Prefrontal bones are absent; post-frontals are possibly indicated by a frequently occurring separate centre of ossification in the postorbital process, to which the frontals always contribute.
Many birds possess a more or less well developed cross-joint in front of the frontals and lacrymals, perhaps best developed in Anseres and Psittaci.
The premaxilla is always unpaired, but each half has three long processes directed backwards; one fuses with the maxillary bone, another helps to form the anterior part of the palate, while the third, together with its fellow, forms the " culmen " and extends backwards to the frontals, or rather to the ethmoid which there crops up on the surface.
Post-orbital processes of the frontals exist in squirrels, marmots and hares; but in all other genera they are rudimentary or altogether absent; and the zygoma seldom sends upwards a corresponding process, so that the orbit is more or less completely continuous with the temporal fossa.
Skull depressed, frontals contracted and without post-orbital processes; p.; or; molars rootless, with transverse enamel-folds.
In front was often a hanging panel of embroidered cloth (the frontal; but frontals of wood, ornamented with carving or enamel, &c., are also to be found).
- In Saxon times the English metal-workers, especially of the precious metals, possessed great skill, and appear to have produced shrines, altar-frontals, retables and other ecclesiastical furniture of considerable size and magnificence.
During the whole medieval period it was much used to decorate church plate, silver altar-frontals, and the like.
The magnificent frontals of Pistoia cathedral and the Florence baptistery are notable instances of this.
Antlers arising at acute angles to the median line of the skull (as in the following genera), at first projecting from the plane of the forehead, and then continued upwards nearly in that plane, supported on short pedicles, and furnished with a brow-tine, never regularly forked at first division, but generally of large size, and with not less than three tines; the skull without ridges on the frontals forming the bases of the pedicles of the antlers.
- Tailed batrachians, with the frontals distinct from the parietals and the palatines from the maxillary.
The squamosal bone is large and either in contact with the frontals and parietals or separated from them by a vacuity; the orbit is sometimes roofed over by bone.
In the Caudata, the frontals remain likewise distinct from the parietals, whilst in the Ecaudata the two elements are fused into one, and in a few forms (Aglossa, some Pelobatidae) the paired condition of these bones has disappeared in the adult.