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Keywords:

  • primates;
  • paleo-diet;
  • tooth roots;
  • Khoratpithecus;
  • 3D image

Abstract

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. CONCLUSION
  8. Acknowledgements
  9. LITERATURE CITED
  10. Appendix

The reconstruction of paleo-diets is an important task in the study of fossil primates. Previously, paleo-diet reconstructions were performed using different methods based on extant primate models. In particular, dental microwear or isotopic analyses provided accurate reconstructions for some fossil primates. However, there is sometimes difficult or impossible to apply these methods to fossil material. Therefore, the development of new, independent methods of diet reconstructions is crucial to improve our knowledge of primates paleobiology and paleoecology. This study aims to investigate the correlation between tooth root apical morphology and diet in primates, and its potential for paleo-diet reconstructions. Dental roots are composed of two portions: the eruptive portion with a smooth and regular surface, and the apical penetrative portion which displays an irregular and corrugated surface. Here, the angle formed by these two portions (aPE), and the ratio of penetrative portion over total root length (PPI), are calculated for each mandibular tooth root. A strong correlation between these two variables and the proportion of some food types (fruits, leaves, seeds, animal matter, and vertebrates) in diet is found, allowing the use of tooth root apical morphology as a tool for dietary reconstructions in primates. The method was then applied to the fossil hominoid Khoratpithecus piriyai, from the Late Miocene of Thailand. The paleo-diet deduced from aPE and PPI is dominated by fruits (>50%), associated with animal matter (1–25%). Leaves, vertebrates and most probably seeds were excluded from the diet of Khoratpithecus, which is consistent with previous studies. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.


INTRODUCTION

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. CONCLUSION
  8. Acknowledgements
  9. LITERATURE CITED
  10. Appendix

Alimentary behaviors are an important element of primate biology for the understanding of their ecology and life history (Fleagle, 1999). Accurate reconstructions of fossil primates diets are thus crucial in studies on primate evolution (Fleagle, 1999). Dental microwear and topography analyses are two methods that rely on the relationship between tooth crown wear and diet (e.g., Merceron et al., 2005, 2006; Scott et al., 2006; Teaford, 2007; Ungar, 2007). These methods have proven useful to reconstruct paleo-diets for human and nonhuman primates (Ungar and Kay, 1995; Merceron et al., 2005, 2006; Teaford, 2007; Ungar, 2007). Isotopic analyses were also used to determine paleo-diets (Van der Merwe et al., 2003), as well as the study of enamel thickness (Alba et al., 2010). However, the application of these methods to fossil specimens is sometimes problematic because of the effects of taphonomy and diagenesis (Galbany et al., 2004; Scott et al., 2006; Teaford, 2007). The development of new methods and comparisons of results obtained through different approaches are therefore important to improve our knowledge of fossil primates diets.

Teeth are the most common material in the fossil record for primates (Hartwig, 2002) and the most commonly used for the reconstruction of paleo-diets. Most of existing methods focus on the study of tooth crown (e.g., Ungar and Kay, 1995; Van der Merwe et al., 2003; Merceron et al., 2005, 2006; Scott et al., 2006; Alba et al., 2010), and dental roots have been largely neglected. During food processing, the loads experienced by dentition are transmitted to dental roots (Kovacs, 1971; Wood et al., 1988; Spencer, 2003). These loads vary with mechanical properties of the different food types consumed by an individual, and an association between the root morphology and the diet is therefore expected.

As roots are protected in the alveolar bone, they are relatively well preserved in the fossil record (Hartwig, 2002). It should be therefore possible to deduce paleo-diets of fossil primates from root morphology, especially for specimens, which preservation does not allow the application of other methods. The aim of the current study is to test the hypothesis that root apical morphology can be an indicator of the proportion of some hard, fibrous or soft food types consumed by primates.

During the development of dental roots, two phases are observed: the eruptive phase beginning with the initiation of the formation of the root and ending when the crown is in occlusion, and the penetrative phase starting when the tooth is in occlusion (Kovacs, 1971). The portion of root developed during the eruptive phase, here named as eruptive portion, has a smooth and regular surface whereas the penetrative portion, developed during the penetrative phase, displays an irregular and corrugated surface (Fig. 1; Kovacs, 1971). Furthermore, the joining of the eruptive and penetrative portions is associated with a curvature of the root (Fig. 1; Kovacs, 1971).

