Palaeontologia Electronica最新文献

{"title":"White shark comparison reveals a slender body for the extinct megatooth shark, <i>Otodus megalodon</i> (Lamniformes: Otodontidae).","authors":"Phillip C Sternes, Patrick L Jambura, Julia Türtscher, Jürgen Kriwet, Mikael Siversson, Iris Feichtinger, Gavin J P Naylor, Adam P Summers, John G Maisey, Taketeru Tomita, Joshua K Moyer, Timothy E Higham, João Paulo C B da Silva, Hugo Bornatowski, Douglas J Long, Victor J Perez, Alberto Collareta, Charlie Underwood, David J Ward, Romain Vullo, Gerardo González-Barba, Harry M Maisch, Michael L Griffiths, Martin A Becker, Jake J Wood, Kenshu Shimada","doi":"10.26879/1345","DOIUrl":"https://doi.org/10.26879/1345","url":null,"abstract":"<p><p>The megatooth shark, †<i>Otodus megalodon</i>, which likely reached at least 15 m in total length, is an iconic extinct shark represented primarily by its gigantic teeth in the Neogene fossil record. As one of the largest marine carnivores to ever exist, understanding the biology, evolution, and extinction of †<i>O. megalodon</i> is important because it had a significant impact on the ecology and evolution of marine ecosystems that shaped the present-day oceans. Some attempts inferring the body form of †<i>O. megalodon</i> have been carried out, but they are all speculative due to the lack of any complete skeleton. Here we highlight the fact that the previous total body length estimated from vertebral diameters of the extant white shark <i>(Carcharodon carcharias)</i> for an †<i>O. megalodon</i> individual represented by an incomplete vertebral column is much shorter than the sum of anteroposterior lengths of those fossil vertebrae. This factual evidence indicates that †<i>O. megalodon</i> had an elongated body relative to the body of the modern white shark. Although its exact body form remains unknown, this proposition represents the most parsimonious empirical evidence, which is a significant step towards deciphering the body form of †<i>O. megalodon</i>.</p>","PeriodicalId":56100,"journal":{"name":"Palaeontologia Electronica","volume":"27 1","pages":"a7"},"PeriodicalIF":2.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7616624/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142481824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Middle Eocene cartilaginous fishes (Vertebrata: Chondrichthyes) of the Dnieper-Donets Basin, northern Ukraine.","authors":"Oleksandr Kovalchuk, Jürgen Kriwet, Kenshu Shimada, Tamara Ryabokon, Zoltán Barkaszi, Anastasiia Dubikovska, Galina Anfimova, Svitozar Davydenko","doi":"10.26879/1283","DOIUrl":"10.26879/1283","url":null,"abstract":"<p><p>Marine basins that existed in present-day Ukraine during the Eocene harboured various groups of cartilaginous and bony fishes, reptiles, aquatic birds, and marine mammals. Fish remains from Paleogene deposits of Kyiv and its vicinities were first collected and described by O.S. Rogovich in the mid-19th century. Here we have carried out a re-examination of chondrichthyan fossils from Rogovich's collection and evaluated several later records, all of which were recovered from middle Eocene deposits. In total, 88 specimens represented by teeth, vertebrae, and other skeletal elements were analysed and described. As a result, the sample revealed to a single chimaeriform species <i>(Edaphodon bucklandi)</i>, and 12 shark and two ray taxa, respectively. Ten sharks were identified to species level, whereas the rays could be identified only at higher systematic ranks (Myliobatidae, Myliobatiformes). Several nomenclatural changes are proposed here, including the synonimisation of <i>Carcharodon megalotis, C. lanceolatus, C. productus, Lamna cuspidata, L. denticulata, L. compressa, L. (Odontaspis) hispida, L. lata, Oxyrhina brevidens</i>, and <i>O. biflena</i> with more recently proposed taxa. Seven species erected by Rogovich <i>(Galeocerdo paradoxus, Otodus microtus, Lamna elegans, Oxyrhina falcata, Oxyrhina leptodon, Chomatodus dubius</i>, and <i>Hybodus helophorus</i>) are suggested to most likely be <i>nomina dubia</i>. Many identified taxa represent the epi- and mesopelagic fishes and only a relatively small number of them belong to benthopelagic, demersal, and bathydemersal forms. The studied sample is of important historical and scientific value and substantially contribute to the understanding of the palaeodiversity of Eocene marine ecosystems that existed in present-day Ukraine and generally in Eastern Europe.