# Insights into cranial anatomy and craniometry of the aardwolf (Proteles cristata) with comparisons to extant hyaenids

## TL;DR

This study compares the skull anatomy of the aardwolf to other hyena species, revealing its unique and specialized cranial features.

## Contribution

The study provides new detailed morphometric and anatomical insights into the aardwolf's skull compared to other hyenas.

## Key findings

- The aardwolf has the smallest and narrowest skull among hyenas, with high morphological stability.
- Spotted and brown hyenas have larger skulls, with the spotted hyena showing greater variability.
- Aardwolf's skull features, like a cylindrical basilar part and prominent nuchal tubercles, are distinct from other hyenas.

## Abstract

The aardwolf skulls were analyzed and compared to the spotted hyena, the brown hyena and the striped hyena, using specimens from Polish and South African collections. Addressing gaps in detailed anatomy and morphometrics, this study used extensive analyzes, encompassing 64 morphometric parameters and 7 indices, to examine the morphology and morphometrics of cranial and mandibular structures and quantify interspecific and intraspecific variation.

The comparative analysis of hyena skulls revealed significant differences between the aardwolf and the other three species. The aardwolf consistently had the smallest and proportionally narrowest skull, characterized by high morphological stability and a wide neurocranium. The brown hyena and spotted hyena had the largest skulls; however, the brown hyena showed greater homogeneity, while the spotted hyena displayed higher absolute variability. Morphologically, the aardwolf’s basilar part was cylindrical, unlike the pyramidal shape in the spotted hyena, and it possessed prominent nuchal tubercles that were reduced in the brown and spotted hyenas.

This study demonstrates that the morphological and morphometric features of the aardwolf’s skull are highly specialized and fundamentally distinct from the other three hyena species, reflecting its unique dietary niche. The powerful skulls of the spotted and brown hyenas, in contrast, correlate with their roles as apex predators and scavengers.