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Figure 1. Virtual vertical slice of M2 of Microcebus murinus showing the morphological differences between eruptive and penetrative portions.

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A growing number of studies focus on the relationship between root surface and bite forces (Spencer, 2003; Kupczik and Dean, 2008; Kupczik and Stynder, 2011). In particular, Spencer (2003) demonstrated that in closely related primate species, tooth root surface increases with the proportion of seeds (i.e., hard food type) in the diet. However, no study has been conducted yet to test the link between root shape and diet in primates. As roots are an important component of teeth anchorage in the jaw, their form, including their curvature and the proportion of penetrative portion, are expected to be adapted to the masticatory forces experienced by teeth. Indeed, Kovacs (1971) noted that the proportion of penetrative portion is greater in herbivores (horses) than in carnivores (lions), but no quantitative study has been done to test this hypothesis. Oyama et al. (2007) showed that orthodontic forces in modern humans were concentrated in the apical part of a bent root, especially at the curvature point, and that the repartition of these forces is influenced by the root apical morphology. Therefore, the study of penetrative portion of roots should provide information about dietary habits of primates.

In the present study, the possible relationship between penetrative portion morphology and diet is investigated using two indicators: the proportion of root developed during the penetrative phase, named penetrative portion index (PPI), and the angle between penetrative and eruptive portions (aPE). These two variables were measured for each mandibular tooth root. We test the influence of the proportion in the diet of some hard (seeds, animal matter, and in particular vertebrates), fibrous (leaves), and soft (fruits) food types on these two variables in order to develop a new method for the reconstruction of paleo-diets in primates. This method is then applied to the fossil TF-6223, a mandible of the hominoid Khoratpithecus piriyai from the Late Miocene of Thailand (Chaimanee et al., 2004, 2006).

MATERIALS AND METHODS

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. CONCLUSION
  8. Acknowledgements
  9. LITERATURE CITED
  10. Appendix

Comparative Sample

Table 1 lists the specimens included in this study. Forty-three mandibles from extant primates were included. All specimens are adults with well-formed roots. The teeth that are used for each specimen are indicated in Appendix (Tables A1, A2). This comparative sample covers a wide range among primates in terms of diet, specimen size, taxonomic attribution, and phylogenetic position. Such a sample should allow a test of the association between diet and root apical morphology while evaluating the effect of size and taxonomy.

Table 1. Composition of the extant sample
TaxonSample sizeSource
Pan sp.10Museum Royal d'Afrique Centrale, Tervuren, Belgium
Gorilla gorilla10Museum Royal d'Afrique Centrale, Tervuren, Belgium
Pongo pygmaeus5Museum Royal d'Afrique Centrale, Tervuren, Belgium
Colobus guereza2Museum Royal d'Afrique Centrale, Tervuren, Belgium
Colobus polykomos1Museum Royal d'Afrique Centrale, Tervuren, Belgium
Procolobus badius1Museum Royal d'Afrique Centrale, Tervuren, Belgium
Procolobus verus1Museum Royal d'Afrique Centrale, Tervuren, Belgium
Cercopithecus neglectus1Museum Royal d'Afrique Centrale, Tervuren, Belgium
Cercopithecus nictitans1Museum Royal d'Afrique Centrale, Tervuren, Belgium
Cercopithecus petaurista1IPHEP, Poitiers, France
Cercocebus sp.1Museum Royal d'Afrique Centrale, Tervuren, Belgium
Erythrocebus patas1Museum Royal d'Afrique Centrale, Tervuren, Belgium
Papio anubis1Museum Royal d'Afrique Centrale, Tervuren, Belgium
Alouatta sp.1IPHEP, Poitiers, France
Microcebus murinus5Université Montpellier II, Montpellier, France
Loris tardigradus1Université Montpellier II, Montpellier, France

A fossil mandible of Khoratpithecus piriyai (TF-6223) is also included. This fossil is an undistorted mandible with well-preserved roots from I2 to M3, discovered in Late Miocene sediments from Thailand. Khoratpithecus is considered as a close relative of extant orangutans (Chaimanee et al., 2004, 2006). The flora and fauna associated to this fossil indicate that K. piriyai lived in a riverine tropical forest (Chaimanee et al., 2004, 2006; Sepulchre et al., 2010).