</p>","PeriodicalId":56100,"journal":{"name":"Palaeontologia Electronica","volume":"1 1","pages":"a32"},"PeriodicalIF":2.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7616602/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69148743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oldest record of Alligator in southeastern North America","authors":"Alexander K. Hastings, B. Schubert, Jason R. Bourque, R. Hulbert","doi":"10.26879/1223","DOIUrl":"https://doi.org/10.26879/1223","url":null,"abstract":"The genus Alligator has been represented by large-bodied, predatory species in southeastern North America for at least 18 million years (early Miocene), in what is now the southeastern United States. However, the first occurrences of the genus were from a smaller-bodied species, A. prenasalis , known from South Dakota and Nebraska that are about 34 million years old (latest Eocene to earliest Oligocene). Ancestors of A. prenasalis were likewise small-bodied and are from the Great Plains. This 16 mil-lion-year-gap has left open questions regarding the arrival and body size shift of Alligator from what is now the Great Plains to southeastern North America. Recently studied fossil material from Florida exhibits the oldest occurrence of Alligator in the region (about 28–26 million years ago). A well-preserved premaxilla (UF 422816) bears the diagnostic premaxillary 'notch' of Alligator . Additional material from this and two other Oligocene sites in Florida are indicative of Alligator as well. These include well-devel-oped osteoderms, which suggest possible maturity at small body size. As of now, no records of larger Alligator from this time (or older) have been recovered from the region, possibly indicating body size may not have increased in Alligator until the Miocene","PeriodicalId":56100,"journal":{"name":"Palaeontologia Electronica","volume":"1 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69148039","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":"New species and evolution of the foraminiferal family Janischewskinidae in the middle–upper Mississippian of South China","authors":"Chaolu Liu, D. Vachard, P. Pedro, I. Coronado","doi":"10.26879/1238","DOIUrl":"https://doi.org/10.26879/1238","url":null,"abstract":"Rich foraminiferal assemblages from the Bama Platform in South China allow clarifying the systematics, composition, and biostratigraphy of the family Janischewski-nidae. The family is comprised of four genera, Janischewskina, Cribrospira, Bibradya, and Parajanischewskina . The genera Rhodesinella and Groessensella are considered to be synonyms of Cribrospira and Bibradya , respectively","PeriodicalId":56100,"journal":{"name":"Palaeontologia Electronica","volume":"1 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69148232","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 Middle Devonian acanthodian Orcadacanthus n. gen. from the Orcadian Basin of Scotland","authors":"M. Newman, Jan de Blaauwen, C. Burrow, Roger Jones, R. Davidson","doi":"10.26879/1240","DOIUrl":"https://doi.org/10.26879/1240","url":null,"abstract":"","PeriodicalId":56100,"journal":{"name":"Palaeontologia Electronica","volume":"1 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69148240","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 anatomy and diversity of the pterosaurian sternum","authors":"D. Hone","doi":"10.26879/1261","DOIUrl":"https://doi.org/10.26879/1261","url":null,"abstract":",","PeriodicalId":56100,"journal":{"name":"Palaeontologia Electronica","volume":"1 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69148537","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":"Approaching the Khersonian Crisis: Fish otoliths from the upper Bessarabian (middle Sarmatian s.l.; Late Miocene) of Jurkine (Kerch Peninsula, Crimea)","authors":"W. Schwarzhans, A. Bratishko, Y. Vernyhorova","doi":"10.26879/1300","DOIUrl":"https://doi.org/10.26879/1300","url":null,"abstract":"After its separation from the world ocean, the Paratethys formed a large inland marine water body during the Serravallian and Tortonian (Middle to Late Miocene) with a diverse environmental setting that underwent multiple fast and short-lived ecological changes. The trapped bony fish fauna either adapted to the rapid ecological changes (forced endemism) or perished. A major event during the late Sarmatian s.l. (Kherso-nian; late Tortonian; Late Miocene) was the Khersonian Crisis in the Eastern Para-tethys, which is postulated to have","PeriodicalId":56100,"journal":{"name":"Palaeontologia Electronica","volume":"2 