Journal of Vertebrate Paleontology最新文献

{"title":"New fossils, new ideas: selected contributions of vertebrate paleontology to scientific knowledge","authors":"Adriana López-Arbarello, Michael Daniel D’Emic","doi":"10.1080/02724634.2022.2267264","DOIUrl":"https://doi.org/10.1080/02724634.2022.2267264","url":null,"abstract":"Published in Journal of Vertebrate Paleontology (Vol. 42, No. 6, 2022)","PeriodicalId":17597,"journal":{"name":"Journal of Vertebrate Paleontology","volume":"187 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138528978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new <i>Rattus</i> species and its associated micromammals from the Pliocene Yangyi Formation in Baoshan, western Yunnan, ChinaCitation for this article: Chang, M., Zhang, C., Ji, X., LI, Q., &amp; Ni, X. (2023) A new <i>Rattus</i> species and its associated micromammals from the Pliocene Yangyi Formation in Baoshan, western Yunnan, China. <i>Journal of Vertebrate Paleontology</i> . https://doi.org/10.1080/02724634.2023.2249063","authors":"Meijing Chang, Chunxia Zhang, Xueping Ji, Qiang Li, Xijun Ni","doi":"10.1080/02724634.2023.2249063","DOIUrl":"https://doi.org/10.1080/02724634.2023.2249063","url":null,"abstract":"ABSTRACTRattus (sensu stricto) is one of the groups of rodents and is most closely related to human activities. The diversity of extant Rattus species is the highest among rodents, but fossil species are rare, mainly found in Asia during the Late Pliocene to Early Pleistocene. Here, we described a Late Pliocene new species of Rattus based on material from the upper Yangyi Formation in Baoshan county, Yunnan Province, China. The primitive morphological characteristics of fewer molar roots, t12 preserved on M1–2, t9 preserved on M3, and buccal stylids well developed on lower molars indicate that the new Rattus is by far the most primitive form in the Rattus genus. In dental morphology of Rattus, the molars have an evolutionary trend of gradually increasing the number of roots and fusing cusps into an arched ridge, reduction to disappearance of the t7 and t12 on upper molars, and reduction to disappearance of the mesiocentral cusp on m1, the anterior buccal stylid on m1–3 and hypoconid on m3. Discovery of the new Rattus from Baoshan confirms that Rattus probably originated in southern Asia before the Late Pliocene, and also provides new fossil evidence to calibrate the molecular clock of the divergence of Rattus from other murines. In addition, we also reported five associated small mammals: Neotetracus sp. nov., Anourosorex qianensis, Soricidae gen. et sp. indet., Ia io, and Kowalskia sp. Most of them inhabit warm and humid tropical or subtropical montane forests or shrubland environments. The composition of this mammalian assemblage indicates that the paleoelevation and paleoclimate of Baoshan area in the Pliocene are very similar to those of the present. ACKNOWLEDGMENTSWe thank Y. M. Hou from the IVPP for his help with the CT-scans and X. C. Zhu from the IOZ for assistance with extant specimen examination at the National Animal Collection Resource Center. Yu Ji screen-washed the fossiliferous matrix and sorted the concentrates. We also appreciate the constructive comments from the editors and reviewers. The work was supported by the National Natural Science Foundation of China (42072209, 41888101, 41988101, 41625005), Second Tibetan Plateau Scientific Expedition and Research Program (STEP) (Grant No. 2019QZKK0705) and the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDB26000000, XDA20070203).AUTHOR CONTRIBUTIONSMJC, QL, and XJN designed the project. MJC conducted phylogenetic analysis and drafted the manuscript. CXZ and XPJ performed fieldwork and collected materials. QL, XJN, and CXZ supervised the project. All authors edited the manuscript.SUPPLEMENTARY FILESSupplementary Data 1: (1) supplementary table about Rattus fossils reported in the world; (2) supplementary idealized figure of murine left molars and 95% confidence ellipses about length and width