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Tytuł:
Carcharocles-bitten odontocete caudal vertebrae from the Coastal Eastern United States
Autorzy:
Godfrey, S.J.
Ellwood, M.
Groff, S.
Verdin, M.S.
Powiązania:
https://bibliotekanauki.pl/articles/22222.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Opis:
A description and analysis is given of three Neogene odontocete caudal vertebrae that were bitten by the extinct megatooth sharks Carcharocles megalodon or Carcharocles chubutensis. The peduncular caudal vertebrae show bilateral gouge marks consistent with having been actively bitten and wedged between adjacent teeth of C. megalodon or C. chubutensis. None of the vertebrae show signs of healing. The occurrence of bite marks on distal caudals suggests active predation (vs. scavenging) in order to immobilize even relatively small prey prior to consumption.
Źródło:
Acta Palaeontologica Polonica; 2018, 63, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dwarfism and feeding behaviours in Oligo-Miocene crocodiles from Riversleigh, northwestern Queensland, Australia
Autorzy:
Stein, M.
Archer, M.
Hand, S.J.
Powiązania:
https://bibliotekanauki.pl/articles/22617.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
dwarfism
feeding behaviour
Oligocene
Miocene
crocodile
Crocodylia
Mekosuchinae
Queensland
Australia
Opis:
Instances of dwarfism in the fossil record are of interest to palaeontologists because they often provide insight into aspects of palaeoecology. Fossil species of Australian-Pacific mekosuchine genus Mekosuchus have been described as dwarf, primarily terrestrial crocodiles, in contrast with the nearly ubiquitous semi-aquatic habitus of extant crocodilians (Willis 1997). This hypothesis has been difficult to test because of limited knowledge of the cranial and postcranial skeleton of extinct taxa and the continuous nature of crocodilian growth. New crocodilian vertebral material from Riversleigh, northwestern Queensland, tentatively referred to Mekosuchus whitehunterensis, displays morphological maturity indicative of adult snout-vent length little over a half-meter, proportionally smaller than extant dwarf taxa. Further, this material displays morphology that indicates a relatively large epaxial neck musculature for its body-size. These attributes suggest this dwarf mekosuchine employed unusual feeding behaviours. The ability to perform normal death-roll, de-fleshing behaviours would be limited in a mekosuchine of such small size. Given the powerful neck muscles and other anatomical features, it is more likely that this mekosuchine killed and/or dismembered its prey using a relatively forceful lifting and shaking of the head.
Źródło:
Acta Palaeontologica Polonica; 2016, 61, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new Miocene sirenian from Kutch, India
Autorzy:
Thewissen, J G M
Bajpai, S.
Powiązania:
https://bibliotekanauki.pl/articles/22608.pdf
Data publikacji:
2009
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Miocene
new species
Sirenia
paleontology
sirenian
India
Domningia
Kutch District
Mammalia
Opis:
We report a new Miocene sirenian from District Kutch, State of Gujarat, India: Domingia sodhae gen. et sp. nov. The new species is a dugongine dugongid with flattened tusk−like upper incisors. Like some other Miocene dugongids, Domningia is large and has complex, bilophodont molars and three−rooted premolars, which are strongly worn. The rostrum is downturned significantly, similar to modern dugongs, and indicative of a specialized feeding mode. Phylogenetically, it is closely related to Dioplotherium, Rytiodus, Corystosiren, and Bharatisiren. Among these, Domningia is most similar to Bharatisiren indica and Dioplotherium manigaulti, in that all three taxa retain multi−rooted premolars. Similar to Bharatisiren, the nasal process of the premaxilla is long. Bharatisiren and Domningia are part of a late Oligocene and early Miocene radiation of dugongines in South Asia.
Źródło:
Acta Palaeontologica Polonica; 2009, 54, 1; 7-13
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ailurid carnivoran mammal Simocyon from the late Miocene of Spain and the systematics of the genus
Autorzy:
Peigne, S
Salesa, M.J.
Anton, M.
Morales, J.
