Meeting Abstract
Pituitary hormones related to growth and reproduction play a central role in regulating mammalian life history. Recent work has shown that pituitary gland size can predict growth rates in extant mammalian species, with larger anterior pituitary lobes linked to faster fetal and postnatal growth. Given the link between pituitary gland volume and growth rates, estimating pituitary size in extinct species would provide a novel way to infer one aspect of growth in the past. The pituitary gland is seated within the sella turcica of the sphenoid bone and the bones of the sella turcica form around the developing pituitary gland. Therefore, we predict that the volume of the sella turcica will track pituitary gland volume such that mammalian species with larger glands will have greater bony dimensions. Additionally, we predict that growth rates increase as sella turcica volume increases. We gathered anterior and posterior pituitary lobe, as well as total gland, volumes for mammalian species from the literature. Data on sella turcica dimensions for representatives of the same species were measured from microCT reconstructions of crania available from online CT databases. Using PGLS, we show that the volume of the sella turcica increases as pituitary gland volume increases (p<0.05) and that one key measure of growth, postnatal growth rate, increases as sella turcica volume increases (p<0.05). This represents a novel approach to reconstructing growth rates in the past and adds a new dimension to explorations of mammalian life history evolution.
