BETWEEN-SPECIES VARIATION IN NEOCORTICAL SULCAL ANATOMY OF THE CARNIVORAN BRAIN

Species of the mammalian order Carnivora, a diverse group including dogs, cats, bears, mustelids, meerkats, and related taxa, display pronounced variation in behaviour, ecology, and social organisation. Despite this diversity, comparative investigations of carnivoran brains and their evolutionary history have predominantly focused on differences in overall brain size, leaving other aspects of cortical organisation less explored. In the present work, we used primarily post-mortem neuroimaging data to reconstruct cortical surfaces from 26 carnivoran species spanning eight families and a wide range of ecological niches and behavioural repertoires. By developing a unified description of major neocortical sulci and corresponding digital atlases, we established a comparative framework for navigating and systematically comparing these diverse brains. Across species, we observed substantial lineage-specific variation in sulcal number, topology, and regional complexity. In particular, occipitotemporal sulcal configurations varied markedly across lineages, suggestive of reorganisation of visual and auditory cortical areas. Rather than reflecting a single global pattern, sulcal differences were regionally specific and aligned with behavioural specialisations: enhanced forepaw dexterity was associated with elongated and more complex sulci in the sensorimotor cortex, while highly cooperative canids exhibited an additional frontal sulcus absent in more solitary relatives. Together, these findings demonstrate that sulcal architecture varies systematically across carnivorans and may covary with differences in species-specific behaviour and ecology. Building on this framework, future work will examine relative cortical expansions across lineages and extend the dataset to include additional ecological extremes, such as aquatic carnivorans, to further elucidate the neuroecological drivers of mammalian brain evolution.