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Keywords:

  • Geometric morphometrics;
  • landmark analysis;
  • gray wolf;
  • coyote;
  • domestic dog;
  • red wolf;
  • thin plate spline

ABSTRACT

  1. Top of page
  2. ABSTRACT
  3. Introduction
  4. Materials and methods
  5. Results
  6. Discussion
  7. Conclusion
  8. Acknowledgements
  9. References
  10. APPENDIX: SPECIMEN LIST

Wild canid populations exhibit different anatomical morphologies compared to domesticated dogs in North America. This is particularly important concerning archaeological sites, which may contain early domesticated species, for the proper identification of osteological remains. Previous studies have indicated domestic dogs exhibit a shorter rostrum accompanied by a crowded tooth row; however, none describe the overall complexity of these changes. Consequently, using a landmark-based geometric morphometric analysis, cranial morphological characteristics were examined in North American wild canids: the gray wolf (Canis lupus), coyote (Canis latrans), red wolf (Canis rufus), and the domestic dog (Canis familiaris). The shape and size of the cranium in lateral and ventral views were compared between the three wild species to the group of domesticated dogs. Wild canids clustered separately from the domestic group in all statistical analyses. Results indicate an expansion of the orbital region, a compression of the rostrum, and an overall warping in the shape and orientation of the skull. In domestic species, there is also a downward shift in the frontal portion of the skull accompanied by the braincase assuming a more upward position. This technique successfully depicted how slight changes in isolated areas of the cranium can have an impact on the overall shape and morphology of the skull. We presume these changes in cranial anatomy reflect the recent selective pressures domestic dogs have undergone since diverging from their wild ancestors. Copyright © 2012 John Wiley & Sons, Ltd.


Introduction

  1. Top of page
  2. ABSTRACT
  3. Introduction
  4. Materials and methods
  5. Results
  6. Discussion
  7. Conclusion
  8. Acknowledgements
  9. References
  10. APPENDIX: SPECIMEN LIST

Evolution of the domestic dog (Canis familiaris) has been the subject of intensive morphologic and genetic studies for more than 40 years (e.g. Scott, 1968; Olsen, 1985; Wayne, 1986; Vilá et al., 1999; Parker et al., 2004; Galibert & Andre, 2005). As a result, several ancestral species have been suggested, including the gray wolf (Leonard et al., 2002), Eurasian wolves (Vilá et al., 1997), and the Pariah dog (Olsen, 1974). However, recent genetic studies have indicated that the gray wolf may be the most likely ancestor, sharing over 99.8% of its genetic sequences with domestic dogs, which is significant because wolves only share roughly 96% with their closest relative, C. latrans (Case, 2008). Consequently, successfully identifying Canis spp. remains from archaeological sites usually proves problematic. Unfortunately, correctly identifying mammalian remains (in general) from archaeological sites is imperative for reconstructing the ecology of the locality (e.g. Chaplin, 1971; Hesse & Wapnish, 1985; Driver, 1992; Baker & Shaffer, 1999; Semken & Wallace, 2002). In most instances, cranial and dental remains are primarily used for identification because postcranial remains are not typically well preserved (Scott, 1968; Mullan & Boycott, 2004). In fact, Olsen (1985) suggested that differentiating an early dog from a wolf is nearly impossible because of the close resemblance in the skulls and dentitions. Therefore, it is important to find sufficient methods that can successfully distinguish wild species from domesticated dogs so the implications of their presence in cultural contexts can be fully understood.

Previous cranial morphological studies indicated the domestic dog is distinct from all other canids (Lawrence & Bossert, 1967; Wayne, 1986) due to a shortening of the rostrum, crowding of the tooth rows, an overall reduction in the size of the teeth, and a change in shape of the braincase (Lawrence & Bossert, 1967; Olsen, 1985). Olsen (1985) also noted that as domestication progressed, the mandibles deepened midway along the horizontal ramus with a more convex inferior margin than that found in similar-sized modern wolves. Moreover, Walker & Frison (1982) noted that the shape of the tympanic bullae in modern domestic dogs is of small to medium size, and is strongly compressed. In contrast, wolves exhibit large, convex, and spherically shaped bullae (Walker & Frison, 1982). In shorter faced breeds such as pugs or boxers, the distance between the eyes and the tip of the nose may be less than one inch, while the skull and cranium above the eye may be wider, but equal in length (relatively), to longer faced breeds and wild canids (Smythe, 1970). The sagittal crest is severely reduced or even nonexistent in smaller breeds compared to wild canids (Smythe, 1970). Aside from distinctions between wolves and domestic dogs, differences in morphology have also been recorded among wild taxa. For example, the skulls of C. rufus approach those of C. latrans in form, but are usually larger and have some morphological differences such as: (i) a higher cranium, (ii) deeper rostrum, (iii) wider zygomatic arches, and (iv) a larger auditory bullae (Young & Gouldman, 1944). Red wolf skulls typically are much smaller than those of C. lupus, although exceptions to this have been noted (Young & Gouldman, 1944).

