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Journal of Human Evolution 54 (2008) 187e195
Three-dimensional primate molar enamel thickness Anthony J. Olejniczak a,*, Paul Tafforeau b,c, Robin N.M. Feeney a, Lawrence B. Martin d,e b
a Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, D-04103 Leipzig, Germany Laboratoire de Ge´obiologie, Biochronologie et Pale´ontologie Humaine, UNR CNRS 6046, 40 avenue du Recteur Pineau, F-86022 Poitiers cedex, France c European Synchrotron Radiation Facility, 6 rue Jules Horowitz, 38043 Grenoble Cedex, France d Department of Anthropology, Suite 2104 Computer Sciences Building, Stony Brook University, Stony Brook, NY 11794, USA e Department of Anatomical Sciences, Suite 2104 Computer Sciences Building, Stony Brook University, Stony Brook, NY 11794, USA
Received 9 November 2006; accepted 30 September 2007
Abstract Molar enamel thickness has played an important role in the taxonomic, phylogenetic, and dietary assessments of fossil primate teeth for nearly 90 years. Despite the frequency with which enamel thickness is discussed in paleoanthropological discourse, methods used to attain information about enamel thickness are destructive and record information from only a single plane of section. Such semidestructive planar methods limit sample sizes and ignore dimensional data that may be culled from the entire length of a tooth. In light of recently developed techniques to investigate enamel thickness in 3D and the frequent use of enamel thickness in dietary and phylogenetic interpretations of living and fossil primates, the study presented here aims to produce and make available to other researchers a database of 3D enamel thickness measurements of primate molars (n ¼ 182 molars). The 3D enamel thickness measurements reported here generally agree with 2D studies. Hominoids show a broad range of relative enamel thicknesses, and cercopithecoids have relatively thicker enamel than ceboids, which in turn have relatively thicker enamel than strepsirrhine primates, on average. Past studies performed using 2D sections appear to have accurately diagnosed the 3D relative enamel thickness condition in great apes and humans: Gorilla has the relatively thinnest enamel, Pan has relatively thinner enamel than Pongo, and Homo has the relatively thickest enamel. Although the data set presented here has some taxonomic gaps, it may serve as a useful reference for researchers investigating enamel thickness in fossil taxa and studies of primate gnathic biology. Ó 2007 Elsevier Ltd. All rights reserved. Keywords: Micro-computed tomography; Primate enamel thickness; Relative enamel thickness; Three-dimensional measurement
Introduction Quantitative investigations of primate enamel thickness, spurred by an interest in the taxonomic status of the genus Ramapithecus (now a junior synonym of Sivapithecus), were undertaken by Gantt (1977, 1982), Kay (1981), and Martin (1983, 1985). These studies (1) demonstrated the utility of enamel thickness quantification for distinguishing primate
* Corresponding author. Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, D-04103 Leipzig, Germany. Tel.: þ49 341 3550 376; fax: þ49 341 3550 399. E-mail addresses:
[email protected] (A.J. Olejniczak), paul.
[email protected] (P. Tafforeau),
[email protected] (R.N.M. Feeney),
[email protected] (L.B. Martin). 0047-2484/$ - see front matter Ó 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.jhevol.2007.09.014
taxa, (2) brought enamel thickness into the fold of dental characters used to interpret paleodiet, and (3) represented a sequence of methodological refinement, culminating in the method of measuring enamel thickness that is the most widely used today (Martin, 1983, 1985). In recent years, enamel thickness has been highlighted in diagnoses of fossil taxa (e.g., Conroy et al., 1992; Begun and Kordos, 1993; White et al., 1994; Brunet et al., 1995; Pickford and Ishida, 1998; Asfaw et al., 1999; Haile-Selassie, 2001; Leakey et al., 2001; Senut et al., 2001; Brunet et al., 2002), largely due to the diagnostic dichotomy between relatively thin-enameled African apes and relatively thick-enameled hominins (e.g., Martin, 1985; for more recent evaluations of this dichotomy, see Shellis et al., 1998; Kono, 2004; and Smith et al., 2005). Enamel thickness has also been measured in several
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A.J. Olejniczak et al. / Journal of Human Evolution 54 (2008) 187e195
previously described fossil hominoid taxa (e.g., Martin and Andrews, 1984; Grine and Martin, 1988; Andrews and Martin, 1991; Beynon et al., 1998; Dean and Schrenk, 2003; Smith et al., 2003; Smith et al., 2004), and enamel thickness has been measured in representatives of all major extant primate radiations (e.g., Shellis et al., 1998; Ulhaas et al., 1999; Schwartz, 2000; Martin et al., 2003; Grine et al., 2005). Previous studies of enamel thickness were typically performed on cross sections of molars produced via histological methods or by grinding the tooth to the location of the desired plane and polishing that surface (e.g., Martin, 1983, 1985; Beynon et al., 1998; Shellis et al., 1998; Ulhaas et al., 1999; Grine, 2002, 2005; Martin et al., 2003; Smith et al., 2003, 2004, 2005, 2006a). Recent advances in microtomographic imaging techniques have advanced methods for measuring enamel thickness