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Tytuł:
New Early Jurassic gastropods from west-central Patagonia, Argentina
Autorzy:
Ferrari, S.M.
Powiązania:
https://bibliotekanauki.pl/articles/23237.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
new gastropod
Early Jurassic
gastropod
Patagonia
Argentina
Gastropoda
Mulanguineu Formation
Pliensbachian
Toarcian
Jurassic
Chubut
Opis:
A new gastropod fauna is reported from Chubut province of west−central Patagonia. Members of Trochoidea, Pseudo− melanoidea, Campaniloidea, and Nerinoidea are recorded from the Early Jurassic (Late Pliensbachian–Early Toarcian) of Mulanguińeu Formation. The gastropod fauna consists of two new species: the pseudomelaniid Pseudomelania feruglioisp. nov. and the protorculid Anulifera chubutensissp. nov. Other members of the association are Pseudomelania sp.; the ampulloispirids Globularia cf. catanlilensis, Globularia sp., and Naricopsina? sp.; the nerineids Nerinea? sp. 1 and Nerinea? sp. 2; the trochids Lithotrochus humblodtii, Lithotrochus cf.rothi, and two indeterminable trochids species. An analysis of diversity was made considering all gastropod fauna recovered so far from five fossiliferous localities sampled in west−central Patagonia. The preliminary results of this study suggests that the Jurassic marine sequences of west central Chubut province are dominated by gastropods of Eucyclidae, Pseudomelaniidae, Procerithiidae, and Ampullinidae groups. However, the rarefaction curves of particular marine gastropod faunas in the Jurassic of Patagonia are still far from saturation requiring further collecting effort.
Źródło:
Acta Palaeontologica Polonica; 2013, 58, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cosmopolitan Early Jurassic marine gastropods from west-central Patagonia, Argentina
Autorzy:
Ferrari, S M
Powiązania:
https://bibliotekanauki.pl/articles/21564.pdf
Data publikacji:
2009
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Early Jurassic
Jurassic
marine gastropod
gastropod
Patagonia
Argentina
Gastropoda
Osta Arena Formation
Toarcian
Chubut
Opis:
A new, relatively diverse gastropod fauna is reported from the Chubut province of west−central Patagonia. The gastropod association at the “El Córdoba” fossiliferous locality (Lower Toarcian of Osta Arena Formation) consists of three new species: the eucyclid Amberleya? espinosa sp. nov. and two procerithiids Cryptaulax damboreneae sp. nov. and Cryptaulax nulloi sp. nov. Other members of the association are the ataphrid Striatoconulus sp., discohelicid Colpomphalus? sp., and an undetermined zygopleurid. Knowledge on Early Jurassic gastropods from South America and other southern continents is reviewed to show that the taxonomic composition of the El Cordoba association strongly resembles other gastropod associations of this age (even those from Europe), suggesting a wide distribution of cosmopolitan genera.
Źródło:
Acta Palaeontologica Polonica; 2009, 54, 3; 449-461
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:
Ontogeny and autecology of an Early Cretaceous trigoniide bivalve from Neuquén Basin, Argentina
Autorzy:
Echevarria, J.
Powiązania:
https://bibliotekanauki.pl/articles/945794.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
mollusca
bivalvia
trigoniida
ontogeny
larval development
shell growth
allometry
life habits
cretaceous
argentina
Opis:
Understanding ontogenetic variation is fundamental for adequate species definition and is the key for recognizing evolutionary relevant processes like heterochrony or developmental constraints. The larval and post-larval shell ontogeny and the ecology of the trigoniide bivalve Myophorella garatei are described in this paper. The species occurs in offshore transition facies of the late Valanginian Pilmatué Member of the Agrio Formation in the Neuquén Basin, Argentina. The larval shell has a rather small prodissoconch I; and if prodissoconch II is present, it is rather weakly developed. From these data, a larval stage of low dispersal capability is inferred for Myophorella garatei, either short-lived planktotrophic or nonplanktotrophic. The study of post-larval development included general shell shape and ornamentation. To assess general shell shape a geometric morphometric analysis was performed on the lateral view, together with a study of allometry for the shell width. As a result, two main allometric stages of development could be identified. During the first stage a relative size reduction of the area co-occurs with a slight elongation of the shell, while the second stage is marked by dorsal bending of the shell and an increase on relative width. Ornamentation was examined qualitatively, but also a geometric morphometric analysis was performed on the flank costae. The first two flank costae are subconcentric; from the third costa onwards they become oblique, intially changing from more curved to less curved shapes, while on a third stage they show the opposite trend. Finally, a general interpretation of the adaptive morphology of adult shell was performed, concluding that M. garatei was adapted to low energy, soft bottom environments, and probably lived with the posterior straight margin levelled at the water-sediment interface.