Prior studies have utilized linear measurements and multiple character analyses (see Lawrence & Bossert, 1967; Morey, 1992), but few have applied geometric morphometric (GM) techniques. Notable exceptions include: successfully separating Dinaric-Balkan and Carpathian gray wolf populations (Milenkovic et al., 2010), investigating the changing skull morphology in arctic wolves (Clutton-Brock et al., 1994), and measuring the nasal passageways of domestic dogs (Craven et al., 2007). Moreover, similar techniques have proven successful in differentiating variation in cranium and mandibles between two subfamilies of felids (Christiansen, 2008); biomechanical differences in Plethodon salamanders (Adams & Rohlf, 2000); cranial allometry in papionins (Frost et al., 2003); and skull evolution in squirrels (Swiderski et al., 2000).

While previous studies have showed the limited success of linear measurements, GM techniques are able to separate size and shape components, while preserving this information relative to spatial arrangements (Milenkovic et al., 2010; Swiderski et al., 2000). Specifically, traditional measurement techniques limit the ability to describe true shape variation in a given sample (Bookstein, 1991), while GM approaches can provide a true depiction of biological and morphological variation within a population (Hood, 2000; Zelditch et al., 2004). It is also unclear how one observable change, like a shortening of the rostrum, has affected other areas of the cranium, and how such changes influence the overall morphology of the domestic dog skull. Consequently, we seek to quantitatively document these cranial changes using a landmark-based morphometric analysis. In addition, thin-plate splines will provide a visualization of the overall variations between canid taxa.

Materials and methods

  1. Top of page
  2. ABSTRACT
  3. Introduction
  4. Materials and methods
  5. Results
  6. Discussion
  7. Conclusion
  8. Acknowledgements
  9. References
  10. APPENDIX: SPECIMEN LIST

Specimens

Three North American species of large wild canid were used for comparative purposes including: the gray wolf (Canis lupus), coyote (C. latrans), and red wolf (C. rufus) (Appendix A). The coyote and red wolf were included because of their close proximity and likely inclusion at North American archaeological sites. Breed distinctions within C. familiaris were not made in this study, as they were not necessary in differentiating ‘wild’ versus ‘domestic’. However, some breeds, such as the Boston Terrier and Boxer, were eliminated because the morphology is so distinct that identification is non-problematic. Also, because of their radically distorted morphology, they lack many of the homologous points utilized for the landmark analysis. Moreover, their extreme morphology would add unnecessary variation to the analysis, while contributing little diagnostic information.

A total of 65 individuals from C. familiaris (n = 25), C. rufus (n = 6), C. latrans (n = 21), and C. lupus (n = 13) were analyzed. The low sample size of red wolves can be attributed to the recent problem of hybridization between this species and coyotes (see Fredrickson and Hendricks, 2006), as well as limited access to confidently identified skulls. Only complete, wild-caught adult specimens were utilized with the exception of four C. rufus skulls, which showed evidence of necropsy, yet exhibited all relevant features. Specimens are housed in the collections of East Tennessee State University's Neogene Vertebrate Paleontology Laboratory, University of Tennessee at Chattanooga, and the Zooarchaeology Department at the University of Tennessee at Knoxville (Appendix A).

