Canadian Journal of Earth Sciences

Scimitar Cat ( Homotherium serum Cope) from Southwestern Alberta, Canada

Journal: Canadian Journal of Earth Sciences

Manuscript ID cjes-2017-0130.R1

Manuscript Type: Article

Date Submitted by the Author: 10-Aug-2017

Complete List of Authors: Ewald, Tatyanna; University of Calgary, Department of Anthropology and Archaeology Hills, Len; The University of Calgary, Department of Geoscience Tolman, Shayne;Draft Independent Kooyman, Brian; University of Calgary , Department of Anthropology and Archaeology

Is the invited manuscript for consideration in a Special N/A Issue? :

Homotherium serum , Homotheriini, Dentition, Wally's Beach, Keyword:

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1 Scimitar Cat ( Homotherium serum Cope) from 2 Southwestern Alberta, Canada

3 Tatyanna Ewald, L.V. Hills*, Shayne Tolman, and Brian Kooyman

4 *Deceased

5 T. Ewald. (email: [email protected]) Department of Anthropology and Archaeology, 6 University of Calgary, 2500 University Dr. NW, Calgary, AB T2N 1N4, Canada.

7 L.V Hills. * Department of Geoscience, University of Calgary , 2500 University Dr. N.W., 8 Calgary, AB T2N 1N4, Canada

9 S. Tolman. (email: [email protected]) Box 1146, Cardston, AB TOK 0Y0, Canada.

10 B. Kooyman. (email: [email protected]) Department of Anthropology and Archaeology, 11 University of Calgary, 2500 University Dr. NW, Calgary, AB T2N 1N4, Canada.

12 Corresponding author: Draft

13 Tatyanna Ewald 14 Email: [email protected] 15 Phone: 14038272245 16 Fax: 14032845467 17 Address: Department of Anthropology and Archaeology 18 2500 University Drive NW 19 T2N 1N4 20 Canada

21 *Deceased.

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22 Abstract 23 Skull and tooth fragments of Homotherium serum recently recovered from the Wally’s Beach

24 site (DhPg8) in southwestern Alberta provide the first indications that scimitar cat populated the

25 area of the St. Mary Reservoir. AMS radiocarbon dating provides a 2 sigma range calibrated age

26 of Cal BP 12 715 to 12 655. This is the fourth known occurrence of the species in Canada, the

27 first outside of Yukon, and is currently the youngest precisely dated occurrence of the species in

28 . Wellpreserved dentition combined with the temporal and geographic context

29 allows the sample to be identified as Homotherium serum . The specimen is significant as it

30 represents an extension of the geographic and chronological range of the species.

31 Keywords Draft 32 Homotherium serum , Homotheriini, Dentition, Wally’s Beach, Pleistocene

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33 Introduction

34 The Wally’s Beach site, near Cardston in southwestern Alberta, consists of a series of

35 Late Pleistocene paleontological and archaeological remains which were exposed by erosion

36 associated with the operation of the St. Mary Reservoir (Hills et al. 2014; Kooyman et al. 2012;

37 Waters et al. 2015). Species present include Equus conversidens , Camelops hesternus ,

38 Bootherium bombifrons , Rangifer tarandus , and antiquus among others. A number of

39 species are also represented by preserved tracks, including Mammuthus (McNeil et al.

40 2005:1255). Recently, skull and tooth fragments of an individual scimitar cat, Homotherium

41 serum, were discovered. The purpose of this paper is to describe and illustrate this specimen, and 42 to discuss its location and date in relationDraft to other known occurrences of the species.

43 Geological Setting and Context

44 The Wally’s Beach site (also known by its Borden designation DhPg8) is located in

45 southwestern Alberta near the town of Cardston (Fig. 1), in the drawdown zone of the St. Mary

46 Reservoir (Hills et al. 2014). While the H. serum remains are paleontological, the Wally’s Beach

47 site is predominately an archaeological site and is therefore defined by the Borden system. The

48 Borden system divides Canada into a series of small blocks inside larger blocks based on latitude

49 and longitude. The capital letters in the Borden designation identify the large block, while the

50 lowercase letters denote the small block to which the site belongs. Each archaeological site is

51 then designated sequentially within these blocks (Borden 1954).

