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Tytuł:
The last Cretaceous ammonites in Latin America
Autorzy:
Stinnesbeck, W.
Ifrim, C.
Salazar, C.
Powiązania:
https://bibliotekanauki.pl/articles/20513.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
paleontology
Cretaceous
ammonite
Latin America
Ammonoidea
Paleogene
Maastrichtian
Chile
Argentina
South America
Opis:
Sections yielding late Maastrichtian ammonite assemblages are rare in Latin America and precise biostratigraphic correlation with European type sections remains difficult. In all, the extinction pattern of ammonites appears to differ between sites in southern high latitudes and those in the tropics to subtropics. In austral sections of Chile, and possibly also in southern Argentina, diverse assemblages range throughout most of the substage and then show a gradual decline prior to the Cretaceous–Paleogene (K–Pg) boundary. Further north, in northeast Brazil, only two genera (Diplomoceras, Pachydiscus) range into the uppermost Maastrichtian, but disappear within the last 0.3 Ma of the Cretaceous. In tropical sections of Columbia and Mexico, the decline of ammonites started earlier and Sphenodiscus is the last ammonite known to occur in the late Maastrichtian. In all sections revised here the disappearance of ammonites was completed prior to the end of the Maastrichtian and was thus independent of the asteroid impact at, or near, the end of the Cretaceous.
Źródło:
Acta Palaeontologica Polonica; 2012, 57, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new Cambrian catillicephalid trilobite from the Shallow Bay Formation of western Newfoundland, Canada
Autorzy:
Westrop, Stephen R.
Dengler, Alyce A.
Powiązania:
https://bibliotekanauki.pl/articles/2216209.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Cambrian
Trilobita
Catillicephala
Laurentia
North America
Opis:
Species of Catillicephala are known from sites around the mid-Cambrian margin of Laurentian North America, including Vermont, Quebec, Newfoundland and North Greenland. Catillicephala cifellii sp. nov. is from the Downes Point Member of the Shallow Bay Formation (Cow Head Group) in western Newfoundland. It occurs in three shelf margin-derived boulders in debris flow conglomerates that accumulated in a continental slope setting. The associated trilobites and agnostoid arthropods, including Ptychagnostus aculeatus and Megagnostus glandiformis, indicate a correlation with the Lejopyge laevigata Zone. As such, C. cifellii is among the oldest representatives of the genus, and is early Guzhangian in age.
Źródło:
Acta Palaeontologica Polonica; 2022, 67, 1; 27-33
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A revaluation of rhipidocystid echinoderms based on a new flattened blastozoan from the Upper Ordovician of Maryland, USA
Autorzy:
Zamora, S.
Sprinkle, J.
Sumrall, C.D.
Powiązania:
https://bibliotekanauki.pl/articles/2082230.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Echinodermata
Blastozoa
Rhipidocystidae
Paleozoic
Chambersburg Formation
North America
Opis:
A new rhipidocystid echinoderm from the Upper Ordovician Chambersburg Formation in western Maryland (USA) is here described based on four exquisitely preserved specimens. Specimens of Durhamicystis americana gen. et sp. nov. preserve both thecal sides and the oral area, with identification of major apertures including peristome, periproct, gonopore, and hydropore. This allows orientation of this species and proper comparison across all rhipidocystids. Durhamicystis americana has a large theca composed of ten marginal plates with only two basals on the posterior side, two ambulacra and seven large oral plates with brachioles attached either on orals or smaller flooring plates. Rhipidocystids include taxa with lateral flattening along the BC-DE axis (i.e., Rhipidocystis) and others along the anterior-posterior A-CD axis (i.e., Durhamicystis, Neorhipidocystis, and Petalocystites) suggesting rhipidocystids may be paraphyletic.
Źródło:
Acta Palaeontologica Polonica; 2020, 65, 3; 455-465
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multispecies leatherback turtle assemblage from the Oligocene Chandler Bridge and Ashley formations of South Carolina, USA
Autorzy:
Fallon, B.R.
Boessenecker, R.W.
