Els Casots (Subirats, Catalonia), a key site for the Miocene vertebrate record of Southwestern Europe

ABSTRACT

Els Casots is one of the richest fossil vertebrate sites of the Vallès-Penedès Basin (Catalonia, Spain). It was discovered in 1989 and excavated briefly during the 1990s, resulting in the recovery of thousands of remains and the erection of several new mammal species. Excavations were resumed in 2018 and continue to date. Here we provide updated results regarding the age, stratigraphy, biota and palaeoenvironment of the site. The age of the site is well constrained to ~15.9 Ma thanks to recent bio- and magnetostratigraphic data, thus coinciding with the Miocene Climatic Optimum (MCO). The stratigraphic succession at the site area indicates lacustrine to palustrine environments with cyclically oscillating water level. There are several fossiliferous layers that have yielded a vertebrate fauna comprising up to 75 different vertebrate species including amphibians, reptiles, birds and mostly mammals. The finding of several articulated partial skeletons indicate that the site records an autochthonous to parautochthonous assemblage. The abundance and completeness of the vertebrate remains together with a well-constrained age and detailed stratigraphic and palaeoenvironmental data, make els Casots a key site for understanding wetland ecosystems in southern Europe during the MCO.

KEYWORDS:

• Miocene Climatic Optimum
• fossil vertebrates
• taphonomy
• palaeoenvironment
• Vallès-Penedès Basin
• Spain

Acknowledgments

The Ajuntament de Subirats [Subirats city council] has supported the excavations from the very beginning and provided funding for the protection of the site and preparation of the fossil remains. We appreciate the interest by Caves Olivé i Batllori (Subirats), which allowed core drilling, survey and excavation in their vineyard. We thank the ICP Preparation & Conservation Area for tireless preparation of els Casots fossils. Preliminary identification of the fish remains by Tomáš Přikryl (Czech Academy of Sciences, Prague) is much appreciated. We especially thank all the colleagues, students and volunteers that have joined us in the excavations: without them this work would not have been possible. We also thank the editors of this special volume for inviting us to contribute to it. The constructive comments by H.-A. Blain, P. Montoya and a third unknown reviewer certainly improved the text. Finally, we want to express our gratitude and admiration to Jorge Morales. Back in 2011, after a visit to els Casots, Jorge spent a whole evening trying to convince some of us to excavate it again. It was a wise advice, as usual coming from Jorge, and we really appreciate it. Thanks, Jorge, for always inspiring and encouraging us.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This publication is part of projects R+D+i PID2020-117289GBI00 funded by MCIN/AEI/10.13039/501100011033/ and CLT009/128/00068 funded by the OSIC (Departament de Cultura, Generalitat de Catalunya). It has also been supported by projects PID2019-106440GB-C21, PID2020-113912GB-100, PID2020-116220GB-I00, PID2020-116908GB-I00 and PGC2018-094122-B-100, all funded by MCIN/AEI/10.13039/501100011033/, as well as by the CERCA Programme and consolidated research groups 2017 SGR 116, 2017 SGR 86, 2017 SGR 596, 2017 SGR 841 of the Generalitat de Catalunya. Additional funding includes: Ministerio de Economía y Competitividad RYC-2013-12470 to I.C.V.; ‘Programa Postdoctoral Beatriu de Pinós de la Secretaria d’Universitats i Recerca del Departament d’Empresa i Coneixement de la Generalitat de Catalunya’ 2017 BP 00223 to J.A and 2019 BP 00154 to À.H.L.; NSP (National Scholarship Program of Slovak Republic for the Support of Mobility of University Researchers) ID 33758 to S.J.V.; Operational Programme Research, Development and Education - Project ‘Postdoc@MUNI’ No. CZ.02.2.69/0.0/0.0/16_027/0008360 to À.H.L.; Juan de la Cierva Formación fellowship FCI2019-039443 to A.Vi., FJC2018-036669-I to A.Va., and Juan de la Cierva Incorporación fellowship IJC2018-037685-I to A.B., all by the MCIN/AEI/10.13039/501100011033/. A.Va. is also supported by Gobierno de Aragón (research group Gobierno de Aragón E33_20R) and by the Universidad Complutense de Madrid and Comunidad Autónoma de Madrid (research group UCM-CAM 910607); C.A. is supported by a Chinese Academy of Sciences Visiting Professor grant of the President’s International Fellowship Initiative of the Chinese Academy of Science and a Ministero dell’Istruzione, dell’Università e della Ricerca Grant to the Department of Science, Roma Tre University (MIUR-Italy Dipartimenti di Eccellenza, ART.1, C-314-337 L- 232/2016).