Data collection

Specimens were photographed in direct dorsal, lateral, and ventral views in high resolution using a D5000 Nikon digital camera mounted on a copy-stand. Landmarks, following Bookstein's (1991) suggested methodology, were assigned based on homologous traits between all four species. A total of 40 landmarks on the lateral image (Figure 1, Table 1) and 42 landmarks in the ventral image (Figure 2, Table 2) were utilized. In the lateral view, landmarks concentrated around the teeth, temporal, and parietal bones, which are the localities focused on in prior studies. In contrast, the teeth, palatine, occipital, and sphenoid region were the major localities for the ventral view. Both views were used in the analysis to understand how the whole skull is changing between the two designated groups instead of focusing on isolated portions of the cranium. A standard millimeter ruler was used for scaling in each photograph. Landmark placements were performed in a suite of TPS statistical software (University of Stony Brook Morphometrics; http://life.bio.sunysb.edu/morph/). Landmarks were recorded as two-dimensional coordinates and were placed on the images using the TPSdig software.

image

Figure 1. Lateral landmarks on a skull of Canis familiaris. Landmarks are numbered according to position and placement on the skull. This figure is available in colour online at wileyonlinelibrary.com/journal/oa.

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Table 1. Description of lateral landmarks
LandmarkDescription
1Anterior joint of premaxilla where incisor meets bone
2Point of greatest curvature in nasal aperture
3End of nasal bone
4Point of greatest curvature of nasal bone
5Suture line of nasals with frontal bone
6Greatest curvature of frontal bones
7Where frontal bones come to a point posteriorly
8Suture between frontal and parietal bones
9Origin of sagittal crest
10Most posterior point of sagittal crest
11Occipital sutures
12Posterior portion of parietal suture
13Triangular interstition of parietal suture between parietal, frontal, and temporal bones
14Postorbital process of malar bone
15Posterior suture of jugal and squamosal bones of zygomatic arch
16Location where squamosal intersects with auditory bullae
17Locality where the squamosal of the zygomatic arch intersects with cranial squamosal bone
18Point on paraoccipital process
19Location where squamosal bone meets occipital bone
20Overlap between paraoccipital process and the auditory bullae
21Posterior phalange of squamosal bone (zygomatic arch)
22Posterior point of pterygoid
23Posterior intersection between incisor and premaxilla
24Suture between premaxilla and maxilla at the canine
25Posterior intersection between canine and maxilla
26–37Anterior/Posterior intersections of teeth with maxilla
38Lowest point of intersection of jugal and maxilla
39Point of greatest curvature anteriorly on jugal bone
40Point where jugal bone meets lacrimal bone anteriorly
41Point of greatest curvature on auditory bullae
42–43Auditory bullae
image

Figure 2. Ventral landmarks on skull of Canis latrans. Note a total of 42 landmarks were assigned to the ventral view of skulls. This figure is available in colour online at wileyonlinelibrary.com/journal/oa.

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Table 2. Description of ventral landmarks
LandmarkDescription
1Medial premaxilla suture at end of skull
2–12, 16,17Anterior/posterior margins of teeth
13Point where second molar touches posterior portion of carnassial
14Most lingual point of m2
15Posterior curvature of m2
18Most labial point of m2
19Lateral palatal suture (orbital region)
20Medial suture line between palatines and maxilla bone
21Suture between palatine and vomer
22Basal portion of presphenoid
23Suture between palatine and alisphenoid
24Suture between basisphenoid and alisphenoid
25Supraoccipital suture
26Lamboidal suture
27Suture between jugal and malar process of maxillary
28Suture between jugal and squamosal
29Most posterior intersection between zygomatic arch and squamosal bone
30–32,35–37Auditory bullae
33,34Lateral/medial occipital condyle points
38Lowest point of intersection between jugal and maxilla
39Intersection between palatine and pterygoid
40Pterygoid and zygomatic arch (anterior)
41Orbitosphenoid
42Point of greatest curvature of squamosal

Geometric morphometric statistical analysis

Data from the three different cranial views were aligned and scaled using a Procrustes superimposition performed by TPSsuper to generate shape variables. Controlling for size and shape by scaling is extremely important because the variability of size within domestic dogs could have severely overwhelmed the overall results of the landmark study. Moreover, the superimposition converted the raw data into shape variables which were then uploaded into SSPS 16.0 for statistical analysis. Principle component analyses, discriminant function analyses, and stepwise discriminant function analyses were used to interpret the significant changes necessary to convert the skull from wild species to that of a domestic dog. For this study, two groups were identified: all three wild species were grouped together as a single ‘morphotype’, while all domestic dogs were placed together as a second.