Powiązania:
https://bibliotekanauki.pl/articles/2082243.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Chelonioidea
Natemys
Egyptemys
Psephophorus
Paleogene
Oligocene
North America
Opis:
Paleogene dermochelyid species richness far exceeded that of today. Leatherback sea turtles were most species rich in the Paleogene, but their richness declined sharply during the Neogene with only one species existing today, Dermochelys coriacea. We describe the fossil remains of three leatherback genera (Natemys, Psephophorus, and Egyptemys) from the upper Oligocene Chandler Bridge Formation and two (Natemys and Psephophorus) from the lower Oligocene Ashley Formation of South Carolina, USA. The fossils consist of isolated and some associated carapacial ossicles. Several ossicles are referred to Natemys sp. because their scalloped edges are indicative of the carapacial sunflower pattern specific to this genus. Additionally, two Natemys morphotypes (Natemys sp. 1 and 2) are distinguished based on differences in ossicle thickness and internal structure. We refer two ossicles to cf. Psephophorus sp. because of their internal diploic structure and because one has a dorsal radial pattern while the other has a prominent ridge that exhibits strong visceral concavity. Finally, we refer one ossicle to cf. Egyptemys sp. because it has a shallow keel that shows little expression on the visceral surface, although we also acknowledge the ossicle’s similarity to some ridged ossicles of the genus Psephophorus. These ossicles represent the first multispecies assemblage of leatherback fossils reported worldwide. Furthermore, the specimens fill both temporal and geographic gaps for extinct leatherback genera and represent the first formally described dermochelyids from South Carolina and the Oligocene of the Atlantic Coastal Plain.
Źródło:
Acta Palaeontologica Polonica; 2020, 65, 4; 763-776
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Geometric morphometric analysis and taxonomic revision of the Gzhelian (Late Pennsylvanian) conodont Idiognathodus simulator from North America
Autorzy:
HOGANCAMP, NICHOLAS J.
BARRICK, JAMES E.
STRAUSS, RICHARD E.
Powiązania:
https://bibliotekanauki.pl/articles/945657.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
conodonta
idiognathodus
morphometrics
pennsylvanian
gzhelian
north america
midcontinent
Opis:
A new morphometric approach was developed to study morphological variation within P1 elements commonly referred to as Idiognathodus simulator, which was selected to be the biostratigraphic marker for the base of the global Gzhelian Stage (Carboniferous). This new approach combines landmark-based geometric morphometrics with eigen analyses to analyze shape variation within P1 elements of the I. simulator group, and could be used to analyze shape variation in other morphologically similar conodont groups. Specimens analyzed were obtained from three sections of the early Gzhelian Heebner Shale of the Oread cyclothem in the North American Midcontinent region, the cyclothem from which I. simulator was originally named. This analysis shows that the I. simulator group comprises a set of at least five species with asymmetrical P1 element pairs, relatively short adcarinal ridges, and a variably developed eccentric groove. Species discrimination is based on the presence of caudal and rostral lobes, character of the adcarinal ridges, and platform shape. The species I. simulator is restricted to P1 elements with a caudal adcarinal ridge that is isolated from the caudal platform margin. Idiognathodus lateralis sp. nov. is erected to include P1 elements with a caudal adcarinal ridge that is not isolated from the caudal platform margin.
Źródło:
Acta Palaeontologica Polonica; 2016, 61, 3; 477-502
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Interatheriinae notoungulates from the middle Miocene Collon Cura Formation in Argentina
Autorzy:
VERA, BÁRBARA
REGUERO, MARCELO
GONZÁLEZ-RUIZ, LAUREANO
Powiązania:
https://bibliotekanauki.pl/articles/945958.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
mammalia
notoungulata
interatheriidae
neogene
south america
patagonia
argentina
Opis:
he Interatheriinae (Notoungulata, Interatheriidae) from the Collón Curá Formation (Colloncuran South American Land Mammal Age, SALMA) are revised here, based on old and new collections from western Neuquén, Río Negro, and Chubut provinces where this geologic unit crops out. After a detailed study of the holotype of Icochilus endiadys, we conclude that its cranial and dental morphology are diagnostic of the genus Protypotherium, and as a result we include I. endiadys in this genus (P. endiadys comb. nov.). Deciduous dentition and postcranial remains are also ascribed to P. endiadys, which allows us to determine its pattern of dental eruption and describe part of its limbs, expanding its diagnosis. In addition, we describe a new species of Protypotherium, P. colloncurensis sp. nov., which differs from P. endiadys in having larger size, a more robust mandible, strongly imbricate upper molars, a well-developed parastyle on P1, a subcircular and non-overlapping p1, a much reduced p2, and a smaller talonid on p3–4. Based on the revision, we identified only one genus of Interatheriinae in the Collón Curá Formation (i.e., Protypotherium). Protypotherium endiadys extends its distribution from Neuquén to Chubut provinces, including Río Negro; the new species, in turn, was only recognized in Río Negro Province, appearing together with P. endiadys in Estancia El Criado, Comallo, and Chico River localities. Discriminant and cladistic analyses were performed including P. endiadys, the new taxon, and other middle Miocene interatheres, and yielded strong support for our systematic conclusions. A thorough phylogenetic analysis of Protypotherium is provided for the first time. Based on this analysis, Protypotherium and Miocochilius form a monophyletic group supported by four synapomorphies.
