A Metrical Study of the Dali Cranium
WU Xin-zhi
2009, 28(03):
217-236.
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The maximum cranial length (g-op, M1) and glabello-inion length (M2) of the Dali cranium are 206.5mm and 190mm respectively. The maximum cranial breadth measured at the supramastoid crest is 150.5mm, and the maximum breadth of the reconstructed skull is 150mm at the level of temporal squama. The difference between the maximum cranial length and glabello-inion length in the Dali cranium and that in the cranium of Petralona are all longer than that in H. erectus from China. So the Dali cranium is closer to Petralona than to H. erectus from China. (Notes: This author did not write the term “H. erectus” in italics because he considers this group of humans as a morphological type instead of a species in the taxonomic sense).
The nasio-occipital length (n-op, M1d)of the Dali cranium is 196.5mm which is close to the upper limit of variation range of that of Middle Pleistocene humans (MPH) in both China and Euro-Africa.
The length of skull base (n-ba, M5) of the Dali cranium is 105.5mm which is within the range of MPH of Europe and the range covering Upper Cave and Liujiang. This measurement is near to that found at Kabwe, Bodo and Ndutu.
The nasion-opisthion length (M5 (1) ) of the Dali cranium is 143mm which is not that distance from Kabwe, Ehrinsdorf or H. erectus from Zhoukoudian(ZKD).
The minimum frontal breadth (ft-ft, M9) of the Dali cranium is 104mm which is longer than that of H. erectus of China and shorter than that of Jinniushan, another MPH of China. Both of them are within the variation range of MPH of Europe and longer than that of Kabwe.
The transverse fronto-parietal index (M9/M8) of the Dali cranium is 69.3 which is much lowerthan that of Jinniushan(77.0) . It is significant to note that these two values are within the range of MPH of Europe.
The maximum frontal breadth (co-co, M10) of the Dali cranium is 119.0mm and its ratio to maximum cranial breadth is within the ranges of both MPH in Europe and Neanderthals.
The biauricular breadth (au-au, M11) of the Dali cranium is 141mm which is in the ranges of both H. erectus of China and MPH of Europe.
The bi-porion distance (po-po) of the Dali cranium is 133 mm which is within the range of MPH in Euro-Africa and slightly higher than that in H. erectus from ZKD and Nanjing.
The bi-asterionic breadth (ast-ast, M12) of the Dali cranium is 115mm, the occipital height (l-sphba) is 119mm, both of which are within the range of MPH of Europe including Ceprano, Atapuerca and Petralona. These numeric figures of the Dali cranium are much shorter than that of Kabwe. The ratio of occipital breadth to its height is 103.5 in Dali. This value is higher than that of Kabwe and MPH of Europe, and is close to the lower limit of variation range of that of modern humans.
The basi-bregmatic height ( ba-b, M17) of the Dali cranium is 117mm. The length-height index (56.7) is lower than that of Jinniushan, H. erectus from ZKD, Kabwe, Steinheim and Petralona, and is much lower than that of Atapuerca SH but slightly higher than that of Ehrinsdorf and Yunxian II.
The auriculo-bregmatic height (po-b, M20) of the Dali cranium is 102.5mm. The index formed by it and the maximum cranial length is 49.6, which is close to that of Yunxian II, H. erectus from ZKD and Hexian, and is lower than that of Ceprano, Atapuerca SH, Steinheim, Petralona and Kabwe.
The calvarial height index of the Dali cranium is 45.5, which is higher than that of H. erectus of China, Pithecanthopus of Java and Neanderthals. This index is close to the lower limit of European Upper Paleolithic humans with a variation range of 46-55. The bregma position index of the Dali cranium is 39.1 which is within the range of that of H. erectus of China and higher than that of Upper Paleolithic humans of Europe (range: 28-37).
The horizontal circumference (g-op-g, M23) of the Dali cranium is 565mm, the transverse arc (po-b-po, M24) is 299mm. These values are all within the range of both MPH and modern humans.
The transverse cranial curvature (M11/M24) of the Dali cranium is 47.2, which is not that distinct from H. erectus found at ZKD, Petralona and Kabwe, but is much higher than that of modern humans.
The total sagittal arc (n-o, M25) is 376mm in the Dali cranium. This value is much longer than that of Chinese H. erectus and close to the upper limit of range of MPH of Europe (Atapuerca SH, Petralona and Ehrinsdorf) as well as Kabwe. It should be noted that this arc measured in the Dali cranium is even longer than the average of modern humans.