in two notable ways. First, these imaging techniques facilitate the nondestructive production of virtual planes of section, preserving valuable museum collections and making available for analysis fossils that could not be physically sectioned (e.g., Kono, 2004; Tafforeau, 2004; Tafforeau et al., 2006; Olejniczak and Grine, 2005; Olejniczak, 2006; Smith et al., 2006b). Second, these techniques facilitate the analysis of three-dimensional, whole-crown enamel thickness measurements, rather than limiting measurements to a single plane of section (e.g., Kono, 2004; Tafforeau, 2004; Olejniczak, 2006). Recent microtomographic studies of whole-crown primate molar enamel thickness have concentrated on the evolution of anatomically modern humans (e.g., Suwa and Kono, 2005; Smith et al., 2006b), great apes (e.g., Kono, 2004; Tafforeau, 2004), and lesser apes (Olejniczak, 2006). This focus on hominoid primates is warranted, as enamel thickness is among the characters distinguishing hominins from African apes, and the first standardized two-dimensional studies of enamel thickness were performed on hominoid molars (e.g., Martin, 1983). Studies of two-dimensional enamel thickness in other primates, however, have provided important tests of functional and phylogenetic hypotheses regarding enamel thickness. For example, these studies have explored molar adaptations to hard-object feeding (e.g., Dumont, 1995; Martin et al., 2003) and the relationship between body size and cross-sectional tooth dimensions (e.g., Shellis et al., 1998). As nondestructive techniques for measuring enamel thickness become commonplace, data from a wide range of taxa with varying dietary proclivities will prove useful as a basis for comparison. The goal of this study is to generate, and make widely available, volumetric primate enamel thickness measurements based on microtomographic imaging and a taxonomically broad sample.
Table 1 The 3D enamel thickness study sample by genus Genus
Maxillary M1
Alouatta Ateles Cebus Cercocebus Eulemur Galago Gorilla Homo Hylobates Loris Macaca Pan Papio Pongo Saimiri Symphalangus Total
Mandibular
M2
M3
M1
M2
M3
7 9
9 10 1
5 7
5
9
3
21 26 1 4 5 1 9 39 11 3 1 26 3 12 3 17
40
63
30
182
1
1
3 1
1 1
5
5
1 14 1
4 1 4 1
3
5
1
3 1
1 1 1 3 1
12
13
1
Total
2
1 1 4 9 4
9 2 4
5 3
7
1 24
molars (Homo sapiens). Each molar was scanned using microCT to produce a high-resolution image stack suitable for imaging and accurately measuring internal and external dental features (such as the enamel-dentine junction; Fig. 1). Three microCT scanning systems were used in the development of the data set examined here: the European Synchrotron
Materials and methods The molars studied here represent 16 primate genera, including representatives of all three extant anthropoid superfamilies and a small sample of strepsirrhines (Table 1). A total of 182 molars were studied, with sample sizes for each taxon ranging from a single molar (e.g., Cebus apella) to 39
Fig. 1. Volume rendering of a Pongo pygmaeus molar image stack, obtained via microtomography, showing the separation of enamel from dentine for enamel thickness calculations. The box in the lower left shows the location of the basal plane, above which coronal measurements are taken.
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Radiation Facility (Grenoble, France), a ScanCo tabletop microCT machine (Department of Biomedical Engineering, Stony Brook University), and a SkyScan microCT tabletop machine (Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology). Differences between scanning systems are thoroughly recounted by Tafforeau et al. (2006) and relate chiefly to the superior quality of the synchrotron light source, which produces monochromatic Xrays (effectively eliminating beam-hardening artifacts from the resultant images). Despite substantial differences between systems and the quality of the resultant images, all three systems have been shown to yield images for which 3D enamel thickness measurements are equally accurate (Olejniczak et al., 2007). Moreover, the accuracy of the synchrotron (Tafforeau, 2004) and ScanCo scanners (Olejniczak and Grine, 2006) have independently been established. A single observer (AJO) collected the data reported in this study to prevent the introduction of interobserver error. Tafforeau (2004) previously measured a subset of the great ape and human sample, and comparisons of measurements taken by AJO and PT show that results are similar (within 3%). Nonetheless, substantial differences in segmentation techniques may introduce interobserver error, and therefore a single observer measured all teeth. The segmentation protocol employed in this study made use of basic image filters (e.g., median filter, anisotropic diffusion filter) and region-growing techniques. A demonstration of the accuracy of this protocol, and its ability to homogenize enamel and dentine in microCT radiographs is given by Olejniczak (2006). A three-dimensional data set was recorded for each of the teeth scanned, following the protocols of Kono (2004), Tafforeau (2004), and Olejniczak (2006) (Fig. 1): 1. The volume of the enamel cap in mm3 (EVOL). 2. The volume of coronal dentine (including the volume of the pulp chamber contained within the enamel cap) in mm3 (DVOL). 3. The surface area of the enamel-dentine junction in mm2 (EDJESA). 