Źródło:
Acta Palaeontologica Polonica; 2017, 62, 4; 845-863
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Recurrent volcanic activity recorded in araucarian wood from the Lower Cretaceous Springhill Formation, Patagonia, Argentina: Palaeoenvironmental interpretations
Autorzy:
Del Fueyo, G.M.
Carrizo, M.A.
Poire, D.G.
Lafuente Diaz, M.A.
Powiązania:
https://bibliotekanauki.pl/articles/2082290.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Araucariaceae
Agathoxylon
volcanic eruptions
wood
Berriasian
Valanginian
South America
Opis:
This paper describes a petrified trunk collected from a conglomerate bed of the Springhill Formation (Berriasian– Valanginian) in the Estancia El Álamo locality, Santa Cruz Province, Argentina. The fossil trunk is classified within the ubiquitous genus Agathoxylon and the wood anatomy shows a close affinity to that of Araucariaceae. This Patagonian wood has a distinct combination of anatomical characteristics unique among all known species from the Jurassic and Cretaceous of Western Gondwana allowing to diagnose a new fossil taxon Agathoxylon mendezii sp. nov. Sedimentological and megafloristic proxies of the Springhill Formation suggest that Agathoxylon mendezii sp. nov. grew under a warm and wet climate, which indicates a subtropical to temperate palaeoenvironment. However, the large number of frost rings in the earlywood of this araucarian tree suggests that the palaeoenvironment at Estancia El Álamo was subjected to recurrent disturbances, most likely caused by regional continuous volcanic activity originating from volcanoes located far away to the west. This activity would have produced periodic stratospheric veils that promoted rapid decreases in surface air temperature; the wood response to such stressful conditions would have been the formation of numerous (at least five) frost rings. Although recurrent eruptions in Patagonia during the Early Cretaceous are well recorded, this study is the first to register eruptions recorded in a coniferous wood.
Źródło:
Acta Palaeontologica Polonica; 2021, 66, 1; 231-253
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Triassic eucynodont Candelariodon barberenai revisited and the early diversity of stem prozostrodontians
Autorzy:
MARTINELLI, AGUSTÍN G.
BENTO SOARES, MARINA
DE OLIVEIRA, TÉO VEIGA
RODRIGUES, PABLO G.
SCHULTZ, CESAR L.
Powiązania:
https://bibliotekanauki.pl/articles/945630.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
cynodontia
probainognathia
prozostrodontia
dinodontosaurus assemblage zone
south america
brazi
Opis:
The dental anatomy of Candelariodon barberenai from the Dino donto saurus Assemblage Zone (Pinheiros-Chiniquá Sequence, Santa Maria Supersequence, late Ladinian–early Carnian) of south Brazil, is redescribed. Candelariodon was originally classified as Eucynodontia incertae sedis and our analysis recovered this taxon deeply nested within Probainognathia, as the sister taxon of Potheriodon plus Prozostrodontia. The lower postcanine dentition of Candelariodon has several apomorphies shared with Prozostrodon, Santacruzgnathus, Brasilodon/Brasilitherium, and some basal mammaliaforms (Morganucodon, Megazostrodon), such as a lingual cingulum with discrete cusps e and g and two distinct morphologies in the tooth row. The reinterpretation of Candelariodon as a probainognatian cynodont more derived than Probainognathus and the rich Brazilian fossil record document an important adaptive radiation of non-mammaliaform prozostrodontians and closely related forms prior to the origin of the mammaliaform clade.
Źródło:
Acta Palaeontologica Polonica; 2017, 62, 3; 527-542
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative bone microstructure of three archosauromorphs from the Carnian, Late Triassic Chanares Formation of Argentina
Autorzy:
Marsa, J.A.G.
Agnolin, F.L.
Novas, F.E.