52 Cranial remains of H. serum were discovered insitu, within a 1618cm radius. The

53 location consists of Late Pleistocene loess and eolian sands, upon which a paleosol

54 developed (Hills et al. 2014:25) The specimen was recovered from the very top portion of the

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55 Pleistocene sediments, embedded in the carbonate horizon that resulted from the development of

56 the overlying paleosol. The enamel layer of one of the canines shows extensive fibrous root

57 etchings on the surface (Fig. 2). This suggests that this tooth was incorporated in the soil horizon

58 while it was actively forming, before the soil’s final burial.

59 A bone sample from the skull provides an AMS (Beta 440230) 2 sigma range calibrated

60 age of Cal BP 12 715 to 12 655 (conventional age of BP 10 740 ±40). This date was calibrated

61 using IntCal13. The CN (carbon:nitrogen) ratio of +3.3 is within the normal range expected for

62 live protein, therefore the collagen was wellpreserved (the δ13C value of 19.3 o/oo and δ15N

63 value of +6.6 o/oo are also both within the normal range expected for live protein). This date

64 places the specimen in the Late Pleistocene and makes it the youngest dated specimen of

65 Homotherium serum in Canada. Draft

66 Materials and Methods

67 The following description is based on fragments of five incisors, two upper canines, the

68 left lower canine, the upper fourth premolar, the lower first , and an unidentifiable root

69 (Fig. 3). Preservation is largely restricted to the enamel layer of each tooth. The canine fragments

70 were measured using electronic calipers providing digital readouts to the nearest millimetre (see

71 Dental Remains Recovered). Several small skull fragments (DhPg83847) are also present

72 within the assemblage, but were not considered in this study. The skull fragments are too small

73 and fragmented for partial skull reconstruction, therefore the teeth were the focus of this analysis.

74 The identification of the tooth fragments was reliant predominately upon Rawn

75 Schatzinger (1983; 1992), although several other sources (Antón et al. 2014; Biknevicius et al.

76 1996; Cope 1893; Martin et al. 2011a; Martin et al. 2011b; Martin et al. 2011c; Martin et al.

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77 2011d; Wheeler 2011) and some comparisons to modern taxa (Felis concolor, Lynx

78 canadensis , and Leopardus pardalis , Department of Anthropology and Archaeology, University

79 of Calgary) were also utilized.

80 Results

81 Systematic Paleontology

82 We follow the systematics proposed by Antón et al. (2014).

83 Mammalia Linnaeus, 1758

84 Order Bowdich, 1821 85 Suborder Kretzoi, 1945 Draft 86 Family Felidae Fischer von Waldheim, 1817

87 Subfamily Gill, 1872

88 Tribe Homotheriini Kurtén, 1962

89 Homotherium Fabrini, 1890

90 Homotherium serum (Cope 1893)

91 Referred Specimens

92 The material used in this study will be stored in the Archaeology collections at the Royal

93 Alberta Museum: DhPg83836, crown of the upper left canine; DhPg83837, crown of the

94 upper right canine; DhPg83838, fragment of the crown from an upper first or second incisor;

95 DhPg83839, fragment of the crown from the lower right second incisor; DhPg83840,

96 fragment of the crown from the lower left second incisor; DhPg83841, fragment of the crown

97 from an upper incisor; DhPg83842, fragment of the crown from an unidentified incisor; DhPg

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98 83843, crown of the lower left canine; DhPg83844, metacone of the upper left fourth

99 premolar; DhPg83845, paracone of the lower right first molar; DhPg83846, partial root;

100 DhPg83847, several small skull fragments. Cataloguing of these materials followed the Borden

101 system.

102 Dental Remains Recovered

103 The Homotherium genus is particularly characterized and separated from other saber

104 tooth cats by its dentition, and this is particularly useful in distinguishing Homotherium from its

105 close relatives, also present in North America during the Pleistocene. A total of 11

106 tooth fragments identified as belonging to Homotherium serum were recovered at Wally’s 107 Beach. The teeth recovered indicate thatDraft only a single individual is represented; no elements are 108 duplicated and the size and wear on the teeth are consistent for a single individual. In addition,

109 the remains were discovered insitu. Distinct, fine serrations are present along the cutting edge of

110 each tooth and are characteristic of H. serum , as serrations are present on all teeth of both

111 juvenile and adult specimens (RawnSchatzinger 1983). “The term “finely serrate” as used by

112 Cope (1983) and Churcher (1966) refers to the consistent and regular serration of H. serum ’s

113 teeth,” (RawnSchatzinger 1992:4). Within this specimen, serrations are most clearly pronounced

114 on the upper canines (Fig. 4), upon which they are present along the entire length of the anterior

115 and posterior edge (RawnSchatzinger 1983; 1992; Wheeler 2011:28).

