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Wyszukujesz frazę "Fox, R." wg kryterium: Autor


Wyświetlanie 1-4 z 4
Tytuł:
An unusual early primate from the Paleocene Paskapoo Formation, Alberta, Canada
Autorzy:
Fox, R.
Powiązania:
https://bibliotekanauki.pl/articles/23216.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Alberta
Canada
Paleocene
Paskapoo Formation
Plesiadapiformes
primate
Primates
new plesiadapiform primate
Phoxomylus puncticuspis
plesiadapiform primate
Earlu Tiffanian
Opis:
A new plesiadapiform primate, Phoxomylus puncticuspis gen. et sp. nov., is described based on an isolated but well−preserved upper molar from the early Tiffanian (late Paleocene) Cochrane 2 locality, southwestern Alberta, Canada. Although possessing a robust postprotoconal fold, an unambiguous synapomorphy of primates, Phoxomylus differs from other plesiadapiforms in its retention of primitive molar features, including acutely pointed major cusps and sharp crests, deep trigon basin, and lack of the bunodont coronal specializations that purportedly marked the transition from insectivorous non−primate ancestors to omnivorous/frugivorous basal primates. Coronal features of the holotype of P. puncticuspis imply that during mastication the mandible was adducted in a near−vertical plane, with little capacity for the transverse movement that is already seen in molar morphology of the earliest and most basal plesiadapiform, Purgatorius. Instead, molar morphology in P. puncticuspis implies emphasis on vertical piercing and shearing, specializations for insectivory unlikely to have been derived via reversal from plesiadapiform ancestors having more bunodont molars adapted for omnivory/frugivory. If that is the case, a long “ghost lineage” must link P. puncticuspis to other, basal plesiadapiforms that have yet to be discovered but that had not yet evolved omnivorous adaptations of the dentition.
Źródło:
Acta Palaeontologica Polonica; 2011, 56, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stagodontid marsupials from the Late Cretaceous of Canada and their systematic and functional implications
Autorzy:
Fox, R C
Naylor, B.G.
Powiązania:
https://bibliotekanauki.pl/articles/23125.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Canada
Cretaceous
Late Cretaceous
Stagodontidae
Mammalia
stagodontid mursupial
Alberta
Marsupialia
paleontology
Opis:
Previously undescribed specimens of stagodontid marsupials from Late Cretaceous deposits in Alberta, Canada, reveal new information concerning the upper dentition of Eodelphisspp. and the lower dentition of Didelphodon coyi. Additionally, an incomplete upper dentition of D. coyi from the Scollard Formation extends the range of this species into the Lancian, co−eval with D. vorax and D. padanicus. Stagodontids are in accord with other North American Late Cretaceous marsupials for which the appropriate parts are known in lacking diastemata between the canines and the molars while possessing well−developed palatal vacuities, implying that these morphologies characterized ancestral marsupials. If so, the diastema between P1 and P2 in the Asian middle Early Cretaceous “metatherian” Sinodelphys szalayi is convergent on that in Cenozoic didelphids, and the absence of palatal vacuities in South American Paleogene and Neogene borhyaenids is derived, representing a paedomorphic truncation of development. Claims that the Asian Late Cretaceous “metatherian” Deltatheridium pretrituberculare had a marsupial−like dental replacement pattern are tautological, deduced from an a priori acceptance of a marsupial model of replacement to the exclusion of other, no less realistic, alternatives. The new specimens of Didelphodon coyi demonstrate that upper and lower premolars occluded broadly, implying that the inflated lingual lobes characteristic of Didelphodon premolars evolved primarily as a crushing mechanism, not for passive protection of the gums. Recent speculations that stagodontids were aquatic are not based on credible morphologic or taphonomic evidence and are dismissed, as is speculation that the Judithian species of Eodelphis are sexual morphs of a single species. Current knowledge of Didelphodon compels correction of numerous errors concerning its morphology as presented in recent analyses of marsupial relationships.
Źródło:
Acta Palaeontologica Polonica; 2006, 51, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New earliest Tiffanian [Late Paleocene] mammals from Cochrane 2, Southwestern Alberta, Canada
Autorzy:
Scott, C S
Fox, R.C.
Youzwyshyn, G.P.
Powiązania:
https://bibliotekanauki.pl/articles/21452.pdf
Data publikacji:
2002
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Paleocene
Late Paleocene
Eutheria
mammal
Canada
new combination
Litomylus grandaletes
Alberta
Ptilodus gnomus
Baiotomeus russelli
Paleotomus junior
fossil
Thryptacodon orthogonius
Paskapoo Formation
Bessoecetor septentrionalis
Pararyctes rutherfordi
new species
paleontology
Multituberculata
Opis:
New mammalian fossils at Cochrane 2, Paskapoo Formation, Alberta, Canada, document five new species and two new combinations: Ptilodus gnomus sp.nov.and Baiotomeus russelli sp.nov.(Multituberculata), Thryptacodon orthogonius comb.nov.and Litomylus grandaletes sp.nov.(“Condylarthra”), Pararyctes rutherfordi sp.nov., Bessoecetor septentrionalis comb.nov., and Paleotomus junior sp.nov.(Eutheria incertae sedis).These new taxa supplement a taxonomically diverse Cochrane 2 local fauna, representing one of the most species rich Paleocene mammalian localities in the world. An earliest Tiffanian age is estimated for the locality based on the presence of the index taxa Plesiadapis praecursor, Nannodectes intermedius, and Ectocion collinus.The Cochrane 2 local fauna fails to demonstrate a decrease in species number relative to those of late Torrejonian localities from the United States, as would be predicted by current paleoclimate scenarios; the rarity of earliest Tiffanian localities in North America suggests sampling error as a partial explanation for the apparent incongruity.
Źródło:
Acta Palaeontologica Polonica; 2002, 47, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-4 z 4

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