# Sella Turcica Shape as a Marker for Breed and Sex Classification in Sheep

## TL;DR

This study shows that the shape of the sella turcica in sheep can help identify different breeds but not the sex.

## Contribution

The study introduces the use of 3D modeling of the sella turcica to classify sheep breeds based on morphological differences.

## Key findings

- The sella turcica shape differs significantly among the three sheep breeds studied.
- Zom sheep showed the most distinct sella turcica morphology compared to other breeds.
- No significant differences in sella turcica shape or size were found between male and female sheep.

## Abstract

The sella turcica is a small bony region at the base of the skull that forms the pituitary gland’s seating, which helps control growth, reproduction, and metabolism. In this study, we examined whether the shape and size of the sella turcica differ among three sheep breeds (Akkaraman, Morkaraman, and Zom) and between females and males. We scanned 102 skulls using computed tomography, which allowed us to create three-dimensional models of the sella turcica without breaking the bones, and then compared these models across groups. We found that the sella turcica differed among breeds, with Zom showing the clearest differences from the other two breeds. In contrast, females and males did not show clear differences.

Recent anatomical and morphometric studies indicate that the sella turcica is a structurally informative region and a distinctive anatomical formation that can exhibit shape variation among individuals. The aim of this study was to evaluate, in three dimensions, the extent to which sella turcica morphology differs among three sheep breeds (Akkaraman, Morkaraman, Zom) and between sexes. A total of 102 specimens were examined. All skulls were CT-scanned specifically for this study; the sella turcica region was reconstructed as a three-dimensional model, and 12 anatomical landmarks were manually digitized for each specimen. The findings showed that sella turcica size differed among breeds, with the Zom group exhibiting the largest sella turcica size. In contrast, no clear size difference was observed between females and males. Shape assessment also revealed differences among breeds, largely driven by the separation of Zom from Akkaraman and Morkaraman, whereas no distinct sex-related shape pattern was detected. Importantly, the breed-related shape differences persisted after accounting for size effects. Overall, these results suggest that the sella turcica carries a breed-associated morphological signal in sheep, while showing no pronounced sexual differentiation in the present sample.