116 The most distinctive of the teeth recovered from Wally’s Beach are the upper canines

117 (Fig. 5), of which only the enamel caps are present. As noted by RawnSchatzinger (1983:53),

118 "the permanent canine has onehalf of its length covered with enamel.” As such, it is reasonable

119 to assume that these enamel caps represent approximately onehalf of the original length of each

120 tooth. The fragment of the left tooth (DhPg83836) is 51.8 mm in length and 20.1 mm wide

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121 anteroposteriorly at its widest aspect, while the right (DhPg83837) is 48.2 mm long and 18.7

122 mm wide. Mediolaterally, the left tooth is 8.3 mm wide and the right is 8.4 mm, once again at

123 their widest aspects. This corresponds with descriptions by RawnSchatzinger (1983:52; 1992:3)

124 of H. serum upper canines which are laterally compressed or flat as compared to conicaltooth

125 cats. Also unique to Homotherium, and exhibited in this specimen, is that the canines are

126 relatively short and broad in comparison to other sabertooths (Martin et al. 2011a:6; Martin et

127 al. 2011d:208; Wheeler 2011:27) and that they are more complex on their lingual surface (Rawn

128 Schatzinger 1983:52). Both teeth are relatively straight with a very slight posterior curvature.

129 The convex nature of the posterior as opposed to the anterior face of the upper canines, as in this

130 specimen, was noted by Cope (1893:897). Both canines exhibit heavy postdepositional root

131 etching. Draft

132 Several incisor fragments were also identified. All display a slight posterior convex

133 curvature and all are procumbent and rather robust, as is characteristic of Homotherium (Martin

134 et al. 2011a:8; Wheeler 2011:28). The first fragment (Fig. 6A; DhPg83838) is comprised of the

135 anterior portion of the enamel cap. Partial cuspules are present on both lateral sides of this

136 fragment, allowing it to be identified as either the upper first or second incisor (Rawn

137 Schatzinger 1983:53), although the side is indeterminable in this state. An additional incisor

138 fragment (Fig. 6B; DhPg83839) consists predominately of the posterior and medial portion of

139 the enamel cap. Basal cuspules are present on both lateral sides of the fragment, one partial and

140 the other complete. This tooth has therefore been identified as the lower second incisor (Rawn

141 Schatzinger 1983:53). The medial cuspule is noticeably higher on the tooth than the lateral,

142 indicating that this is the right second incisor (Martin et al. 2011b: Figure 4.8). Yet another

143 incisor fragment, consisting predominately of the posterior and lateral portion of the enamel cap,

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144 exhibits mirrored identical features (Fig. 6C; DhPg83840). This tooth has been identified as the

145 lower left second incisor.

146 Yet another obviously incisiform fragment consists of a lateral portion of the enamel cap,

147 and terminates just below a basal cuspule (Fig. 6D; DhPg83841). This tooth has been identified

148 as part of the upper incisor dentition; however further identification is not possible. It is larger

149 than the lower second incisors already identified for this specimen and is therefore not a lower

150 first incisor, as the lateral incisors are typically larger and more robust in both sabertooth cats

151 and modern carnivores (Biknevicius et al. 1996). The obvious cuspule present on this fragment

152 also excludes it from being identified as the lower third incisor, as this tooth lacks basal cuspules 153 in H. serum (RawnSchatzinger 1983:52).Draft This incisor is therefore part of the upper dentition, 154 however is not identifiable within a sequence. A fifth incisor fragment (DhPg83842) is poorly

155 preserved and further identification is not possible.