4. Average enamel thickness in mm (AET3D). Average enamel thickness is the average straight-line distance between the enamel-dentine junction and the outer enamel surface. This is calculated as the quotient of the enamel volume (EVOL) and the enamel-dentine junction surface area (EDJESA): AET3D ¼ (EVOL / EDJESA). 5. Relative enamel thickness, a scale-free measurement (RET3D). This is the average enamel thickness (AET3D) scaled by the dentine volume: RET3D ¼ (AET3D / [DVOL]1/3) 100. The cube root is used in order to make the result scale-free (following Martin, 1983), and therefore appropriate for interspecies comparisons; the result is multiplied by 100 for ease of interpretation. The measurement of coronal dentine volume is defined to include the aspect of the pulp chamber that extends into the molar crown. The coronal pulp-chamber volume is included in the dentine volume measurement in order to be consistent
189
with the planar methods developed for measuring enamel thickness by Martin (1983). The enamel cervix of a molar is sinuous, and defining a single cervical plane (above which is crown and below which is root) is difficult in light of areas of enamel that ‘‘sleeve’’ towards the root apex. Following Olejniczak (2006), the most apical plane of section through the cervix that shows a continuous ring of enamel was first located; next, this plane was gradually moved apically until the most apical plane of section still containing enamel was located. The plane exactly halfway between that containing the most apical continuous ring of enamel and that containing the most apical extension of enamel was taken as the cervical plane, above which coronal measurements were recorded. Results Results of the 3D enamel thickness measurements for each tooth examined in this study appear in Appendix A. Variable definitions and units are as given in the materials and methods section. Summary enamel thickness measures (both absolute and relative) for each genus are given in Table 2. Results of 3D measurements of great ape and human molar relative enamel thickness are in general agreement with 2D studies. Gorilla molar enamel is relatively the thinnest (mean RET3D ¼ 9.77), and Homo molar enamel is relatively the thickest (mean RET3D ¼ 23.97). Pan molar enamel is relatively thicker than Gorilla molar enamel, and relatively thinner than Pongo molar enamel, but with overlapping ranges in both cases (mean RET3D ¼ 11.80). The mean value for Pongo molar relative enamel thickness is less than that of Homo and greater than that of Pan (mean RET3D ¼ 14.49). The lesser ape sample presented here is also in agreement with 2D data (Olejniczak, 2006), in that hylobatids have relatively thicker enamel than previously thought (e.g., Martin, 1983; Shellis et al., 1998). Hylobates relative enamel thickness is similar to that of Pongo on average (mean RET3D ¼ 14.72). Symphalangus relative enamel thickness is similar to that of Pan on average (mean RET3D ¼ 11.15). Table 2 The 3D average (AET) and relative (RET) enamel thickness by genus Genus
Alouatta Ateles Cebus Cercocebus Eulemur Galago Gorilla Homo Hylobates Loris Macaca Pan Papio Pongo Saimiri Symphalangus
n
21 26 1 4 5 1 9 39 11 3 1 26 3 12 3 17
AET (mm)
RET
Mean
Range
Mean
0.40 0.39 0.65 0.75 0.23 0.12 0.98 1.43 0.49 0.10 0.73 0.75 0.85 1.01 0.16 0.55
0.26e0.54 0.26e0.53
9.90 12.27 23.60 17.55 8.68 6.33 9.77 23.97 14.72 5.77 13.69 11.80 14.84 14.49 8.19 11.15
0.64e0.91 0.18e0.29 0.67e1.25 0.65e2.3 0.36e0.6 0.09e0.1 0.56e0.92 0.55e1.2 0.81e1.42 0.12e0.21 0.35e0.72
Range 7.23e13.77 7.45e16.94 15.44e18.53 6.97e11.5 7.12e12.7 12.56e40.71 11.29e18.68 4.85e6.33 9.03e14.72 13.08e16.7 11.22e19.03 7.69e8.77 7.44e14.11
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190
Table 3 3D enamel thickness in great apes and humans (present study; Kono, 2004) and 2D data from Smith et al. (2005) Taxon
Gorilla Homo Pan Pongo
Present study
Kono (2004)
Smith et al. (2005)
n
Mean AET (mm)
Mean RET
n
Mean AET (mm)
Mean RET
9 39 26 12
0.98 1.43 0.75 1.01
9.77 23.97 11.80 14.49
4 40 22 7
0.98 1.33 0.81 1.01
9.5 20.6 12.3 12.9
The cercopithecoid sample studied here is comprised entirely of cercopithecine molars, which are known from 2D studies to be relatively thicker-enameled than colobine molars (Ulhaas et al., 1999). Cercocebus molars have greater relative enamel thickness (mean RET3D ¼ 17.55) than Papio or Macaca molars. Papio and Macaca molars are similar in terms of relative enamel thickness (Papio mean RET3D ¼ 14.84; Macaca RET3D ¼ 13.69). Ceboid molars are relatively thinly enameled compared to cercopithecoid molars when measured in 3D, with the exception of the relatively thick-enameled Cebus apella (RET3D ¼ 23.60; n ¼ 1). The relatively thinnest-enameled ceboid molars in the sample studied here are those of Saimiri (mean RET3D ¼ 8.19). Alouatta molar enamel (mean RET3D ¼ 9.90) is slightly thicker than that of Saimiri. Relative molar enamel thickness in Ateles is greater than in both Saimiri and Alouatta (mean RET3D ¼ 12.27). The strepsirrhine molars studied here are relatively the thinnest, on average. The two lorisid genera have relatively thinner enamel than the single lemurid genus: Eulemur mean RET3D ¼ 8.68, Galago mean RET3D ¼ 6.33, and Loris meanRET3D ¼ 5.77. This result is consistent with previous measurements reported for strepsirrhine primates relative to anthropoids (Shellis et al., 1998).
