  A study on primates has established that gyral size is largely independent of
overall brain size. Building on this, and other research suggesting that brain
gyrification may mitigate the effects of head impacts, our study aims to
explore potential correlations between gyral size and the risk of head impact
across a diverse range of mammalian species. Our findings corroborate the idea
that gyral sizes are largely independent of brain sizes, especially among
species with larger brains, thus extending this observation beyond primates.
Preliminary evidence also suggests a correlation between an animal's gyral size
and its lifestyle, particularly in terms of head-impact risk. For instance,
goats, known for their headbutting behaviors, exhibit smaller gyral sizes. In
contrast, species such as manatees and dugongs, which typically face lower
risks of head impact, have lissencephalic brains. Additionally, we explore
mechanisms that may explain how narrower gyral sizes could offer protective
advantages against head impact. Finally, we discuss a possible trade-off
associated with gyrencephaly.
