Alcheringa: An Australasian Journal of Palaeontology最新文献

{"title":"Muscle scars in Miaolingian helcionelloids from Laurentia and the diversity of muscle scar patterns in Cambrian univalve molluscs","authors":"J. S. Peel","doi":"10.1080/03115518.2023.2243501","DOIUrl":"https://doi.org/10.1080/03115518.2023.2243501","url":null,"abstract":"Abstract Two pairs of equidimensional muscle-attachment scars are described on the dorso-lateral surfaces of internal moulds of the helcionelloid molluscs Hensoniconus gen. nov. and Vendrascospira from the Henson Gletscher Formation (Cambrian, Miaolingian Series, Wuliuan Stage) of North Greenland (Laurentia). Two patterns of muscle scars are recognized in helcionelloids. In the Hensoniconus–Vendrascospira group, two pairs of sub-equally sized scars are located on the dorso-lateral surfaces. In the Bemella–Figurina group, thin, band-like scars are distributed on the sub-apical surface and along the dorsal (supra-apical) surface. Comparison of these rare described occurrences of muscle scars in bilaterally symmetrical molluscs indicates that the simple shell form may obscure recognition of distinct lineages within Cambrian univalves that are based on anatomical features, such as musculature. John S. Peel [john.peel@pal.uu.se], Department of Earth Sciences (Palaeobiology), Uppsala University, Villavägen 16, SE-75236, Uppsala, Sweden.","PeriodicalId":272731,"journal":{"name":"Alcheringa: An Australasian Journal of Palaeontology","volume":"358 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115880410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Early Ordovician trilobites from Barnicarndy 1 stratigraphic well of the southern Canning Basin, Western Australia","authors":"Patrick M. Smith, Heidi J. Allen","doi":"10.1080/03115518.2023.2226194","DOIUrl":"https://doi.org/10.1080/03115518.2023.2226194","url":null,"abstract":"Abstract Twenty-three trilobite taxa are described here from the Early Ordovician (Tremadocian to Floian) Nambeet Formation retrieved from the Barnicarndy 1 drillcore, Canning Basin, Western Australia. This includes one new genus, Veeversaspis gen. nov., and six new species: Asaphellus zheni sp. nov., Madiganaspis lauriei sp. nov., Norasaphus (Norasaphus) jagoi sp. nov., Rodingaia leggi sp. nov., Sanbernardaspis excalibur sp. nov., and Veeversaspis jelli gen. et sp. nov. This fauna can be divided into three stratigraphically distinct assemblages, the Apatokephalus sp.–Veeversaspis jelli gen. et sp. nov. Assemblage (2177.50–2382.94 m depth), Asaphellus trinodosus Assemblage (2030.07–2177.52 m depth), and Asaphellus zheni sp. nov. Assemblage (1595.83–2001.88 m depth). The two stratigraphically lowest assemblages are consistent with a late to latest Tremadocian age (both within the Paroistodus proteus Zone). The third, and highest, assemblage is consistent with a mid-Floian age (within the Oepikodus communis Zone). This systematic contribution refines previous biostratigraphic work based on an age-diagnostic conodont fauna and demonstrates the stratigraphic utility of using multiple taxonomic groups for more robust biostratigraphic age estimates. P.M. Smith [ Patrick.Smith@austmus.gov.au ], Palaeontology Department, Australian Museum Research Institute, Sydney, New South Wales, 2010, Australia, and Department of Biological Sciences, Macquarie University, Sydney, New South Wales, 2109, Australia. H.J. Allen [ heidi.allen@dmirs.wa.gov.au ], Geological Survey of Western Australia, Department of Mines, Industry Regulation and Safety, Mineral House, 100 Plain Street, East Perth, Western Australia, 6004, Australia.","PeriodicalId":272731,"journal":{"name":"Alcheringa: An Australasian Journal of Palaeontology","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128699670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Glyptotherium cylindricum (Cingulata, Glyptodontidae) from the Late Pleistocene of Guatemala: the most complete record of Glyptodontinae from Central America","authors":"Francisco Cuadrelli, J. Escamilla, A. Zurita, D. Gillette, Lorena S. Dávila","doi":"10.1080/03115518.2023.2242440","DOIUrl":"https://doi.org/10.1080/03115518.2023.2242440","url":null,"abstract":"Abstract Glyptodontinae stand out among the lineages of Glyptodontidae in having the greatest latitudinal distribution, including participation in the Great American Biotic Interchange, with significant