Powiązania:
https://bibliotekanauki.pl/articles/21488.pdf
Data publikacji:
2005
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Ailuridae
red panda
Miocene
mammal
Mammalia
Carnivora
Simocyon
Europe
Ailurus fulgens
Spain
Madrid Basin
paleontology
Opis:
We describe the most complete and best−preserved materials assigned to Simocyon from Spain. Specimens come from the late Miocene (Vallesian) locality of Batallones−1, Province of Madrid and are assigned to Simocyon batalleri. Cranial, mandibular and dental anatomy of S. batalleri from Batallones−1 is described and compared with those of known species of Simocyon. We review the systematic status and the definition of the species of Simocyon and we analyse the morphological variation within Simocyon. Three species are recognized as valid. S. batalleri is known from several Vallesian localities (mainly MN 10) of Spain. S. diaphorus, from the early Vallesian of Germany (Mammal Zone MN 9), is the geologically oldest European species. The type species S. primigenius is Turolian in age and known from several localities of Europe, North America, and China. The species includes the junior synonyms S. zdanskyi and S. marshi. The status of Simocyon hungaricus is not resolved. Simocyon simpsoni is excluded here from Simocyon and reassigned to its original generic name Protursus. On the basis of the material described here, we propose a differential diagnosis for Simocyon batalleri. This species is morphologically intermediate between the more primitive S. diaphorus, which has a less reduced p3; and the more derived S. primigenius, characterized by a modified mandible (e.g., more vertical and more expanded coronoid process, longer angular process). The evolution of the genus Simocyon is characterized by a trend toward a more crushing adaptation involving at least a modification of the posterior part of the mandible. A reconstruction of the skull and life appearance of Simocyon is proposed.
Źródło:
Acta Palaeontologica Polonica; 2005, 50, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quail-thrush birds from the Miocene of northern Australia
Autorzy:
Nguyen, J.M.T.
Archer, M.
Hand, S.J.
Powiązania:
https://bibliotekanauki.pl/articles/23484.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Opis:
Quail-thrushes (Passeriformes: Cinclosomatidae: Cinclosoma) are ground-dwelling corvoid songbirds endemic to Austra lia and New Guinea. Until now, the only known quail-thrush fossils have been from late Quaternary cave deposits in Australia. A new species of quail-thrush, Cinclosoma elachum sp. nov., is described from the early to middle Miocene deposits in the Riversleigh World Heritage Area, Queensland, Australia. A second, larger quail-thrush is identified from the middle Miocene of Riversleigh. The new fossils considerably extend the geographic and temporal ranges of cinclosomatids, and indicate the presence of two species of quail-thrushes in the Miocene of northern Australia, located more than 300 km from the nearest extant member of Cinclosoma. These fossils provide a minimum age of ~18 million years for Cinclosomatidae. They cannot be confidently assigned to the crown group of the genus Cinclosoma, but can be used to calibrate the split between this genus and Ptilorrhoa in molecular dating studies of the Corvides radiation and Passeriformes overall. This material also adds to the growing diversity of songbirds identified from the pre-Pleistocene record of Australia, and reemphasises the global significance of the Riversleigh deposits in developing understanding about the early evolutionary history of passerines.
Źródło:
Acta Palaeontologica Polonica; 2018, 63, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New genus of dimeropygid trilobites from the earliest Ordovician of Laurentia
Autorzy:
Adrain, J.M.
Westrop, S.R.
Powiązania:
https://bibliotekanauki.pl/articles/21221.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Dimeropygidae
Hystricuridae
Ordovician
silicified fossil
Trilobita
dimeropygid trilobite
new genus
paleontology
trilobite
fossil
Ibexian
locality
stratigraphy
ecology
systematics
Opis:
The new genus Tulepyge includes a type species, T. tulensis nov., from the Barn Canyon Member of the House Formation, western Utah, USA, and T. paucituberculata from the Broom Point Member of the Green Point Formation, western Newfoundland, Canada. Both species are earliest Ordovician in age, with occurrence immediately above the Cambrian–Ordovician boundary. Together with the hystricurid taxon Millardicurus, the new genus is likely to serve as an indicator fossil for the Cambrian–Ordovician boundary in Laurentia, as it is already known from different biofacies on opposite margins of the continent. Tulepyge is not closely comparable with contemporaneous taxa assigned to Hystricuridae but in its dorsally convex and coarsely tuberculate exoskeleton it resembles taxa which have been referred to Dimeropygidae, most of which are considerably younger in age.