Visualization and interpretation

Thin plate splines were produced in order to provide a visual representation of the morphological differences in the skull between groups. Results from the thin plate splines were compared to the variables that were chosen by the stepwise discriminant analysis in order to determine if both analyses depicted similar morphological changes in the skull. Specifically, deformation of a grid tied to the landmarks allows greater interpretation of shape change between the landmarks, in addition to their movement relative to one another. The variation in the rostrum suggested by previous studies is illustrated by the thin plate splines because of the severity of the deformation necessary to complete the morph.

Results

  1. Top of page
  2. ABSTRACT
  3. Introduction
  4. Materials and methods
  5. Results
  6. Discussion
  7. Conclusion
  8. Acknowledgements
  9. References
  10. APPENDIX: SPECIMEN LIST

Although all three views produced results, only the lateral and ventral positions proved statistically significant in determining variations between the four species of canids. Therefore, only these two views will be discussed. Perhaps new landmarks will better display any morphological changes that are occurring on the dorsal surface of the skull. Regardless, the two views, statistical tests, and thin plate splines clearly separated and highlighted various differences between all species.

Discriminant function analyses of morphometric data

The discriminant analyses for both the lateral and ventral views (Figure 3) depict clear separations between wild and domesticated canids, with 100% of the variance explained. As expected, all the wild canids grouped together on one side of the axis, whereas all of the domestic specimens fell to the other side of the plot. Both views produced a bimodal distribution, with one group (wild) falling to the negative portion of the axis, and the domestic group falling to the positive portion of the x-axis. Few coordinates were eliminated by the statistical software in both views, which enabled a high amount of variables to be considered in the test, as well as to be compared in the thin plate splines. Based on the high amount of variables utilized in the discriminant analysis, a stepwise discriminant analysis was performed on both the lateral and ventral landmark data in order to isolate which characters are most significant to differentiating the two groups. Noteworthy variables from the discriminant analysis were utilized (Table 3) and produced good separation between wild and domestic species. The lateral landmarks had no overlap, whereas the ventral data produced what appears to be a bimodal distribution pattern (Figure 4).

image

Figure 3. Histogram of scores from the discriminant analysis. Separation between both groups of canids is clearly depicted on both the ventral and lateral views of the graphs. This figure is available in colour online at wileyonlinelibrary.com/journal/oa.

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Table 3. Stepwise discriminant variables selected by the analysis.
Stepwise Discriminant Variables
Lateral LandmarksX2, Y7, Y19, X22, Y29, X37, X39, Y43
Ventral LandmarksY14, Y5, Y36, Y13, Y37, Y31, Y39, Y3, Y38, X33, X1, Y29
image

Figure 4. Histogram of scores from the stepwise discriminant analysis. This figure is available in colour online at wileyonlinelibrary.com/journal/oa.

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Thin plate splines

Landmark analysis indicated that the orbital and frontal regions on the lateral view (Figure 5) seemed to demonstrate the greatest transformation, which includes the nasal and frontal bones. Results also suggest the braincase, including the temporal and parietal bones, experienced a significant amount of change between the wild group and domestic species. Results of the spline support the statistical analysis of the data by the discriminant analyses. Morphing on the lateral view appears to be focused around the orbital region, spreading from there and encompassing the forehead and braincase areas. Specifically, the orbit has been enlarged in the domestic dog, the forehead transitions from a flattened structure to one having a more angled appearance, and the braincase has shifted in position and size. Thin plate spline of the ventral view depicts an expansion of the palate width and a more laterally flaring zygomatic arch in the domestic dog that is not typical in wild morphology. The most posterior portion of the occipital bone appears to have a downward inflection in the domestic variety.

image

Figure 5. Thin Plate Spline of the lateral view. Consensus of wild dogs ‘deformed’ to the domestic consensus to illustrate zones of major change. Points in red/shaded were selected by the stepwise discriminant as significantly different between the two groups. This figure is available in colour online at wileyonlinelibrary.com/journal/oa.