Imaging

Specimens from Museum Royal d'Afrique Centrale, Tervuren, in Belgium (Table 1) were scanned by Guy and Coudyzer using a medical X-ray CT-scanner at the department of Radiology, U.Z.-Gasthuisberg of Leuven. The cubic voxel size ranges from 293 μm to 537 μm, depending on specimen size. Alouatta sp. and Cercopithecus petaurista were imaged by Guy using a Microtomograph Viscom X8050 at the IPHEP in Poitiers, France. The cubic voxel size was 139 μm and 97 μm, respectively. The Microcebus and Loris specimens were scanned by Tafforeau using synchrotron X-ray microtomography (Tafforeau et al., 2006) at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France, on the beamline ID19 with a cubic voxel size of 10.13 μm in absorption mode. Tafforeau also performed the imaging of the fossil specimen Khoratpithecus piriyai TF-6223 at the ESRF on the biomedical beamline ID17, with a cubic voxel size of 45.71 μm.

Measurements

According to Kovacs (1971), the proportion of root developed during the penetrative phase seems to be linked to diet, this proportion being greater in herbivores than in carnivores. In this study, we quantify this proportion by an index, the Penetrative Portion Index (PPI). PPI is defined as:

  • equation image

Moreover, the study of Oyama et al. (2007) suggests that the curvature of the root should provide information about masticatory forces, and therefore indirectly about diet. In the present study, the three-dimensional angle between penetrative and eruptive portions, named aPE, is thus measured.

PPI and aPE are calculated using points measured along the central axis of each root (Fig. 2). For each tooth, a mean cervical plane was calculated using a least squares regression on at least 15 points measured along the cervix. The point where the roots meet is named the bifurcation (Kovacs, 1971). The bifurcation plane is parallel to the mean cervical plane and includes the bifurcation (Fig. 2). Five points were measured around each root on the bifurcation plane, and the barycenter of these points is named intermediary point (inp, Fig. 2). The cervical point (cep, Fig. 2) is the orthogonal projection of the intermediary point on the cervical plane. The plane of maximal curvature was calculated using a last squares regression on six regularly spaced points measured at the junction between eruptive and penetrative portions. The curvature point (cup, Fig. 2) is the orthogonal projection of the barycenter of these six points on the plane of maximal curvature. The apical point (app, Fig. 2) was measured at the apex of the root.

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Figure 2. Measurements points represented on two virtual vertical slices of the same second lower molar of Microcebus murinus. aPE, angle between Penetrative and Eruptive portions; app, apical point; cep, cervical point; cup, curvature point; inp, intermediary point; (app), apical point (not in the same vertical plan as other points).

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The index PPI was calculated using this formula:

  • equation image

for each root, where d(cup,app) is the three-dimensional Euclidian distance between the points cup and app. The angle aPE is defined as the angle formed by the points cep, cup, and app (Fig. 2) and calculated in a three-dimensional Cartesian space.

For teeth having more than two roots, mesial (respectively distal) roots were studied as one root, and the values of PPI and aPE were averaged. Each tooth from P3 to M3 is thus considered as two-rooted, and each specimen is consequently represented by 26 values (13 PPI and 13 aPE). For lacking roots, PPI and aPE are replaced by average values of the other extant specimens of the sample.

To test the correlation between data and specimen size, the occlusal surface of M1 of each specimen was measured as size estimation (Gingerich et al., 1982; Conroy, 1987).

Diet

The diet of primates is often composite and therefore difficult to characterize (Rowe, 1996 and references herein). Many primates are fruits-eaters (e.g., Pan, Pongo, Cercopithecus), but adaptations to folivory or insectivory are also often observed (e.g., Gorilla and Colobus for folivory, Loris for insectivory). Predominant diet is often completed by other food types, for example Chimpanzees are mainly frugivores, but also eat leaves, animal matter, seeds, barks and piths (Tutin and Fernandez, 1992; Newton-Fisher, 1999; Rodman, 2002).

Here, we study the impact of the proportion in diet of five food types: leaves (fibrous), animal matter and more precisely vertebrates, seeds (hard) and fruits (soft). All these food types are consumed by at least one fourth of the species of the sample. For each food type, we defined categories depending on the frequency of consumption (Table 2): Predominant (>50%), High (25–50%), Low (1–25%), and Negligible (<1%).