Powiązania:
https://bibliotekanauki.pl/articles/2082158.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Archosauromorpha
Lagerpeton
Tropidosuchus
paleobiology
paleohistology
Mesozoic
South America
Opis:
The Chañares Formation exhibits one of the most important archosauriform records of early Carnian ecosystems. Here we present new data on the palaeohistology of Chañares archosauriforms and provide new insights into their paleobiology, as well as possible phylogenetically informative traits. Bone microstructure of Lagerpeton chanarensis and Tropidosuchus romeri is dominated by fibro-lamellar tissue and dense vascularization. On the other hand, Chanaresuchus bonapartei is more densely vascularized, but with cyclical growth characterized by alternate fibro-lamellar, parallel-fibered and lamellar-zonal tissues. Dense vascularization and fibro-lamellar tissue imply fast growth and high metabolic rates for all these taxa. These histological traits may be tentatively interpreted as a possible adaptative advantage in front of Chañares Formation environmental conditions.
Źródło:
Acta Palaeontologica Polonica; 2020, 65, 2; 387-398
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Carved teeth and strange jaws: how glyptodonts masticated
Autorzy:
Farina, R A
Vizcaino, S F
Powiązania:
https://bibliotekanauki.pl/articles/20133.pdf
Data publikacji:
2001
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
glyptodont
biomechanics
paleobiology
tooth
strange jaw
jaw mechanics
South America
Opis:
In this paper, the highly peculiar masticatory apparatus of glyptodonts is studied. The general morphology of the skull is analysed using a morphometric procedure, the Resistant Fit Theta Rho Analysis, which allows comparison among different biological forms. Here, a large terminal form, the late Pleistocene genus Glyptodon, is compared with the smaller primitive Miocene genus Propalaehoplophorus, and with the generalised Recent armadillo Chaetophractus. The masticatory musculature of glyptodonts is reconstructed. Their tooth form and wear facets, as well as their mandibular symphysis and jaw joint, are analysed. A model of jaw movement is constructed based on these analyses. It is demonstrated that the masticatory apparatus of glyptodonts had undergone a telescoping process, which was already underway in the most ancient forms whose skull is known. This process created problems in regard to the way stresses produced by mastication were absorbed by the mandible, and therefore it might be regarded as non-adaptive. Some functional explanatory hypotheses are discussed, such as a requirement of keeping the moment of the weight of the cranium small enough to be counterbalanced by the neck muscles, or fitting the head into the armour.
Źródło:
Acta Palaeontologica Polonica; 2001, 46, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Givetian (Middle Devonian) sharks from Cairo, New York (USA): Evidence of early cosmopolitanism
Autorzy:
Potvin-Leduc, D.
Cloutier, R.
Landing, E.
Hernick, L.V.
Mannolini, F.
Powiązania:
https://bibliotekanauki.pl/articles/945591.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Chondrichthyes
Elasmobranchii
Antarctilamnidae
Omalodontiformes
taxonomy
ontogenesis
paleobiogeography
Devonian
North America
Opis:
Whereas cosmopolitan distribution patterns are established for many Late Devonian vertebrates (e.g., placoderms, onychodontiforms), few palaeobiogeographic studies have considered chondrichthyans. Recent discoveries of shark material demonstrate that some chondrichthyans were cosmopolitan by the Middle Devonian. Abundant Givetian microremains have been recovered from the Cairo quarry in eastern New York State, USA. These include teeth of two shark species with Gondwanan affinities, the omalodontid Portalodus mannoliniae sp. nov. and the antarctilamnid Wellerodus priscus. Abundant teeth of P. mannoliniae sp. nov. are characterized by a smooth diplodont crown, polarized cusps, and a labially oriented base. The teeth demonstrate monognathic heterodonty. The juvenile morph is distinguished from the adult by smaller size, slender cusps, and variation in the shape of the base. W. priscus is represented by rare juvenile teeth. Two groups of scales that show affinity to material from northern (Spain) and East Gondwana (Antarctica) are tentatively attributed to the two described species. Antarctilamnid distribution suggests a north Gondwanan origin and a colonization of the margin of the landmass before dispersing to Laurentia by the Middle Devonian. This material further indicates that vertebrate global dispersal was initiated by the Middle Devonian, and emphasizes earlier palaeogeographic interpretations that the Middle Devonian “Hamilton fauna” of North American Laurussia originated in the Early Devonian in South American Gondwana.
Źródło:
Acta Palaeontologica Polonica; 2015, 60, 1; 183-200
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Diversity of cingulate xenarthrans in the middle–late Eocene of Northwestern Argentina
Autorzy:
CIANCIO, MARTÍN R.