Źródło:
Acta Palaeontologica Polonica; 2014, 59, 2; 407-420
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Anisodontherium from the Late Miocene of north-western Argentina
Autorzy:
Brandoni, D.
Powell, J.E.
Gonzales, O.E.
Powiązania:
https://bibliotekanauki.pl/articles/20115.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Anisodontherium
Late Miocene
Miocene
paleontology
Argentina
Xenarthra
Megatheriinae
ground sloth
diversity
Upper Miocene
Opis:
The fossil record of Megatheriinae (Tardigrada, Megatheriidae) in Argentina extends from the Colloncuran (Middle Miocene of Patagonia) to the Lujanian (Late Pleistocene–Early Holocene of the Pampean region). In the Late Miocene of north−western Argentina, Megatheriinae is represented by just three species belonging to a single genus, Pyramiodontherium. Here, we describe a partial mandible and the phalanges of a third digit of the manus recovered from the Saladillo Formation (Upper Miocene) of Tucumán Province, and assign them to Anisodontherium sp. Anisodontherium is primarily characterized by mesiodistally compressed molariforms, an anterior margin of the coronoid process located posterior to m4, and a posterior margin of the mandibular symphysis located anterior to m1. While these features can also be observed in A. halmyronomum from the Arroyo Chasicó Formation (Buenos Aires Province, Pampean region), Anisodontherium sp. is smaller and more slender than the former. The shape of each molariform of Anisodontherium affects the total length of the molariform tooth row, and thus the interpretation of some characters used in cladistic and paleobiological analyses. The material described here adds to the knowledge of the mandibular and dental anatomy of early megatheriines. In addition, the occurrence of Anisodotherium in Tucumán Province provides the first record of this genus outside the Pampean region, and increases the diversity of megatheriines during the Late Miocene–Pliocene of north−western Argentina.
Źródło:
Acta Palaeontologica Polonica; 2012, 57, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A review of the endocerid cephalopod Protocyptendoceras from the Floian [Lower Ordovician] of the Eastern Cordillera, Argentina
Autorzy:
Cichowolski, M
Powiązania:
https://bibliotekanauki.pl/articles/20173.pdf
Data publikacji:
2009
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Cephalopoda
Floian
endocerid cephalopod
paleontology
cephalopod
Ordovician
Lower Ordovician
Proterocameroceratidae
Endocerida
Argentina
Opis:
Ordovician cephalopods from Western Gondwana are still poorly known and published data is in need of systematic and stratigraphical revision. In this work, the endocerid proterocameroceratid Protocyptendoceras from the Floian of the Eastern Cordillera of Argentina is revised using new material from La Ciénaga, 5 km upstream from Purmamarca. The species P. corvalani and P. teicherti are considered to be junior synonyms of P. fuenzalidae, which is redescribed in detail and reillustrated. Specimens preserve adapical parts of isolated siphuncles, related here to the presence of endocones in a posterior portion. Evidently P. fuenzalidae had a nektobenthic mode of life in a shallow water environment, oriented horizontally. Its palaeobiogeographical affinities are mainly with Floian proterocameroceratids from Eastern Gondwana, such as Anthoceras decorum and the related genera Lobendoceras, Ventroloboceras, and Notocycloceras.
Źródło:
Acta Palaeontologica Polonica; 2009, 54, 1; 99-109
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New insights into the early diversification of the Ostracoda: Tremadocian ostracods from the Cordillera Oriental, Argentina
Autorzy:
Salas, M.J.
Vaccari, N.E.