Table 2. Repartition of extant specimens into the dietary categories
Food typeProportion in the dietSpecies in the category
  1. Tutin and Fernandez, 1992; Dasilva, 1995; Nishihara, 1995; Rowe, 1996; Isbell, 1998; Wahungu, 1998; Newton-Fisher, 1999; Nekaris and Rasmussen, 2001; Chapman et al., 2002; Rodman, 2002; Kanamori et al., 2010.

Fruits<1% (Negligible)C. polykomos
1–25% (Low)P. badius, P. verus, P. anubis, Alouatta sp., L. tardigradus
25–50% (High)G. gorilla, C. neglectus, C. guereza, Cercocebus sp., E. Patas
>50% (Predominant)P. pygmaeus, Pan sp., C. nictitans, C. petaurista, M. murinus
Leaves<1% (Negligible)C. petaurista, E. patas, M. Murinus
1–25% (Low)P. pygmaeus, Pan sp., C. neglectus, C. nictitans, C. petaurista, Cercocebus sp., L. tardigradus
25–50% (High)G. gorilla, C. guereza, C. polykomos, P. Anubis
>50% (Predominant)P. badius, P. verus, Alouatta sp.
Animal matter<1% (Negligible)C. guereza, C. polykomos, P. badius, P. verus, Alouatta sp.
1–25% (Low)G. gorilla, P. pygmeus, Pan sp., C. neglectus, C. nictitans, C. petaurista, Cercocebus sp., E. patas, P. anubis, M. murinus
>50% (Predominant)L. tardigradus
Vertebrates<1% (Negligible)G. gorilla, C. neglectus, C. nictitans, C. petaurista, C. guereza, C. polykomos, P. badius, P. verus, Alouatta sp., M. murinus
>1% (Significant)P. pygmaeus, Pan sp., Cercocebus sp., E. patas, P. anubis, L. tardigradus
Seeds<1% (Negligible)G. gorilla, P. pygmaeus, C. nictitans, C. petaurista, C. guereza, P. badius, Alouatta sp., L. tardigradus, M. murinus
1–25% (Low)Pan sp., P. verus
25–50% (High)C. neglectus, C. polykomos, Cercocebus sp., E. patas, P. anubis

Statistical Analyses

Discriminant analyses are recommended to describe and predict the belonging of specimens to groups (McLachlan, 2005). Linear discriminant analyses were thus performed to test the link between tooth root morphology and taxonomy (represented by genus) and diet, and the a posteriori correct attribution to the categories calculated. The effect of sex on measures was tested using a Student's T-test, and a linear regression was performed to test the impact of specimen size (represented by M1 occlusal surface). For these analyses, we used the R software with MASS package (R Development Core Team, 2011).

RESULTS

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. CONCLUSION
  8. Acknowledgements
  9. LITERATURE CITED
  10. Appendix

Specimen Size, Sex, and Taxonomy

The effect of occlusal surface of M1, which is highly correlated to specimen size (Gingerich et al., 1982; Conroy, 1987), on measures, was tested with two linear regressions. The results indicate no significant association between specimen size and tooth root morphology (r2 values of 0.12 and 0.46 for aPE and PPI, respectively).

Sex was known for 35 specimens, and its effect on the two variables measured here was tested using two Student's T-test (one for aPE and one for PPI). The high P values of 0.86 and 0.89, respectively, indicate that there is no significant correlation between tooth root apical morphology and sex.

A discriminant analysis was performed to test the link between measures and taxonomy (groups were genera). The percentage of a posteriori correct attribution is 100% (Table 3), which indicates a high association between generic attribution and penetrative portion morphology, also observable when plotting linear discriminant axis (LD) 1 versus LD2 (Fig. 3). The effect of taxonomy is thus significant and must be discussed for correct interpretation of the results concerning the link between diet and root morphology.

Table 3. Percentage of a posteriori correct attribution for each discriminant analysis
Taxonomy100%
  1. Categories for taxonomy are genera. Categories for diet are Negligible (<1%), Low (1–25%), High (25–50%), and Predominant (>50%), except for vertebrates consumption (Negligible and Significant, respectively, <1% and >1%).

