley section, with larger, newly emerging species dominating the immediate post‐extinction assemblage for a short time. Individual ostracod species and instars do not show dwarfing or a change in body size as an adaptation to the temperature stress during the end‐Permian crisis. This may indicate that the ostracods in the Aras Valley section might have been exceptions to the temperature–size rule (TSR), using an adaptation mechanism that does not involve a decrease in body size. This adaptation might be similar to the accelerated development despite constant instar body sizes that can be observed in some recent experimental studies of ostracod responses to thermal stress.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42291767","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}
Various terrestrial tetrapods convergently evolved to gigantism (large body sizes and masses), the most extreme case being sauropod dinosaurs. Heavy weight‐bearing taxa often show external morphological features related to this condition, but also adequacy in their limb bone inner structure: a spongiosa filling the medullary area and a rather thick cortex varying greatly in thickness along the shaft. However, the microanatomical variation in such taxa remains poorly known, especially between different limb elements. We highlight for the first time the three‐dimensional microstructure of the six limb long bone types of a sauropod dinosaur, Nigersaurus taqueti. Sampling several specimens of different sizes, we explored within‐bone, between‐bones, and size‐related variations. If a spongiosa fills the medullary area of all bones, the cortex is rather thin and varies only slightly in thickness along the shaft. Zeugopod bones appear more compact than stylopod ones, whereas no particular differences between serially homologous bones are found. Nigersaurus' pattern appears much less extreme than that in heavy terrestrial taxa such as rhinoceroses, but is partly similar to observations in elephants and in two‐dimensional sauropod data. Thus, microanatomy may have not been the predominant feature for weight‐bearing in sauropods. External features, such as columnarity (shared with elephants) and postcranial pneumaticity, may have played a major role for this function, thus relaxing pressures on microanatomy. Also, sauropods may have been lighter than expected for a given size. Our study calls for further three‐dimensional investigations, eventually yielding a framework characterizing more precisely how sauropod gigantism may have been possible.
{"title":"What's inside a sauropod limb? First three‐dimensional investigation of the limb long bone microanatomy of a sauropod dinosaur, Nigersaurus taqueti (Neosauropoda, Rebbachisauridae), and implications for the weight‐bearing function","authors":"R. Lefebvre, R. Allain, Alexandra Houssaye","doi":"10.1111/pala.12670","DOIUrl":"https://doi.org/10.1111/pala.12670","url":null,"abstract":"Various terrestrial tetrapods convergently evolved to gigantism (large body sizes and masses), the most extreme case being sauropod dinosaurs. Heavy weight‐bearing taxa often show external morphological features related to this condition, but also adequacy in their limb bone inner structure: a spongiosa filling the medullary area and a rather thick cortex varying greatly in thickness along the shaft. However, the microanatomical variation in such taxa remains poorly known, especially between different limb elements. We highlight for the first time the three‐dimensional microstructure of the six limb long bone types of a sauropod dinosaur, Nigersaurus taqueti. Sampling several specimens of different sizes, we explored within‐bone, between‐bones, and size‐related variations. If a spongiosa fills the medullary area of all bones, the cortex is rather thin and varies only slightly in thickness along the shaft. Zeugopod bones appear more compact than stylopod ones, whereas no particular differences between serially homologous bones are found. Nigersaurus' pattern appears much less extreme than that in heavy terrestrial taxa such as rhinoceroses, but is partly similar to observations in elephants and in two‐dimensional sauropod data. Thus, microanatomy may have not been the predominant feature for weight‐bearing in sauropods. External features, such as columnarity (shared with elephants) and postcranial pneumaticity, may have played a major role for this function, thus relaxing pressures on microanatomy. Also, sauropods may have been lighter than expected for a given size. Our study calls for further three‐dimensional investigations, eventually yielding a framework characterizing more precisely how sauropod gigantism may have been possible.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48830182","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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