prefrontali

Prefrontali are paired skull bones that form part of the anterior skull and the orbit in many vertebrates. Their exact position and relationships vary by lineage, but they typically lie on the medial anterior margin of the eye socket, between the frontal bone and either the lacrimal or the nasal bone.

In reptiles and birds, the prefrontali commonly contribute to the medial orbital margin and articulate with the frontal and lacrimal bones, with some contact to the nasal bone depending on the species. In mammals, the prefrontal is often reduced or fused with the frontal bone, making it difficult to distinguish as a separate element in the adult skull. In fossil taxa, the presence, size, and connections of the prefrontali can be important for identifying relationships and reconstructing skull morphology.

Functionally, the prefrontali help define the orbital boundaries, contributing to the protection of the eye and to the overall architecture of the anterior skull. They may serve as sites for ligamentous or soft-tissue attachments and influence the shape of the orbital opening and surrounding bones.

Development and evolution: prefrontali arise from dermal skull elements within the dermatocranium and typically ossify intramembranously. Their pattern of development and articulation reflects broader evolutionary changes in skull construction across vertebrates.

Note: the term prefrontali is sometimes used in parallel with the English term prefrontal bones. It should not be confused with the prefrontal cortex, which is a brain region. See also: frontal bone, lacrimal bone, nasal bone, orbit.