Powiązania:
https://bibliotekanauki.pl/articles/22883.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
insight
early diversification
Ostracoda
Tremadocian
ostracod
Argentina
Andes Mountains
Opis:
New species of ostracods from the Tremadocian in the northwest region of Argentina are described. These are among the earliest well−documented records of ostracods, which shed new light onto the early diversification of the group. The described fauna consists of seven species, five of which are new: Saltite uchuy sp. nov., Saltite kuraq sp. nov., Conchoprimitia? iglesiasi sp. nov., Orechina violetae sp. nov., and Orechina catalinae sp. nov. The fauna consists primarily of soanellids, a non−dimorphic family of palaeocopids, and of binodicopids. One factor leading to diversification of the group in this region may have been the complex configuration of the northwest basin, which had a restricted pattern of circulation. The distribution of the first ostracods is largely restricted to Gondwana and peri−Gondwana regions. Accordingly, it is possible to envision that the origin or at least an important radiation of the group was centred in this region. Both the Soanellidae and the genus Orechina would have originated in Gondwana and would have become widespread later during the Middle Ordovician. The Tremadocian fauna located in Argentina show significant affinities with fauna located in the warm−water setting of the east Gondwana, mainly in Australia and China.
Źródło:
Acta Palaeontologica Polonica; 2012, 57, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The bivalve Pholadomya gigantea in the Early Cretaceous of Argentina: taxonomy, taphonomy, and paleogeographic implications
Autorzy:
Lazo, D G
Powiązania:
https://bibliotekanauki.pl/articles/23388.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Argentina
Early Cretaceous
Pholadomya gigantea
Cretaceous
Bivalvia
Anomalodesmata
paleoecology
paleogeography
taxonomy
bivalve
paleontology
Opis:
Pholadomya gigantea is a widely distributed Early Cretaceous bivalve mollusc. It has been recorded in the North Temperate, Tethyan, and South Temperate Realms. Based on recent field work and newly collected material from the Neuquén Basin, the taxonomy, mode of occurrence and palaeobiogeography of this species is reviewed. In the Agrio Formation (Valanginian–Barremian) P. gigantea is neither abundant nor dominant, but occurs throughout the unit. It was facies−dependent being restricted to well−oxygenated waters and soft to firm, sandy and bioclastic substrates of shoreface to inner shelf environments. The life habit of P. gigantea was similar to that of Recent Pholadomya candida, deep burrowing and sedentary, but it has not a pedal gape and accessory muscle scars related to valve closure. Thus a suspension−feeding habit, not a pedal−feeding system, may be inferred as is commonly suggested in other Jurassic and Cretaceous Pholadomya species. Pholadomya agrioensis is a valid taxon that is recorded in the Berriasian–Valanginian of Neuquén. It is similar in outline to P. gigantea and had probably the same basic palaeoecology, even though it has a blunt anterior margin, deep umbonal−ventral sulcus and distinct anterior ornamentation. Once in life position this species was capable of further digging in the sediment. This species probably burrowed in muddy substrates in the offshore zone. Pholadomya sanctaecrucis from the Valanginian of Europe and also recorded in Argentina is ornamented only with commarginal lines and should be removed to the genus Homomya.
Źródło:
Acta Palaeontologica Polonica; 2007, 52, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The eoorthid brachiopod Apheoorthina in the Lower Ordovician of NW Argentina and the dispersal pathways along western Gondwana
Autorzy:
MUÑOZ, DIEGO F.
BENEDETTO, JUAN L.
Powiązania:
https://bibliotekanauki.pl/articles/945694.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
brachiopoda
palaeobiogeography
ordovician
tremadocian
gondwana
perunica
argentina
Opis:
The eoorthid brachiopod Apheoorthina is reported for the first time from the Lower Ordovician of NW Argentina. It is represented by a species similar to A. ferrigena from the Tremadocian of the Prague Basin, increasing the faunal affinities between the Central Andean Basin and the South European microcontinents, in particular the Bohemian region (Perunica). Nine out of the fourteen brachiopod genera reported from the Tremadocian of the Central Andean Basin (~64%) are shared with the Mediterranean region, four of which (~28%) have been recorded in the Prague Basin, and two (Kvania and Apheoorthina) are restricted to the Central Andes and Perunica. Dispersal pathways around Gondwana are analyzed in the light of major factors affecting large-scale distribution of brachiopods (environment, larval capacity for dispersal, oceanic currents). The presence in Apheoorthina aff. ferrigena of a well-preserved larval protegulum measuring 420 μm in width and 210 μm in length strongly suggests that this species had planktotrophic larvae capable of long-distance dispersal. According to recent ocean-atmosphere general circulation models for the Ordovician Period, the Central Andean margin was dominated by the cold-water Antarctica Current. Despite the complex non-zonal pattern produced by current deflections around the peri-Gondwanan microcontinents, the general westward circulation sense favoured larval dispersal from the Andean region to North Africa, Avalonia, the Armorican Terrane Assemblage, and Perunica. On the other hand, the eastwards flowing Gondwana Current connected the North Gondwana waters with the South American epicontinental seas, which could explain the reversed migration of some brachiopods.
