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TABLE 1. Summary of Canis dirus cranial material used in the course of this study. Pit deposit information and dates in years before present condensed from O'Keefe et al., 2009; for calibration information see that reference and Meachen et al., 2014. The quoted pit ages are median ages in the windows of deposition, and constraint on the duration and time of each window is currently poor for most pits. For further discussion see O'Keefe et al., 2009.

 

Pit Number

Pit Age

N, Fracture

N, Wear

N, Skulls

61/67

13.8 kya

1120

106

17

13

17.9 kya

797

37

16

2051

26.1 kya

568

115

22

91

28 kya

367

75

18

TABLE 2. Fracture and Wear Data. Table shows number of teeth examined for fracture in each pit, number of broken teeth found, and percentage. For wear data, N = the number of worn teeth identified, SW denotes slight wear, SMW slight to moderate wear, MW, medium wear, MHW, medium to heavy wear, H, heavy wear. Weighted wear percent is the average wear score for each pit. These data are plotted in Figures 1 and 2.

 

Pit

Teeth, N

Teeth, Broken

Broken %

SW

SMW

MW

MHW

H

N

Weighted Wear %

61/67

1120

25

2.23

39

29

28

8

2

106

2.104

13

797

55

6.90

5

16

12

3

1

37

2.432

91

367

27

7.36

17

23

20

9

6

75

2.520

2051

568

12

2.11

40

38

20

11

6

115

2.174

TABLE 3. Pairwise comparisons among pits for tooth fracture and tooth wear. P values calculated from correspondence analysis and Wilcoxon nonparametric rank sums test; values were very similar for both tests. For raw percentages and wear values see Figures 1 and 2. Single stars indicate significance below the 0.05 level; double stars indicate significance below the 0.01 level.

 

Comparison

61/67-2051

61/67-13

61/67-91

13-91

2051-91

2051-13

Tooth Fracture

p<.8743

p<.0001**

p<.0001**

p<.7778

p<.0001**

p<.0001**

Tooth Wear

p<.8464

p<.0455*

p<.0180*

p<.9306

p<.0275*

p<.0518

TABLE 4. Description of landmarks used in this study. See Figure 3 for locations.

 
 

Landmark

Description

1

prosthion

Premaxilla between medial incisors

2

nasion

Farthest posterior extent of nasals on midline

3

bregma

Frontal/parietal suture at midline

4

inion

Posterior tip of sagittal crest

5

opisthion

Posterior border of foramen magnum at midline

6

basion

Inferior border of foramen magnum at midline

7

staphylion

Posterior tip of palatines at midline

8

pal/max sut

Palatine-maxillary suture at midline

9

incisivon

Midline suture at anterior border of incisive foramina

10

postI3

Posterior border of I3 alveolus

11

antC1

Anterior margin of C1 alveolus

12

postC1

Posterior margin of C1 alveolus

13

antP1

Anterior margin of P1 alveolus

14

antP4

Anterior margin of P4 alveolus

15

P4/M1

Posterior margin P4 alveolus/anterior margin M1 alveolus

16

postM2

Posterior margin M2 alveolus

17

prm/max/nas

Posterior end of dorsal premaxillary process

18

orbitinf

Inferior margin of orbit

19

postorb

Tip of postorbital process

20

opticinf

Inferior border of optic canal

21

par/tmpzyg

Location on parietal-temporal suture directly above posterior root of zygomatic process

22

porion

Superior margin of external auditory meatus

23

antbulla

Posterior border of pharyngotympanic tube

24

prm/maxC1

Location of premaxilla-maxilla suture on medial margin of C1 alveolus

25

prm/maxinc

Location of the premaxilla-maxilla suture on lateral margin of incisive foramen

26

M2postmed

Closest point of M2 alveolus to the midline

27

M1med

Closest point of M1 alveolus to the midline

TABLE 5. Centroid size pairwise comparisons.Significance of pairwise comparisons among pits based on one-way Student's T tests among means. For distributions see Figure 4. Single stars indicate significance below the 0.05 level; double stars indicate significance below the 0.01 level.

 

Comparison

61/67-2051

61/67-13

61/67-91

13-91

2051-91

2051-13

Size

p<.3300

p<.0669

p<.0735

p<.0021**

p<.3493

p<.0092**

TABLE 6. Results of a permutation test on Procrustes shape coordinates. Reported values are summed Procrustes distances among all landmarks for each pairwise pit comparison, as listed. All pits are significantly different in aggregate. For visualization of landmark locations among mean shapes from each pit, see Supplementary Animations 1, 2, 3. Single stars indicate significance below the 0.05 level; double stars indicate significance below the 0.01 level.