Fruits93%
Leaves98%
Animal matter98%
Vertebrates93%
Seeds93%
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Figure 3. Repartition of specimens according to LD1 and LD2 of the discriminant analysis performed on genus.

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Diet

The percentage of correct a posteriori attribution according to the discriminant analyses are listed in Table 3. All food types display percentages >90%, which indicates a strong relationship between root morphology and diet. The graphical results of the discriminant analyses for each food type are displayed in Figure 4.

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Figure 4. Repartition of specimens according to the axes of the discriminant analyses performed on diet. A: LD1 and LD2 of the analysis on leaves proportion. B: LD1 and LD2 of the analysis on animal matter proportion. C: LD versus vertebrates consumption. D: LD1 and LD2 of the analysis on seeds proportion. E: LD1 and LD2 of the analysis on fruits proportion.

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Specimens that do not consume leaves are well segregated according to the LD1 (Fig. 4A). This axis also allows the segregation of specimens which diet includes between 25 and 50% of leaves, whereas specimens that consume low proportion (<25%) of leaves on the one hand, and specimens that are mainly folivorous on the other hand, are separated according to the LD2 axis (Fig. 4A).

In Figure 4B, the only specimen that consumes a high proportion of animal matter (L. tardigradus, which is mainly insectivorous) is isolated according to the LD1. LD2 allows the distinction between specimens that do not consume animal matter and those which include a low proportion (<25%) of this food type in their diet (Fig. 4B). Specimens that consume vertebrates have greater values of LD than specimens that do not (Fig. 4C), which reflects higher values of PPI (average value of 47 for vertebrates eaters instead of 42 for vertebrates non-eaters, P value from Student's T-test of 10−8) and aPE (average value of 164° for vertebrates eaters instead of 162° for vertebrates non-eaters, P value from Student's T-test of 0.04).

When considering seeds (Fig. 4D), the three categories are well segregated according to LD1 and LD2, the values of LD1 increasing with the proportion of seeds in the diet. The proportion of fruits, that is, soft items, in the diet is highly correlated to PPI and aPE (Table 3 and Fig. 4E). In particular, C. polykomos, which is the only specimen that consume a very low proportion of fruits, display very high value of LD1 (Fig. 4E). Values of LD1 lower than −45 indicate a low proportion (<25%) of fruits in the diet, whereas values between −45 and −40 are typical of specimens that include >25% of fruits in their diet (Fig. 4E). Specimens that are mainly frugivorous have greater LD2 values than specimens that consume <50% of fruits (Fig. 4E).

Diet of Khoratpithecus piriyai

aPE and PPI were measured for the specimen TF-6223 of Khoratpithecus piriyai. The attribution of Khoratpithecus to the diet categories for each food type, and the probability associated, are displayed in Table 4. The projection of the fossil specimen on the linear discriminant axes is also plotted in Figure 4. The diet of Khoratpithecus piriyai, as inferred from our measures, is likely dominated by fruits (>50%), includes a low proportion of animal matter (between 1 and 25%), but no vertebrate, and excludes leaves (Table 4 and Fig. 4). Khoratpithecus most probably did not consume seeds either, or only in a very low proportion (Table 4 and Fig. 4D).

Table 4. Diet of Khoratpithecus piriyai according to the discriminant analyses
Food typeProportion in the dietProbability
Fruits>50%0.99
Leaves<1%1
Animal matter1–25%0.98
Vertebrates<1%0.90
Seeds<1%0.70
 1–25%0.30

DISCUSSION

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. CONCLUSION
  8. Acknowledgements
  9. LITERATURE CITED
  10. Appendix

The results of this study indicate a significant relationship between dental root apical morphology and diet in primates. This suggests that the loads exerted on teeth during food processing strongly influence the development of dental roots. In particular, the proportion of hard and/or fibrous food types in the diet is linked to the curvature of the root (aPE) and the proportion of root developed during the penetrative phase (PPI). As Oyama et al. (2007) have demonstrated that the repartition of stress is significantly changed in bent roots, the variation of aPE according to the diet can be interpreted as an adaptation to the mechanical properties of preferred food types. aPE therefore likely reflects an exclusively environmental signal. Differences in PPI indicate that variations in diet are linked to changes either in the duration of penetrative phase or in the growth speed of root during this phase. In each case, it implies an adaptation of the timing of root development to different loads exerted on teeth. This adaptation could be genetically transmitted in a species, and therefore reflects both phylogeny and environment.

