THE SPECIAL FEATURES AND STATUS O F THE SALDANHA SKULL

M. R. DRENNAN Department of Anatoiny, University of Cape Town, Xowbray, Cape Town,

Sotith Africa

FIVE FIQURES

Thc Saldanha skull has no individual feature that is not found in one or other of the known human fossils, but it has an interesting combination of primitive characters that give it a distinctive position in the human pedigree. It is another es- ample of the diversity of character which appears to pervade fossil man, and seems to indicate that the variation in type of modern man, such as is shown by the contrasting Australian and South African Bushman, has a much more fundamental basis and significance than is usually given to it.

I n this short note several features of Saldanha man will be discussed and conclusions stated regarding his taxonomic po- sition.

The most striking feature of the Saldanha skull is undoubt- edly the great development of its brow-ridges. In their medial two-thirds they show the same general contour and massivc- ness as the Rhodesian torus. This part of the Saldanha torus is inflated to a considerable extent by big frontal sinuses, but the author has no comparative data for the Rhodesian skull.

The outer third of the Saldanha torus tapers definitely to- wards its outer end, whereas the Rhodesian buttress maintains its massiveness right out to the zygomatic suture. Keith ( '25) considered that the special robustness of the outer end of the Rhodesian torus must have been for the attachment of the frontal part of a particularly powerful temporal muscle, such ;IS would have been in keeping with his massive -jaws and face.

625

626 M. It. DRENNAN

l’lie relative refiiiemcnt of the outer part of the Saldanha torus might be regarded as an indication that the Saldanha skull had belonged to a female of the Rhodesian type, but there are no other special suggestions of femaleness in this skull, and sex- ual variation usually affects the ridges as a whole.

It seems to the author that the relative attenuation of the outer ends of the Saldanha torus is best interpreted as indi- cating that this skull had a different type of masticatory appa- ratus from that of the Rhodesian skull. F o r this view there is actual evidence from the mandibular fragment which suggests that the Saldanha jaw was typically Neanderthaloid in shape, and quite out of harmony with the Rhodesian skull. My view, then, is that where the Saldanha torus differs from that of the Rhodesian it is in a Neanderthal direction.

The author’s interpretation of the differences between the brow-ridges and indeed of most of the differences between these two skulls may he expressed differently in terms of the general principle which seems to lie hehind the presence, modi- fication or absence of brow-ridges. It is known that in any race which shows brow-ridges, these are developed in the adult as secondary sexual characters of the male. Their presence can therefore be described as both a gerontomorphic and an aiidromorphic character, whereas their absence or diminution denotes a paedomorphic and gynomorphic condition. The in- teresting thing is that this developmental and sexual antithesis of ontogeny fiucls a wider expression in racial phylogeny. In the Homo sopiens group, for example, we have the great con- t rast between the Australian aboriginal with his well-devel- oped brow-ridges and the South African Bushman who is practically devoid of such ridges. The former is therefore an example of a gerontomorphic and andromorphic race, whereas the latter is paedomorphic and gynomorphic.

The whole primate phylum abounds with examples of what can thus be regarded as “male” and “female” types or races relative to one another. For the present argument, the author regards the Rhodesian skull as that of an archandromorph.

THE SALDANHA SKULL 627

relative to ivhich tlie Salclaiilia skull is to a degree a g p o - morph in this aid other respects.

It follows also froni the principle outlined above that brow- ridges or their absence are only fortuitous specializations of different races in much the same way as tliere are horned and hornless breeds of cattle. They are not in themselves deter- minants of morphological status or the Australian and South African aboriginals coultl not both I)c classified as sapient.

S o distinction can be drawn betu-ecii thc Saldanha and Ithoclcsian skulls in respect of the slope of the forehead (see fig. 1) which puts both into the Keaiidertlial category. The condition of tlie nncierlying frontal lobes of the brain, liowever, must have been dwiclcdlp different, Iwcause the frontal region of the Salctanha ciiclocast has a much iiiore primitive slope than that of the Rhodesian endocast (see fig. 2 ) . In tlic pre-hregniatic part of tlie froiital sqnama we en-

counter an important divergence in character. In this region tlic Rhodesiaii sqnama shows a vestigial niedian crest, and 1)cliind this thwc is a dcfiiiitc kceliiig of this slrull (see fig. 3) .

628 M. R. DBENNAN

The Saldanha skull, on the other hand, shows no suggestion of these important features, being smoothly rounded from side to side, so that in this way it resembles the Neanderthals and the great majority of modern men. That this is a funda- mental morphological Cliff erence has been clearly showii by Sergi ('30), who has traced simian and gerontomorphic keel-

/

Fig. 2 Projection (1ranGlig of tlic sagittal contour of the Saldanha endocast - continuous line, eoniparcd with that of the Rhodesian endocast - broken line, after lVei~2cnreich ( '36).

I

! !

0 , , 1, , ', cma.

