“Sauroposeidon head suggestions no labels.jpg” [above] shows a mock-up of the skull, a traditional restoration of the head, the skull with accurate soft tissues, and an updated restoration. The traditional restoration looks like a lot of paleoart from the past two decades–it looks like someone shrink-wrapped the skull. But this is not what the heads of real animals look like at all. If you look at almost any animal, whether it is a lizard, croc,* turtle, snake, bird, cow, horse, rodent, or human, you can’t see the holes in the skull because they are filled with muscles or air sacs and smoothed over with skin. Here are the 8 specific features I fixed in the updated restoration:

* I got a little carried away here–some of the holes in croc skulls are not hard to make out, because their skin is unusually tightly bound to the very rugose skull. Most dinosaurs didn’t have that same skull texture, and there is little reason to think that their heads were similarly shrink-wrapped. Abelisaurs, maybe. Sauropods, not so much.

(1) the profile of the top of the head and start of the neck would have been smoothed out by jaw muscles bulging through holes in the top of the head (strange but true), and by neck muscles coming up onto the back of the skull.

(2) The fleshy nostril should be down on the snout at the end of the nasal troughs. The bony nostrils make that huge hump on top of the head, but they are continuous with these two grooves that run down the front of the face, and almost certainly the whole bony-nostril-plus-groove setup was covered by soft tissues and the actual air holes were down on the snout. That fleshy covering would have been propped up and not sucked down tight to the skull, so you wouldn’t be able to see the boundaries of bony nostrils from the outside. The fleshy nostril should also be fairly big; it is unlikely that a 50-ton animal with a head a yard long had nostrils the size of a horse’s.

(3) The holes in the skull should not be visible. The habit of drawing and painting dinosaurs with shrink-wrapped heads is so entrenched that smooth heads look undetailed and a little fake, but smooth heads are undoubtedly more accurate. The head wasn’t necessarily a completely smooth bullet–it probably had decorative scales and patches of color–but we can be fairly certain that the holes in the skull were not visible through the skin.

(4) The jaw joint is all the way at the back of the head, but past the tooth row the upper and lower jaws were bound together by jaw muscles.  When the jaws opened, as shown in the lower images, the muscles were covered by skin. This skin might have been outside the jaws and stretchy, as shown in the attached image “bird cheeks.jpg”, or it might have been tucked in between the jaws as shown in “croc cheeks.jpg” [below].

Another caveat in my own defense: I know that condors do not have muscular, mammal-style cheeks, so the “cheek” skin here is doing more than just covering jaw muscles (farther back on the  jaw the skin is covering jaw muscles). Remember that I was writing quick art suggestions for a less technically sophisticated audience, not a dissertation on condor heads. The take home point is that you can’t tell from looking at the condor below where the jaw muscles start or where the jaw joint is located (unless you already know something about bird skulls). Other than the  gross outline, there simply isn’t much osteology on display–and this is a naked head!

(5) The eyes are usually reconstructed as small, dull, and centered in the vertical middle of the eye socket. In fact the eyes were probably located toward the top end of the eye socket, they were probably colorful as in most reptiles and birds, and they may have been pretty big. [But not that big; see Mickey's comment below, and note that Brian got it right anyway.]

(6) The external ear hole is usually left out. It should be behind the back of the skull and in front of the hindmost jaw muscles.

(7) The profile of the back of the head follows jaw muscles, not the boundaries of the skull bones.

(8) Sauropods had true flip-top heads. The skull of Giraffatitan looks like nothing so much as an upside down toilet bowl, with the toilet seat for the lower jaw. Sauropods probably used that big gape to shove in as much plant material as possible per unit time. Crocodiles and many birds have an extensible throat pouch that allows them to bolt larger bites than you’d think, and the same was probably true of most dinosaurs, especially sauropods. There may have been a visible division between the muscular neck and this fleshy “gullet”. See “croc throat.jpg” and “bird throat.jpg” [below].