of selected Rattus; (3) supplementary phylogenetic analysis results.Supplementary Data 2: morphological matrices analyzed with TNT.DISCLOSURE STATEMENTNo potentia","PeriodicalId":17597,"journal":{"name":"Journal of Vertebrate Paleontology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135732551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reassessment of <i>Tegehotherium burmeisteri</i> Ameghino 1903–1904 ( <i>Notoungulata</i> , <i>Hegetotheriidae</i> ) and a new phylogenetic analysis of <i>Hegetotheriidae</i> Citation for this article: Seoane, F. D., Cerdeño, E., &amp; Gaetano, L. C. (2023) Reassessment of <i>Tegehotherium burmeisteri</i> Ameghino ( <i>Notoungulata</i> , <i>Hegetotheriidae</i> ) and a new phylogenetic analysis of <i>Hegetotheriidae. Journal of Vertebrate Paleontology</i> . https://doi.org/10.1080/02724634.2023.…","authors":"Federico D. Seoane, Esperanza Cerdeño, Leandro C. Gaetano","doi":"10.1080/02724634.2023.2258172","DOIUrl":"https://doi.org/10.1080/02724634.2023.2258172","url":null,"abstract":"ABSTRACTWithin the notoungulate family Hegetotheriidae, some species have not been analyzed since their original publication more than a century ago. Here we present the first re-evaluation of Tegehotherium burmeisteri, including a detailed description of its holotype in an updated comparative framework, a species presumably coming from the Trelew Member of the Sarmiento Formation (Chubut Province, Argentina). Tegehotherium burmeisteri is included for the first time in a phylogenetic analysis centered in the interrelationships of hegetotheriids and defining clades according to the PhyloCode. Tegehotherium burmeisteri is recovered as a hegetotheriine closely related to Sallatherium and Hegetotherium; Hegetotheriopsis sulcatus is the earliest branch of the clade Hegetotheriidae, whereas Prohegetotherium and Paedotherium turn out to be paraphyletic, reinforcing results obtained in recent studies. The family Hegetotheriidae and both subfamilies, Hegetotheriinae and Pachyrukhinae, are recovered as monophyletic groups and defined phylogenetically, as well as two new clades: Pachyrukhini and Hemihegetotheriomorpha. ACKNOWLEDGMENTSThe authors thank the editors and reviewers (A. Kramarz and an anonymous reviewer) for their useful comments on the manuscript. M. Ezcurra and A. Martinelli (MACN), M. Reguero and S. Bargo (MLP), and M. E. Pérez (MPEF), for making available the collections under their care. M. T. Dozo and F. Busker, for the photographs of MPEF-PV 693 (Medistylus dorsatus). We acknowledge that the TNT program is being made available with the sponsorship of the Willi Hennig Society. This work was partially financed by the project PICT 2017-0797 (to EC), and it is R-468 contribution by FDS and LCG to the Instituto de Estudios Andinos “Don Pablo Groeber” (IDEAN, Buenos Aires).DISCLOSURE STATEMENTNo potential conflict of interest was reported by the author(s).","PeriodicalId":17597,"journal":{"name":"Journal of Vertebrate Paleontology","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135885039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The fossil assemblage from Pontils, a middle Eocene primate-bearing locality from Northeastern SpainCitation for this article: Minwer-Barakat, R., Bolet, A., Anadón, P., Alegret, L., Badiola, A., Blanco, A., Cotton, L., Femenias-Gual, J., Furió, M., Godinot, M., Moyà-Solà, S., Peláez-Campomanes, P., Sanjuan, J., &amp; Marigó, J. (2023) The fossil assemblage from Pontils, a middle Eocene primate-bearing locality from Northeastern Spain. <i>Journal of Vertebrate Paleontology</i> . https://doi.org…","authors":"Raef Minwer-Barakat, Arnau Bolet, Pere Anadón, Laia Alegret, Ainara Badiola, Alejandro Blanco, Laura Cotton, Joan Femenias-Gual, Marc Furió, Marc Godinot, Salvador Moyà-Solà, Pablo Peláez-Campomanes, Josep Sanjuan, Judit Marigó","doi":"10.1080/02724634.2023.2259970","DOIUrl":"https://doi.org/10.1080/02724634.2023.2259970","url":null,"abstract":"ABSTRACTThe Pontils fossil site (middle Eocene, Ebro