speciation in new migration areas. The oldest records of Glyptodontinae occur in northern South America with Boreostemma from the middle Miocene–Pliocene. A later radiation incorporated the austral representatives ‘Glyptodontidium tuberifer’, ‘Paraglyptodon’ spp., Glyptodon munizi, Glyptodon reticulatus and Glyptodon jatunkhirkhi in the late Miocene–Late Pleistocene of southern South America, and the septentrional representatives Glyptotherium texanum and Glyptotherium cylindricum in the Pliocene–Late Pleistocene of North America, Central America and northeastern South America. Although knowledge of North and South American forms has increased in recent years, records from Central America are still scarce and fragmentary. Here we describe the most complete Central American glyptodontine fossils documented to date, which were recovered from the latest Pleistocene of Guatemala. The remains comprise: (1) an incomplete skull, the right and left hemimandibles, a fragmentary pelvis, cervical and caudal vertebrae, and articulated and isolated osteoderms; (2) a fragmentary pelvis, left hind limb (incomplete autopodium) and seven caudal vertebrae; (3) most of a dorsal carapace; (4) six incomplete caudal armature rings; and (5) a left hemimandible with complete dental series. Comparative assessment indicates that these remains are referrable to G. cylindricum. The presence of this species in northern Central America and northern South America during the latest Pleistocene spans more than 2200 km, suggesting a continuous distribution across this region, at least during the Last Glacial Maximum and the early Younger Dryas. Francisco Cuadrelli [ f.cuadrelli@gmail.com ]*, Juan Escamilla [ juanitoesca@gmail.com ] and Alfredo Zurita [ aezurita74@yahoo.com ], Laboratorio de Evolución de Vertebrados y Ambientes Cenozoicos–Centro de Ecología Aplicada del Litoral (CECOAL–CONICET) y Universidad Nacional del Nordeste, Corrientes, Argentina, 3400; David D. Gillette [daviddgillette@gmail.com ], 24 W. Travertine Trail, Flagstaff, AZ 86005, USA; Lorena S. Dávila [ sylodavila@gmail.com ], Colección de Fósiles, Museo Historia Natural, Universidad de San Carlos de Guatemala, Calle Mariscal Cruz 1–56, Zona 10, Ciudad de Guatemala, Guatemala, 01010.","PeriodicalId":272731,"journal":{"name":"Alcheringa: An Australasian Journal of Palaeontology","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114743710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Early Devonian Ostracoda from the Norton Gully Sandstone, southeastern Australia","authors":"Tamara T. A. Camilleri, E. Weldon, M. Warne","doi":"10.1080/03115518.2023.2223658","DOIUrl":"https://doi.org/10.1080/03115518.2023.2223658","url":null,"abstract":"Abstract The Lower Devonian (Emsian) Norton Gully Sandstone contains rich invertebrate fossil faunas including ostracods. Seven ostracod taxa are recognized and illustrated herein: Bungonibeyrichia copelandi, Bungonibeyrichia wooriyallockensis, Bungonibeyrichia treslata sp. nov., Bungonibeyrichia australiae, Bairdiocypris sp., and two indeterminate genera. The ostracods are preserved in sandstone and mudstone as natural moulds. There are two distinct biofacies identified within the Norton Gully Sandstone: one dominated by ornate ostracods belonging to Bungonibeyrichia; and the other by smooth species of Bairdiocypris. We also conclude that most southeast Australian species previously placed in Velibeyrichia are more appropriately placed in Bungonibeyrichia on the basis of lobe morphology. Consequently, both these genera can be recognized as having discrete Silurian-Devonian palaeobiogeographical distributions, with Velibeyrichia spp. occurring in the shallow seas of Laurentia, while Bungonibeyrichia spp. was restricted to shallow seas around eastern Gondwana. Tamara T.A. Camilleri [ tamara.camilleri@deakin.edu.au ], and Mark T. Warne [ mark.warne@deakin.edu.au ], School of Life and Environmental Sciences, Deakin University (Waurn Ponds Campus), Geelong, Victoria 3220, Australia; Museums Victoria, GPO Box 666, Melbourne, Victoria 3001, Australia. Elizabeth A. Weldon [ l.weldon@deakin.edu.au ], School of Life and Environmental Sciences, Deakin University (Melbourne Campus), Melbourne, Victoria 3220, Australia.","PeriodicalId":272731,"journal":{"name":"Alcheringa: An Australasian Journal of Palaeontology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131211614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First