Źródło:
Acta Palaeontologica Polonica; 2006, 51, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The early fossil record of dinosaurs in North America: a new neotheropod from the base of the Upper Triassic Dockum Group of Texas
Autorzy:
Nesbitt, S.J.
Ezcurra, M.D.
Powiązania:
https://bibliotekanauki.pl/articles/22614.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Opis:
The dinosaur record from the stratigraphically-lowest portions of Upper Triassic deposits of western North America is poor and only consists of a handful of fragmentary hind limb elements. Here we present an articulated segment of the ankle region of a dinosaur that consists of the distal ends of the tibia and fibula and a complete astragalocalcaneum. Additionally, we suggest that an isolated femur and maxilla from the same locality may belong to the same taxon. Using the most comprehensive analysis of early theropod relationships currently available, we determined that the new specimen pertains to a coelophysoid neotheropod (i.e., more closely related to Coelophysis bauri than to Allosaurus fragilis). The stratigraphic position of the locality where the new specimen was discovered is equivalent to the famous Otis Chalk localities and this set of localities likely predates the rest of the Dockum Group and possibly the entirety of the fossiliferous portion of the Chinle Formation on the Colorado Plateau. Therefore, the new specimen represents one of the oldest neotheropods. Accordingly, neotheropods were present at or just after the onset of both the Chinle Formation and Dockum Group deposits.
Źródło:
Acta Palaeontologica Polonica; 2015, 60, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An early Cambrian fauna of skeletal fossils from the Emyaksin Formation, northern Siberia
Autorzy:
Kouchinsky, A.
Bengtson, S.
Clausen, S.
Vendrasco, M.J.
Powiązania:
https://bibliotekanauki.pl/articles/20089.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Opis:
An assemblage of mineralised skeletal fossils containing molluscs, hyoliths, halkieriids, chancelloriids, tommotiids, lobopodians, paleoscolecids, bradoriids, echinoderms, anabaritids, hyolithelminths, hexactinnelid, and heteractinid sponges is described from the early Cambrian Emyaksin Formation exposed along the Malaya Kuonamka and Bol’shaya Kuonamka rivers, eastern flanks of the Anabar Uplift, northern Siberian Platform. The sampled succession is attributed to the Tommotian–Botoman Stages of Siberia and correlated with Stage 2 of Series 1–Stage 4 of Series 2 of the IUGS chronostratigraphical scheme for the Cambrian. Carbon isotope chemostratigraphy is applied herein for regional correlation. The fauna contains the earliest Siberian and probably global first appearances of lobopodians, paleoscolecids, and echinoderms, and includes elements in common with coeval faunas from Gondwana, Laurentia, and Baltica. For the first time from Siberia, the latest occurrence of anabaritids is documented herein from the Atdabanian Stage. Problematic calcium phosphatic sclerites of Fengzuella zhejiangensis have not been previously known from outside China. The sellate sclerites, Camenella garbowskae and mitral sclerites, C. kozlowskii are unified within one species, C. garbowskae. In addition to more common slender sclerites, Rhombocorniculum insolutum include broad calcium phosphatic sclerites. A number of fossils described herein demonstrate excellent preservation of fine details of skeletal microstructures. Based on new microstructural data, sclerites of Rhombocorniculum are interpreted as chaetae of the type occurring in annelids. A new mollusc Enigmaconus? pyramidalis Kouchinsky and Vendrasco sp. nov. and a hyolith Triplicatella papilio Kouchinsky sp. nov. are described.
Źródło:
Acta Palaeontologica Polonica; 2015, 60, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The postcranial skeleton of the Early Triassic parareptile Sauropareion anoplus, with a discussion of possible life history
Autorzy:
MacDougall, M.J.
Modesto, S.P.
Botha-Brink, J.