156 Also present within this sample is a lower canine (Fig. 7; DhPg83843), of which the

157 entire crown appears to be present. As noted by RawnSchatzinger (1983:53), enamel covers

158 approximately onethird of this tooth, which indicates that this fragment is likely representative

159 of onethird of the original length of the tooth. Although the lower canines of Homotherium are

160 diagnostically reduced and incisorlike (Biknevicius et al. 1996:518; Wheeler 2011:32), at 19.6

161 mm long this tooth fragment is noticeably larger than all the incisor fragments present in this

162 sample, which is typical in H. serum (RawnSchatzinger 1983:50). In their description of

163 Homotherium serum , Antón et al. (2014:263) state that in the occlusal view the lower canine has

164 “a strong lateral flattening, and a small size, just slightly larger than the i3.” This lateral

165 compression is also exhibited in this specimen and is also characteristic of H. serum (Rawn

166 Schatzinger 1983:53). It is also much smaller than the upper canines, which would allow the cat

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167 more clearance when biting (Wheeler 2011:29). A small basal cuspule located on its medial

168 aspect (RawnSchatzinger 1983:53) indicates that this tooth is the left. This specimen also

169 exhibits a distinct convex posterior curvature which is more pronounced than in the upper

170 canines.

171 A single cusp of the upper fourth premolar, or the upper carnassial (Fig. 8; DhPg83844)

172 is also present. This cusp is identifiable as such because the edge is nearly straight, allowing it to

173 function in its role as a specialized cutting tooth, a characteristic unique to Homotherium (Rawn

174 Schatzinger 1983:52; RawnSchatzinger 1992:3). The shape of this specimen also indicates that

175 it is the metacone, which is the only cusp within H. serum which is distinctively flat (Rawn

176 Schatzinger 1983). The main ridge of the cusp leans slightly medially and two slight bulges are

177 present on the buccal aspect of the tooth,Draft with a slight vertical groove between them (Cope

178 1893:897). Combined with indications of postmortem breakage on the anterior portion of the

179 cusp and a lack of such evidence on the posterior portion, this fragment has been identified as the

180 most posterior cusp (metacone) of the left upper carnassial (RawnSchatzinger 1983:54). The

181 identification of this tooth was corroborated by comparisons to modern Felidae samples ( Felis

182 concolor, Lynx canadensis , and Leopardus pardalis , Department of Anthropology and

183 Archaeology, University of Calgary).

184 A cusp with a pointed and rather symmetrical apex was also recovered (Fig. 9; DhPg8

185 3845). The lower carnassial, or lower first molar, of Homotherium is distinguished by its two

186 bladelike cusps (RawnSchatzinger 1983:54). The paracone in particular is both large and

187 vertical (Martin et al. 2011c:193), indicating that this fragment is the paracone of the lower

188 carnassial. The presence of two vertical concavities on the lingual aspect of the cusp, as well as

189 indications of postmortem breakage on the posterior but not anterior aspect of the cusp, further

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190 indicates that this is a fragment of the right carnassial. Comparisons with modern Felidae

191 samples ( Felis concolor, Lynx canadensis , and Leopardus pardalis , Department of Anthropology

192 and Archaeology, University of Calgary) corroborated this identification. Shearing wear is also

193 present on both carnassial fragments; this is particularly wellpreserved on the fragment of the

194 lower carnassial (see Fig. 9A).

195 The final fragment is a partial root (Fig. 10; DhPg83846). Three separate roots are

196 identifiable on this fragment, the middle of which projects outwards from the other two. Based

197 on comparisons with modern Felidae samples ( Felis concolor, Lynx canadensis , and Leopardus

198 pardalis, Department of Anthropology and Archaeology, University of Calgary), it is likely that 199 this belongs to a molar or premolar of HomotheriumDraft serum . As this fragment is not diagnostic, 200 further evaluation of the tooth roots in Homotherium is beyond the scope of this study.

201 In the present material, the upper canines are lenticular in cross section with serrations

202 present on both the anterior and posterior edges. The canines are blunted with numerous flake

203 scars and the serrations are polished and worn (Fig. 11), indicative of a mature individual. Rawn

204 Schatzinger (1983) subdivided the scimitar cat into an eightstage age progression ranging from

205 Stage I, deciduous teeth just erupting beyond the alveolus, to Stage VIII, with extensive wear and

206 teeth blunted by wear polish. These last features are visible on this specimen; hence it is

207 classified as a Stage VIII adult. RawnSchatzinger (1983) did not provide an age for Stage VIII

208 adults, however that for Stage VII is two or more years, which equates to the approximate age

209 for complete functional permanent dentition. No teeth in this specimen are in an extreme state of

210 wear evidenced by broken teeth or teeth worn to the pulp cavity (RawnSchatzinger 1983:52).