potential occurrence of the large aquatic snake Pterosphenus (Serpentes, Palaeophiidae) from Nigeria, with further documentation of Pterosphenus schweinfurthi from Egypt","authors":"G. Georgalis","doi":"10.1080/03115518.2023.2217874","DOIUrl":"https://doi.org/10.1080/03115518.2023.2217874","url":null,"abstract":"Abstract Pterosphenus was a genus of giant aquatic snakes distributed across North and South America, Asia and Africa. In Africa, the known occurrences of the genus are scarce, comprising isolated vertebrae and ribs from Egypt, Libya, Morocco and Angola. Here, a trunk vertebra from the middle Eocene Ameki Formation of Ameki in Nigeria is tentatively referred to Pterosphenus. For comparative purposes, multiple previously undocumented trunk vertebrae from the upper Eocene of Fayum in Egypt are also illustrated—these pertain to Pterosphenus schweinfurthi, the only named species of Pterosphenus currently recognized from Africa. The Ameki Formation vertebra is significantly smaller and likely represents an osteologically immature individual. This new find hints at a higher diversity of palaeophiids from Nigeria, which otherwise include Palaeophis africanus from the age-equivalent middle Eocene Oshosun Formation. Georgios L. Georgalis [georgalis@isez.pan.krakow.pl], Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Sławkowska 17, 31‑016 Kraków, Poland.","PeriodicalId":272731,"journal":{"name":"Alcheringa: An Australasian Journal of Palaeontology","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128509955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Conservation implications of a new fossil species of hopping-mouse, Notomys magnus sp. nov. (Rodentia: Muridae), from the Broken River Region, northeastern Queensland","authors":"V. Vakil, Jonathan Cramb, G. Price, G. Webb, Julien Louys","doi":"10.1080/03115518.2023.2210192","DOIUrl":"https://doi.org/10.1080/03115518.2023.2210192","url":null,"abstract":"Abstract The Australian hopping-mouse Notomys includes 10 species, eight of which are considered extinct, vulnerable, near-threatened or endangered. Here we report a new fossil species from the Broken River Region, northeastern Queensland. Notomys magnus sp. nov. is represented by craniodental material from late Quaternary cave deposits. It was a relatively large-bodied species of Notomys with a mass estimated to be ca 83 g. Notomys magnus sp. nov. is immediately distinguishable from the spinifex hopping-mouse (Notomys alexis), the northern hopping-mouse (Notomys aquilo), the fawn hopping-mouse (Notomys cervinus), the dusky hopping-mouse (Notomys fuscus), Mitchell’s hopping-mouse (Notomys mitchellii) and the big-eared hopping-mouse (Notomys macrotis) by its larger size (especially its longer upper molar crown length). Notomys magnus sp. nov. differs from the large-bodied Darling Downs hopping-mouse (Notomys mordax), long-tailed hopping-mouse (Notomys longicaudatus), short-tailed hopping-mouse (Notomys amplus) and broad-cheeked hopping-mouse (Notomys robustus) by possessing a unique first upper molar (M1) morphology including relatively well-developed buccal cusps, cusp T1 prominently isolated from T4, a relatively narrow posterior loph and an incipient anterior accessory cusp. Fossils of N. magnus sp. nov. are found in association with remains of several arid-adapted taxa, including the plains mouse (Pseudomys australis), the northern pig-footed bandicoot (Chaeropus yirratji), and N. longicaudatus, possibly indicating that N. magnus sp. nov. was also arid-adapted. Dating of fossil deposits containing N. magnus sp. nov. demonstrates that it was extant in the mid-Holocene (ca 8.5 ka) so it may have been still extant at the time of European colonization but suffered extinction soon after, mirroring the fate of similarly arid-adapted contemporaneous taxa (Chaeropus yirratji and N. longicaudatus). Historical extinctions in Notomys are biased towards larger species (N. amplus, N. longicaudatus and N. robustus), and the discovery of N. magnus sp. nov. adds further to that list. Given the already high number of extinct and endangered species within Notomys, the discovery of another member that suffered geologically recent extinction has conservation implications for modern critical weight range mammals (including other species of rodents) that are particularly