Wyniki wyszukiwania

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Functional morphology of the upper and lower eyelids, third eyelid, lacrimal gland and superficial gland of the third eyelid in the red kangaroo (Macropus rufus)

100%

Kleckowska-Nawrot J., Gozdziewska-Harlajczuk K., Barszcz K., Janeczek M.

Folia Biologica

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2016

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tom 64

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nr 3

2

The cerebellar paraflocculus and the subarcuate fossa in Monodelphis domestica and other marsupial mammals - ontogeny and phylogeny of a brain-skull interaction

84%

Sanchez-Villagra M. R.

Acta Theriologica

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2002

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tom 47

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nr 1

The development of the subarcuate fossa and the cerebellar paraflocculus was studied in an ontogenetic series of Monodelphis domestica Wagner, 1842 The spatial relation between these structures was examined qualitatively in adult specimens of several marsupial taxa. The fossa is first formed without participation of the cerebellar paraflocculus, which fills the fossa first fully and then partially later in development. The correlation between the size of the petrosal lobule of the paraflocculus and the subarcuate fossa in adults is weak. The volume of the subarcuate fossa was measured in 68 specimens representing 19 species of recent marsupials. Its size is negatively allometric with respect to skull size. The didelphids examined ('large opossums') have relatively smaller subarcuate fossae than the other marsupials examined, and Sarco- philus laniarius is the major outlier, with a very small fossa. Loss of the subarcuate fossa has occurred at least twice in metatherian evolution (some sparassodonts and wombats). All marsupials examined to date, with the exception of wombats, have a differentiated petrosal lobule of the paraflocculus.

3

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Stagodontid marsupials from the Late Cretaceous of Canada and their systematic and functional implications

84%

Fox R. C., Naylor B. G.

Acta Palaeontologica Polonica

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2006

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tom 51

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nr 1

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.

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A revision of 'pediomyid' marsupials from the Late Cretaceous of North America

84%

Davis B. M.

Acta Palaeontologica Polonica

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2007

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tom 52

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nr 2

“Pediomyids” are a diverse group of smallto medium−sized marsupials which comprise a significant portion of many Late Cretaceous North American mammalian faunas. Known almost exclusively from isolated teeth and jaw fragments, “pediomyids” exhibit far more diversity than any other contemporaneous group of North American mammals. This has led some to suggest that the family “Pediomyidae” is an artificial, polyphyletic assemblage composed of multiple lineages that independently acquired various traditionally−recognized “pediomyid” molar characters, such as a reduction of the anterior stylar shelf, reduction of the stylocone and a labial shift in the attachment of the cristid obliqua. The present study seeks to elucidate the interrelationships of “pediomyid” marsupials and test the monophyly of the group using cladistic methodology, including a broad sampling of Late Cretaceous North American taxa and a comprehensive set of qualitative molar characters. Results suggest that the family “Pediomyidae” and the genus “Pediomys” are both polyphyletic and are in need of systematic revision. Iqualadelphis lactea (Aquilan) appears to be unrelated to the “pediomyid” radiation, and rests as a stem taxon near the base of the cladogram. The large Aquilan Aquiladelphis nests in a trichotomy with a strictly−defined “Pediomyidae” and the enigmatic Lancian taxon Glasbius, suggesting the possibility of a distant relationship (above the familial level). Three clades are recognized within the “Pediomyidae”: a restricted Pediomys, Leptalestes gen. nov. (containing the three smallest species), and Protolambda (containing the remaining three larger species). Results suggest that “Pediomys” exiguus is a stem taxon lacking a close relationship to Pediomyidae sensu stricto, and is removed to permit recognition of the family as monophyletic. The results carry implications for the role “pediomyids” might have played in the initial North American marsupial radiation sometime prior to the Campanian, and the pattern of molar evolution throughout major Late Cretaceous lineages.

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A peculiar faunivorous metatherian from the early Eocene of Australia

67%

Beck R. M. D.

Acta Palaeontologica Polonica

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2015

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tom 60

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nr 1

I describe Archaeonothos henkgodthelpi gen. et. sp. nov., a small (estimated body mass ~40–80 g) tribosphenic metatherian from the early Eocene Tingamarra Fauna of southeastern Queensland, Australia. This taxon, known only from a single isolated upper molar (M2 or M3) is characterised by a very distinctive combination of dental features that, collectively, probably represent faunivorous adaptations. These include: a straight, elevated centrocrista; a metacone considerably taller than the paracone; a wide stylar shelf (~50% of the total labiolingual width of the tooth); reduced stylar cusps; a long postmetacrista; a small and anteroposteriorly narrow protocone; an unbasined trigon; and the absence of conules. Some of these features are seen in dasyuromorphians, but detailed comparisons reveal key differences between A. henkgodthelpi and all known members of this clade. A. henkgodthelpi also predates recent molecular estimates for the divergence of crown-group Dasyuromorphia. Similar dental features are seen in a number of other metatherians, including the South American sparassodonts, Wirunodon chanku from the ?middle–late Eocene Santa Rosa local fauna of Peru, and Kasserinotherium tunisiense from the early Eocene Chambi fauna of Tunisia, although whether A. henkgodthelpi is closely related to any of these taxa is unclear based on available evidence. I therefore refer A. henkgodthelpi to Metatheria incertae sedis. Potential relatives of A. henkgodthelpi are unknown from any other Australian fossil deposit.

Ograniczanie wyników

3 Acta Palaeontologica Polonica

1 Acta Theriologica

1 Folia Biologica

1 Barszcz K.

1 Beck R. M. D.

1 Davis B. M.

1 Fox R. C.

1 Gozdziewska-Harlajczuk K.

1 Janeczek M.

1 Kleckowska-Nawrot J.

1 Naylor B. G.

1 Sanchez-Villagra M. R.

1 2016

1 2015

1 2007

1 2006

1 2002

Functional morphology of the upper and lower eyelids, third eyelid, lacrimal gland and superficial gland of the third eyelid in the red kangaroo (Macropus rufus)

The cerebellar paraflocculus and the subarcuate fossa in Monodelphis domestica and other marsupial mammals - ontogeny and phylogeny of a brain-skull interaction

Stagodontid marsupials from the Late Cretaceous of Canada and their systematic and functional implications

A revision of 'pediomyid' marsupials from the Late Cretaceous of North America

A peculiar faunivorous metatherian from the early Eocene of Australia