n 15 257 40 41
Mean AET (mm)
Mean RET
1.04 1.22 0.75 1.10
11.68 20.06 13.23 15.49
Pan occupies a range of relative enamel thickness intermediate between that of Gorilla and Pongo, consistent with some previous research using 2D sections (Martin, 1985; Smith et al., 2005; see Table 3). Sample sizes in the present study and those of Kono (2004) are similarly small for great ape taxa (Table 3), and small samples may be responsible for differences in the reporting of different results for relative enamel thickness (although data for Gorilla in both studies are similar, and it is the least represented taxon in both studies). In both studies, it is unknown which subspecies are represented, or whether individuals were wild or zoological specimens, which may influence measurements. Nonetheless, it is notable that, in both studies, average enamel thickness is identical, or very similar, for all taxa (Table 3), suggesting that fundamental differences in measurement or image-segmentation protocols are not responsible for differences in relative enamel thickness. Rather, the
Discussion The relative enamel thickness data presented here are generally in agreement with measurements from 2D sections (see Appendix B in Martin et al., 2003). Hominoid primates have a wide range of relative enamel thicknesses, with Gorilla and Symphalangus at the thin end of this range, followed in order from relatively thinnest to relatively thickest enamel by Pan, Hylobates, Pongo, and Homo. Cercopithecoids have intermediate relative enamel thickness, which is greater than that of ceboids, on average. Relative enamel thickness in strepsirrhines is the lowest among primates. The evolution of enamel thickness in great apes and humans has been the subject of many studies, and hominoids were the subject of the first microtomographic study of relative enamel thickness (Kono, 2004). Kono (2004) suggested that, based on 3D data, Pan and Pongo molar enamel is not substantially different (contra Martin [1985] and in agreement with Shellis et al. [1998]). The results presented here demonstrate that Pan molar enamel (mean RET3D ¼ 11.80) is, on average, thinner than that of Pongo (mean RET3D ¼ 14.49).
Fig. 2. Relative enamel thickness in the sample of primate molars studied here, grouped by superfamily (hominoid primates are separated by genus to show differences among taxa, as well as the wide range of variation in hominoid molar enamel thickness). Boxes represent 25% and 75% of the data, lines represent the range of the data, and lines within boxes are mean values.
A.J. Olejniczak et al. / Journal of Human Evolution 54 (2008) 187e195
morphology of the molars studied appears to be different. The data presented here are in line with the 2D results of Martin (1983, 1985) and Smith et al. (2005), the latter study reporting that Pan molar enamel is slightly thicker than Gorilla molar enamel in relative terms (but not statistically significantly thicker), but that Pongo has thicker enamel than Pan (which is statistically significant at some molar positions). There is a notable similarity in primate-wide enamel thickness, given 2D data (e.g., Figure 4 in Martin et al., 2003) and the 3D data presented here. Both 2D and 3D data show increases in enamel thickness corresponding to cladistic events in primate evolution (Fig. 2). When this broad, superfamily-level view of primate enamel thickness evolution is taken, it is clear that the terms thin enamel and thick enamel must be used with caution. Gorilla is often considered to be thin-enameled, for instance, but this is only relative to other catarrhines; Gorilla molar enamel is relatively thicker than that of many ceboid and strepsirrhine primates. Moreover, despite substantial differences between 2D and 3D data-collection techniques (e.g., the inclusion of the mesial-distal length of crown morphology in 3D measurements), at this broad level of comparison, the results of 2D and 3D measurements approximate one another. Nonetheless, the full 3D summary of relative enamel thickness should be preferred over 2D measurements in future studies of wholecrown enamel thickness, as this measurements takes into account not only tooth length, but also local variations in enamel thickness that are not captured in 2D section planes (e.g., Kono, 2004; Suwa and Kono, 2005), and is thus better suited as a description of the whole crown. Several recent studies have advocated the comparison of enamel thickness between species at specific tooth locations (e.g., first mandibular molars of one taxon should be compared
191
only to first mandibular molars in a second taxon) (e.g., Macho, 1994; Smith et al., 2005). This view stems largely from the realization that relative enamel thickness tends to increase from the first to the third molar in many primate taxa. We concur that tooth-specific comparisons are more valuable when comparing closely related species, and we encourage future researchers to build upon the data presented in Appendix A to make such comparisons possible and statistical analyses per tooth type feasible. The goal of the present study was to make available a taxonomically broad set of enamel thickness data for future research regarding primate dietary adaptations and phylogenetic studies. Future work will expand this data set to be more comprehensive in its scope, and to facilitate within-taxon comparisons (e.g., by tooth position). It is our hope that these data will be useful for comparative purposes where a small number of fossil molars are studied (as in previous work in 2D; e.g., Smith et al., 2003, 2004) and that they will be incorporated into future studies of the primate gnathic system. Acknowledgements We are grateful to Tanya Smith and Jean-Jacques Hublin for the invitation to present this work at the Max Planck Institute for Evolutionary Anthropology, as well as our fellow workshop participants. Fred Grine provided access to some of the material studied here, for which we are grateful. We also thank Fred Grine, Callum Ross, Stefan Judex, Bill Kimbel, Tanya Smith, Jean-Jacques Hublin, and two anonymous reviewers for critical comments on aspects of this manuscript. The European Synchrotron Radiation Facility, Shiyun Xu, Stefan Judex, Tanya Smith, and Heiko Temming graciously provided assistance with and access to scanning facilities.