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211 Discussion

212 The Wally’s Beach scimitar cat specimen provides a significant new addition to the Late

213 Pleistocene paleofauna of southwestern Alberta, Canada. It is the fourth known occurrence of H.

214 serum in Canada (Debicki 1983:24; Harington 1977:526528, 529531; Harington 1989:95;

215 Harington 1997; Harington 2003:385; RawnSchatzinger and Collins 1981:18) and the first in

216 Alberta. The calibrated age of Cal BP 12 715 to 12 655 is corroborated by the specimen’s

217 stratigraphic context and makes this the youngest precisely dated occurrence of this species in

218 North America.

219 Due to the fragmented nature of the skull fragments recovered, an analysis of the

220 specimen recently recovered from Wally’sDraft Beach was entirely dependent upon the partial

221 dentition. While the distinctive tooth morphology (e.g., fine serrations present along the cutting

222 edge of all teeth) exhibited here was the basis for identifying this specimen, the geographic and

223 temporal context of the finds supports this identification.

224 The sabertooth cats were common primarily during the and Pleistocene, periods

225 correspondingly characterized by large prey species which these cats were well adapted to hunt.

226 Homotherium is recognized as a wideranging genus from throughout Europe, Asia, , and

227 North America (RawnSchatzinger 1992), and as the most abundant scimitar cats from northern

228 and North America (Martin et al. 2011d). Recently, a specimen from

229 (Homotherium venezuelensis ) has also been described (Rincón et al. 2011), adding South

230 America to the range of Homotherium and making it the most geographically dispersed genus of

231 the sabertooth cats (Antón et al. 2014). Homotherium was the only sabertooth cat that achieved

232 such a wide range (Martin et al. 2011a).

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233 The genus Homotherium is the last of a long line of machairodont Homotheriini, ranging

234 in age between four million and 10,000 years (Antón et al. 2014). Their correlated

235 with megafauna as well as climatic fluctuations (Martin et al. 2011a). Diagnosis of

236 species within Homotherium remains a debated issue among researchers. While a single species

237 tends to be recognized for Europe and Asia ( Homotherium latidens ), there are several

238 classifications of North American species (Antón et al. 2014). Homotherium ischyrus is often

239 described as an earlier North American species recovered most often from Pliocene and early

240 Pleistocene contexts, while Homotherium serum characterizes the Late Pleistocene of North

241 America (Martin et al. 2011c). Homotherium serum, while abundant primarily during the later

242 stages of the Pleistocene, was not uncommon earlier in this epoch (Antón et al. 2014). Draft 243 While both H. ischyrus and H. serum occupied North America, H. serum characterized

244 the Late Pleistocene and may have been the only scimitar species on the continent at the time

245 (Antón et al. 2014). The distribution of Homotherium in North America is predominately within

246 the Camelops Faunal Province, “which was considered to be composed mostly of pine parkland

247 and characterized by the most cursorially adapted large ,” (Martin et al. 2011d:206).

248 Homotherium serum is known from over 30 sites in North America which are concentrated in the

249 United States (see Fig. 1; Table 1). Only three sites within Canada (not including Wally’s

250 Beach) are currently known to contain H. serum remains (Debicki 1983:24; Harington 1977:526

251 528, 529531; Harington 1989:95; Harington 1997; Harington 2003:385; RawnSchatzinger and

252 Collins 1981:18). As the only known specimen in Alberta, the remains from Wally’s Beach

253 represent an extension of the range of H. serum . Furthermore, as the youngest occurrence in

254 Canada by a significant margin, this specimen may represent a Late Pleistocene extension of the

255 species northward into modern Canada from the United States.