Basin, Spain) includes several vertebrate-bearing levels situated in a sequence recording a continental to marine transition. Although the locality has been known since the 1980s and scarce mammal remains have been already documented, an intensive sampling has not been developed until now. This work presents the first results of the recent field campaigns carried out at this site. Seven levels have yielded significant vertebrate remains, revealing a diverse assemblage which includes chondrichthyans, actinopterygians, amphibians, crocodilians, squamates, metatherians, eulipotyphlans, apatotherians, chiropterans, rodents, artiodactyls, perissodactyls, and primates, besides other non-vertebrate fossils. The Pontils assemblage indicates a mangrove swamp environment with warm and humid conditions and increasing marine influence towards the top of the sequence. Among mammals, primates are particularly diverse, including abundant remains of a minuscule, still undetermined omomyiform, and scarce teeth of Pseudoloris, Necrolemur, and an undetermined anchomomyin. The occurrence of larger benthic foraminifera allows the assignment of Pontils to Shallow Benthic Zone 17 (Bartonian), solving the debate about the age of the locality, previously assigned either to the Bartonian or the Lutetian. These data, together with previous magnetostratigraphic analyses, allow correlation to chrons C18r or C18n.1r, constraining the age of Pontils to between 39.58 and 41 Ma. Therefore, the Pontils site represents a new reference section for the correlation of marine and continental biostratigraphy during the middle Eocene. ACKNOWLEDGMENTSWe are indebted to all the people who participated in the collection and treatment of the samples, especially to D. M. Alba, J. M. Méndez, V. Fondevilla, G. Pons-Monjo, J. Lahiguera, E. Tarragó, A. Tamaral, Ó. Castillo, M. Acosta, M. Grau, S. Gómez, J. V. Bertó, P. López-Guerrero, A. Oliver, and A. R. Gómez-Cano. We are also grateful to J. Aguirre, who studied the invertebrate remains, and C. Grenier for his comments on the bryozoans. We want to thank L. Marivaux, M. Vianey-Liaud, B. Marandat (Institut des Sciences de l'Évolution-Université de Montpellier), L. Costeur (Naturhistorisches Museum Basel), J. J. Hooker (Natural History Museum, London), and the rest of the staff of these institutions, for their help and assistance when visiting their collections. We also want to acknowledge the editor Faysal Bibi, and the reviewers (Fabrice Lihoreau and an anonymous reviewer) for their constructive comments that greatly improved the quality of the manuscript. This work has been supported by CERCA Programme/Generalitat de Catalunya, research project PID2020-116908GB-I00 financed by MCIN/AEI/10.13039/501100011033, project CLT009/18/00069 financed by the Culture Department of the Generalitat de Catalunya, and project P20_00066 financed by the Consejería de Universidad, Investigación e Innovación, J","PeriodicalId":17597,"journal":{"name":"Journal of Vertebrate Paleontology","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135994989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A large, freshwater chanid fish (Ostariophysi: Gonorynchiformes) from the Upper Cretaceous of MadagascarCitation for this article: Murray, A. M., Brinkman, D. B., Friedman, M., &amp; Krause, D. W. (2023) A large, freshwater chanid fish (Ostariophysi: Gonorynchiformes) from the Upper Cretaceous of Madagascar. <i>Journal of Vertebrate Paleontology</i> . https://doi.org/10.1080/02724634.2023.2255630","authors":"Alison M. Murray, Donald B. Brinkman, Matt Friedman, David W. Krause","doi":"10.1080/02724634.2023.2255630","DOIUrl":"https://doi.org/10.1080/02724634.2023.2255630","url":null,"abstract":"ABSTRACTIsolated fossil bones from freshwater Upper Cretaceous (Maastrichtian) deposits in the Mahajanga Basin of northwestern Madagascar are identified as belonging to a gonorynchiform fish. Multiple elements representing the same bone, including opercles, hyomandibulae, frontals, and