Appendix A. Compete data set of measurements recorded for this study Voxel
Jaw
Tooth
Genus
Species
41.1 17.5 17.5 10.5 12.5 12.5 15.0 17.5 15.0 12.5 17.5 12.5 15.0 12.5 12.5 15.0 17.5 17.5 15.0 15.0 15.0 10.5
Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand
M2 M1 M1 M1 M1 M1 M1 M2 M2 M2 M2 M2 M2 M2 M3 M3 M3 M3 M1 M2 M3 M1
Alouatta Alouatta Alouatta Alouatta Alouatta Alouatta Alouatta Alouatta Alouatta Alouatta Alouatta Alouatta Alouatta Alouatta Alouatta Alouatta Alouatta Alouatta Alouatta Alouatta Alouatta Ateles
pigra seniculus seniculus seniculus seniculus seniculus seniculus seniculus seniculus seniculus seniculus seniculus seniculus seniculus seniculus seniculus seniculus seniculus sp. sp. sp. geoffroyi
EVOL
DPVOL
EDJSA
BASAREA
51.09 31.07 26.42 29.88 34.56 32.34 38.39 33.15 27.66 34.06 39.14 45.02 54.75 51.61 29.20 32.03 35.51 47.48 24.30 23.65 26.07 15.50
101.21 48.31 67.05 64.18 78.62 82.52 89.76 57.75 65.48 70.82 80.83 87.26 91.29 104.95 56.22 60.12 63.45 53.93 34.36 61.04 43.02 29.11
94.18 117.91 80.68 87.43 68.30 85.75 93.80 95.90 67.99 113.14 109.91 108.63 116.20 108.31 91.24 72.65 81.03 91.25 62.80 59.53 61.96 40.56
30.16 25.94 25.15 24.76 25.52 28.15 33.04 27.12 23.20 30.40 27.48 29.21 34.45 31.30 23.09 20.39 25.37 30.72 18.96 21.68 20.65 12.86
AET3D
RET3D
0.54 11.64 0.26 7.23 0.33 8.06 0.34 8.54 0.51 11.81 0.38 8.66 0.41 9.14 0.35 8.94 0.41 10.09 0.30 7.28 0.36 8.24 0.41 9.34 0.47 10.46 0.48 10.10 0.32 8.35 0.44 11.25 0.44 10.99 0.52 13.77 0.39 11.90 0.40 10.09 0.42 12.01 0.38 12.43 (continued on next page)
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192 Appendix A (continued) Voxel
Jaw
Tooth
Genus
Species
EVOL
DPVOL
EDJSA
BASAREA
AET3D
RET3D
10.5 12.5 12.5 12.5 12.5 12.5 12.5 10.5 12.5 10.5 12.5 10.5 12.5 12.5 10.5 12.5 12.5 10.5 12.5 12.5 10.5 12.5 6.0 10.5 10.5 6.0 30.3 41.1 41.1 41.1 10.1 10.1 10.1 10.1 10.1 10.1 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 41.1 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.0 30.3 30.0
Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Max Max Max Mand Max Mand Max Max Mand Mand Mand Mand Mand Mand Mand Mand Mand Max Max Max Mand Max Max Max Mand Max Mand Mand Max Max Mand Mand Mand Mand Max Max Mand Mand
M1 M1 M1 M1 M1 M1 M2 M2 M2 M2 M2 M2 M2 M2 M2 M3 M3 M3 M3 M3 M3 M3 M1 M1 M2 M2 M1 M1 M1 M1 M1 M1 M2 M2 M3 M2 M1 M1 M1 M1 M2 M2 M2 M2 M3 M1 M1 M1 M1 M1 M1 M2 M2 M2 M2 M2 M2 M2 M2 M2 M2 M2 M2 M2 M2
Ateles Ateles Ateles Ateles Ateles Ateles Ateles Ateles Ateles Ateles Ateles Ateles Ateles Ateles Ateles Ateles Ateles Ateles Ateles Ateles Ateles Ateles Ateles Ateles Ateles Cebus Cercocebus Cercocebus Cercocebus Cercocebus Eulemur Eulemur Eulemur Eulemur Eulemur Galago Gorilla Gorilla Gorilla Gorilla Gorilla Gorilla Gorilla Gorilla Gorilla Homo Homo Homo Homo Homo Homo Homo Homo Homo Homo Homo Homo Homo Homo Homo Homo Homo Homo Homo Homo
