bcreisler@gmail.com
A new paper available online but not yet posted on the Spanish Journal of Palaeontology website in open access. For now, the paper can be accessed from Research Gate link:
Femke M. Holwerda & Diego Pol (2018)
Phylogenetic analysis of Gondwanan basal eusauropods from the Early-Middle Jurassic of Patagonia, Argentina.
Spanish Journal of Palaeontology 33(2):Â 289-298
DOI: 10.7203/sjp.33.2.13604
Gondwanan Jurassic non-neosauropod eusauropods are key for the understanding of sauropod evolution, although their phylogenetic interrelationships remain poorly understood. However, following the revision of the holotype of a key taxon from the early Middle Jurassic CaÃadÃn Asfalto Formation Patagonia, Argentina, Patagosaurus fariasi, the phylogenetic affinities need to be tested with new osteological information gathered during the redescription of the holotype of Patagosaurus. A new phylogeny presented here shows a close affiliation of Patagosaurus with Cetiosaurus from the Middle Jurassic of the UK. The close relationship of Patagosaurus with Barapasaurus, often found in previous phylogenies, was not recovered here. Instead, Patagosaurus is retrieved as more derived than most Early and Middle Jurassic sauropods, although more basal to Mamenchisaurus, Omeisaurus, turiasaurians, and neosauropods. Another sauropod taxon found together with Patagosaurus, Volkheimeria, is retrieved several nodes more basal than the former, which shows, together with evidence of several other sauropod taxa in the CaÃadÃn Asfalto Formation, that a high evolutionary diversity existed in Southwest Gondwana in the early Middle Jurassic, a pattern which is also seen in fossil groups other than sauropods (e.g., theropods).