basioccipitals, indicate that only a single gonorynchiform species is present. The most diagnostic element is here named as a new genus and species, †Vango fahiny; the other elements likely belong to the same taxon. The Madagascan gonorynchiform material shares features with members of the subfamily Chaninae and is assigned to that group. It is similar to the extant milkfish Chanos chanos but can be easily distinguished from that species by numerous features, such as the basioccipital and maxilla being relatively shorter than those of C. chanos, and the opercle being overall rounder and having a shorter auricular process. The presence of a chanid in Madagascar in the Maastrichtian most likely represents an invasion of a marine lineage into fresh waters. The previously known Cretaceous fossils of gonorynchiforms are spread throughout the Tethys Sea in mid-latitude to northern regions from the east (e.g., Lebanon, Europe) through to the southwest (e.g., Mexico, Brazil). †Vango faniny gen. et sp. nov. represents the first Mesozoic/Paleogene record of gonorynchiforms in East Gondwana, comprising primarily Antarctica, Australia, Madagascar, and the Indian subcontinent. ACKNOWLEDGMENTSWe thank the ministries of Mines, Higher Education, and Culture of the Republic of Madagascar and the Mention Bassins Sédimentaires Evolution Conservation of the Université d’Antananarivo for permission to conduct research in Madagascar, and the Madagascar Institut pour la Conservation des Ecosystèmes Tropicaux and the villagers in the Berivotra and Lac Kinkony study areas for logistical support of fieldwork; A. Lownsdale, K. MacKenzie, S. Pevsner, and S. Swenson for assistance with cataloging specimens; and B. Rakotozafy for assistance with Malagasy names. We are also grateful to D. Mayrinck, and two anonymous reviewers for providing constructive criticisms of the manuscript, and to phylogenetics editor P.L. Godoy and handling editor T. Argyriou for their efforts. This research was supported by grants from the National Science Foundation (DEB-9224396, EAR-9418816, EAR-9706302, EAR-0106477, EAR-0446488, EAR-1123642, EAR-1528273, EAR-1664432, and DBI-2242716) and the National Geographic Society (6400-99, 6940-00, 7645-04, 8597-09, 9057-12), and the David B. Jones Foundation to DWK. Museum research trips to Denver were supported by Natural Sciences and Engineering Research Council of Canada Discovery Grant 327448 (AMM), and patrons of the Denver Museum of Nature & Science (DBB).AUTHOR CONTRIBUTIONSAMM, DBB, and DWK designed the project. AMM developed the first draft of the manuscript and all authors contributed sections as well as editing. MF first recognized the presence of a gonorynchiform ","PeriodicalId":17597,"journal":{"name":"Journal of Vertebrate Paleontology","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136033511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rare osteohistological evidence of skeletal maturity in the early diverging traversodontid <i>Scalenodon angustifrons</i> , with comments on histological sampling coverage in CynodontiaCitation for this article: Kulik, Z. T. (2023) Rare osteohistological evidence of skeletal maturity in the early diverging traversodontid <i>Scalenodon angustifrons</i> , with comments on histological sampling coverage in Cynodontia. <i>Journal of Vertebrate Paleontology</i> . https://doi.org/10.1080/02724634.…","authors":"Zoe T. Kulik","doi":"10.1080/02724634.2023.2249964","DOIUrl":"https://doi.org/10.1080/02724634.2023.2249964","url":null,"abstract":"ABSTRACTTo date, 25 species of non-mammalian cynodonts have been histologically sampled, but few record a definitive and well-developed external fundamental system (EFS) indicative of skeletal maturity. Here, I report an EFS in the femoral histology of Scalenodon angustifrons and discuss the factors that could explain why skeletally mature tissue is rarely documented in cynodont osteohistology. My sample includes two equivalently sized individuals that document marked histological variation, as