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256 The calibrated age of Cal BP 12 715 to 12 655 for this specimen corroborates its

257 identification as H. serum, which characterized the Late Pleistocene of North America, rather

258 than the much older H. ischyrus (Antón et al. 2014). More significantly, this specimen is the

259 youngest known precisely dated occurrence of the species in North America. In Canada, three

260 other specimens have been identified from Yukon, however these are significantly older than that

261 recovered from Wally’s Beach. These Yukon specimens date to over 40,000 years BP at

262 Sixtymile Loc. 3 (the only Yukon specimen which has been precisely dated) (Harington 1997;

263 Harington 2003:385), over 25,000 years BP at Old Crow Loc. 21 (Harington 1977:526528;

264 Harington 1989:95), and 39,900 to 22,200 years BP at Dawson Loc. 9 (Debicki 1983:24;

265 Harington 1977:529531; RawnSchatzinger and Collins 1981:18). In North America more

266 broadly, most specimens date to an earlierDraft Pleistocene context (see Table 1). Only one site

267 contains specimens which have been precisely radiocarbon dated to the last 15,000 years:

268 Laubach Cave No. 2, Texas (13,970 years BP; Graham and Lundelius 2010). The Wally’s Beach

269 specimen is therefore currently the most recent precisely dated specimen in North America and

270 may be a useful indicator of the survival of the species into the Younger Dryas (as defined in

271 Widga et al. 2017).

272 Conclusions

273 The scimitar cat Homotherium serum was a specialized predator which lived during the

274 Late Pleistocene and was widely dispersed across North America (Martin et al. 2011c; Martin et

275 al. 2011d). Homotherium serum is most notably identified by its dentition. The serrations present

276 on all teeth allowed for a bladelike function (RawnSchatzinger 1983) while the robustness of

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277 the dentition, compared to its sister taxa, allowed for the capture and consumption of large

278 bodied prey (RawnSchatzinger 1992).

279 The dental materials recovered from Wally’s Beach permit identification of this specimen

280 as H. serum based primarily on the presence of serrations on all teeth in addition to other

281 diagnostic aspects of the morphology. Individual teeth can be identified based on distinguishing

282 characteristics outlined by previous researchers, and by comparisons to modern felid taxa. The

283 upper canines are particularly diagnostic due to their laterally compressed form, the serrations

284 present on the entire posterior and anterior edges, and their smaller size and slight curvature

285 which differs from Smilodon relatives. The assignment of this specimen to H. serum is 286 corroborated based on geographic and temporalDraft criteria. The context of the find is important as it 287 expands the known distribution of the species, while the age of the specimen, at Cal BP 12 715

288 to 12 655, is currently the youngest precisely dated occurrence of the species in North America

289 and further extends its range temporally. This specimen is significant as it represents the fourth

290 record of H. serum in Canada and the first in Alberta, contributing to our knowledge of the

291 distribution of the species in North America, and provides an indicator of the survival of the

292 species into the Younger Dryas (Widga et al. 2017).

293 Acknowledgments

294 Grants from the Alberta Historical Resources Foundation, Alberta Transportation,

295 Natural Sciences and Engineering Research Council of Canada (NSERC) (L.V.H.), and

296 Westwinds School Division (S.T.) are gratefully acknowledged. The assistance of Tracy Wyman

297 with ArcGIS to produce Figure 1 is greatly appreciated. We are also thankful to the reviewers

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298 and editorial staff of the Canadian Journal of Earth Sciences for their suggestions for improving

299 the manuscript.

Draft

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346 Kretzoi, M. 1945. Bemerkungen über das Raubtiersystem. Annales historiconaturales Musei

347 nationalis hungarici, 38 : 59–83.

348 Kurtén, B. 1962. The sabretoothed cat from the Pleistocene of Java. Zoologiscge

349 Mededelingen Leiden, 38 : 101–104.

350 Linnaeus, C. 1758. Systema naturae perDraft regna tria naturae, secundum classes, ordines, genera,

351 species, cum characteribus, differentiis, synonymis, locis. (tenth edition), Laurentius Salvius,

352 Stockholm.

353 Martin, L.D., Babiarz, J.P., and Naples, V.L. 2011a. Introduction. In The other sabertooths:

354 scimitartooth cats of the Western Hemisphere. Edited by V.L. Naples, L.D. Martin, and J.P.

