New chiropterans from the middle Eocene of Shanghuang (Jiangsu Province, Coastal China): new insight into the dawn horseshoe bats (Rhinolophidae) in Asia
Résumé
Until recently, the fossil record of Paleogene bats in Asia primarily included extinct families(i.e. ‘Eochiroptera’) from the early Eocene of Vastan in India and from the middle-lateEocene of the Liguanqiao and Yuanqu basins in central China. Here, we describe a newfauna of Chiroptera from the middle Eocene Shanghuang fissure fillings of China. Thefauna includes abundant material referred to a new rhinolophid (Protorhinolophus shanghuangensisgen. and sp. n.), one specimen of a possible rhinopomatid and several indeterminaterhinolophoids. This new bat assemblage constitutes the earliest record of extant families ofmicrobats in Asia. Because it lacks representatives of ‘Eochiroptera’, this Shanghuang batfauna indicates significant turnover in Asian bat communities. The dental pattern ofP. shanghuangensis shows a mosaic of primitive and derived features (‘Eochiroptera’ vs Rhinolophidaedental characteristics), suggesting that this taxon occupies a basal position amongthe Rhinolophidae. Rhinolophids were already well diversified at the end of the late Eocenein Europe. Interestingly, many dental characteristics of Protorhinolophus are also found in aprimitive rhinolophoid taxon, Vaylatsia, from the middle Eocene to late Oligocene ofEurope, supporting a close relationship between these taxa. These affinities testify to thewidespread Eurasian distribution of rhinolophoids during the Eocene and are consistentwith a westward dispersal of the group from eastern Asia to Europe owing to the greaterantiquity of Protorhinolophus.