The results of the discriminant analysis indicate that there is a strong association between generic attribution and root apical morphology (Table 3). Actually, most of the species that belong to a same genus are the results of adaptative responses to different ecological conditions. Therefore, it is not surprising that taxonomy reflects morphology, especially for anatomical feature that has strong connection with feeding habits. Our results indicate a link between data and taxonomy, but do not allow a conclusion about an effect of phylogeny. Moreover, as the modification of PPI may imply genetic changes, the link between phylogeny and root morphology should be investigated in further studies.

The comparative sample includes six very small specimens (five Microcebus murinus and one Loris tardigradus), the other taxa being relatively large. The effect of specimen size might be misestimated because the small specimens include five individuals of the same species, and there are no specimens of intermediate body size. Further studies including specimens of intermediate body size should allow a more reliable test of the effect of body size on measures, and improve our understanding of the link between root morphology and diet.

The application of this new method to the fossil hominoid Khoratpithecus piriyai from Miocene of Thailand indicates a diet dominated by fruits and including animal matter. It excludes vertebrates, leaves, and most probably seeds. Investigating jaw form in Pongo and Khoratpithecus, Taylor (2006) has concluded that K. piriyai had a diet with a great amount of fruits, which implied less repetitive or large loads than extant Pongo's diet. Moreover, based on dental micro-wear analysis, Khoratpithecus was neither hard object feeder nor leaf eater but instead a fruit-eater (Merceron et al., 2006). Our reconstruction is in agreement with these results, with additional precision concerning the consumption of animal matter.

The method developed here proved to be relevant for the reconstruction of paleo-diets. Moreover, as it is based on tooth root morphology, it can be applied to fossil specimens that are broken, with missing or extremely worn tooth crown. Such specimens are considered useless for dietary reconstructions. Our method would provide new data on primates paleo-diet and, therefore, improve our knowledge and understanding of primates evolution. However, the present study is a preliminary work and increasing the comparative sample with, for example, more mainly insectivorous specimens (e.g., lemurs), should improve the method and allow its application to more diverse fossil specimens.

CONCLUSION

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. CONCLUSION
  8. Acknowledgements
  9. LITERATURE CITED
  10. Appendix

The results of this study indicate that root apical morphology is closely linked to diet in primates. Measuring the two variables defined here, aPE and PPI, allows accurate reconstructions of paleo-diets for fossil primates. However, the understanding of the effect of taxonomy and body size on these variables requires further analyses including more specimens.

The application of the method to the fossil hominoid Khoratpithecus piriyai confirms that its diet was mainly composed of fruits and excluded leaves and seeds, and indicates that it also included animal matter, but no vertebrate.

This work enlightens the possibility of using the penetrative portion morphology as a tool for dietary reconstructions in fossil primates. The method can be applied to most gnathic material and should be extended to maxilla data. The comparison of results from different methods should provide precise reconstructions of paleo-diets for fossil primates.

The nature of the relationship between penetrative portion of root morphology and diet is not well understood. Few studies focus on tooth roots, and root development is poorly documented. Experiments on root development in non-human primates during the penetrative phase should improve the understanding of the link between root morphology and diet, and particularly the way in which PPI is modified.

Acknowledgements

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. CONCLUSION
  8. Acknowledgements
  9. LITERATURE CITED
  10. Appendix

The authors thank E. Gilissen and W. Weidelen of the Central African Royal Museum (Tervuren, Belgium) for granting access to the primate collections, Pr. G. Marchal and W. Coudyzer of the Department Radiology U.Z.-Gasthuisberg of Leuven for granting access to CT-scan facility. W. Coudyzer also helped them to perform the scans used in the present study. They greatly thank the ESRF for having provided beamline ID19 and ID17 to scan some of the specimens studied here, and they especially thank José Baruchel, Elodie Boller, Peter Cloetens, Alberto Bravin, and Christian Nemoz for their help during these experiments. These experiments were performed during the ESRF proposals sc918, sc1112, and sc1488. They are grateful to Pr. Louis de Bonis for helpful comments on this work and constructive discussion. They also thank the two anonymous reviewers for their comments and corrections on the present work. $$This work was supported by the EVAH program, ANR-09-BLAN-0238-02.