only one shows evidence of slowing growth rate and an EFS. Variation in the bone histology between femora of the same size suggests that attainment of skeletal maturity does not follow a discrete developmental pattern for S. angustifrons, a pattern that is also seen in the bone histology of other traversodontids and some non-gomphodontian cynodonts. From these results, a flexible growth strategy is inferred for S. angustifrons. To contextualize the validity of this pattern among other cynodont species, I summarize the sampling coverage of cynodonts that have been thin-sectioned and report limited coverage across size classes/ inferred development stages. This is often a result of sampling one isolated element that is not standardized to one skeletal element, which contributes to a poorly constrained comparative sample (in terms of size coverage, spatial and temporal resolution, and taxonomic coverage). Despite this, many cynodont species show shifts towards slow growth, but very few instances of unequivocal evidence of skeletal maturity. This result underscores the need for standardized iterative histological sampling to assess longevity, life history, and developmental patterns of non-mammalian cynodonts more accurately. ACKNOWLEDGMENTSI thank the 2007 and 2012 field crews to Tanzania (K. Angielczyk, L. Nampunju, S. Nesbitt, C. Sidor, R. Smith, S. Steyer, M. Stocker, N. Tabor, A. Tibaijuka, L. Tsuji), C. Abramson for preparing NMT RB581, and K. Abrams for her expertise in molding, casting, and specimen preparation. Thanks to L. Marilao for her skilled thin-section preparation, to S. Powers and J. Ricks for their help in curating the Tanzanian collection housed at the Burke Museum, and to Crystal Shin for her expert scientific illustration. For their helpful feedback, edits, and advice, I thank M. Whitney, B. Gee, T. Popowics, A. Huttenlocker, and C. Sidor. Lastly, two anonymous reviewers are thanked for their comments and suggestions that greatly improved the quality of this work. Fossils were collected with support from NGS 7787-05 and NGS 8962-11 (to C. Sidor), NSF DBI-0306158 (to K. Angielczyk).DISCLOSURE STATEMENTNo potential conflict of interest was reported by the author.DATA AVAILABILITY STATEMENTThe osteohistological data that support the findings of this study are openly available in MorphoBank at http://morphobank.org/permalink/?P4541, reference number P4541.","PeriodicalId":17597,"journal":{"name":"Journal of Vertebrate Paleontology","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135858046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The first small-bodied ornithopod dinosaur from the Lewisville Formation (middle Cenomanian) of TexasCitation for this article: Tykoski, R. S., Contreras, D. L., &amp; Noto, C. (2023) The first small-bodied ornithopod dinosaur from the Lewisville Formation (middle Cenomanian) of Texas. <i>Journal of Vertebrate Paleontology</i> . https://doi.org/10.1080/02724634.2023.2257238","authors":"Ronald S. Tykoski, Dori L. Contreras, Christopher Noto","doi":"10.1080/02724634.2023.2257238","DOIUrl":"https://doi.org/10.1080/02724634.2023.2257238","url":null,"abstract":"Sediments of the Woodbine Group exposed in northeastern Texas were deposited along the southwestern margin of Appalachia as a series of near-shore, shoreline, distal lowland swamp, lake, and fluvial deposits during a regression of the Western Interior Seaway in early and middle Cenomanian time. The Lewisville Formation (upper Woodbine Group) of north Texas preserves the most diverse terrestrial fossil assemblage known from Appalachia, but remains of small ornithischian dinosaurs have been conspicuously absent from it. An almost complete left dentary from the Lewisville Formation represents a new, small-bodied ornithopod taxon, Ampelognathus coheni gen. et sp. nov. The dentary is generally similar to those in non-iguanodontian ornithopods such as Hypsilophodon, Changchunsaurus, Haya, and Convolosaurus. Ampelognathus occupied an expected but previously