Fossil endocasts of two Pleistocene bovines (Bovidae, Mammalia) from the Upper Siwaliks of northern India

Abstract

ABSTRACT Natural fossil endocasts are a direct source of information on palaeoneurology of extinct species and, in recent years, there has been a dramatic revival of interest in palaeoneurological investigations. Endocasts of bovines (family Bovidae), however, remain hitherto undescribed. Here we describe two well preserved natural endocasts of Pleistocene bovines from the Upper Siwalik deposits exposed near Panchkula (Haryana), in the vicinity of Chandigarh city, northern India. The two endocasts, referred here to cf. Bubalus platyceros and Bovini indet., are similar in gross morphology but differ significantly in several respects. Comparison with modern bovines reveals important similarities between the Siwalik endocasts and the brains of Bos taurus and Bubalus bubalis, especially in size of their cerebral hemispheres and placement of fissures. However, the Siwalik endocasts differ significantly in being less replete with gyri and sulci, suggesting that bovines have undergone an increase in complexity of their neuroanatomy during the later part of the Pleistocene. This study also supports the recently proposed hypothesis that mammalian taxa with relatively large brain size were more likely to survive the Pleistocene megafaunal extinctions.