HERRERA, CLAUDIA
ARAMAYO, ALEJANDRO
PAYROLA, PATRICIO
BABOT, JUDITH
Powiązania:
https://bibliotekanauki.pl/articles/945707.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
mammalia
cingulata
dasypodidae
palaeogene
eocene
south america
central andean puna
Opis:
The study of Paleogene mammals of intermediate and low latitudes has increased in the last decades and has been clearly demonstrated their importance in the comprehension of the evolution and faunistic changes outside Patagonia. The study of these faunas permits establishing new comparisons among contemporaneous faunistic associations, completing the distributional patterns, and evaluating evolutionary changes in the lineages in relation to climatic conditions prevailing in each of the different regions. In this work we study the diversity of Dasypodidae recovered from the Geste Formation (Northwestern Argentina). Bearing levels of Geste Formation were referred alternatively to a Barrancan subage of Casamayoran SALMA (middle Eocene, Lutetian–Bartonian) or a Mustersan SALMA (middle–late Eocene, Bartonian–Priabonian) on faunistic comparations with their equivalent in Patagonia, although absolute isotopic data indicates ca. 37–35 Ma (late Eocene, Priabonian). We described the following taxa of Dasypodidae: (i) Dasypodinae Astegotheriini: cf. Astegotherium sp., ?Prostegotherium sp., Parastegosimpsonia cf. P. peruana; (ii) Dasypodinae indet.; (iii) Euphractinae Euphractini: Parutaetus punaensis sp. nov.; (iv) Dasypodidae incertae sedis: Pucatherium parvum, Punatherium catamarcensis gen. et sp. nov. In comparison with other beds bearing Eocene cingulate faunas from Northwestern Argentina, Geste Formation presents the greatest diversity of dasypodids. This association is consistent with a late Eocene age and shows a taxonomic and biogeographic relevant features given by a unique specific composition: (i) it differs from that known for contemporaneous faunas from Southern latitudes and younger associations from more tropical areas; (ii) it includes genera with close affinities to those distant areas; (iii) it presents unique taxa typical from Eocene units exposed at Northwestern Argentina. This highlights the evolutionary and biogeographic meaning of the cingulate of the Geste Formation and supports the idea that the faunistic regionalization probably obeyed to latitudinal than to temporal factors.
Źródło:
Acta Palaeontologica Polonica; 2016, 61, 3; 575-590
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A unique dentary suggests a third genus of batrachosauroidid salamander existed during the latest Cretaceous in the western USA
Autorzy:
Gardner, James D.
Powiązania:
https://bibliotekanauki.pl/articles/2216212.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Lissamphibia
Caudata
Batrachosauroididae
Cretaceous
Maastrichtian
Lance Formation
North America
Opis:
An incomplete salamander dentary (AMNH FARB 22965) described herein from the upper Maastrichtian Lance Formation, Wyoming, USA, exhibits a puzzling suite of features. Four features—a prominent bony trough extending anteriorly and curving upwards along the lingual surface of the ramus, lack of an obvious Meckelian fossa or groove, an apparent gap in the tooth row, and a symphysial-like first tooth—are likely anomalies. However, the remaining features are interpreted as normal structures and suggest that AMNH FARB 22965 represents a new genus and species of batrachosauroidid, an extinct family of neotenic salamanders that were prominent components of Cretaceous to Neogene freshwater and floodplain paleocommunities in North America and Europe. The new taxon differs from other batrachosauroidids in a unique suite of dentary and dental features, most notably in having a lingual bony flange paralleling the posterior two-thirds of the dentary tooth row, a prominent and robust coronoid process bearing a grooved anterior face, and the anterior portion of the corpus dentalis behind the symphysis is broadly expanded ventrolingually. The presence of a third batrachosauroidid taxon in the Lance Formation was unexpected, considering that the formation has been well sampled and that its two previously recognized batrachosauroidids, namely Opisthotriton kayi and Prodesmodon copei, are known by abundant isolated bones, including dozens of dentaries, from numerous localities in the unit and elsewhere in the North American Western Interior. Known by a unique dentary from the Bushy Tailed Blowout locality, the taxon represented by AMNH FARB 22965 evidently was uncommon within the Lance Formation paleoenvironment.
Źródło:
Acta Palaeontologica Polonica; 2022, 67, 1; 35-50
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
First North American occurrence of hairy cicadas discovered in the Cenomanian (Late Cretaceous) of Labrador, Canada
Autorzy:
Demers-Potvin, A.V.