LITERATURE CITED

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. CONCLUSION
  8. Acknowledgements
  9. LITERATURE CITED
  10. Appendix
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Appendix

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. CONCLUSION
  8. Acknowledgements
  9. LITERATURE CITED
  10. Appendix
Table A1. Species, sex, and teeth used for each specimen
SpecimenSpeciesSexAvailable teeth
I1I2CP3P4M1M2M3
  • R, right; L, left.

  • a

    Chaimanee et al. (2006).

Pa1Pan sp.MaleR/LR/LR/LLR/LR/LR/LL
Pa2Pan sp.MaleR/LR/LRR/LLRR/LR/L
Pa3Pan sp.FemaleRLR/LLLR/LR/LR/L
Pa4Pan sp.Female   R/LR/LR/LR/LR/L
Pa5Pan sp.FemaleR/LR/LR/LR/LLR/LR/LR/L
Pa6Pan sp.MaleR/LR/LR/LR/LR/LR/LR/LR/L
Pa7Pan sp.MaleR/LR/LR/LR/LR/LR/LR/LR/L
Pa8Pan sp.FemaleR/LR/LR/LR/LRR/LR/LR/L
Pa9Pan sp.FemaleR/LR/LR/LR/LR/LR/LR/LR/L
Pa10Pan sp.MaleLR/LL R/LR/LR/LR/L
G1G. gorillaFemaleR/LR/LR/LR/LR/LR/LR/LR/L
G2G. gorillaFemaleR/LR/LR/LR/LR/LR/LR/LR/L
G3G. gorillaFemaleR/LR/LR/LR/LR/LR/LR/LR/L
G4G. gorillaFemaleR/LR/LR/LR/LR/LR/LR/L 
G5G. gorillaFemaleR/LRR/LR/LR/LR/LR/L 
G6G. gorillaFemaleR/LR/LR/LR/L R/LR/LR/L
G7G. gorillaMaleR/LR/LR/LR/LR/LR/LR/LR/L
G8G. gorillaMaleR/LR/LR/LR/LR/LR/LR/LR/L
G9G. gorillaMaleR/LR/LR/LR/LR/LR/LR/LR/L
G10G. gorillaMaleR/LR/LR/LR/LR/LR/LR/LR/L
Po1P. pygmaeusMaleR/LR/LR/LR/LR/LR/LR/LR/L
Po2P. pygmaeusMaleR/LLLR/LR/LLR/LR/L
Po3P. pygmaeusMaleR/LR/LLLR/LR/LR/LR/L
Po4P. pygmaeusFemaleR/LR/LR/LR/LR/LR/LR/LR/L
Po5P. pygmaeusFemaleR/LR/LR/LR/LR/LR/LR/LR/L
Cg1C. guerezaMaleR/LR/LR/LR/LR/LR/LR/LR/L
Cg2C. guerezaFemaleR/LR/LR/LR/LR/LR/LR/LR/L
CpC. polykomosFemaleR/LR/LR/LR/LR/LR/LR/LR/L
PbP. badiusMaleR/LR/LR/LR/LR/LR/LR/LR/L
PvP. verusMaleR/LR/LR/LR/LR/LR/LR/LR/L
CneC. neglectusMaleR/LR/LR/LR/LR/LR/LR/LR/L
CniC. nictitansFemaleLLRR/LR/LR/LR/LL
CpeC. petauristaUnknownR/LR/LR/LR/LR/LR/LR/LR/L
CspCercocebus sp.FemaleR/LR/LR/LR/LR/LR/LR/L 
EpE. patasMaleR/LR/LR/LR/LR/LR/LR/LR/L
PhaP. anubisFemaleR/LR/LR/LR/LR/LR/LR/LR/L
AspAlouatta sp.UnknownR/LR LR/LR/LR/L 
Mm1M. murinusUnknownLLLLLLLL
Mm2M. murinusUnknownLLLLLLLL
Mm3M. murinusUnknownLLLLLLLL
Mm4M. murinusUnknownLLLLLLLL
Mm5M. murinusUnknownLLLLLLLL
LtL. tardigradusUnknownLLLLLLLL
TF-6223K. piriyaiMalea  RRRRRR
Table A2. Scores along axes of each specimen for the four linear discriminant analyses