geoffroyi geoffroyi geoffroyi geoffroyi geoffroyi geoffroyi geoffroyi geoffroyi geoffroyi geoffroyi geoffroyi geoffroyi geoffroyi geoffroyi geoffroyi geoffroyi geoffroyi geoffroyi geoffroyi geoffroyi geoffroyi geoffroyi paniscus sp. sp. apella sp. sp. sp. sp. sp. sp. sp. sp. sp. sp. gorilla gorilla gorilla gorilla gorilla gorilla gorilla gorilla gorilla sapiens sapiens sapiens sapiens sapiens sapiens sapiens sapiens sapiens sapiens sapiens sapiens sapiens sapiens sapiens sapiens sapiens sapiens sapiens sapiens
13.51 13.73 16.01 17.53 18.23 20.25 11.61 16.48 16.01 17.79 18.56 16.13 16.92 21.52 24.11 9.85 12.89 13.27 15.41 17.04 21.69 20.12 14.13 20.73 23.22 12.56 27.20 58.62 49.90 67.06 5.82 7.35 7.95 11.47 8.34 1.62 244.97 321.06 309.75 307.93 350.97 329.89 470.98 566.33 446.19 185.59 185.21 215.65 214.32 219.42 229.89 181.94 188.55 219.62 191.51 222.85 214.99 227.43 221.31 232.00 239.77 238.05 293.86 252.98 354.43
31.51 36.50 35.49 36.37 36.50 45.05 27.37 28.97 32.59 32.97 33.43 36.62 36.58 40.89 40.71 24.34 23.27 26.17 26.26 25.29 29.30 33.45 41.03 34.06 35.43 20.78 40.98 72.31 92.93 123.91 15.70 20.77 17.01 26.04 15.66 6.05 820.47 819.89 874.62 905.93 1117.59 1146.78 1154.02 1418.46 950.86 285.79 296.10 289.83 294.90 292.26 304.19 135.34 179.58 180.82 240.61 210.68 245.41 236.21 249.40 259.20 263.90 271.17 284.08 339.76 305.28
38.65 32.24 47.22 47.54 51.88 66.40 31.61 48.78 43.49 36.51 52.23 36.42 41.19 54.85 45.78 27.00 36.08 37.61 30.60 41.31 47.78 51.16 54.98 50.42 51.35 19.35 42.56 78.50 71.37 73.42 31.74 38.36 33.63 46.00 29.01 14.07 367.46 380.98 350.51 309.91 368.42 387.16 382.35 478.79 357.39 163.86 184.57 205.32 255.00 226.91 145.36 282.04 105.67 95.40 128.45 153.42 153.32 119.93 196.79 216.79 180.33 177.71 218.18 141.70 238.64
12.10 11.03 16.02 14.10 15.42 13.64 11.29 12.92 12.06 11.91 13.67 12.95 12.52 13.10 13.26 10.62 8.92 13.41 10.80 10.64 10.55 10.57 18.43 13.20 14.35 11.08 16.83 24.92 25.54 35.85 6.80 12.73 7.62 14.14 11.44 4.93 153.38 143.71 133.26 132.08 180.77 181.42 134.48 169.90 143.37 69.10 74.49 75.51 73.91 73.63 74.04 60.19 54.17 72.52 60.49 64.45 72.22 65.38 58.83 67.16 80.74 73.61 82.68 71.75 100.25
0.35 0.43 0.34 0.37 0.35 0.31 0.37 0.34 0.37 0.49 0.36 0.44 0.41 0.39 0.53 0.36 0.36 0.35 0.50 0.41 0.45 0.39 0.26 0.41 0.45 0.65 0.64 0.75 0.70 0.91 0.18 0.19 0.24 0.25 0.29 0.12 0.67 0.84 0.88 0.99 0.95 0.85 1.23 1.18 1.25 1.13 1.00 1.05 0.84 0.97 1.58 0.65 1.78 2.30 1.49 1.45 1.40 1.90 1.12 1.07 1.33 1.34 1.35 1.79 1.49
11.07 12.84 10.31 11.13 10.59 8.57 12.18 11.00 11.53 15.19 11.03 13.34 12.38 11.39 15.31 12.59 12.51 11.88 16.94 14.05 14.73 12.21 7.45 12.68 13.77 23.60 18.53 17.92 15.44 18.32 7.32 6.97 9.20 8.41 11.50 6.33 7.12 9.00 9.24 10.27 9.18 8.14 11.74 10.53 12.70 17.19 15.06 15.87 12.63 14.57 23.52 12.56 31.63 40.71 23.97 24.41 22.40 30.68 17.87 16.78 20.73 20.70 20.49 25.59 22.06
A.J. Olejniczak et al. / Journal of Human Evolution 54 (2008) 187e195
193
Appendix A (continued ) Voxel
Jaw
Tooth
Genus
Species
EVOL
DPVOL
EDJSA
BASAREA
30.0 30.3 30.0 30.0 30.0 30.0 30.3 30.0 30.0 30.3 30.0 30.0 30.0 30.1 30.1 30.3 30.3 30.0 10.0 10.5 10.5 10.5 12.5 10.5 10.5 10.5 12.5 10.5 10.5 12.5 10.1 10.1 10.1 41.1 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 30.3 41.1 41.1 10.0 41.1
