Sagittal Crest

Sagittal Crests on the Great Primates


Fig. 1 Felix

I have recently become aware of a problem of interpretation arising within our research community.  This incipient problem has arisen through some basic misinterpretations and misunderstandings surrounding what constitutes the skull of an ape versus the skull of a sasquatch.

Understand, please that I am not an anatomist nor any kind or sort of paleontologist.  I can show you examples in photos, but don’t ask me why this is as it is… I don’t know… it just IS.  I am an engineer.  I hold a degree from University of Washington in Logging Engineering and as such, I do understand numbers.  I am also most familiar with the effects of fulcrums, joints, and forces.  Vectors, and trajectors…these I understand… many other aspects of moving forces from point A to point B I understand and It is through these eyes that I will try to cast some light on the subject… without becoming too mired in either the math or the symmetry of the subject.

Fig 2. Skull of Great Ape

To bring us up to date, let me describe the events that inspired this peek into our large friend’s anatomy.  I was perusing an online conversation in one of the many groups of which I am part and a lady, one who I normally consider well educated, thoughtful and interested, made the statement concerning a skull, “That has to be an ape as it has the crest showing on it.”


Immediately, my attention was riveted to that statement.  It then occurred to me that, perhaps, the subject was not well understood, so decided to try and explain it better.  A sagittal crest is not merely attributed to the ape family.  In fact, most of earlier man had it as well but to understand why demands some examination.

Why Do Crests Exist?

Fig. 3 Human Masseter Muscle – note size

Just now, a careful look at Fig 1 at the top of page one is in order.  This is Felix (my name for him, not his) who I saw on 20 Jun 2014 at a range of less than 20 feet, standing directly in front of my car in the company of a second, older Sas Person… I knew her, so I concentrated on Felix and later had an artist do this reconstruction of him.  At this point, there are only a couple of points of interest we need to concern ourselves with in our look.

These people eat a rough diet.  They neither cook their meat nor treat their vegetables.  If they wish to have ground wheat of other grains, the only way to attain it is to grind it in their mouth.  To eat thusly requires great force to remove the raw flesh from the bones for ingestion.  In order to effect this, they must literally tear the flesh away with their teeth and jaws.  To do this, they must have powerful jaws and this is where we are now… There is a muscle that controls the closing of the jaw.  It is mounted below the lower mandible on the bottom end and on the skull proper on the upper end.

A quick glance at Figure 3 with an illustration of the human (Homo sapiens sapiens) jaw structure shows this muscle clearly and since muscles ONLY work to close things, one can easily see how a drawing in of this muscle causes the jaw                                                                    Fig. 4 Ape Skulls

to ratchet up into the closed position while the release of pressure will allow the mandible to fall away for the next evolution.  Also, please notice the relatively small muscle at work here as compared to that shown in Figure 2, where the Masseter appears to have joined with the Temporalis muscle creating a force vector that now extends from the top of the skull to the lower mandible.  This would certainly make a formidable drive line to lift that massive jaw to masticate any food they wished.

Now, the next step is, how do we anchor that top section of muscle?

One of the very first things an engineer learns is that if you can create an angle with whatever you are using to support a load, you will increase the load carrying capacity of that system.

Look at the two skulls in Figure 4 and

Fig. 5 Low Crest                    it becomes obvious early on that the crest affords just that advantage in the system!  As we looked further into this study, we found some very unusual concepts arise… from the odd to the weird.

Notice the short, low crest illustrated in the skull shown in Fig. 5.  It is unique in my searching.  I can imagine that the owner of this setup could raise his hair or scalp at will to make displays.  This is something those of us who have researched in the sasquatch world, have seen on even such a famous personality as Patty in the PGF…

In conclusion, remember this.  The Sagittal Crest is an anchor point with mechanical advantage affording the owner the ability to attain food from the roughest sources and to not only survive but to thrive thereon.