Paleolophus was not a large fish, with the complete skull of the holotype measuring in length. The skull is at its widest near the
supratemporal bones, where its width is almost equal with its length. The prepineal region of the skull makes up about one third of the skull's length which is similar to what is seen in
Uranolophus. The back of the
skull roof, like in other lungfish, is made up of a number of bones. The B bone is a large, hexagonal bone that is positioned at the midline of the skull. Two other bones, the I bones, meet one another posterior to the B bone at its midline. Both of these bones are very wide, being about twice as wide as they are long. The J bone is positioned laterally to the B bone and anteriorly to the I bones. The lateral-most bones of this section of the skull roof are the X,Y1, and Y2 bones in order from more anterior to posterior. Y2 is in contact with the I bone and all three of these bones are in contact with the J bone. The anterior-most of the three, the X bone, is only in contact with the J bone medioposteriorly. Unlike what is seen in the posterior section of the skull roof, the anterior bones that make it up are fused together. The supraorbital canal system begins towards the front of the skull where it is positioned at the midline, only to branch out towards the edges more posteriorly. There is a gap between this canal and the
infraorbital canal, though this could be due to preservation. The anterior portion of the infraorbital canals located on the upper lip of the skull are linked together by the ethmoid commissure. The trunk
lateral-line canals connect with the infraorbital canal. These canals start at the Y1,Y2, and X bones, only to curve when going through the X bone until they reach the other canal. The upper lip of the skull is split into three sections due to the paired anterior nares. The anterior-most section of the upper lip possesses a single row of low-crowned teeth. Located right behind these teeth are the
vomers and large paired nasal cavities. Each of these cavities equal about one third of the length of the
palate. The surface of the vomers have grooves which mark their attachment areas along with an internasal ridge. This ridge is short though is both taller and thinner than the ridge seen in
Uranolophus. Mediolateral to the nasal canal is the postnasal wall which is thin, in contrast to the more basal
Diabolepis. The palate of
Paleolophus is overall similar to what is seen in
Uranolophus, with the surface being covered by a large number of small cone-shaped
denticles that are more worn down towards the middle of the palate. The posterior area of the palate contrasts this in being overall smooth. The
parasphenoid is located along a majority of the palate. It is shaped like an elongate triangle. The
pterygoids are located on each side of the parasphenoid, extending until just behind the vomers where they meet with a short suture. Internally, the
palatoquadrate is fused to these bones. The palatoquadrate possesses a ridge that runs from the medial palatoquadrate margin to the front lateral edges of the bone. Two processes are located at the anterior portion of the ridge which suggests that the fish had a pars autopalatina. This combination of features suggests that Paleolophus had a strong
ethmoid articulation. A chamber is located under the Y1 bone, with it most likely being where large adductor muscles were located. These muscles would have most likely went through a large embayment on the palatal margin of the skull, only to then connect to the lower jaw. Also supporting adductor muscles are a total of five cristae; two of these are positioned laterally, two dorsolaterally, and one medially. These anatomical features indicate that the fish had a strong, palatal bite. Two teardrop-shaped supraoptic cavities are located under the
temporalis fossa. Behind these is a rough surface that most likely correlates to trunk muscles. The posterior-most portion of the skull, the
basioccipital region, is not completely ossified at its midline with this forming an embayment that is most likely for the
notochord.
Internal anatomy The large nasal cavity of
Paleolophus is connected to the
cranial cavity via a short olfactory canal. Overall the cranial cavity is wide, though does narrow and rise posteriorly. The major part of the cavity holds
cerebral hemispheres with the
hypophysial organ being located under them. The hypophysial canal is located at the bottom of the brain where it extends downwards and backwards. The canals for the pituitary vein extend backwards and outwards from the previously mentioned canal. Posterior to the hemispheres are the parapineal and pineal canals with end at the skull roof. The foramen is located right behind the pineal canal, with this being for the optic nerve. Both the
mesencephalon and
diencephalon are short with their combined length only being about one third of the length of the skull. A pair of crescent-shaped cavities are located near the
myelencephalon, these most likely housing the
inner ears. == Classification ==