The ratio of nasio-occipital length to total sagittal arc (M1d/M25) of the Dali cranium is 52.3 which is slightly higher than that of Upper Paleolithic humans of China and lower than that of H. erectus from ZKD, and is within the range of European MPH ( Atapuerca SH, Petralona and Ehrinsdorf). This value is close to that of Kabwe.
The ratio of nasio-opisthion length to total sagittal arc (M5(1)/M25)of the Dali cranium is 38.0 which is much lower than that of H. erectus from ZKD and falls within the range of Upper Paleolithic humans of China. It is also not far from that of Ehrinsdorf and Kabwe.
The frontal chord(M29) is of the Dali cranium 114mm which is close to the upper limit of the ranges of both Chinese H. erectus and MPH of Europe. The frontal arc (M26) is 135mm in the Dali cranium, this arc is much longer than that in H. erectus of China and MPH of Europe except that of Ehrinsdorf, but is slightly shorter than that of Kabwe.
There is a wormian bone between the parietal and occipital of the Dali cranium, This author locates the lambda as the point of intersection of the sagittal suture and the elongation of left lambdoidal suture. The parietal chord (M30) of the Dali cranium is 107mm which is much shorter than that of Yunxian II and slightly longer than the longest one of other H. erectus specimens of China. This chord in the Dali cranium is within the range of MPH of Europe (Ceprano, Petralona, Arago, Atapuerca SH, Steinheim and Ehrinsdorf), but is shorter than that of Kabwe. The parietal arc (M27) of the Dali cranium is 115mm which is much shorter than that of Yunxian II and slightly longer than that in Maba and other H. erectus specimens from China. This arc in Dali is close to that of Kabwe and within the range of the European MPH listed above.
The occipital chord (M31) of the Dali cranium is 88mm which is longer than that of H. erectus of China and shorter than most of the MPH of Europe. The occipital arc (M28) of the Dali cranium is 122mm which is longer than that of H. erectus of China, Kabwe and within the range of MPH of Europe.
In the Dali cranium, the curvature index of parietal bone is higher than that of frontal which is higher than that of the occipital bone.
The left bregma-asterion chord (M30c) of the Dali cranium is 131mm. The ratio of it to the occipital breadth is 113.9 which is close to the upper limit of variation range of Atapuerca SH(97.8-117.5).
The chords of anterior margin of parietal (b-sphn, M30(2)) of the Dali cranium are 91.2mm and 88.6mm for left and right sides respectively. These values are slightly longer than that of H. erectus from ZKD. The arcs of the anterior margin (b-sphn, M27 (2) ) of the Dali cranium are 104mm and 103mm respectively for both sides. These values are slightly longer than that of H. erectus from ZKD. The chord and arc of the Dali cranium are within the range of European MPH.
The chord and arc of posterior margin of left parietal (M30 (3) and M27 (3) ) of the Dali cranium are 92.0mm and 105mm respectively, and the ratio of these measurements is within the range of European MPH including Ceprano, Petralona and Arago, and slightly lower than that in H. erectus from ZKD.
The upper scale chord and arc of the occipital bone (l-i chord and arc, M31 (1) and M28 (1) ) of the Dali cranium are 71mm and 84mm respectively, and the upper scale curvature index is 8415 which is lower than that of H. erectus from ZKD and modern humans.
The lower scale chord and arc (i-o ,chord and arc, M31 (2) and M28 (2) ) of the Dali cranium are 40mm and 41mm respectively. The chord is much shorter than that of H. erectus from ZKD and is within the range of Atapuerca SH, and close to that of Neanderthals, but the lower scale curvature of the Dali cranium is slightly higher than that of H. erectus from ZKD.
The foramen magnum of the Dali cranium is measured as 38mm in length and 28mm in breadth , and the length2breadth index is close to the upper limit of that of Atapuerca SH specimens.
The distance between inion and endinion in the Dali cranium is 18mm which is shorter than all of adults of H. erectus from ZKD and Nanjing , but is close to that of Hexian, Ehringsdorf, Swanscombe, Ceprano, and the upper limit of Neanderthals.
The total length of left temporal bone of the Dali cranium is 89mm. which is close to that of H. erectus from ZKD, Kabwe and Narmada, but shorter than that of Petralona. The length of mastoid portion of the Dali cranium is 24mm which is close to the upper limit of the range of H. erectus from ZKD and much longer than that in Narmada. The length and height of temporal squama of the Dali cranium are 72mm and 47mm respectively giving an index of 64.6 which is much higher than that of Yunxian II, H. erectus from ZKD and Hexian, but is close to that of Xujiayao, and much lower than that of Atapuerca SH specimens.
