Cranial endocast of Anagale gobiensis (Anagalidae) and its implications for early brain evolution in Euarchontoglires

• DOI: 10.1111/pala.12650
• Publication Date: 2023-06-01T11:30:00Z
• Authors: Sergi López‐Torres; Ornella C. Bertrand; Madlen M. Lang; Łucja Fostowicz‐F...; Mary T. Silcox; Jin Meng
• Keywords: Endocast; Fossorial; Encephalization; Mammal; Crania; Evolution of mammals

Abstract Anagalids are an extinct group of primitive mammals from the Asian Palaeogene thought to be possible basal members Glires. Anagalid material is rare, with only a handful crania known. Here we describe first virtual endocast anagalid, based on holotype Anagale gobiensis (AMNH 26079; late Eocene, China), which allows for comparison published endocasts fossil modern euarchontogliran lineages (i.e. primates, rodents, lagomorphs). The displays traits often observed in fossorial mammals, such as relatively small petrosal lobules and low neocortical ratio, would consistent previous inferences about use subterranean food sources heavy dental wear. In fact, has lowest ratio yet recorded euarchontogliran. This species was olfaction‐driven, large olfactory bulbs laterally expansive palaeocortex. supports that bulbs, partial midbrain exposure encephalization quotient ancestral Euarchontoglires, although likely adaptations may also partly explain these traits. While mammal many aspects, some its derived endocranial point towards new, different trajectory brain evolution within Euarchontoglires.