susceptible to extinction. Most historical extinctions of critical weight range mammals were in southern and central Australia, but the discovery of N. magnus sp. nov. suggests that species in the tropical north also were detrimentally affected. Vikram Vakil [vikram.vakil@uqconnect.edu.au], School of Earth and Environmental Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia; Jonathan Cramb [jonathan.cramb@qm.qld.gov.au], Queensland Museum, Brisbane, Australia; Gilbert J. Price [g.price1@uq.edu.au], School of Earth and Environmental Sciences, The University of Queensland, B","PeriodicalId":272731,"journal":{"name":"Alcheringa: An Australasian Journal of Palaeontology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130785886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geologically oldest evidence of ‘lumpy jaw’ (Macropod Progressive Periodontal Disease) in kangaroos of Australia: implications for conservation management","authors":"G. Price, Julien Louys, J. Wilkinson","doi":"10.1080/03115518.2023.2207624","DOIUrl":"https://doi.org/10.1080/03115518.2023.2207624","url":null,"abstract":"Abstract At a time of widespread concern over the prevalence of viruses and infectious diseases in global ecosystems, it is helpful to consider the history of afflictions in the geological record. Amongst captive species of Australian kangaroos, one of the most common pathological conditions observed is the occurrence of ‘lumpy jaw’, or Macropod Progressive Periodontal Disease (MPPD). Macropods (including both kangaroos and wallabies) affected by the disease commonly exhibit osteological swellings in either the mandible or maxilla, or both, including in areas surrounding the cheek teeth. Diseased individuals struggle to eat, often resulting in death. The specific cause of MPPD is unclear, although it may be multifactorial. When present in wild populations, the condition is more likely to occur in situations that result in the mass-gathering of individuals around critical resources such as drying waterholes. Here we report a case of MPPD in a Pliocene (ca 3 Ma) kangaroo, the geologically oldest record of this condition within macropods. The fossil is identified as Osphranter ?pan and was excavated from a deposit in the Chinchilla Sand, southeast Queensland. The osteomyelitis is expressed by a noticeable lateral mandibular swelling on the horizontal ramus; this is clearly pathological and has not been observed in any other member of the species. The specific circumstance that led to the development of MPPD in this individual likely reflects palaeoenvironmental stress, principally drought, in the Pliocene ecosystem. Lumpy jaw is evidently a geologically young disease, with its higher incidence through the late Cenozoic closely tied to long-term shifts towards progressively drier and more arid conditions. Given predictions that future climate change will follow such trajectories across many regions of Australia, MPPD is expected to become an increasingly important pathology for management in extant populations. This includes conservation projects that may lead to resource-limited settings such as fenced (including re-wilding) and translocated island populations. Gilbert J. Price [g.price1@uq.edu.au], School of Earth and Environmental Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia; Julien Louys [j.louys@griffith.edu.au], Australian Research Centre for Human Evolution, Griffith University, Brisbane, Queensland 4101, Australia; Joanne E. Wilkinson [joanne.wilkinson@qm.qld.gov.au], Queensland Museum Geosciences, 122 Gerler Road, Hendra, Queensland 4011 Australia.","PeriodicalId":272731,"journal":{"name":"Alcheringa: An Australasian Journal of Palaeontology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128676334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Myth of the QANTAS leap: perspectives on the evolution of kangaroo locomotion","authors":"C. Janis, Adrian M. O’Driscoll, B. Kear","doi":"10.1080/03115518.2023.2195895","DOIUrl":"https://doi.org/10.1080/03115518.2023.2195895","url":null,"abstract":"Abstract The distinctive QANTAS ‘flying kangaroo’ motif of Australia’s national airline signifies what many people regard as the pinnacle of kangaroo evolution—a large-bodied marsupial specialized for endurance-hopping. However, while almost all extant macropodoids (the crown group including kangaroos) use hopping gaits to