355 Babiarz. The John Hopkins University Press, Baltimore, Md. pp. 3–18.

356 Martin, L.D., Babiarz, J.P., and Naples, V.L. 2011b. The osteology of a cookiecutter cat,

357 hodsonae . In The other sabertooths: scimitartooth cats of the Western Hemisphere.

358 Edited by V.L. Naples, L.D. Martin, and J.P. Babiarz. The John Hopkins University Press,

359 Baltimore, Md. pp. 43–98.

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360 Martin, L.D., Naples, V.L, and Babiarz, J.P. 2011c. Revision of the New World Homotheriini. In

361 The other sabertooths: scimitartooth cats of the Western Hemisphere. Edited by V.L. Naples,

362 L.D. Martin, and J.P. Babiarz. The John Hopkins University Press, Baltimore, Md. pp. 185–194.

363 Martin, L.D., Babiarz, J.P., and Naples, V.L. 2011d. A framework for the North American

364 Homotheriini. In The other sabertooths: scimitartooth cats of the Western Hemisphere. Edited

365 by V.L. Naples, L.D. Martin, and J.P. Babiarz. The John Hopkins University Press, Baltimore,

366 Md. pp. 201–209.

367 McNeil, P.L., Hills, L., Kooyman, B., and Tolman, S.M. 2005. tracks indicate a

368 declining Late Pleistocene population in southwestern Alberta, Canada. Quaternary Science 369 Reviews, 24 : 1253–1259. Draft 370 RawnSchatzinger, V. 1983. Development and eruption sequence of deciduous and permanent

371 teeth in the sabertooth cat Homotherium serum Cope. Journal of Vertebrate Paleontology, 3:

372 49–57.

373 RawnSchatzinger, V. 1992. The scimitar cat Homotherium serum Cope: osteology, functional

374 morphology, and predatory behaviour. Illinois State Museum, Springfield, Ill.

375 RawnSchatzinger, V., and Collins, R.L. 1981. Scimitar cats, Homotherium serum Cope from

376 Gassaway Fissure, Cannon County, Tennessee and the North American distribution of

377 Homotherium . Journal of the Tennessee Academy of Science, 56 : 15–19.

378 Rincón, A.D., Prevosti, F.J., and Parra, G.E. 2011. New sabertoothed cat records (Felidae:

379 Machairodontinae) for the Pleistocene of Venezuela, and the Great American Biotic Interchange.

380 Journal of Vertebrate Paleontology, 31 : 468–478.

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381 Smith, K.S., and Cifelli, R.L. 2000. A synopsis of the Pleistocene vertebrates of Oklahoma.

382 Oklahoma Geological Survey Bulletin 147, The University of Oklahoma, Norman, Okla.

383 Waters, M.R., Stafford, Jr. T.W., Kooyman, B., and Hills, L.V. 2015. Late Pleistocene horse and

384 camel hunting at the southern margin of the icefree corridor: reassessing the age of Wally’s

385 Beach, Canada. Proceedings of the National Academy of Sciences of the United States of

386 America, 112 : 4263–4267.

387 Widga, C., Fulton, T.L., Martin, L.D., and Shapiro, B. 2012. Homotherium serum and Cervalces

388 from the Great Lakes Region, USA: geochronology, morphology and ancient DNA. Boreas 41 :

389 546–556.

390 Widga, C., Lengyel, S.N., Saunders, J.,Draft Hodgins, G., Walker, J.D., and Wanamaker, A.D. 2017. 391 Late Pleistocene proboscidean population dynamics in the North American Midcontinent.

392 Boreas: 1–11. doi:10.1111/bor.12235.

393 Wheeler, H.T. 2011. Experimental paleontology of the scimitartooth and dirktooth killing bites.

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395 L.D. Martin, and J.P. Babiarz. The John Hopkins University Press, Baltimore, Md. pp. 19–34.

396 Woodruff, A. 2014. Fairmead Landfill, California [online]: Available from

397 http://cenozoiclife.blogspot.ca/2014/02/fairmeadlandfillcalifornia.html [cited 28 July 2017].

