Where: Chubut, Argentina (43.8° S, 71.6° W: paleocoordinates 41.6° S, 30.9° W)

• coordinate based on political unit

• small collection-level geographic resolution

When: Cañadón Asfalto Formation (Sierra de Olte Group), Aalenian to Aalenian (174.1 - 168.4 Ma)

• The sediments are predominantly thin-layered, marly mudstones, representing the lacustrine sequence of the Cañadón Asfalto Formation...

•Recent palynological studies and radiometric dates in the Cañadón Asfalto Formation indicate that this unit is older than the traditionally proposed Callovian-Oxfordian age. Volkheimer et al. (2008) obtained a Bajocian-lowermost Bathonian age from a palynological sample from a section some kilometres south of the type locality of Eoabelisaurus. This age was confirmed on the basis of more extensive palynological samples by Zavattieri et al. (2010), who argued for an Aalenian-Bathonian age. Likewise, a K-Ar date of a basaltic intercalation close to Cerro Cóndor resulted in an Aalenian-Bajocian age (171 ± 5 Ma; Salani 2007), whereas an U-Pb age from a pyroclastic deposit gave an uppermost Bajocian-lowermost Bathonian age (167 ± 4 Ma; Cabaleri et al. 2010). Finally, a U-Pb date from a tuff near the base of the formation has even yielded a Toarcian age (Cúneo & Bowring 2010). These data thus indicate that the lacustrine levels of the Cañadón Asfalto Formation in the area of Cerro Cóndor probably range from the uppermost Toarcian to the lowermost Bathonian. Since Eoabelisaurus comes neither from the lowest, nor the highest parts of the sequence, we consider an Aalenian-Bajocian age as most likely for the sediments that have yielded this taxon.

Environment/lithology: lacustrine - large; calcareous mudstone

Size class: macrofossils

Collected by Diego Pol, Oliver Rauhut and team

Collection methods: quarrying, surface (in situ),

• Museo Paleontologico Egidio Feruglio (MPEF) collection

Primary reference: D. Pol and O. W. M. Rauhut. 2012. A Middle Jurassic abelisaurid from Patagonia and the early diversification of theropod dinosaurs. Proceedings of the Royal Society of London, B 279:3170-3175 [R. Benson/R. Benson/O. Rauhut]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 130985: authorized by Roger Benson, entered by Roger Benson on 16.07.2012

Creative Commons license: CC BY (attribution)