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69149038","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":"New primates from the Eocene of Saskatchewan, Canada: Revision of the primates from the Cypress Hills Formation with description of new taxa","authors":"Jonathan M. G. Perry, A. Dutchak, J. Theodor","doi":"10.26879/1246","DOIUrl":"https://doi.org/10.26879/1246","url":null,"abstract":"True primates in the Canadian fossil record are known from only the Eocene epoch of southwestern Saskatchewan. They were originally described in the 1980s from two sets of localities: the Lac Pelletier localities (Duchesnean) and the Swift Current Creek (SCC) locality (Uintan). Additional fieldwork and sample sorting were carried out over the last decade. The present study includes a description of new primate dental material from the Swift Current Creek (SCC) locality. We name a new genus and two new species and revise the known primates for both the Lac Pelletier and SCC faunas. The Cypress Hills region of Saskatchewan likely represented a haven for small primates in the Eocene and may have supported an endemic primate fauna.","PeriodicalId":56100,"journal":{"name":"Palaeontologia Electronica","volume":"1 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69147851","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 Pliocene goodeid fish of the Paleolake Amajac, Sanctórum, Hidalgo, Mexico","authors":"C. Caballero-Viñas, J. Alvarado‐Ortega, Kleyton Magno Cantalice Severiano","doi":"10.26879/1259","DOIUrl":"https://doi.org/10.26879/1259","url":null,"abstract":"The splitfin fossil species Paleocharacodon guzmanae gen. and sp. nov. is erected based on the osteological study of 14 fossil male and female specimens recovered in the Pliocene deposits of the Paleolake Amajac, in Sanctórum, Hidalgo, Mexico. This new cyprinodontiform fish exhibits the diagnostic features of the family Goodeidae and subfamily Goodeinae; like all the goodeids, its premaxilla has a straight distal end, and its premaxillary ascending process is small; and, like the goodeines, this new species was viviparous, its first anal fin ray is rudimentary, and the males show an andropodium. Although P. guzmanae displays numerous primitive features, it is not possible to place it in any of the goodeine tribes, which currently are vaguely defined by osteological features. This new species seems to be closely related to Characodon; both share a peculiar osteological character; the articular facet for the quadrate is a donut-like structure, in which the retroarticular forms the central region, and a couple of semicircular anguloarticular processes form the surrounding part. This species differs from other goodeids mainly in two features; it has a posttemporal bone with small anteroventral processes, and the openings of its supraorbital canal show the formula12a, 2b-3a, 3b-4a, 4b-5a, and 5b-7. The discovery of this extinct goodeid species in the great Pánuco-Salado Basin on the eastern slope of Mexican territory represents an unexpected historical element. Carmen Caballero-Viñas. Departamento de Paleontología, Instituto de Geología, Universidad Nacional Autónoma de México. Circuito de la Investigación S/N, Ciudad Universitaria, Coyoacán, Ciudad de México, 04510, Mexico. c-caballero@live.com.mx Jesús Alvarado-Ortega. Departamento de Paleontología, Instituto de Geología, Universidad Nacional Autónoma de México. Circuito de la Investigación S/N, Ciudad Universitaria, Coyoacán, Ciudad de México, 04510, México. alvarado@geología.unam.mx Kleyton Magno Cantalice Severiano. Departamento de Paleontología, Instituto de Geología, Universidad CABALLERO-VIÑAS ET AL.: PLIOCENE GOODEID FROM MEXICO 2 Nacional Autónoma de México. Circuito de la Investigación S/N, Ciudad Universitaria, Coyoacán, Ciudad de México, 04510, México. kleytonmc@geologia.unam.mx","PeriodicalId":56100,"journal":{"name":"Palaeontologia Electronica","volume":"1 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69148460","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":"Differentiating convergent pathologies in turtle shells using computed tomographic scanning of modern and fossil bone","authors":"Stephanie K Drumheller, Hannah F. Maddox, M. Stocker, Christopher R. Noto","doi":"10.26879/1230","DOIUrl":"https://doi.org/10.26879/1230","url":null,"abstract":"","PeriodicalId":56100,"journal":{"name":"Palaeontologia Electronica","volume":"1 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69148054","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}