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398 Tables

399 Table 1. Localities containing Homotherium serum in Canada and the United States.

Site State/Province Geologic Age

Fairbanks Alaska Rancholabrean 1

Wally’s Beach Alberta Late Wisconsinan/Younger Dryas

111 Ranch Local Fauna Arizona Blancan 1

Coyote Local Fauna California Irvingtonian 1

Fairmead Landfill Locality California Middle Irvingtonian 2

Vallecito Creek Local Fauna California Irvingtonian1 Bass Point Waterway I Draft Florida Blancan 1 Inglis IA Florida Irvingtonian 1

Leisey Shell Pits Florida Irvingtonian 1

Reddick 1A Florida Wisconsinan 1

Santa Fe River 1 (includes 1A and 1B) Florida Blancan 1

American Falls Idaho Early Wisconsinan; Rancholabrean 1

Birch Creek Idaho Blancan 1

Dam Local Fauna Idaho Middle Wisconsinan 1

Duck Point Idaho Wisconsinan 1

Anderson Gravel Pit Local Faunule Kansas Rancholabrean 1

Filmore County Minnesota Late Wisconsinan 3

Merrell Montana Middle Wisconsinan 1

Quinlan Local Fauna Oklahoma Irvingtonian 4

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Delmont Local Fauna South Dakota Blancan 1

Gassaway Fissure Tennessee Wisconsinan 1

Blanco Local Fauna Texas Blancan 1

Friesenhahn Cave Texas Late Wisconsinan 5

Gilliland Local Fauna Texas Irvingtonian 1

Laubach Cave No. 2 Texas Late Wisconsinan 1

Marmot Quarry Texas Blancan 1

Slaton Quarry Local Fauna Texas Rancholabrean 1

Dawson Loc. 9 Yukon Middle to Late Wisconsinan 6–8

Old Crow Loc. 21 Yukon Middle Wisconsinan 7, 9

Sixtymile Loc. 3 Draft Yukon Middle Wisconsinan 10, 11

400 1Graham and Lundelius 2010

401 2Woodruff 2014

402 3Widga et al. 2012

403 4Smith and Cifelli 2000

404 5Graham 1987

405 6Debicki 1983

406 7Harington 1977

407 8RawnSchatzinger and Collins 1981

408 9Harington 1989

409 10 Harington 1997

410 11 Harington 2003

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411 Figure Captions

412 Figure 1. Distribution of Homotherium serum in Canada and the United States (for locality

413 information see Table 1).

414 Figure 2. Root etching on the upper right canine, lateral aspect. Scale bar = 10mm.

415 Figure 3. Position of tooth fragments within the dentition of H. serum (shaded area represents

416 Wally’s Beach specimen).

417 Figure 4. Serrations on the posterior aspect of the left upper canine. Scale bar = 10mm.

418 Figure 5. Upper canines, medial aspect. A, left canine (DhPg83836). B, right canine (DhPg8

419 3837). Scale bars = 10mm. 420 Figure 6. Identifiable incisor fragments.Draft A, upper first or second incisor, anterior aspect (DhPg 421 83838). B, lower right second incisor, medial/lingual aspect (DhPg83839). C, lower left

422 second incisor, lateral/lingual aspect (DhPg83840). D, upper incisor, lateral or medial aspect

423 (DhPg83841). Scale bars = 10mm.

424 Figure 7. Lower left canine (DhPg83843). A, anterior aspect. B, posterior aspect. Scale bars =

425 10mm.

426 Figure 8. Metacone of the upper left fourth premolar (DhPg83844). A, lingual aspect. B,

427 buccal aspect. Scale bars = 10mm.

428 Figure 9. Paracone of the lower right first molar (DhPg83845). A, lingual aspect. B, buccal

429 aspect. Scale bars = 10mm.

430 Figure 10. Root fragment, possibly from a molar or premolar (DhPg83846). Scale bar = 10mm.

431 Figure 11. Polish on the anterior aspect of the right upper canine. Scale bar = 10mm.

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432 Figures

433 Figure 1

Draft

434

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435 Figure 2

436

Draft

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437 Figure 3

Draft

438

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439 Figure 4

440

Draft

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441 Figure 5

442 443

Draft

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444 Figure 6

Draft 445

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446 Figure 7

447

Draft

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448 Figure 8

449

Draft

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450 Figure 9

451

A Draft B

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452 Figure 10

Draft

453

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454 Figure 11

455

Draft

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