SpecimenFruitsLeavesAnimal matterSeeds
LD1 (65.3%)LD2 (23.9%)LD3 (10.8%)LD1 (72.3%)LD2 (19.3%)LD3 (8.4%)LD1 (91.4%)LD2 (8.6%)LD1 (63.7%)LD2 (36.3%)
Pa1−43.74.932.8−36.0−7.3−24.3−38.230.729.2−7.8
Pa2−42.76.232.0−38.8−6.7−24.4−35.931.328.8−8.3
Pa3−43.96.132.3−39.1−6.1−24.6−34.530.830.7−6.9
Pa4−42.13.731.8−38.5−8.4−24.3−36.228.329.7−9.2
Pa5−43.95.232.6−39.4−7.1−24.7−35.230.331.5−7.5
Pa6−44.56.932.2−38.0−5.4−24.2−37.131.428.5−7.8
Pa7−45.27.233.6−37.3−5.8−25.0−38.131.829.3−7.4
Pa8−42.06.533.5−38.0−5.1−25.0−37.631.729.4−9.5
Pa9−44.15.432.5−37.6−7.4−24.0−38.730.029.6−7.7
Pa10−43.96.632.3−38.0−5.8−24.9−35.831.128.5−7.0
G1−44.57.931.1−39.7−2.7−22.7−36.031.630.5−4.7
G2−43.310.431.9−40.1−3.1−22.4−37.430.832.0−3.9
G3−45.98.931.0−40.1−5.1−21.7−37.630.531.5−4.7
G4−44.210.032.2−40.0−3.4−22.9−37.931.331.2−5.0
G5−44.66.032.7−37.9−5.7−23.9−37.432.830.2−7.0
G6−41.49.131.6−41.6−3.8−23.7−35.731.130.1−6.9
G7−45.29.630.1−41.4−4.9−21.5−36.931.430.7−4.9
G8−45.67.631.9−40.4−4.7−22.8−37.131.131.9−6.9
G9−45.29.530.0−41.3−5.0−21.7−36.229.730.0−5.7
G10−44.09.132.9−40.6−3.7−23.7−37.031.132.7−5.1
Po1−44.84.532.9−38.0−8.6−26.3−35.831.028.3−7.4
Po2−42.75.932.4−38.8−7.3−24.0−37.329.731.4−6.4
Po3−42.96.032.2−38.0−6.9−24.9−36.631.729.7−3.5
Po4−43.84.631.4−37.5−7.6−22.5−38.929.030.9−5.7
Po5−44.06.633.2−37.8−7.1−24.6−37.831.430.4−6.2
Cg1−44.78.830.8−40.5−4.3−22.0−38.225.731.0−5.6
Cg2−43.69.533.1−39.5−3.0−24.5−39.429.229.9−5.1
Cp−28.56.129.8−40.1−4.2−24.0−39.427.325.0−4.8
Pb−46.05.329.1−39.5−9.6−20.4−37.627.331.6−4.9
Pv−46.74.330.2−36.4−10.4−20.6−39.228.230.2−8.5
Cne−43.17.332.1−36.7−6.8−25.7−36.330.726.0−4.3
Cni−45.27.132.7−37.3−6.5−24.6−37.631.129.4−5.5
Cpe−44.15.332.6−30.4−7.2−22.4−37.029.330.1−6.1
Csp−42.88.829.4−38.9−6.0−23.4−36.329.725.1−2.8
Ep−44.78.034.5−32.2−4.7−25.9−35.733.127.5−6.5
Pha−45.66.730.5−42.7−6.0−24.3−37.830.727.1−6.2
Asp−45.93.330.1−38.4−9.9−21.3−37.528.231.9−6.6
Mm1−42.76.333.0−30.5−3.5−22.8−36.330.730.5−4.1
Mm2−44.35.434.2−30.3−5.5−23.1−38.032.231.8−5.5
Mm3−42.65.834.0−30.6−4.1−23.4−35.931.031.9−5.2
Mm4−43.05.831.8−30.4−3.9−21.2−37.030.330.3−4.9
Mm5−44.06.033.6−32.2−4.4−23.1−36.031.232.3−5.6
Lt−47.14.328.5−36.9−7.2−25.6−13.229.231.0−5.3
TF-6223−40.73.233.1−30.2−8.0−24.2−35.828.929.5−6.3