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Discussion

  1. Top of page
  2. ABSTRACT
  3. Introduction
  4. Materials and methods
  5. Results
  6. Discussion
  7. Conclusion
  8. Acknowledgements
  9. References
  10. APPENDIX: SPECIMEN LIST

Clear separation by all discriminant function analyses indicates a significant difference between the cranium of wild canids and domestic dogs. Variables chosen by the stepwise discriminant analysis for the lateral view are highlighted in Figure 5, where the landmark data is superimposed onto the results of the thin plate spline. As shown, the spline highlights an expansion of the orbit, a slight compression of the rostrum, a general downward shift of the nose and facial region, and a slight upward shift of the cranium and braincase; all of which combine to generate the ‘doming’ appearance that is commonly observed in domestic dogs. The expansion of the orbit gives domestic dogs the unique large-eyed appearance, a paedomorphic trait that has been selected for by humans. The results support past observations of changes that have occurred in the skull of domestic dogs from wild species (e.g. Olsen, 1974; Morey, 1992).

Landmarks selected by the stepwise analysis are well distributed throughout the skull. Some of the points chosen were expected, such as landmark number two, but others were somewhat surprising. For example, landmark two is consistent with the variability in the rostrum region, and landmark seven represents the doming; both features noted by previous authors. Some unexpected landmarks include the points on and surrounding the zygomatic arches. Prior observations on canid cranial changes rarely discuss variation in this region. However, the thin plate spline results indicate alterations in the zygomatic arch are likely a consequence of other changes occurring nearby, such as the condensing of the braincase region. There are also some changes occurring in the dentition of domestic dogs, though this is not as well reflected in either the stepwise discriminant or the thin plate spline. More points surrounding the teeth were expected to be chosen for example, especially due to severe tooth crowding in some breeds of C. familiaris; however, few were significant between the two groups. It seems likely that the extreme variation typical of domestic dogs likely caused those landmarks to be too variable and therefore to fail tolerance tests within the analysis.

Results from the ventral view enable further understanding of morphological changes occurring in domestic dogs, especially in the tooth row. The stepwise discriminant analysis chose several variables on the teeth, especially surrounding the carnassials. This is expected, especially since the carnassials seem to be one of the major components that vary in locality in domestic dogs. In addition, as suggested by Walker & Frison et al. (1982), there are also major changes occurring in the auditory bullae. Although previous studies have described observable differences in this area between wild species and domesticated canids, here we support these variations statistically. The thin plate splines illustrate these changes in the auditory bullae as well, including a sort of compression of the posterior portion, while the stepwise analysis focuses on the variation of the overall shape and position of the bullae themselves. Evidence of a widening palate supports this commonly observed trait in domestic dogs. According to the spline, the palate seems to widen while becoming shorter, causing the crowding of the teeth. This widening of the palate may also explain why the zygomatic arches appear to flare more laterally in the C. familiaris.

Conclusion

  1. Top of page
  2. ABSTRACT
  3. Introduction
  4. Materials and methods
  5. Results
  6. Discussion
  7. Conclusion
  8. Acknowledgements
  9. References
  10. APPENDIX: SPECIMEN LIST

Multivariate analyses provided great statistical insight into the morphological changes that are occurring between wild canids and domestic dogs. Our findings are unique in that they quantify the morphological changes that occurred in the skull in wild canids during the process of domestication to the modern dog. Moreover, this study represents one of the first attempts to quantify the observable variations in the cranium of canids. It is important to understand how one slight change, such as the shortening of the rostrum, affects other cranial elements. This key point has previously been lost when just defining basic observable traits, but has reemerged as a primary factor in these statistical analyses. As a result, the statistical and visual analyses presented here provide a more complete description of the morphological changes that occurred in the skull of C. familiaris as a result of domestication. Features not previously noted, however, include variation in the zygomatic arch and an increase in orbit size. These variations are presumably due to the heavy selective pressures experienced by domesticated breeds in recent decades and are likely to continue to distinguish them further from their wild ancestors.

It is important for archaeologists to be able to identify canid remains as either wild or domestic, as this will impact inferences made about the lifestyle and species utilization of that human population. Fortunately, archaeologists and other field scientists can utilize these methods and results to identify canid remains at cultural sites. While breeds such as boxers or chihuahuas are more easily discernable, other breeds that maintain a wild-like morphology will present the biggest challenge in field identification. Future research will involve quantifying differences between wild species and specific breeds, as well as the current understanding of phylogenetic classifications of the domestic dog.