 

Pairwise Pit Comparisons

Total Procrustes Distance

P value, alpha <

UCMP vs. p13

0.0189778

0.000**

UCMP vs. p61

0.0187161

0.000**

UCMP vs. p91

0.0267971

0.000**

p13 vs. p61

0.0154740

0.004**

p13 vs. p91

0.0191137

0.000**

p61 vs. p91

0.0226563

0.000**

TABLE 7. Proportions of total Procrustes distance accounted for by the factors centroid size, individual pits, and all pits.

 

Factor

Procrustes sum of squares

Percentage of total

Total

0.0012216192

100.0%

Ln(centroid size)

0.0000400096

3.3%

All Pits

0.0001652656

13.5%

Pit 61

0.0000373441

3.1%

Pit 13

0.0000259306

2.1%

Pit UCMP

0.0000761901

6.2%

Pit 91

0.0000838070

6.9%

Size + Pits

0.0001933500

15.8%

TABLE 8. One-way ANOVAs of principal components by pit derived from ordination of the covariance matrix of three-dimensional landmark data. First five components are shown; they account for 47% of the variance in the data set. Ninety percent of the variance was accounted for by 28 principal components. Regression results for correlation with centroid size are also shown. For plots of PCs 1 and 4 see Figure 6; for plots of PCs 2 and 3 see Figure 7. Shape transitions along each principal component are visualized in Supplementary Animations 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, and 15. Single stars indicate significance below the 0.05 level; double stars indicate significance below the 0.01 level.

 

PC

Percent Explained

One-way ANOVA, by Pit

Means, T

61/67-2051

61/67-13

61/67-91

13-91

2051-91

2051-13

Regression, Centroid size

PC I

14.42

F ratio 0.8770

p < 0.4574

0.4361

0.4564

0.6867

0.2509

0.7162

0.1224

F ratio 4.8319

p < 0.0312*

PC II

13.09

F ratio 20.1406

p < 0.0001**

0.0119*

0.3909

0.0001**

0.0003**

0.0001**

0.0009**

F ratio 1.5024

p < 0.2244

PC III

7.75

F ratio 3.9191

p < 0.0121*

0.0590

0.9496

0.1868

0.2162

0.0012**

0.0547

F ratio 1.5624

p < 0.2154

PC IV

6.81

F ratio 6.0364

p < 0.0010**

0.0046**

0.0173*

0.0001**

0.1061

0.1468

0.7706

F ratio 4.1100

p < 0.0464*

PC V

5.60

F ratio 4.9423

p < 0.0036**

0.0019**

0.9834

0.440

0.4348

0.0164*

0.0021**

F ratio 0.0775

p < 0.7815

TABLE 9. Interlandmark Distances. Significance of pairwise comparisons of wireframe distances among pits based on one-way Student's T tests among means. Single stars indicate significance below the 0.05 level; double stars indicate significance below the 0.01 level. Illustrated in Figures 8 and 9.

 

Comparison

61/67-2051

61/67-13

61/67-91

13-91

2051-91

2051-13

Prosthion-Nasion

0.2964

0.0001**

0.1639

0.0035**

0.6697

0.0006**

Prosthion-Staphylion

0.3797

0.0066**

0.9458

0.0071**

0.4118

0.0393*

Staphylion-Basion

0.8047

0.0054**

0.048*

0.3555

0.0194*

0.0016**

antC1-postC1

0.2661

0.0031**

0.0002*

0.4126

0.0027**

0.0354*

P4/M1-PostM2

0.0197*

0.0084**

0.0198*

0.6880

0.9104

0.5972

postC1-antP4

0.0329*

0.0217

0.0022**

0.4585

0.2469

0.7275

postC1-PrMxC1

0.0080**

0.0419*

0.0403*

0.9646

0.5838

0.6286

Staphylion-postmedM2

0.1439

0.4394

0.0005**

<0.0001**

0.0199*

0.0259*

Prosthion-C1mxpremx

0.1411

0.1356

0.0855

0.0018**

0.0012**

0.8909

P4/M1-postmedM2

0.1411

0.1356

0.0855

0.0018**

0.0012**

0.8909

antC1-PrMxC1

0.2067

0.9331

0.0776

0.0687

0.0021**

0.2487

Prosthion-antC1

0.0696

0.0671

0.2301

0.0030**

0.0023**

0.8728

Pros-M1med

0.0736

0.2629

0.2344

0.0230*

0.0026**

0.5580

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