Inferring eco-climate parameters for the Pliocene Climate Optimum using frog body size as a new proxy

Identifier:  imarina:9330264

Handle: https://hdl.handle.net/20.500.11797/imarina9330264

Authors:  Martinez-Monzon, A; Prikryl, T; Sanchez-Bandera, C; Bisbal-Chinesta, JF; Agusti, J; Vall-Llosera, G; De Soler, BG; Blain, HA

Abstract:
Climate conditions during the Pliocene Climate Optimum (3.2 - 2.5 Ma) are significant due to their proposed correspondence with future climate. There are various difficulties involved in obtaining terrestrial temperatures for this period, so new sources of information are therefore important. This work proposes a new approach based on frog body size, facilitating a palaeoclimate reconstruction of the palaeontological site of Camp dels Ninots (Caldes de Malavella, NE Spain), a Pliocene Konservat-Lagerstatte, dated at around 3.2 Ma. For this purpose, an extensive database of current populations of the genus Pelophylax from across Eurasia has been generated making it possible to establish a correlation between frog body size and eco-climate parameters such as temperature, precipitation rates and real evapotranspiration. Eco-climate values were obtained using OLS regression models and compared with previous palaeoclimate reconstructions from other archaeo-palaeontological sites of interest (Barranco Leon and Fuente Nueva 3, SE Spain). Our new proxy results in a palaeotemperature of 14.3 +/- 2.6 degrees C and a palaeoprecipitation rate of 846.8 +/- 165.4 mm; according to primary productivity values, a 'Summer-green broad-leaved forest'-like biome is proposed for Camp dels Ninots, in line with previous palaeobotanical studies. The new values generated for the other sites follow the same trends as previous reconstructions, although with lower values in most cases, especially in terms of temperature. This method is a promising new approach to complement previous palaeoclimate reconstructions and could also generate new data.