Limiting sulcus of olfactory trigon

The limiting groove of the olfactory trigone exists in humans and marks the boundary of the triangular space at the angle of separation between the medial and lateral olfactory tracts. In macrosmatic animals such as domestic mammals, the trigone is not considered anatomically distinct: the space between the two tracts is much larger, and the gray matter occupying it forms a broad, rounded prominence called the olfactory tubercle. Therefore, the limiting sulcus of the olfactory trigone does not exist in these species.