Źródło:
Acta Palaeontologica Polonica; 2016, 61, 3; 633-644
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Lamellorthoceratid cephalopods in the cold waters of southwestern Gondwana: Evidences from the Lower Devonian of Argentina
Autorzy:
Cichowolski, M.
Rustan, J.J.
Powiązania:
https://bibliotekanauki.pl/articles/2082150.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Cephalopoda
Lamellorthoceratidae
Arthrophyllum
Palaeozoic
Talacasto Formation
Malvinokaffric
Realm
Precordillera Basin
Argentina
Opis:
Based on three specimens assigned to Arthrophyllum sp., the family Lamellorthoceratidae is reported from the Lower Devonian Talacasto Formation in the Precordillera Basin, central western Argentina. These Devonian cephalopods have been known only from low to mid palaeolatitudes and its presence in the cold water settings of southwestern Gondwana is notable. A nektonic mode of life, not strictly demersal but eventually pelagic, with a horizontal orientation of the conch is proposed for adults lamellorthoceratids, whereas a planktonic habit is suggested for juvenile individuals. These features would had allow their arrival to this southern basin, explaining their unusual presence in the Malvinokaffric Realm, and reinforcing the need of re-evaluate the distribution pattern of several groups of cephalopods.
Źródło:
Acta Palaeontologica Polonica; 2020, 65, 2; 305-312
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Systematic and biostratigraphic significance of a chinchillid rodent from the Pliocene of eastern Argentina
Autorzy:
Rasia, L.L.
Candela, A.M.
Powiązania:
https://bibliotekanauki.pl/articles/22264.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
systematics
biostratigraphy
significance
chinchillid rodent
rodent
Mammalia
Rodentia
Caviomorpha
Chinchillidae
paleontology
Pliocene
Argentina
Opis:
Two species of chinchillid rodents, Lagostomus (Lagostomopsis) incisus and “Lagostomus (Lagostomopsis) spicatus”, have been recorded from the Monte Hermoso Formation (Montehermosan–Lower Chapadmalalan, Early Pliocene) of southern Buenos Aires Province, eastern Argentina. L. (L.) incisus is based on skull remains,while “L. (L.) spicatus” is based onmandible remains and fragmentary skulls. Detailed study of specimens recovered from the upper section of the Monte Hermoso Formation, from the Irene “Formation”, and the Chapadmalal Formation (late Early–early Late Pliocene, Buenos Aires Province), some of them represented by associated skull and mandible remains, indicates that L. (L.) incisus and “L. (L.) spicatus” are synonymous, with the valid name being L. (L.) incisus. The differences between both nominal species are here attributed to different ontogenetic states and sexual dimorphism. The stratigraphic provenance of the fossil material of L. (L.) incisus indicates a temporal distribution of this species restricted to theMontehermosan?–Chapadmalalan (Early–early Late Pliocene), instead of the Montehermosan (Early Pliocene).
Źródło:
Acta Palaeontologica Polonica; 2013, 58, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new pentatomoid bug from the Ypresian of Patagonia, Argentina
Autorzy:
PETRULEVIČIUS, JULIÁN F.
Powiązania:
https://bibliotekanauki.pl/articles/945464.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Opis:
A new pentatomoid heteropteran, Chinchekoala qunita gen. et sp. nov. is described from the lower Eocene of Laguna del Hunco, Patagonia, Argentina. The new genus is mainly characterised by cephalic characters such as the mandibular plates surpassing the clypeus and touching each other in dorsal view; head wider than long; and remarkable characters related to the eyes, which are surrounded antero-laterally and posteriorly by the anteocular processes and the pronotum, as well as they extend medially more than usual in the Pentatomoidea. This is the first pentatomoid from the Ypresian of Patagonia and the second from the Eocene in the region, being the unique two fossil pentatomoids in Argentina.
Źródło:
Acta Palaeontologica Polonica; 2016, 61, 4; 863-868
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new burmagomphid dragonfly from the Eocene of Patagonia, Argentina
Autorzy:
PETRULEVIČIUS, JULIÁN F.
