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The eggshell of the Eocene bird Lithornis

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Grellet-Tinner G., Dyke G. J.

Acta Palaeontologica Polonica

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2005

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tom 50

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nr 4

831-835

Although the fossil bird Lithornis has been known for more than a century, only in the 1980s were its affinities within the palaeognathous birds (Aves, Palaeognathae) realized and demonstrated by use of osteological characters. Other lines of evidence could, however, be used to test hypotheses of its affinities. To add data to this ongoing investigation, we present the first detailed description of the microscopic morphology of the eggshell of this fossil bird. Our description of eggshells of two species of Lithornis is consistent with the placement of this fossil bird within Palaeognathae. Characters that corroborate this position include the presence of three aprismatic structural layers visible by use of scanning electron microscopy (SEM) in the eggshell microstructure. The placement of Lithornis phylogenetically close to the extant flighted South American group Tinamidae is supported on the basis of characters present in the structural composition of the eggshell layers of both these taxa.

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Caudipteryx as a non-avalian theropod rather than a flightless bird

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Dyke G. J., Norell M. A.

Acta Palaeontologica Polonica

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2005

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tom 50

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nr 1

Caudipteryx zoui is a small enigmatic theropod known from the Early Cretaceous Yixian Formation of the People’s Republic of China. From the time of its initial description, this taxon has stimulated a great deal of ongoing debate regarding the phylogenetic relationship between non−avialan theropods and birds (Avialae) because it preserves structures that have been uncontroversially accepted as feathers (albeit aerodynamically unsuitable for flight). However, it has also been proposed that both the relative proportions of the hind limb bones (when compared with overall leg length), and the position of the center of mass in Caudipteryx are more similar to those seen in extant cusorial birds than they are to other non−avialan theropod dinosaurs. This conclusion has been used to imply that Caudipteryx may not have been correctly interpreted as a feathered non−avialan theropod, but instead that this taxon represents some kind of flightless bird. We review the evidence for this claim at the level of both the included fossil specimen data, and in terms of the validity of the results presented. There is no reason—phylogenetic, morphometric or otherwise—to conclude that Caudipteryx is anything other than a small non−avialan theropod dinosaur.

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A new eutherian mammal from the Late Cretaceous of Kazakhstan

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Averianov A., Archibald J. D., Dyke G. J.

Acta Palaeontologica Polonica

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2014

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tom 59

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nr 3

A dentary fragment containing the last two molars (m2–3) from the Late Cretaceous (Santonian–?Campanian) Bostobe Formation exposed at the locality of Shakh Shakh, northeast Aral Sea region, Kazakhstan, is attributed to a new taxon of Zhelestidae, Zhalmouzia bazhanovi Averianov and Archibald gen. et sp. nov. This specimen is only the second mammal described from Shakh Shakh, the unidentifiable eutherian Beleutinus orlovi Bazhanov, 1972, being the first, and it is only the fifth Mesozoic mammal named from Kazakhstan. Zhalmouzia Averianov and Archibald gen. nov. belongs to the endemic clade of Middle Asian zhelestids (Zhelestinae), better known from the Turonian of Uzbekistan.

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A euenantiornithine bird from the Late Cretaceous Hateg Basin of Romania

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Wang X., Dyke G. J., Codrea V., Godefroit P., Smith T.

Acta Palaeontologica Polonica

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2011

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tom 56

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nr 4

We present the first record of a euenantiornithine bird from Romania. A small collection of fossil remains from the Maastrichtian add to the known distribution of large euenantiornithines and descriptions of birds from the Haţeg Basin augment the known vertebrate fauna from this famous region of Transylvania. The new specimens referred here to an indeterminate taxon of euenantiornithine further demonstrate that the larger members of this diverse Cretaceous lineage were globally distributed, as many birds are today.

Ograniczanie wyników

4 Acta Palaeontologica Polonica

4 Dyke G. J.

1 Archibald J. D.

1 Averianov A.

1 Codrea V.

1 Godefroit P.

1 Grellet-Tinner G.

1 Norell M. A.

1 Smith T.

1 Wang X.

1 2014

1 2011

2 2005

The eggshell of the Eocene bird Lithornis

Caudipteryx as a non-avalian theropod rather than a flightless bird

A new eutherian mammal from the Late Cretaceous of Kazakhstan

A euenantiornithine bird from the Late Cretaceous Hateg Basin of Romania