Dispersal and early evolution of the first modern cricetid rodents in Western Europe: new data from the Vallès-Penedès Basin (Catalonia)

Sílvia Jovells-Vaqué,Isaac Casanovas-Vilar

doi:10.5852/cr-palevol2021v20a22

Abstract

Modern cricetids originated in Asia and dispersed into Western Europe by the end of the early Miocene, where they quickly became major components of the rodent faunas. Here we review the early Miocene rodent record of the genera Democricetodon Fahlbusch, 1964 and Megacricetodon Fahlbusch, 1964 in the Vallès-Penedès Basin (Catalonia, Spain). Democricetodon is represented by four species in the studied sites (D. hispanicus Freudenthal, 1967, D. cf. decipiens (Freudenthal & Daams, 1988), D. gracilis Fahlbusch, 1964 and a large-sized undetermined species) and Megacricetodon by one (M. primitivus (Freudenthal, 1963)). The cricetid succession bears several similarities with that of the nearby Calatayud-Montalbán Basin (East-Central Spain) to the point that the same detailed local biostratigraphy could be extended to the Catalan basin. The rare presence of certain Democricetodon species (D. gracilis) and other small mammal taxa also reveal affinities with regions beyond the Iberian Peninsula and indicate that the Vallès-Penedès Basin was more humid and forested than inland Iberian basins during the early Miocene.

Highlights

The cricetids Democricetodon Fahlbusch, 1964 and Megacricetodon Fahlbusch, 1964 are major components of the early and middle Miocene rodent faunas of Eurasia, to the point that one or two species of these cricetids may account for more than 90% of the recovered rodent remains in some sites (e.g. Daams & Freudenthal 1988)
Modern cricetids are a common component of MN4 faunas and include four species of the genus Democricetodon (D. hispanicus, D. cf. decipiens, D. gracilis, D. sp. 4) and one of the genus Megacricetodon (M. primitivus)
The rich and detailed rodent succession of the Calatayud-Montalbán Basin (Spain) and the Swiss Molasse Basin has shown that Democricetodon is the first genus of modern cricetids to disperse in western Europe, Megacricetodon occurring slightly later (Kälin & Kempf 2009; Van der Meulen et al 2012)

Summary

Introduction

The cricetids Democricetodon Fahlbusch, 1964 and Megacricetodon Fahlbusch, 1964 are major components of the early and middle Miocene rodent faunas of Eurasia, to the point that one or two species of these cricetids may account for more than 90% of the recovered rodent remains in some sites (e.g. Daams & Freudenthal 1988). The first appearance and evolution of different Democricetodon and Megacricetodon species in combination with other rodent taxa is used to define most of the local biozones for the early and middle Miocene in several European regions (Daams et al 1999; Abdul Aziz et al 2008, 2010; Kälin & Kempf 2009; Van der Meulen et al 2012; Casanovas-Vilar et al 2016a; Prieto & Rummel 2016) They play an important role in continental biochronology, the first appearance of these genera (as well as that of certain widely dispersed species) marking the boundaries between higher-ranking biochronological units, such as mammal ages in China (Qiu et al 2013) and MN (Mammal Neogene) zones in Europe (Mein 1999; Agustí et al 2001; Hilgen et al 2012)

Methods

Findings

Discussion

Conclusion