Max Max Max Mand Mand Max Max Max Max Max Max Max Max Mand Max Max Mand Max Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Max Max Max Mand Mand Mand Max Mand Mand Mand Mand Mand Mand Mand Max Mand Mand Mand Mand Mand Mand Max Mand Mand Mand Mand Mand Max Max Mand Mand Max Mand
M3 M3 M3 M3 M3 M3 M3 M3 M3 M3 M3 M3 M3 M3 M3 M3 M3 M3 M3 M1 M1 M1 M1 M2 M2 M2 M2 M3 M3 M3 M1 M1 M3 M2 M1 M1 M1 M1 M1 M1 M2 M2 M2 M2 M2 M2 M2 M2 M2 M2 M3 M3 M3 M3 M3 M3 M3 M3 M3 M3 M2 M2 M2 M1
Homo Homo Homo Homo Homo Homo Homo Homo Homo Homo Homo Homo Homo Homo Homo Homo Homo Homo Homo Hylobates Hylobates Hylobates Hylobates Hylobates Hylobates Hylobates Hylobates Hylobates Hylobates Hylobates Loris Loris Loris Macaca Pan Pan Pan Pan Pan Pan Pan Pan Pan Pan Pan Pan Pan Pan Pan Pan Pan Pan Pan Pan Pan Pan Pan Pan Pan Pan Papio Papio Papio Pongo
sapiens sapiens sapiens sapiens sapiens sapiens sapiens sapiens sapiens sapiens sapiens sapiens sapiens sapiens sapiens sapiens sapiens sapiens sapiens muelleri muelleri muelleri muelleri muelleri muelleri muelleri muelleri muelleri muelleri muelleri gracilis gracilis gracilis nemestrina troglodytes troglodytes troglodytes troglodytes troglodytes troglodytes troglodytes troglodytes troglodytes troglodytes troglodytes troglodytes troglodytes troglodytes troglodytes troglodytes troglodytes troglodytes troglodytes troglodytes troglodytes troglodytes troglodytes troglodytes troglodytes troglodytes sp. sp. ursinus pygmaeus
170.13 142.22 189.95 178.53 181.56 214.12 185.41 197.73 215.57 183.26 197.75 197.13 227.19 196.10 227.43 224.08 263.03 317.72 299.26 16.34 22.55 28.11 28.41 20.44 32.14 35.95 35.45 18.25 25.69 26.72 0.96 1.06 0.97 70.41 84.53 95.25 123.18 114.84 152.32 140.84 117.67 116.35 134.56 134.12 147.99 147.19 177.97 175.17 170.14 174.73 108.41 109.91 126.90 132.80 127.16 138.27 137.75 136.78 160.46 176.83 137.78 246.93 42.60 192.85
103.53 131.84 119.83 149.70 146.81 142.76 173.65 162.05 150.40 194.75 185.50 198.68 194.23 242.06 231.07 243.69 250.84 288.09 372.37 31.23 32.31 40.64 40.64 31.59 44.79 44.60 51.80 26.17 28.89 32.97 4.29 6.77 4.85 150.27 195.69 247.82 264.02 293.06 304.69 316.67 205.07 213.52 241.15 284.63 275.24 310.31 323.45 332.56 349.61 366.36 169.95 229.87 221.13 226.47 243.82 237.31 241.17 244.49 275.00 304.38 221.66 373.94 53.08 311.28
106.26 82.48 118.33 121.09 125.05 136.73 122.82 137.58 130.47 101.13 150.69 171.08 158.98 149.94 117.20 246.78 182.51 229.39 162.05 45.92 51.67 58.81 53.10 57.24 59.34 69.94 58.92 46.92 44.82 45.11 9.34 11.51 9.42 96.74 129.61 162.96 146.28 173.19 206.15 185.67 159.55 152.11 170.80 164.86 210.77 171.63 233.44 264.44 230.04 204.95 139.75 121.87 180.79 179.60 225.32 173.01 179.97 186.13 204.51 191.97 174.04 205.23 76.86 220.83
44.53 39.14 49.09 45.31 45.30 65.98 47.12 52.23 53.87 56.26 59.23 63.37 61.06 60.59 52.04 61.81 68.49 79.87 78.55 13.75 14.04 14.86 16.98 15.19 16.20 16.84 18.17 13.69 12.60 13.87 4.75 7.11 5.41 33.47 62.50 59.80 62.04 61.67 68.58 73.02 67.95 68.37 65.59 61.49 74.97 63.78 79.41 76.75 78.14 74.01 60.01 60.36 58.78 56.77 59.99 55.61 61.47 61.81 67.01 62.28 53.66 86.09 29.75 79.99