Fig. 3 Transverue contour through the vertex of the Saldanha endocast - cow tinuous line, compared with that of the Rhodesian endocast - broken line, :16

shown by Morant 's ( '28) standard drawing.

T H E SALI)A S HA SKULL 629

ing or cresting of the skull from the Rhodesian to the Aus- tralian type, and he has given many examples of its distribu- tion in Africa, Europe, Oceania and among early Americans. It is quite clear, however, that from an early stage in human development this archaic type of skull has been giving way to the more rounded one. Here we see again an interplay of geront omorphism and paedomorphism, and that the Rhode- sian and Saldanha skulls are expressions of this antithesis.

It is also worth noting in passing that the Saldanha skull is not alone amongst African primitives in having this laterally rounded shape of the vertex of the skull, because it is also shown by Eyassi man (Africauathropus), with whom Saldanha man has other features in common. Thus the uniformly curved sagittal contour of the Saldanha skull parallels that of Afri- cnnthropzis, but at a higher level. On the other hand the profile of the R.hodesian skull is very uneven with flattened facets on it.

There is a specially marked depression in the obelionic region of the latter (see fig. l), which has usually been in- terpreted as signifying a marked degree of morphological primitiveness. More striking than this is the ultra-gorilline indentation which appears in this region of the endocast (see fig. 2) . This latter has been regarded as indicating that the development of this important part of the brain has been specially retarded in Rhodesian man. Such an estreme degree of local arrest of development, however, is very unusual in human phylogeny, although there is some evidence of thc same phenomenon in the mid-sagittal contour of endocast I of Sincmthropus (Weiclenreich, '36).

Because it might have been expected that the Saldaiihn skull, being somewhat Rhodesioid, would show this depression and not the relatively more marked elevation present in this region, the question arises as to whether there may not be an- other explanation for this extreme inconsistency in the shape of these two skulls.

Figure 3 shows Morant's ( '28) standard drawing of the transverse contour of the Rhodesian skull. Well up on the left

630 M. R. DRENNAN

side there is an iiidentatioii ; this indentation and a depression in this region of the vault of the skull are very suggestive of post-mortem deformation. Opposite this, in an obliquely down- ward direction, the right basal part of the skull is missing and may have been broken inwards by counterpressure. It is in- teresting in this connection to recall that, according to one geological theory, the Broken Hill cave and the whole lropjie above it had suffered a general subsidence, and the skull, ac- cording to Harris (’21) had “tons of hones” above it.

Having mooted this possibility of deformation so that it may be kept in mind, should further evidence one way or nn- other turn up, the writer will proceed on the assumption that the obelionic indentation is morphological, and it strengthens the present argument considerably to do so. The disharmony between the two endocasts in the region under discussion is acceptable in the light of the heteromorphism in other features of the two types being compared.

With regard to the braincasts in general there is no doubt, from measurements and calculations, that the relative small- ness of the Saldanlia cast, as shown in figure 2, substantiates a degree of cerebral inferiority in this type. This suggestion of primitiveness is endorsed by a consideration of the impor- tant occipital region of the skull a i d endocast. The squama of the occipital hone of the Saldanha skull is shorter and con- siderably narrower than that of the Rhodesian, and it has an area which is quite 15% smaller than that of the latter. This occipital plane also meets what there is of the nuclial plane of the Saldanha skull at a more primitive angle, than is shown by the Rhodesian (see fig. 1). In this respect the Raldanha skull agrees with the Xeanderthals and lo\v~r types, whereas the Rhodesian disposition is quite sapient.

The impressions on the inner aspect of the Saldanha occi- pital bone, as reflected 011 the endocast, show that the occipital poles of the Saldanha cerebrum must have been rather feebly developed, whereas the corresnondinq imle of the Rhodesian is full and rounded (see fig. 2 ) . In this 1-esncct the Rhodesian closely resembles the Neanderthals, whereas the Saldenha

THE SALDANHA S K U L L 631

brain reverts ~i iorc towards Pithecanthropus (sce fig. 4). This inferior status is corroborated by the position of the cere- bellum, which is little more than covered by the occipital pole of the cerebrum as in Pithecunthropus, whereas the Rhodesian cerebellum is in as forward and sheltered a position as in both sapient and Neanderthal brains (see fig. 4).

The degree of refinement of the occipital torus of the Sal- danha skull, relative to this marked feature of the Rhodesian occiput, argues both ways. It may be an advance towards the condition found in many Australian skulls, which it resembles

-_____ Bantu

------- La Chapells alx Saints ------_ Rhodesian ------ Saldanha

Pithecanthropus

------- Gorilla

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Fig. 4 Coiltours of the occipital region of a series of endocast (see t e x t ) .

very much, but it must also be remembered that Pithecamthro- pus has no torus occipitalis, and it is not very well developed in the typical Neanderthals.

The last feature of Saldanha man which I wish to discuss is the mandibular fragment which we have presumed to belong to the Saldanha skull (Drennan and Singer, '55). There is no doubt that the features of this part of the ramus of a human mandible closely resemble those of the corresponding part of the Heidelberg jam.