Powiązania:
https://bibliotekanauki.pl/articles/21394.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Opis:
The skeletal anatomy of the Early Triassic (Induan) procolophonid reptile Sauropareion anoplusis described on the basis of three partial skeletons from Vangfontein, Middelburg District, South Africa. Together these three specimens preserve the large majority of the pectoral and pelvic girdles, articulated forelimbs and hindlimbs, and all but the caudal portion of the vertebral column, elements hitherto undescribed. Our phylogenetic analysis of the Procolophonoidea is consonant with previous work, positing S. anoplus as the sister taxon to a clade composed of all other procolophonids exclusive of Coletta seca. Previous studies have suggested that procolophonids were burrowers, and this seems to have been the case for S. anoplus, based on comparisons with characteristic skeletal anatomy of living digging animals, such as the presence of a spade−shaped skull, robust phalanges, and large unguals.
Źródło:
Acta Palaeontologica Polonica; 2013, 58, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cyanobacterial key to the genesis of micritic and peloidal limestones in ancient seas
Cyjanobakteryjna geneza wapieni mikrytowych i peloidalnych w dawnych zbiornikach morskich
Autorzy:
Kazmierczak, J
Coleman, M L
Gruszczynski, M
Kempe, S
Powiązania:
https://bibliotekanauki.pl/articles/20317.pdf
Data publikacji:
1996
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
osady wapniowe
Gory Swietokrzyskie
wapienie peloidalne
srodowisko morskie
aragonit
wapienie mikrytowe
jura
kalcyt
mikroorganizmy
paleontologia
sinice
zbiorniki morskie
Opis:
The origin of micritic and peloidal limestones comprising the bulk of many ancient marine carbonate deposits represents a major unsolved problem of carbonate sedimentology. Our studies of such limestones from a sequence of Late Jurassic open marine sediments exposed in central Poland revealed them as products of in situ calcified mats of benthic coccoid cyanobacteria. Remains of the cyanobacteria are visible in scanning electron microscope (SEM) images as characteristic patterns closely resembling the common mucilage sheaths of modern entophysalidacean and/or pleurocapsalean cyanobacteria comparable to those we found producing micritic and peloidal microbialites in Lake Van, Turkey. We suggest, by analogy, that many subtidal micritic and peloidal limestones common in the marine sedimentary record might be products of similar in situ calcified cyanobactend microbiota. Such an intensive calcification of marine cyanobacteria could have proceeded only in environments more than modern seawater supersaturated with respect to calcium carbonate minerals. Advection of excess alkalinity, originating from deeper, anaerobic or dysaerobic zones to shallow water areas is proposed as the main factor enhancing colonization of extensive sea bottom areas by the alkaliphilic cyanobacteria and promoting their in uiuo calcification.
Geneza wapieni mikrytowych i peloidalnych, głównych składników większości kopalnych morskich formacji wapiennych, nie została do tej pory rozwiązana i od ponad stu lat jest jednym z bardziej kontrowersyjnych problemów sedymentologii i petrologii skał węglanowych. Przedstawione w pracy wyniki badań nad takimi wapieniami z utworów późnej jury (kimerydu) Gór Świętokrzyskich wykazały, że osady te są wytworem in situ zwapniałych bentosowych mat kokkoidalnych cyjanobakterii (= sinic). Szczątki tych mikroorganizmów widoczne są w skaningowym mikroskopie elektronowyrn w postaci charakterystycznych struktur, przypominających wspólne osłony śluzowe (glycocalyx) otaczające komórki i grupy komórek w koloniach dzisiejszych bentosowych kokkoidalnych cyjanobakterii zaliczanych do grup Chroococcales (szczególnie Entophysalis) i Pleurocapsales (Pleurocapsa). Szczegółowe badania porównawcze przeprowadzone zostały na dzisiejszych, w różnym stopniu zwapniałych matach takich cyjanobakterii występujących w alkalicznym (sodowym) Jeziorze Wan (wschodnia Turcja). Wyniki tych badań pozwalają wnioskować, że zarówno mikrytowe i peloidalne wapienie jurajskie, jak i miąższe serie podobnych morskich wapieni pospolitych w zapisie litologicznym innych okresów geologicznych są produktem in situ zwapniałych mat kokkoidalnych cyjanobakterii. Istnieją podstawy aby przypuszczać, iż tak intensywna kalcyfikacja morskich cyjanobakterii mogła odbywać się jedynie w środowisku, które w porównaniu z dzisiejszą wodą morską było bardziej przesycone w stosunku do produktu rozpuszczalności takich pospolitych minerałów węglanowych jak kalcyt i aragonit. Głównym czynnikiem utrzymującym wyższy od obecnego poziom przesycenia węglanem wapnia w dawnych środowiskach morskich był najprawdopodobniej napływ do fotycznej strefy zasiedlonej przez cyjanobakterie ekscesywnie alkalicznych wód pochodzących z głębszych, anaerobowych (stratyfikowanych) lub dysaerobowych partii zbiorników, których podwyższona alkaliczność była wynikiem metabolicznej aktywności bakterii redukujących siarczany w procesie remineralizacji substancji organicznej w strefach deficytu tlenowego.