The mandibular fossa of the Dali cranium is 25mm in length on both sides which is close to the average of modern humans and longer than that of H. erectus from ZKD. The width of this feature in the Dali cranium for both sides are 35mm and 32mm which show that they are wider than those in both H. erectus from ZKD and modern humans; the depth of this feature in the Dali cranium is 11.5mm for both sides which is close to the lower limit of H. erectus from ZKD and modern humans. It should be noted that both depth/length ratio and depth/width ratio of the Dali cranium are lower than that in H. erectus from ZKD.
The frontal profile (M 32a) of the Dali cranium is 72° which is much larger than that of H. erectus from ZKD, Hexian, Nanjing and Kabwe, and only slightly larger than that of Neanderthals from western Europe. This value is slightly smaller than that of Ehrinsdorf and is much smaller than that of modern humans.
The frontal inclination, nasion-bregma angle, b-n-i, M32 (1) of the Dali cranium is 54°which is much larger than that of H. erectus from ZKD.
The bregma angle (b-g-i, M32 (2) ) of the Dali cranium is 50° which is larger than that of Yunxian II and H. erectus from ZKD, Hexian and Nanjing and Kabwe. This angle of the Dali cranium is close to that of Ehrinsdorf and the upper limit of that in Neanderthals from western Europe and is lower than that of modern humans.
The frontal angle (M32 (5), FRA) of the Dali cranium is 128°, which is smaller than that of Atapuerca SH specimens (139.8°-145.8°). The parietal angle (M33e, PAA) of the Dali cranium is 151° which is slightly larger than that in Atapuerca SH. The occipital angle(M33d, OCA) of the Dali cranium is 93°which is not only much smaller than that of Atapuerca SH but also smaller than that in early Pleistocene humans of Africa. The l-i-o angle (M33 (4) ) of the Dali cranium is 99° which is much smaller than that in Atapuerca SH and Ceprano. This value is close to the lower part of the range of H. erectus from ZKD, and smaller than that from Nanjing.
Naso-malar angle(fmo-n-fmo, M77)of the Dali cranium is 143°which is close to that of Liujiang and No. 103 of Upper Cave. This value is larger than that in other two Upper Cave crania.
Nasio-frontal angle (fm: a-n-fm: a, M77, NFA) of the Dali cranium is 143° which is larger than that of European MPH and Neanderthas, and is slightly larger than the average of Upper Paleolithic humans of Europe.
Although the maxilla of the Dali cranium was broken and its lower part has been shifted upward and sideways but it can be reconstructed. The depth of facial bones(ba-pr, M40) of the reconstructed cranium is 105mm which is shorter than that of MPH in Europe (Atapuerca SH 5 and Petralona) and in Africa(Kabwe and Bodo) and more concordant with that of fossil humans in China.
In the Dali cranium the true least frontal breadth is 106.4mm with the largest distance of the frontal bone at the level of brow ridge being 125.0mm. The post-orbital constriction index obtained by calculating the ratio of these two measurements, is 85.1, it is higher than that of H erectus from ZKD. In an article by de Lumley et al (2008) the post-orbital constriction index is calculated based on the true least frontal breadth and upper facial breadth represented as fmt-fmt. The upper facial breadth of the Dali cranium is 121mm. According to the definition used in de Lumley et al (2008) , therefore the index of the Dali cranium is 87.9, and is higher than that of Ceprano, Arago, Atapuerca SH and Petralona, and much higher than that of Kabwe and Bodo.
The bifrontal breadth (fm: a-fm: a, M43a, FMB) of the Dali cranium is 114mm which is close to the averages for both MPH of Euro-Africa and Neanderthals, but is longer than that of European Upper Paleolithic humans. The nasio-frontal subtense (M43b, NAS) of the Dali cranium is 18.8mm which is shorter than that of MPH in Euro-Africa and close to that of Upper Paleolithic humans of Europe. Rightmire (1990) used ft-ft and fm: a-fm:a to calculate the postorbital constriction index, according to his definition the index of Dali should be 91.2 which is much higher than that of Petralona and Kabwe.
