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Cranial osteology and ontogeny of Saurolophus angustirostris from the Late Cretaceous of Mongolia with comments on Saurolophus osborni from Canada

100%

Bell P. R.

Acta Palaeontologica Polonica

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2011

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tom 56

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nr 4

Reanalysis of the skull of the crested Asian hadrosaurine Saurolophus angustirostris confirms its status as a distinct species from its North American relative, Saurolophus osborni. In addition to its greater absolute size, S. angustirostrisis differentiated from Saurolophus osborni by an upturned premaxillary body, a more strongly reflected oral margin of the premaxilla, the absence of an anterior notch in the prenarial fossa, a sigmoidal contour of the ventral half of the anterior process of the jugal, a shallow quadratojugal notch on the quadrate, and by a strongly bowed quadrate in lateral view. Phylogenetic analysis corroborates a sister taxon relationship between S. angustirostris and S. osborni. Saurolophusitself is characterised by a solid, rod−like crest composed of the nasals, frontals, and prefrontals; secondary elongation of the frontal and prefrontal resulting in the backwards extension of the frontal platform; a frontal platform that extends dorsal to the anterior portion of the supratemporal fenestra; a parietal that is excluded by the squamosals from the posterodorsal margin of the occiput; and the presence of two supraorbital elements. Although the palaeobiogeographic history of Saurolophus remains unresolved, at least two possible dispersal events took place across Beringia during the late Campanian leading to the evolution of the clade composed of Kerberosaurus, Prosaurolophus, and Saurolophus.

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Have necrohormones a role in embryogenesis?

100%

Bell P. R.

Acta Societatis Botanicorum Poloniae

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1996

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tom 65

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nr 1-2

7-9

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The phase change in ferns

75%

Bell P. R.

Acta Societatis Botanicorum Poloniae

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1981

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tom 50

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nr 1-2

4

Intracellular RNA during microsporogenesis in plants: Texus baccata as a model system

63%

Ponnel R. I., Bell P. R.

Acta Societatis Botanicorum Poloniae

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1986

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tom 55

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nr 1

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A New Deinonychosaurian Track from the Lower Cretaceous Hekou Group, Gansu Province, China

33%

Xing L., Li D., Harris J. D., Bell P. R., Azuma Y., Fujita M., Lee Y.-N., Currie P. J.

Acta Palaeontologica Polonica

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2013

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tom 58

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nr 4

Herein we describe deinonychosaurian (Dinosauria: Theropoda) tracks in the Lower Cretaceous Hekou Group at sites I and II of Liujiaxia Dinosaur National Geopark, Gansu Province, China. The site preserves 71 didactyl tracks, the largest concentration of deinonychosaurian tracks in Asia. The tracks pertain to a new dromaeopodid ichnospecies: Dromaeosauripus yongjingensis ichnosp. nov., which is diagnosed by: a digital pad formula of x−1−3−4−x and a mean divarication angle between digits III and IV of 19°, and having the proximal portion of digit II contacting the anterior margin of a large, rounded metatarsophalangeal pad. Six Dromaeosauripustrackways from site II comprise at least two, and possibly three, turning trackways in which the track maker(s) turned without slowing down. None of the Dromaeosauripus trackways are parallel or closely spaced, suggesting that they were made by solitary track makers. Estimates of dromaeopodid track−maker sizes are between 61–300 cm, well within the size range established by body fossils of both dromaeosaurids and troodontids.

Ograniczanie wyników

3 Acta Societatis Botanicorum Poloniae

2 Acta Palaeontologica Polonica

5 Bell P. R.

1 Azuma Y.

1 Currie P. J.

1 Fujita M.

1 Harris J. D.

1 Lee Y.-N.

1 Li D.

1 Ponnel R. I.

1 Xing L.

1 2013

1 2011

1 1996

1 1986

1 1981

Cranial osteology and ontogeny of Saurolophus angustirostris from the Late Cretaceous of Mongolia with comments on Saurolophus osborni from Canada

Have necrohormones a role in embryogenesis?

The phase change in ferns

Intracellular RNA during microsporogenesis in plants: Texus baccata as a model system

A New Deinonychosaurian Track from the Lower Cretaceous Hekou Group, Gansu Province, China