missing component of the ‘mid’ Cretaceous terrestrial fauna of southwestern Appalachia. The growing diversity of fossil vertebrates and renewed paleobotanical study in the Lewisville Formation reinforces the importance of the unit’s fossil record for understanding eastern North American terrestrial ecosystems during an important transitional period in the earliest Late Cretaceous.http://zoobank.org/urn:lsid:zoobank.org:pub:02642649-ED6F-483A-994A-EC5F3FDF2AC7","PeriodicalId":17597,"journal":{"name":"Journal of Vertebrate Paleontology","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135854150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Patterns and function of pneumaticity in the vertebrae, ribs, and ilium of a titanosaur (Dinosauria, Sauropoda) from the Upper Cretaceous of TexasCitation for this article: Fronimos, J. A. (2023) Patterns and function of pneumaticity in the vertebrae, ribs, and ilium of a titanosaur (Dinosauria, Sauropoda) from the Upper Cretaceous of Texas. <i>Journal of Vertebrate Paleontology</i> . https://doi.org/10.1080/02724634.2023.2259444","authors":"John A. Fronimos","doi":"10.1080/02724634.2023.2259444","DOIUrl":"https://doi.org/10.1080/02724634.2023.2259444","url":null,"abstract":"ABSTRACTMany sauropod dinosaurs exhibit extensive postcranial skeletal pneumaticity that may have facilitated the evolution of extreme body sizes. Among titanosauriforms, complex, irregularly branching camellate chambers are found throughout the presacral vertebral column, often invading the ribs and ilium as well. To explore the function of these camellae, including reduction in bone volume, pneumaticity was examined in a titanosaur sauropod from the Upper Cretaceous Black Peaks Formation of Big Bend National Park, Texas, that includes pneumatic dorsal ribs and ilia. Using natural breaks to non-destructively observe the internal structure, patterns of camellate pneumaticity are described for the dorsal vertebrae, ribs, and ilium. The space occupied by camellae is quantified as the airspace proportion, which is reported here in a sauropod ilium for the first time. Airspace proportions exceed 70% in parts of the dorsal vertebrae and ilium, with lower values near the cotyles of the vertebral centra and the acetabulum. Values in the ribs decrease distally. These values are not appreciably different from those of sauropods with simpler camerate pneumaticity. If camellae did not offer greater weight reduction than camerae, they may have enhanced structural strength, as the chambers appear to align with stress in the vertebral centra and ilium. Apneumatic trabecular bone around the acetabulum, preacetabular process, and postzygapophyses, however, may indicate stresses too great for camellate bone to bear, although an ontogenetic influence cannot be ruled out. ACKNOWLEDGMENTSI thank T. M. Lehman for the opportunity to work on the specimen and guiding the initial direction of the project. Collection of the material was assisted by A. Brink, J. Browning, D. Evans, J. Schubert, and S. Wick. C. Schulte prepared the dorsal ribs examined here. The cross sections were digitized and analyzed by S. Cutler, J. Grosjean, D. Leaphart, and J. Mayes. I am grateful to M. Brown, J. C. Sagebiel, and T. Rowe for access to specimens now reposited at the Texas Memorial Museum, University of Texas, Austin. I also acknowledge the park service staff of Big Bend National Park for their continued stewardship of fossil resources that made this work possible. Editors D. Schwarz, M. D'Emic and the reviewers provided thoughtful guidance that improved this manuscript.DISCLOSURE STATEMENTNo potential conflict of interest was reported by the author(s).AUTHOR CONTRIBUTIONSJAF designed and executed the data collection, analyzed the results, and wrote and edited the manuscript.SUPPLEMENTARY FILESSupplementary File 1: cross section image files used in this analysis (Figs. S1–19) and table of sauropod taxa for which ASP measurements are available (Table S1).","PeriodicalId":17597,"journal":{"name":"Journal