Powiązania:
https://bibliotekanauki.pl/articles/945957.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Opis:
A new burmagomphid anisopteran, Satelitala soberana gen. et sp. nov. is described from the lower Eocene of Laguna del Hunco, Patagonia, Argentina. The new genus is characterised by hindwing characters such as the subdiscoidal triangle not elongated; anal loop divided longitudinally; paranal cell divided longitudinally; five terminal cells between RP and MA; five terminal cells between MP and CuA; and obtuse angle between PsA and CuP+AA. Burmagomphid dragonflies were represented so far only by one specimen from the middle Cretaceous of Southeast Asia. This new record extends the distribution to Patagonia, to the Cenozoic, and also to paleolake deposits.
Źródło:
Acta Palaeontologica Polonica; 2017, 62, 4; 779-783
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Paleoecology of the large carnivore guild from the late Pleistocene of Argentina
Autorzy:
Prevosti, F.J.
Vizcaino, S.F.
Powiązania:
https://bibliotekanauki.pl/articles/23538.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Carnivora
carnivore
Late Pleistocene
Pleistocene
South America
paleoecology
population density
Argentina
paleontology
fossil carnivore
locality
biomass
ecology
Opis:
The paleoecology of the South American fossil carnivores has not been as well studied as that of their northern relatives. One decade ago Fariña suggested that the fauna of Río Luján locality (Argentina, late Pleistocene–early Holocene) is not balanced because the metabolic requirements of the large carnivores are exceeded by the densities and biomass of the large herbivores. This conclusion is based on the calculation of densities using allometric functions between body mass and population abundance, and is a consequence of low carnivore richness versus high herbivore richness. In this paper we review the carnivore richness in the Lujanian of the Pampean Region, describe the paleoecology of these species including their probable prey choices, and review the available information on taphonomy, carnivore ecology, and macroecology to test the hypothesis of “imbalance” of the Río Luján fauna. The carnivore richness of the Río Luján fauna comprises five species: Smilodon populator, Panthera onca, Puma concolor, Arctotherium tarijense, and Dusicyon avus. Two other species are added when the whole Lujanian of the Buenos Aires province is included: Arctotherium bonariense and Canis nehringi. With the exception of D. avus and Arctotherium, these are hypercarnivores that could prey on large mammals (100–500 kg) and juveniles of megamammals (>1000 kg). S. populator could also hunt larger prey with body mass between 1000 and 2000 kg. The review of the “imbalance” hypothesis reveals contrary evidence and allows the proposal of alternative hypotheses. If high herbivore biomass occurred during the Lujanian, a higher density of carnivores could be supported than as inferred from the power function of body size and population density.
Źródło:
Acta Palaeontologica Polonica; 2006, 51, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pleistocene burrows in the Mar del Plata area [Argentina] and their probable builders
Autorzy:
Vizcaino, S F
Zarate, M.
Bargo, M.S.
Dondas, A.
Powiązania:
https://bibliotekanauki.pl/articles/21211.pdf
Data publikacji:
2001
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Argentina
burrow
Mylodontidae
deposit
Pleistocene
Mar del Plata area
South America
fossil animal
Opis:
Structures discovered near Mar del Plata are attributed to palaeoburrows built by fossil animals on the basis of morphological patterns, transgressive boundaries in relation to the sedimentary units, and the presence of claw marks on the walls and roofs. They are discrete features of several metres in length, and with subrounded cross sections. Their diameters range from 0.80 to 1.80 m, with the width generally exceeding the height. These structures occur in Pleistocene deposits containing mammals referable to the Ensenadan and Lujanian Ages. Several Xenarthra are good candidates as builders of these burrows. Palaeoburrows were attributed before to the large Pleistocene armadillos Propraopus, Eutatus, and Pampatherium. We consider the possibility that the mylodontid ground sloths were responsible for excavating the burrows. The similar diameters of the burrows and the sloths are consistent with this observation. Anatomical, allometric, and biomechanical analysis of sloths limbs indicates that they were well designed to perfonn such activity. The shape of some claw marks preserved on the sides and roof of the burrows fits the form of their hand skeleton. Thus, the mylodontid sloths Scelidotherium and Glossotherium are considered as possible builders for the large late Cenozoic burrows present in the Pampean region.
Źródło:
Acta Palaeontologica Polonica; 2001, 46, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł

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