Źródło:
Acta Palaeontologica Polonica; 1996, 41, 4; 319-338
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Trachyplax arctica, a new multiplated problematic fossil from the Lower Cambrian of North Greenland
Autorzy:
Larsson, C M
Peel, J.S.
Hogstrom, A.E.S.
Powiązania:
https://bibliotekanauki.pl/articles/20953.pdf
Data publikacji:
2009
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Trachyplax arctica
fossil
paleontology
Lower Cambrian
Cambrian
North Greenland
Greenland
Trachyplax
Problematica
sclerite
scleritome
Multiplacophora
Paralledal Formation
Opis:
A new scleritome−bearing organism with eight sclerite types, Trachyplax arctica gen. et sp. nov., is described from the lower Cambrian Paralledal Formation of North Greenland. The originally calcareous sclerites are now silicified; no microstructures are preserved. The dominant sclerite type (A; maximum dimension 19.3 mm) is bilaterally symmetrical, strongly arched, with an oval shield showing co−marginal growth lines and a projecting rostrum with prominent radial ornamentation. A similar sclerite morphology can be identified in Silurian–Carboniferous multiplacophoran molluscs but the remaining sclerite types, which also display a combination of concentric and radial ornamentation, find no clear equivalents. Two models for scleritome reconstruction are presented, based on the relative abundance of the sclerites, but neither promotes a satisfactory assignment to a higher taxon. Despite the morphological dissimilarities, possibly reflecting the age discrepancy, reference to the Multiplacophora is most attractive and entails a substantial extension of the known geological range of that group.
Źródło:
Acta Palaeontologica Polonica; 2009, 54, 3; 513-523
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Systematic revision of a Miocene sperm whale from Patagonia, Argentina, and the phylogenetic signal of tympano-periotic bones in Physeteroidea
Autorzy:
Paolucci, F.
Buono, M.R.
Fernandez, M.S.
Cuitino, J.
Powiązania:
https://bibliotekanauki.pl/articles/2082284.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Mammalia
Physeteroidea
Preaulophyseter gualichensis
Miocene
Patagonia
Argentina
Opis:
Sperm whales (Physeteroidea) include today only two genera of morphologically disparate odontocetes: the largest toothed whale known (Physeter macrocephalus) and small sized forms (Kogia spp.). In contrast, their fossil record indicates a high diversity for the group during the Miocene, with over 20 species recognized. Miocene marine sediments from Patagonia (Argentina) record this diversity, including at least five species. Among them, Preaulophyseter gualichensis, from the Miocene of Gran Bajo del Gualicho Formation, has been one of the most enigmatic. Despite the fragmentary nature of the type and referred materials (isolated teeth and periotics), which casts some doubts on its validity, this species has not been revised since its original description. In this contribution, we re-describe the materials referred to P. gualichensis, revise the taxonomic status of the species and evaluate the phylogenetic signal of ear bones among Physeteroidea. Our results indicate that the physeteroid tympano-periotic complex morphology is poorly diagnostic at the species level. Intraspecific variation (including ontogeny and sexual dimorphism) and/or taphonomic processes cannot be ruled out as the causes of the minor differences observed among specimens. We suggest that sperm whale tympano-periotics retain many plesiomorphic characters and are diagnostic only between kogiids and non-kogiid physeteroids. Based on the fragmentary and isolated state of the studied specimens, and the lack of diagnostic characters in both teeth and periotics, we consider P. gualichensis as nomen dubium and we re-assign the referred specimens as Physeteroidea indet. A conservative morphology of the tympano-periotic and, to a lesser extent, the nasal complex in sperm whales, might result from the morpho-functional constraints imposed by a highly specialized but successful echolocation system.