of Vertebrate Paleontology","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136062461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new typothoracine aetosaur (Archosauria, Pseudosuchia) from the Upper Triassic of India with insights on biostratigraphy, diversification, and paleobiogeographySUPPLEMENTARY FILES—Supplementary files are available for this article for free at www.tandfonline.com/UJVPCitation for this article: Haldar, A., Ray, S., &amp; Bandyopadhyay, S. (2023) A new typothoracine aetosaur (Archosauria, Pseudosuchia) from the Upper Triassic of India with insights on biostratigraphy, diversification, and …","authors":"Atrayee Haldar, Sanghamitra Ray, Saswati Bandyopadhyay","doi":"10.1080/02724634.2023.2253292","DOIUrl":"https://doi.org/10.1080/02724634.2023.2253292","url":null,"abstract":"ABSTRACTA new typothoracine aetosaur is described based on multiple isolated and articulated left paramedian and lateral osteoderms recovered from the Upper Triassic lower Dharmaram Formation of India. The partial carapace of the new taxon is reconstructed as strongly discoidal based on the curvature of the paramedian osteoderms with the widest one positioned dorsal to the mid-dorsal trunk vertebra. Asymmetric lateral osteoderms with acute flexion are considered as precaudals with the angle of flexion decreasing posteriorly. Phylogenetic analysis recovered the new taxon as deeply nested within the clades Typothoracinae and Paratypothoracini, and a sister taxon to Kocurypelta silvestris. The autapomorphic characters involving paramedian osteoderms dorsal to the trunk vertebrae include dorsal surface ornamented by large, irregular pits surrounding the dorsal eminence and radiating ridges in other areas, straight anterior margin of the anteromedial corner of the anterior bar in dorsal view, and raised or ridged and ornamented posteromedial corner. The current study highlights the significance of the new aetosaur, and the age of the lower Dharamaram Formation is modified here as mid-Norian to Rhaetian based on global correlation with other coeval horizons. The recovery of this taxon marks the first record of Paratypothoracini from high paleolatitudes of the Gondwanan region. The study corroborates the earlier findings of a strong Laurasian faunal influx in India during the Late Triassic suggesting possible land bridges and/or conducive environmental conditions for faunal dispersal.http://zoobank.org/urn:lsid:zoobank.org:pub:FCC37C0E-107F-4B15-9460-4E802B465865 ACKNOWLEDGMENTSThe fossil specimens were collected by T. S. Kutty, Geological Studies Unit, Indian Statistical Institute, Kolkata. We thank D. Mukherjee of the same Institute, and D. Datta, Department of Earth Sciences, Indian Institute of Technology, Roorkee for advice and help throughout the study. We thank A. Huttenlocker, T. Sulej, P. L. Godoy, and an anonymous reviewer for thorough revision and constructive suggestions. D. Pradhan and L. Mahankur are gratefully acknowledged for preparation and removal of matrices from the fossil specimens. The financial assistance was provided by Science and Engineering Research Board, India (SERB/CRG/000388) to SR. The Indian Institute of Technology Kharagpur and Indian Statistical Institute Kolkata are acknowledged for providing infrastructural facilities to AH and SR, and SB, respectively.DISCLOSURE STATEMENTNo potential conflict of interest was reported by the authors.SUPPLEMENTARY FILESSupplementary File 1.docx: Details of the characters used for the phylogenetic analysis.Supplementary File 2.nex: Combined characters and data matrix used for phylogenetic analysis.Supplementary File 3.docx: Resampled MPTs (ordered).Supplementary File 4.tre: MPTs of the parsimony analysis (unordered).Supplementary File 5.docx: List of synapomorphies.Additional informati","PeriodicalId":17597,"journal":{"name":"Journal of Vertebrate Paleontology","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135352376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}