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Velociraptorine dromaeosaurid teeth from the Kimmeridgian [Late Jurassic] of Germany

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van der Lubbe T., Richter U., Knotschke N.

Acta Palaeontologica Polonica

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2009

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tom 54

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nr 3

401-408

Six theropod teeth from a Late Jurassic (Kimmeridgian) bone bed in Langenberg Quarry of Oker (Goslar, Germany) are identified as a new dromaeosaurid taxon, here left in open nomenclature. Direct comparison reveals that the teeth are very similar to velociraptorine dromaeosaurid teeth from the Guimarota coal mine (Late Jurassic, Portugal) and to velociraptorine dromaeosaurid teeth from Uña (Barremian, Cuenca Province, Spain). Our data indicate that the teeth from the Kimmeridgian of Lower Saxony are of velociraptorine dromaeosaurid type, and therefore represent one of the oldest occurrences of the group Dromaeosauridae.

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The titanosaur sauropods from the late Campanian-early Maastrichtian Allen Formation of Salitral Moreno, Rio Negro, Argentina

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Garcia R. A., Salgado L.

Acta Palaeontologica Polonica

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2013

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tom 58

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nr 2

The dinosaur record of the Salitral Moreno locality (Río Negro Province, Argentina) is characterized by a high diversity of herbivore taxa, among them hadrosaurs, ankylosaurs, and titanosaur sauropods, but carnivores are rare, consisting of only a few fragmentary bones of small forms. Titanosaurs are represented by Rocasaurus muniozi and Aeolosaurus sp., and at least four other taxa, represented by fragmentary material. The elements preserved include a cervical, dorsal and caudal vertebrae, chevron, humerii, ulnae, radii, metacarpal, femora, tibiae, metatarsal, ischia, pubis, and ilium. The Allen Formation is thought to be correlated with the Marília Formation in Brazil, and their faunas have certain elements in common such as aeolosaurines, but saltasaurines and hadrosaurs, are known exclusively from the Allen Formation. These absences, and particularly that of the saltasaurines, may be because those sauropods originated late in the Cretaceous, probably in southern South America (Northern Patagonia?), and they did not have time to disperse to northern South America.

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Cranial anatomy of tyrannosaurid dinosaurs from the Late Cretaceous of Alberta, Canada

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Currie P. J.

Acta Palaeontologica Polonica

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2003

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tom 48

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nr 2

Beautifully preserved, nearly complete theropod skeletons from Alberta (Canada) allow re−evaluation of the taxonomic status of North American tyrannosaurids. It is concluded that the most parsimonious interpretation of relationships leads to the separation of the two species of Albertosaurus(sensu Russell 1970) into Gorgosaurus libratusfrom the Campanian Dinosaur Park Formation and Albertosaurus sarcophagus from the upper Campanian/lower Maastrichtian Horseshoe Canyon Formation. Albertosaurus and Gorgosaurus are closely related, but can be distinguished from each other by more characters than are known to justify generic distinction within another tyrannosaurid clade that includes Daspletosaurus, Tarbosaurus and Tyrannosaurus. Daspletosaurus is known from multiple species that cover extensive geographic, ecological and temporal ranges, and it is sensible to maintain its generic distinction from Tyrannosaurus. All tyrannosaurid species have consistent ontogenetic trends. However, one needs to be cautious in assessing ontogenetic stage because many characters are size−dependent rather than age−dependent. There are relatively few osteological differences that can distinguish tyrannosaurid species at any age. For example, Nanotyrannus lancensis is probably a distinct species from Tyrannosaurus rex because there is no evidence of ontogenetic reduction of tooth counts in any other tyrannosaurid species. Some characters that are good for separating mature tyrannosaurids, such as differences in the sizes and shapes of maxillary fenestrae, are not useful for identifying the species of juveniles.

Ograniczanie wyników

3 Acta Palaeontologica Polonica

1 Currie P. J.

1 Garcia R. A.

1 Knotschke N.

1 Richter U.

1 Salgado L.

1 van der Lubbe T.

1 2013

1 2009

1 2003

Velociraptorine dromaeosaurid teeth from the Kimmeridgian [Late Jurassic] of Germany

The titanosaur sauropods from the late Campanian-early Maastrichtian Allen Formation of Salitral Moreno, Rio Negro, Argentina

Cranial anatomy of tyrannosaurid dinosaurs from the Late Cretaceous of Alberta, Canada