Using a reconstructed cranium of the Dali specimen, the bizygomatic breadth (zy-zy, M45) is 141mm, the upper facial height (n-pr, M48) is 75mm, the upper facial index of this specimen is 53.1 which is higher than that of Nanjing and Jinniushan. But this index is close to the lower limit of the range of that of MPH in Europe (Atapuerca SH5, Steinheim, and Petralona) and lower than that of Kabwe and Bodo. Thus based on these measurements and indices the Dali cranium is probably intermediate between the MPH of China and Euro-Africa.
The facial length (au-fmo) of the Dali cranium is 80mm which is slightly longer than that of Petralona and longer than that of Steinheim. It is within the range of Upper Cave and Liujiang.
The zygomatic arch length (au-ju) of the Dali cranium is 60? mm which is close to that of Petralona and Steinheim, and is within the range of Upper Cave and Liujiang.
The length of zygomatico-maxillary suture of the Dali cranium is 31mm which is shorter than that of Petralona, Steinheim and Kabwe.
The bijugal breadth (ju-ju ,M45 (1) ) of the Dali cranium is 126.5mm which is within the range of Atapuerca SH(No. 5. and No. 6).
The lower part of left zygomatic bone of the Dali cranium was broken , the bimalar breadth (zm-zm, M46) is estimated at 103mm in this specimen, this value is much shorter than that of Petralona and Arago, and is close to that of anatomically modern human fossils of Upper Cave and is longer than that in Liujiang.
The bimaxillary breadth (zm: a-zm: a, M46b, ZMB) of the reconstructed cranium of the Dali fossil is 103mm which is within the range of Atapuerca SH.
The right zygomatic bone is well preserved in the Dali cranium, the cheek height (M48d, WMH) is 23.0mm which is very close to that of Nanjing and within the range covering Liujiang and Upper Cave. However, this measurement is shorter than that of MPH of Europe and Africa.
The anterior interorbital breadth (mf-mf, M50, IOW) of the Dali cranium is 21.0mm which is much shorter than that of MPH of Europe, Africa and western Asia and is close to that of Neanderthals and Upper Paleolithic humans of Europe. The Dali cranium is close to Nanjing, Maba, Liujiang, Upper Cave in this measurement.
The mf-mf subtense of the Dali cranium is 617mm which is slightly longer than that of Liujiang and Maba, but shorter than that of three Upper Cave crania.
The index formed with the mf-mf subtense divided by mf-mf in the Dali cranium is 31.9 which is lower than that of Upper Cave and higher than that of Liujiang.
The thickness (in mm) of the Dali cranium at various locations are as follows:
Frontal bone: center of squama: 8.8 ; temporal facies: 6.0 (rt);
Parietal bone: bregma: 10.0, tuberosity: 11.2 (lt); mastoid angle: 12.3 (lt);
Occipital bone: center of squama: 13.0?; center of torus: 20.0; cerebellar fossa 3.7 (lt), 3.2(rt);
Temporal bone: center of squama: 7.0(lt), 6.9(rt);
Parieto-mastoid suture behind parietal notch: 10.5 (lt), 8.5 (rt);
Occipito-mastoid suture medial to mastoid process: 8.8 (rt).
In general, the cranial wall of the Dali cranium is as thick as that of H. erectus from ZKD and H. sapiens fossils from Xujiayao, but is thicker than other Middle Pleistocene fossils of China such as those found at Jinniushan and Maba.
Based on these comparisons, the morphological features of the Dali cranium could be classified into several kinds as follows:
1, The Dali cranium has many features intermediate between H. erectus and modern humans, it shows the morphological mosaic between these categories; 2, Some features of the Dali cranium are closer to modern humans than to many other Middle Pleistocene humans, these features even fall in the range of modern humans; 3, Some features of this specimen are within the variation range of MPH both in China and Euro-Africa; 4, Many features of this fossil are more closely associated with that of other Pleistocene humans in China than to MPH in Euro-Africa; 5, Some morphological features in the Dali cranium are closer to that of MPH in Euro-Africa than to other H. erectus from China; 6, Some features of the Dali cranium seem to be in the status intermediate between MPH of the eastern and western parts of Eurasia.
In conclusion, the features mentioned above together with some non-metric features (such as the special shape of median sagittal ridge and the suture between nasal, maxilla and frontal bones, the most protruding point of median sagittal profile of frontal bone locating at its lower half, nearly vertical nasal profile, orientation of the fronto-sphenoidal process of zygomatic bone, rounded infero-lateral orbital margin, curved lower margin of zygomatic process of maxilla etc) indicate that the Dali specimen represents one of the members of the continuous human lineage in China, meanwhile it shows morphological evidences indicating probable gene flow from the western part of the Old World to China.