Acknowledgements

  1. Top of page
  2. ABSTRACT
  3. Introduction
  4. Materials and methods
  5. Results
  6. Discussion
  7. Conclusion
  8. Acknowledgements
  9. References
  10. APPENDIX: SPECIMEN LIST

We would like to thank the following for their contributions to this study: Department of Geosciences for access to specimen collections and reviews; and Dr. Jim Mead and Sandra Swift at East Tennessee State University, Dr. Timothy Gaudin at the University of Tennessee Chattanooga (UTC) and Dr. Klippel at the University of Tennessee Knoxville (UTK) for access to skeletal specimens housed in their respective university collections. We also thank Laura Gilmore for helpful reviews of this manuscript.

References

  1. Top of page
  2. ABSTRACT
  3. Introduction
  4. Materials and methods
  5. Results
  6. Discussion
  7. Conclusion
  8. Acknowledgements
  9. References
  10. APPENDIX: SPECIMEN LIST
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APPENDIX: SPECIMEN LIST

  1. Top of page
  2. ABSTRACT
  3. Introduction
  4. Materials and methods
  5. Results
  6. Discussion
  7. Conclusion
  8. Acknowledgements
  9. References
  10. APPENDIX: SPECIMEN LIST
SpeciesSpecimen numberLocationSpeciesSpecimen NumberLocation
Canis lupusUTCM 696UTCCanis latransUTK 2233UTK
Canis lupusNAU QSP 7344ETSUCanis latransUTK 359UTK
Canis lupusNAU QSP 5936ETSUCanis latransUTK 360UTK
Canis lupusUTK 7170UTKCanis latransUTK 2234UTK
Canis lupusUTK 4590UTKCanis familiarisUTCM 805UTC
Canis lupusUTK 383UTKCanis familiarisUTCM 234UTC
Canis lupusUTK 7866UTKCanisfamiliarisUTCM 236UTC
Canis lupusUTK 7196UTKCanis familiarisUTCM 235UTC
Canis lupusUTK 6144UTKCanis familiarisNAU QSP 6594ETSU
Canis lupusUTK 9567UTKCanis familiarisNAU QSP 6585ETSU
Canis lupusUTK 10691UTKCanis familiarisGreyhound - ETSUETSU
Canis lupusUTK 11024UTKCanis familiarisBoxer - ETSUETSU
Canis lupusUTK 10030UTKCanis familiarisGolden Retriever -ETSUETSU
Canis rufusUTCM 1496UTCCanis familiarisBlack Lab - ETSUETSU
Canis rufusUTCM 1510UTCCanis familiarisShar Pei - ETSUETSU
Canis rufusUTCM 1517UTCCanis familiarisBoston TerrierETSU
Canis rufusUTK 6670UTKCanis familiarisSheltie- ETSU 9864ETSU
Canis rufusUTK 6669UTKCanis familiarisDauchshund - ETSUETSU
Canis rufusUTK 6668UTKCanis familiarisFoxhound-8134ETSU
Canis latransUTCM 770UTCCanis familiarisBassett Hound- ETSU 6981ETSU
Canis latransUTCM 239UTCCanis familiarisGerman Shepherd, Mt Misery NJETSU
Canis latransUTCM 796UTCCanis familiarisGerman Shepherd - ETSUETSU
Canis latransUTCM 1095UTCCanis familiarisNAU QSP 5932ETSU
Canis latransUTCM 240UTCCanis familiarisCC 175ETSU
Canis latransNAU QSP 6584ETSUCanis familiarisDauchshund - UTK 9869UTK
Canis latransNAU QSP 6582ETSUCanis familiarisAlaskan Malamute - UTK 9791UTK
Canis latransETSU KansasETSUCanis familiarisGerman Shepherd - UTK 9671UTK
Canis latransETSU-260000ETSUCanis familiarisRottweiler - UTK 10018UTK
Canis latransNAU QSP 7603ETSUCanis familiarisGolden Retriever - UTK 10020UTK
Canis latransNAU QSP 6586ETSUCanis familiarisGerman Shepherd - UTK 501UTK
Canis latransCC 251ETSUCanis familiarisLabrador - UTK 10019UTK
Canis latransUTK 2325UTKCanis familiarisBoxer - UTK 10922UTK
Canis latransUTK 3052UTKCanis familiarisRottweiler - UTK 9893UTK

ETSU = East Tennessee State University Collection

UTK = University of Tennessee, Knoxville Zooarchaeology Collection

UTC = University of Tennessee, Chattanooga Collection