some extent, the fossil record reveals that the locomotory capabilities of extinct macropodoids were comparatively diverse. The earliest recognized Oligocene–middle Miocene macropodoids probably employed quadrupedal bounding, climbing and slower speed hopping as their primary modes of locomotion. Yet, all were apparently small-bodied (<12 kg), with larger-bodied (>20 kg) forms not appearing until the late Miocene coincident with increasing aridity and the spread of openly vegetated habitats. Hopping is functionally problematic at larger body sizes. Consequently, the later radiation of macropodids (kangaroos, wallabies and their relatives) achieved an optimal mass for efficient higher-speed hopping at ∼35 kg, with a theorized extreme limit of ∼140–160 kg. Modern kangaroos otherwise approach the peak mass range for such gaits at ∼50–90 kg, with the gigantic Pliocene–Pleistocene species of Protemnodon (‘giant wallabies’) at ∼100–160 kg likely being predominantly quadrupedal, and sthenurines (short-faced kangaroos) at ∼50–250 kg seemingly using bipedal striding. Here, we review the fossil evidence of macropodoid locomotion over the last ∼25 million years, and present preliminary analyses of limb bone and tarsal metric data. These indicate that the higher-speed endurance-hopping typical of modern large-bodied kangaroos was probably rare or absent in all but a few crown macropodoid lineages. The intrinsic gait variability of macropodoids has therefore diminished with Late Pleistocene megafaunal extinctions. As a result, the famous QANTAS ‘flying kangaroo’ actually depicts only one of what was once many successful locomotory strategies employed by macropodoids to conquer a range of terrestrial and arboreal habitats. Christine M. Janis [christine_janis@brown.edu], Bristol Palaeobiology Group, School of Earth Sciences, University of Bristol, Bristol BS8 1RJ, UK; Adrian M. O’Driscoll [aod523@york.ac.uk], Centre for Anatomical and Human Studies, Hull York Medical School, University of York, York YO1O 5DD, UK; Benjamin P. Kear [benjamin.kear@em.uu.se], The Museum of Evolution, Uppsala University, Norbyvägen 16, Uppsala SE-75236, Sweden.","PeriodicalId":272731,"journal":{"name":"Alcheringa: An Australasian Journal of Palaeontology","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115313086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Migrations, diversifications and extinctions: the evolutionary history of crocodyliforms in Australasia","authors":"Jorgo Ristevski, P. Willis, A. Yates, Matt A. White, Lachlan J. Hart, Michael D. Stein, G. Price, S. Salisbury","doi":"10.1080/03115518.2023.2201319","DOIUrl":"https://doi.org/10.1080/03115518.2023.2201319","url":null,"abstract":"Abstract Crocodyliform palaeontology in Australasia has a productive research record that began in the late nineteenth century and continues today. In this study, we summarize the current understanding on the taxonomic diversity and phylogenetic relationships of Australasian crocodyliforms based on first-hand knowledge of relevant fossil material and a review of the published literature. The currently known fossil record of Crocodyliformes in Australasia spans more than 113 million years, from the Early Cretaceous to the Holocene, and largely consists of body fossils discovered on continental Australia. Whilst only two crocodyliform genera are recognized from Australasia’s Mesozoic, the Cenozoic is distinguished by a remarkable taxonomic diversity of crocodylian crocodyliforms. By far the most common crocodylians from Australasia are members of Mekosuchinae, whose fossils are unambiguously known from the early Eocene until the Holocene. In addition to mekosuchines, during the Cenozoic Australasia was also inhabited by gavialoids and species of Crocodylus, with four extant species of the latter being the only surviving crocodylians in Australia and New Guinea. The phylogenetic relationships of Australasia’s crocodylians, particularly mekosuchines, have been a topic of interest to palaeontologists for over two decades. We performed several phylogenetic analyses to test the relationships of Mekosuchinae and other extinct crocodylians. Most results from our analyses found Mekosuchinae as a basal crocodyloid clade within Longirostres. However, some of the results recovered an alternative position for the majority of mekosuchines outside of Longirostres and the Late