Szwedo, J.
Paragnani, C.P.
Larsson, H.C.E.
Powiązania:
https://bibliotekanauki.pl/articles/2082146.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Insecta
Cicadoidea
Tettigarctidae
Cretaceous
Cenomanian
Redmond Formation
North America
Opis:
We report the discovery of Maculaferrum blaisi gen. et sp. nov, the first occurrence of the family Tettigarctidae, informally known as hairy cicadas, in North America. Maculaferrum blaisi is part of a new collection assembled during recent fieldwork in the Redmond Formation, Labrador, Canada, near Schefferville. It consists in a single isolated forewing whose venational characters allow a classification to Tettigarctinae at the subfamily level. Classification at a higher level remains uncertain since it displays a combination of characters supposedly unique to tribes Protabanini, Meunierini, and Tettigarctini. Thus, this discovery adds credence to suggestions of a revision of the definitions of these tribes since they seem to be based on many convergent or plesiomorphic characters. Remnants of a spotted pattern on the wing membrane and probable setae along some veins are also preserved. Observations of the holotype’s fine anatomical characters have been facilitated by the use of Reflectance Transformation Imaging (RTI), an emerging method for the visualization of compression and impression fossils. Considering that the estimated age of the Redmond Formation is the Cenomanian (Late Cretaceous), the discovery of M. blaisi contributes to a very recent expansion of the tettigarctid fossil record that fills a gap between Early Cretaceous and Cenozoic genera. It suggests that hairy cicadas maintained a global distribution and thrived in a variety of climate regimes well into the Late Cretaceous, and that their competitive exclusion by singing cicadas occurred definitely closer to the end of the Cretaceous, or even during the Cenozoic. This discovery is only the start of a thorough description of the recently expanded entomofauna in the Cretaceous of Labrador.
Źródło:
Acta Palaeontologica Polonica; 2020, 65, 1; 85-98
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The paleoecology of the Late Miocene mammals from the Optima Local Fauna of Oklahoma, USA
Autorzy:
Frederickson, Joseph A.
Cohen, Joshua E.
Engel, Michael H.
Hunt, Tyler C.
Wilbert, Greg A.
Castaneda, Olga S.
Czaplewski, Nicholas J.
Powiązania:
https://bibliotekanauki.pl/articles/2216233.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Mammalia
grassland
tooth breakage
Neogene
North America
mesowear
savanna
stable isotopes
Opis:
The Optima Local Fauna represents an important glimpse into the ecological transition between savannah and grassland during the late Miocene (Hemphillian) of what is now the southcentral Great Plains of North America. Though dominated by horses, herbivores from the Optima are morphologically diverse, bearing adaptations for both browsing and grazing lifestyles. Likewise, the carnivorans show similar ranges of size and presumed dietary behavior. In this study, we used carbonate isotope, mesowear, and tooth breakage and wear analyses to investigate the dietary complexity of mammals from a single site collected by the Oklahoma Museum of Natural History. Seventeen taxa were analyzed, including five perissodactyls (Teleoceras hicksi, Dinohippus interpolatus, Neohipparion eurystyle, Nannippus ingenuus, and Astro hippus ansae), four artiodactyls (Texoceros guymonensis, Pediomeryx hemphillensis, Megatylopus matthewi, and Platy gonus sp.), a single proboscidean (Mammut sp.), two rodents (Dipoides indet. and Umbogaulus monodon), and five carni vorans (Agriotherium schneideri, Amphimachairodus coloradensis, Borophagus secundus, Eucyon davisi, Pliotaxi dea cf. nevadensis). Both stable isotope analysis and dental mesowear indicate a broad dietary partitioning occurred among the Optima herbivores, where the artiodactyls were identified as mixed feeders and the perissodactyls were recovered as grazers. In the carnivorans, the large felid Amphimachairodus coloradensis was a hypercarnivore with limited tooth breakage and an enriched δ13C signature, indicating low carcass utilization and a prey preference for horses. The canids had a more generalized diet, with B. secundus showing a greater proportional consumption of carcasses through a higher tooth breakage rate. The large ursid Agriotherium schneideri is here interpreted as an omnivore based on depleted δ13 C values. Overall, we found evidence for a diversity of dietary niches in both carnivores and herbivores during the late Hemphillian in Oklahoma, likely driven by the expansion of grasslands in the region.
Źródło:
Acta Palaeontologica Polonica; 2022, 67, 1; 221-238
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł

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