Heidelberg man was the first human fossil to show a square gibbon-like ramus and in this way to break away from the taller narrow ramus of the hominids and prehominids. Ry SO

632 AM. R. DRENNAN

doing he put himself on the early pari of a genetic line which can be traced to the Neanderthals and to the later Khoisan types of South Africa.

To the extent that this shape of ramus is found in infantile mandibles it is a paedomorphic character, which, in those races that show it, defies the “stretch” put on the ramus by the erupting teeth. In other races the square shape of the in- fantile ramus is, so to speak, stretched longer and narrower shape of the adult, their mandibles they are gerontomorphs.

into the relatively so that as regards

Fig. 5 Projectioii drawiiig of a cast of the Heidelberg mandible-continu- ous heavy line, with, superimposed on its ramus, the shape of this part of the mandible required by the Rhodesian skull -broken line. Thin continuous line represents the Saldanha fragment in its appropriate position,

It is a relatively easy matter to get an approximation to what the Rhodesian mandible must have looked like, and Dart (’55) has recently done this. In the skull itself we have the three factors that determine the length and breadth of the ramus, namely the mandibular fossa, which gives the upper limit of the condyloid process ; the oval ring within the zygo- matic arch, the long diameter of which determines the for- ward projection of the coronoid process ; and the upper teeth, which give the occlusal plane and the position of the lower teeth. It requires a relatively long and narrow ramus to con- form to the three determinants I have mcntioncd, so that there

THE SALDANHA SKULL 633

can be no doubt that Rhodesian man was gerontomorphic in this respect.

Figure 5 gives a drawing of the ramus of the author’s re- construction of the Rhodesian mandible superimposed on the ramus of the Mauer jaw. On this latter also I have placed a drawing of the fragment of the Saldanha mandible in its ap- propriate position. The indications from this latter compari- son are that the Saldanha mandible had a short wide ramus closely resembling that of Heidelberg man, and that both are relatively paedomorphic. If, therefore, the argument from this admittedly inferential evidence about the shape of the Rhodesian and Saldanha mandibles is valid, these two types here present their greatest and most significant contrast.

SUMMARY AND COSCLUSION

In the foregoing discussion of the salient features of Sal- danha man it has been recognized that, in order to arrive at a correct assessment of his morphological status, it would be adventageous to use as a comparative standard his nearest and best known compeer, namely Rhodesian man.

Although there is a degree of resemblance between the skulls of these two fossil men, analysis of their features nevertheless shows that, far from having been cast in similar moulds, they show a wealth of contrast.

It is reasonable to deduce from this that, whatever tlicir relative status may turn out to be, it will not be lineal but collateral. Expressing gerontomorphism in practically all features, Rhodesian man seems to have some backward link- age with the Neanderthals, with Sinanthropus, with Paraa- thropus, and even with the gorilla, whilst he has a close for- ward linkage with the australoid types of Hoino sapieas. Sal- danha man, on the other hand, would appear to have some backward linkage with a Heidelberg type of Neanderthal, with Africauzthropus, with Pithecanthropus, and ultimately per- haps with some giant gibbon, whilst judging by his jaw and other paedomorphic tendencies he has some forward linkage with the South African paedomorphic types of H o m o snpieiz.9.

634 M. It. DRENNAN

It is iiot an easy matter to assess the relative position of Rhodesian and Salclanha man on these two separate lines. Rugged and primitive as the features of the former obviously are, one is forced to regard these as relatively late specialiea- tions, because his undoubted predecessors were not so crude anatomically. The relative refinement or paedomorphism of the Saldanha skull, which might argue for a higher morpho- logical status than that of the Rhodesian, need not therefore do so, all the more so as it shows no advance in cerebration. It is in fact the relative smallness and the primitive features of the Saldanha brain cast that do most to establish the Saldanha skull on a lower morphological grade. When with this there is taken into account the great thickness of the bones and other distinctive features of the Salclanha skull, the author consiclcrs it logical to designate Saldanha man as FiTon?o scrldnlzensis.

TJTERATURE CITEn

DART, R. A. 1955 Estinct and extnnt liumnn niandibles. South African Jour.

T ~ A R R I S , W. E. 1921 Illustrated London News, 19th November. KEITH, A. The Antiquity of Man. Vol. 11, p. 403. Williams and Xorgatc,

MORANT, 0. M. 1928 Studies of palaeolitliie man. Ann. Eugenics, vol. 111, pts.

SEROI, 0. 1930 La piu antica iimanita vivente. Toriiia: Fratelli Boeea, Editori. WEIDENREICH, F. Observations on the form and proportions of the enrlo-

cranial casts of Sinanthropus pebinensia, otlirr lioiniriids and the great apes: a comparative study of brain size. Pekiii : Palacontologia Siiiica, Series D, Vol. VII, Fascicle 4.

Sci., 61: 258.

1925 Ltd., London.

3 and 4.

1936