Cretaceous–early Paleogene Orientalosuchina as its deeply nested subclade. These results suggest that Mekosuchinae had its origins in Asia during the Cretaceous, and that mekosuchines arrived from southeast Asia into Australia no later than the late Paleocene. If this hypothesis is correct, then Mekosuchinae would no longer be an Australasian endemic clade since mekosuchines also seem to have persisted on continental Asia until the late Eocene. Jorgo Ristevski [jorgo.ristevski@gmail.com], School of Biological Sciences, The University of Queensland, Brisbane, 4072, Queensland, Australia; Paul M. A. Willis [paul@palaeopictures.com], School of Biological Sciences, Flinders University, Adelaide, 2100, South Australia, Australia; Adam M. Yates [Adamm.Yates@magnt.net.au], Museum of Central Australia, Museum and Art Gallery of the Northern Territory, Alice Springs, 0870, Northern Territory, Australia; Matt A. White [fossilised@hotmail.com], Palaeoscience Research Centre, University of New England, Armidale, 2351, New South Wales, Australia, Australian Age of Dinosaurs Museum of Natural History, The Jump-Up, Winton, 4735, Queensland, Australia; Lachlan J. Hart [l.hart@unsw.edu.au], Earth and Sustainability Science Research Centre, School of Biological, Earth and Environmental Sciences (BEES), Unive","PeriodicalId":272731,"journal":{"name":"Alcheringa: An Australasian Journal of Palaeontology","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116721273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Urrayira whitei gen. et sp. nov.: a dasyuromorphian (Mammalia: Marsupialia) with incipient zalambdodonty from the Middle Pleistocene of Queensland, Australia","authors":"Jonathan Cramb, S. Hocknull, R. Beck, S. Kealy, G. Price","doi":"10.1080/03115518.2023.2169351","DOIUrl":"https://doi.org/10.1080/03115518.2023.2169351","url":null,"abstract":"Abstract Urrayira whitei gen. et sp. nov. is described based on dental remains from middle Pleistocene cave sites at Mount Etna, Queensland. Its higher-level systematic affinities are unclear but it appears to be a dasyuromorphian. It is unusual in having a specialized reduced dentition characterized by reduction of the stylar cusps, protocone and talonid, resulting in an incipiently zalambdodont morphology that emphasizes the shearing crests. In addition, only two upper premolars are present, and we assume that it is P3 that has been suppressed, as has occurred multiple times within Dasyuridae. Maximum parsimony and undated Bayesian analyses of a 174 morphological character matrix intended to resolve relationships within Dasyuromorphia, with a molecular scaffold enforced, suggest that Urrayira is a dasyurid. In the maximum parsimony analysis, Urrayira is sister to Planigale gilesi (which also lacks P3), whereas in the undated Bayesian analysis, Urrayira resolves as part of a trichotomy at the base of Dasyuridae, together with Sminthopsinae and Dasyurinae; however, support values are generally low throughout the tree. While the majority of rainforest-adapted taxa in the Mount Etna sites became either extinct or were locally extirpated at, or soon after, 280 ka, there is no evidence that U. whitei gen. et sp. nov. even persisted until that time. Urrayira whitei was likely a rainforest-specialist, thus may have been particularly vulnerable to incipient effects of the Mid-Brunhes climatic shift towards aridity that eventually drove the disappearance of the Mount Etna rainforest and its associated fauna. Jonathan Cramb* [jonathan.cramb@qm.qld.gov.au], Queensland Museum, PO Box 3300, South Brisbane BC, Queensland 4101, Australia; Scott Hocknull [scott.hocknull@qm.qld.gov.au], Queensland Museum, PO Box 3300, South Brisbane BC, Queensland 4101, Australia; Robin M. D. Beck [r.m.d.beck@salford.ac.uk], School of Science, Engineering and Environment, University of Salford, Manchester M5 4WT, UK; Shimona Kealy [shimona.kealy@anu.edu.au], Archaeology and Natural History, College of Asia and the Pacific, The Australian National University, Canberra, ACT, 2601, Australia; Gilbert J. Price [g.price1@uq.edu.au], School of Earth and Environmental Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia.","PeriodicalId":272731,"journal":{"name":"Alcheringa: An Australasian Journal of Palaeontology","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130243701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}