AET3D
RET3D
1.60 34.10 1.72 33.88 1.61 32.56 1.47 27.77 1.45 27.52 1.57 29.96 1.51 27.06 1.44 26.36 1.65 31.07 1.81 31.26 1.31 23.01 1.15 19.75 1.43 24.68 1.31 20.99 1.94 31.62 0.91 14.54 1.44 22.85 1.39 20.97 1.85 25.67 0.36 11.30 0.44 13.70 0.48 13.90 0.54 15.56 0.36 11.29 0.54 15.25 0.51 14.49 0.60 16.14 0.39 13.10 0.57 18.68 0.59 18.47 0.10 6.33 0.09 4.85 0.10 6.12 0.73 13.69 0.65 11.23 0.58 9.31 0.84 13.13 0.66 9.98 0.74 10.98 0.76 11.13 0.74 12.51 0.76 12.80 0.79 12.66 0.81 12.37 0.70 10.79 0.86 12.67 0.76 11.11 0.66 9.56 0.74 10.50 0.85 11.91 0.78 14.01 0.90 14.72 0.70 11.61 0.74 12.13 0.56 9.03 0.80 12.91 0.77 12.30 0.73 11.75 0.78 12.07 0.92 13.69 0.79 13.08 1.20 16.70 0.55 14.75 0.87 12.89 (continued on next page)
A.J. Olejniczak et al. / Journal of Human Evolution 54 (2008) 187e195
194 Appendix A (continued) Voxel
Jaw
Tooth
Genus
Species
EVOL
DPVOL
EDJSA
BASAREA
AET3D
RET3D
30.3 41.1 30.3 30.3 30.3 30.3 41.1 30.3 30.3 41.1 30.3 10.1 10.1 6.7 15.0 12.5 15.0 10.5 10.0 10.5 15.0 10.5 12.5 10.5 15.0 15.0 10.5 10.0 15.0 10.5 15.0
Mand Max Mand Max Max Mand Max Max Max Mand Mand Max Max Max Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand Mand
M1 M1 M1 M1 M2 M2 M2 M2 M2 M2 M2 M1 M2 M3 M1 M1 M1 M1 M1 M2 M2 M2 M2 M2 M2 M2 M2 M2 M3 M3 M3
Pongo Pongo Pongo Pongo Pongo Pongo Pongo Pongo Pongo Pongo Pongo Saimiri Saimiri Saimiri Symphalangus Symphalangus Symphalangus Symphalangus Symphalangus Symphalangus Symphalangus Symphalangus Symphalangus Symphalangus Symphalangus Symphalangus Symphalangus Symphalangus Symphalangus Symphalangus Symphalangus
pygmaeus pygmaeus pygmaeus pygmaeus pygmaeus pygmaeus pygmaeus pygmaeus pygmaeus pygmaeus pygmaeus sp. sp. sp. syndactylus syndactylus syndactylus syndactylus syndactylus syndactylus syndactylus syndactylus syndactylus syndactylus syndactylus syndactylus syndactylus syndactylus syndactylus syndactylus syndactylus
186.10 188.01 177.71 180.76 201.55 219.07 199.53 196.42 193.93 220.29 218.67 2.87 6.91 0.72 39.90 44.07 53.16 56.00 88.21 39.82 49.69 76.57 68.14 71.88 66.62 78.07 74.50 71.58 45.91 61.81 73.04
324.83 333.33 349.35 382.33 289.89 303.51 324.47 330.50 339.43 330.66 413.06 8.33 19.74 2.37 92.85 99.04 106.88 106.08 186.85 105.16 115.59 110.51 123.38 120.54 127.27 133.20 144.51 148.90 95.19 91.90 125.33
203.61 203.89 215.69 221.98 202.22 217.63 184.01 202.01 158.67 212.20 154.27 17.46 33.26 6.17 88.36 93.06 84.85 159.00 159.43 92.54 87.92 179.68 119.92 124.45 99.93 108.35 152.05 137.16 78.62 106.35 103.91
80.65 71.19 78.39 99.63 72.18 82.78 70.08 70.38 64.80 81.05 75.82 5.39 10.23 2.01 32.50 31.95 30.06 31.94 44.11 29.28 36.52 37.64 36.61 34.84 35.31 36.72 37.55 34.75 34.21 31.89 36.74
0.91 0.92 0.82 0.81 1.00 1.01 1.08 0.97 1.22 1.04 1.42 0.16 0.21 0.12 0.45 0.47 0.63 0.35 0.55 0.43 0.57 0.43 0.57 0.58 0.67 0.72 0.49 0.52 0.58 0.58 0.70
13.30 13.30 11.70 11.22 15.06 14.98 15.78 14.06 17.52 15.01 19.03 8.12 7.69 8.77 9.97 10.24 13.20 7.44 9.68 9.12 11.60 8.88 11.41 11.69 13.25 14.11 9.34 9.85 12.79 12.88 14.05
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