[1][2] The lateral or orbital surface is divided by a vertical ridge, the posterior lacrimal crest, into two parts.

Of the four borders: The lacrimal is ossified from a single center, which appears about the twelfth week in the membrane covering the cartilaginous nasal capsule.

The lacrimal articulates with four bones: two of the neurocranium, the frontal and ethmoid, and two of the viscerocranium, the maxilla and the inferior nasal concha.

In primitive forms, it is often accompanied by a much smaller septomaxilla bone, lying immediately behind the nasal opening, but this is lost in most modern species.

The lacrimal bone is often smaller in living vertebrates, and is no longer always directly associated with the nasal opening, although it retains its connection with the orbit.

In some theropods (e.g. Allosaurus, Ceratosaurus, Albertosaurus) the upper part of the lacrimal bone grew in such a manner as to form a horn on the top of the dinosaur's head, usually situated above, and anterior to the eye.