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- Agnolin, Federico L., et al.
(författare)
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New alvarezsaurid (Dinosauria, Theropoda) from Latest Cretaceous of North-western Patagonia with associated eggs
- 2012
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Ingår i: Cretaceous research (Print). - : Elsevier BV. - 0195-6671 .- 1095-998X. ; 35, s. 33-56
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Tidskriftsartikel (refereegranskat)abstract
- The Alvarezsauridae represents a branch of peculiar basal coelurosaurs with an increasing representationof their Cretaceous radiation distributed worldwide. Here we describe a new member of the group, Bonapartenykus ultimus gen. et sp. nov. from Campanian-Maastrichtian strata of Northern Patagonia, Argentina. Bonapartenykus is represented by a single, incomplete postcranial skeleton. The morphologyof the known skeletal elements suggests close affinities with the previously described taxon from Patagonia, Patagonykus, and both conform to a new clade, here termed Patagonykinae nov. Two incomplete eggs have been discovered in association with the skeletal remains of Bonapartenykus, andseveral clusters of broken eggshells of the same identity were also found in a close proximity. These belong to the new ooparataxon Arriagadoolithus patagoniensis of the new oofamily Arriagadoolithidae, which provides first insights into unique shell microstructure and fungal contamination of eggs laid by alvarezsaurid theropods. The detailed study of the eggs sheds new light on the phylogenetic position of alvarezsaurids within the Theropoda, and the evolution of eggs among Coelurosauria. We suggest thatplesiomorphic alvarezsaurids survived in Patagonia until the latest Cretaceous, whereas these basal forms became extinct elsewhere.
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2. |
- Novas, Fernando E., et al.
(författare)
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A new large pterosaur from the Late Cretaceous of Patagonia
- 2012
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Ingår i: Journal of Vertebrate Paleontology. - UK : Informa UK Limited. - 0272-4634 .- 1937-2809. ; 32:6, s. 1447-1452
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Tidskriftsartikel (refereegranskat)abstract
- Here, we expand the meager record of Late Cretaceous South American pterosaurs with the description of a partial rostrum belonging to a large azhdarchid pterodactyloid. The specimen was collected close to the Bajo de Arriagada locality, corresponding to the uppermost Cretaceous Allen Formation of Argentina, around 80 km northwest of the well-sampled Bajo de Santa Rosa locality. The specimen represents the first unambiguous evidence of an azhdarchid pterosaur from South America. This specimen represents a new genus and species, Aerotitan sudamericanus, which is diagnosed based ona unique combination of characters, including one autapomorphy,and represents one of the largest known South Americanpterosaurs. The fossil here described resulted from a joint Argentine-Swedish paleontological expedition to Patagonia.
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