Źródło:
Acta Palaeontologica Polonica; 2021, 66, 1; 63-76
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ontogenetic stages of ceratopsian dinosaur Psittacosaurus in bone histology
Autorzy:
Zhao, Q.
Benton, M.J.
Hayashi, S.
Xu, X.
Powiązania:
https://bibliotekanauki.pl/articles/20498.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Opis:
The early ceratopsians Psittacosaurus and Protoceratops have provided important information on dinosaurian development because of abundant specimens of adults, subadults, juveniles, and even hatchlings. Here we present new data and methods for identifying key growth stages from bone histology. Previous studies on Psittacosaurus lujiatunensis from the Early Cretaceous Jehol Biota of China did not present in-depth analysis of growth patterns. Based on a histological study of 43 thin sections from 17 individuals of this species, we recognize four histological ontogenetic stages, i.e., hatchling, juvenile, sub-adult, and adult, but no fully-grown stage. We estimate life history and longevity from diaphyseal growth line counts and other features of histology. We show that P. lujiatunensis grew fast in early stages (hatchling, juvenile, and subadult), according to the density of vascular canals and the different type of bone tissue; the deposition of parallel fibred bone tissue in the outer cortex of the subadult stage indicates that growth rate was slowing down. We introduce a new graphical method to estimate the occurrence and volumes of vascular canals from thin sections more accurately than current two-dimensional approaches.
Źródło:
Acta Palaeontologica Polonica; 2019, 64, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New sauropodomorph and cynodont remains from the Late Triassic Sacisaurus site in southern Brazil and its stratigraphic position in the Norian Caturrita Formation
Autorzy:
Marsola, J.C.A.
Bittencourt, J.S.
Da Rosa, A.A.S.
Martinelli, A.G.
Ribeiro, A.M.
Ferigolo, J.
Langer, M.C.
Powiązania:
https://bibliotekanauki.pl/articles/21152.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Opis:
Sacisaurus agudoensis is the only silesaurid known from the Triassic beds of the Santa Maria Supersequence and the correlation of its type locality to the other Triassic deposits of south Brazil has always been controversial. In an attempt to improve this, a handful of dinosaur and cynodont remains found associated to S. agudoensis are here described and compared. The anatomy of the sauropodomorph is more similar to that of Norian forms such as Pantydraco caducus and Unaysaurus tolentinoi than to that of Carnian taxa such as Saturnalia tupiniquim and Pampadromaeus barberenai. The cynodonts recovered based on isolated teeth include a brasilodontid and a Riograndia-like form. This assemblage is consistent with a Norian age, as is also suggested by local stratigraphic correlation, which positions the site in the Caturrita Formation.
Źródło:
Acta Palaeontologica Polonica; 2018, 63, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reappraisal of the south American Miocene snakes of the genus Colombophis, with description of a new species
Autorzy:
Hsiou, A S
Albino, A.M.
Ferigolo, J.
Powiązania:
https://bibliotekanauki.pl/articles/22416.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
South America
Miocene
snake
Colombophis
new species
Serpentes
Alethinophidia
paleontology
systematics
location
Solimoes Formation
Opis:
A redescription of the extinct snake genus Colombophis is presented, on the basis of new specimens from the late Miocene of southwestern Brazilian Amazonia, and those previously reported for the middle Miocene of Colombia and Venezuela. The reappraisal of Colombophis allows the recognition of a new species,C. spinosussp. nov. The revised diagnosis of the genus is based on the midtrunk vertebrae, distinct from those of other snakes mainly in the features of the neural arch, position and shape of the neural spine, inclination of the zygapophyses, shape of the centrum, and development of the haemal keel. The affinities of Colombophis with “Anilioidea” are still unresolved; it is distinguished from all known extinct and extant “anilioids” due to its great vertebral size and the frequent presence of paracotylar foramina. The posterior paired apophyses of the haemal keel in some vertebrae, and the high neural spine of C. spinosus also contrast significantly with the “anilioid” genera, making the allocation of the genus into this probably paraphyletic group not well supported. Here, we recognized Colombophis as a basal alethinophidian of uncertain relationships.
Źródło:
Acta Palaeontologica Polonica; 2010, 55, 3; 365-379
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł

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