Rook et al.—Pliocene Canidae from Sighnaghi, Georgia
MG 29-2013/606 right hemimandible with c1; MG 29-2013/ 820 left hemimandible with p2–m3; MG 29-2013/612 (K236) c/C; MG 29-2013/613 incisors, c1 and p1; MG 29-2013/605 (K256) left p4; MG 29-2013/611 right m2; MG 29-2013/593 vertebral fragments (K502 and K504); MG 29-2013/458 left humerus (K251), ulna, and radius (K250);MG29-2013/594 left humerus (K241), ulna (K239), radius (K245), metacarpals II–V, and I phalanx; MG 29-2013/596 (K232) left radius; MG 29-2013/602 (K503) right pelvis; MG 29-2013/598 (K501) left femur; MG 29-2013/600 (K226) right femur; MG 29-2013/599 (K820) right tibia; MG 29-2013/601 left calcaneum; MG 29-2013/597 (K253) metapodial fragments and phalanges; MG 29-2013/460 (K254) left phalanges.
Description.—The cranium is elongated rostro-caudally, with a long muzzle and long nasals, which end beyond the maxillo- frontal suture. In lateral view, the cranial profile is rather straight on the nasals and frontals aspects and becomes arched only in the caudal portion of the braincase (e.g., Fig. 1). The frontals show a depression on the midline of the cranium at the level of the postorbital processes. These are expanded laterally and are well developed. The postorbital constriction is short and marked, so that the frontal sinuses are slightly developed and have a flat external surface. The braincase is rather inflated and globular in shape. The sagittal crest is poorly developed, with some specimens (e.g., K219) showing long parasagittal crests that fuse distally from the fronto-parietal suture and others (e.g., K215) having parasagittal crests that fuse at the level of the fronto-parietal suture. In caudal view, the supraoccipital shield is “bell”-shaped, with prominent borders and a marked knob- like expansion at level of the mastoid process. In lateral view, the inion does not overhang the condyles. The tympanic bullae are fairly inflated. The paraoccipital processes are not fused with the bulla and are posteriorly directed. Unfortunately, the only juvenile cranium (MG 29-2013/
455 [K234]) is too poorly preserved to assess correctly its morphological features. It appears to be low in dorso-ventral height, in lateral view. In dorsal view, the braincase is inflated and the postorbital constriction seems rather marked. The incisors possess a main cusp with two small accessory
cuspids on both sides of the main cusp. I3 is slightly larger compared to I1-I2, but still maintains an incisor morphology (not canine form) and does not possess the basal cingulum.C1 is very thin and its crown is not very high. Short diastemata are visible between upper premolars. The premolars do not show distal accessory cuspids. The P3 possesses a tiny cuspid on the distal cingulum. The P4 is rather slender and elongated mesio- distally. The protocone is small, pointy, and anteriorly positioned compared to the mesial margin of the tooth. Some specimens (e.g., K217) seem to show a parastyle in the mesio- lingual portion of the P4. The paracone is high and the metastylar blade is sharp and short. There is a strong lingual cingulum. The M1 is subquadrate in shape. It possesses an equally developed paracone and metacone, bounded buccally by a strong cingulum. There is a prominent parastyle. The M1 shows a large trigon basin, a prominent protocone, a large protoconule and a low, but well-developed, metaconule. Lingually, there is a cingular hypocone. On the mesial side, there is a strong cingulum that forms a bulging of enamel in the
1261
shape of a small cuspid. The M2 is large mesio-distally and possesses an equal-sized paracone and metacone, a protocone, a protoconule, and a small metaconule. There is a lingual cingulum. The mandible is long and rather shallow, with a straight ventral margin. In the angular region, the subangular lobe is well developed and high-angled, in lateral view. The angular process is large and stout. The masseteric fossa is deep. MG 29-2013/590 (K235) possesses dm1 with a broken
paraconid and a pointy and high protoconid; its talonid basin is wide and bounded by an entoconid, hypoconid, and a prominent distal accessory cuspulid. Of the lower premolars, only p4 possesses a distal accessory cuspulid, although there is a cuspulid-like distal cingulid on p3 and p4. The p4 also possesses a slightly visible mesial cingulid. The m1 paraconid is short, lower than the p4 protoconid. The protoconid is high, whereas the large metaconid is individualized from the protoconid, slight lingually, and distally positioned compared to the distal margin of the protoconid. In the talonid, the hypoconid is larger based compared to the entoconid, but not sensibly higher. In K4177, there are accessory cuspulids on the talonid (e.g., mesially to the entoconid or distally to the hypoconid). The m2 is enlarged in the mesial portion, especially with a great expansion of the mesio-buccal cingulid. The protoconid and the metaconid are equal in size. Distal to the protoconid is a hypoconid with accessory cuspulids on both mesial and lingual sides. The m3 possesses two large cuspulids and a distal accessory one. The postcranial remains from Kvabebi are generally in a
bad state of preservation, so the features of the various bones are difficult to discern. MG 29-2013/458 (K251) and MG 29-2013/ 594 (K241) are the distal epiphysis of the left humeri (Bd: 21.0 mm and 22.2mm, respectively), showing a prominent medial epicondyle compared to the lateral one; the trochlea has a sharp ridge. MG 29-2013/594 (K239) is fragmentary ulna (BPC: 8.6mm) that possesses a faint lateral coronoid process, whereas the medial one is round and expanded. The ulna ofMG 29-2013/458 (K251) has DPA = 18.5mm and BPC = 9.6mm. Radius fragments MG 29-2013/458 (K251) and MG 29-2013/ 596 (K232) have Bp = 11.8mm and 13.5mm, and Bd = 9.0mm and 9.0mm. Two femur fragments are recorded, MG 29-2013/598 (K501) and MG 29-2013/600(K226); the former (Bp = 23.3mm and DC = 12.3mm) shows a large head departing from a short neck. The greater trochanter is high and slender, with a deep trochanteric fossa. The lesser trochanter of MG 29-2013/598 (K501) is prominent. In the distal epiphysis, the lateral condyle is considerably larger than the medial, which is also thinner. There is no proximal epiphysis of the tibiae preserved, but only a diaphysis with the distal portion MG 29-2013/599 (K820), with Bd = 17.4mm and Dd = 11.9 mm. The calcaneum MG 29-2013/601 is rather compressed mediolaterally, so that the sustentalum tali is very reduced (GL = 31.9 mm). MG 29-2013/594 and MG 29-2013/597 are metapodial fragments with associated phalanges. MG 29-2013/ 594 measures are: Mc II—GL = 39.6mm; Bp = 4.7mm; Dp = 7.6mm; Mc III—GL = 47.4mm; Bp = 6.3mm; Dp = 72mm;Mc IV—GL = 46.5mm; Bp = 4.1mm; Dp = 6.5mm; Mc V—GL = 38.6mm; Bp = 7.5mm; Dp = 6.3mm.
Remarks.—Most of the Canidae specimens of Kvabebi are ascribable to the genus Nyctereutes based on the size and
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116 |
Page 117 |
Page 118 |
Page 119 |
Page 120 |
Page 121 |
Page 122 |
Page 123 |
Page 124 |
Page 125 |
Page 126 |
Page 127 |
Page 128 |
Page 129 |
Page 130 |
Page 131 |
Page 132 |
Page 133 |
Page 134 |
Page 135 |
Page 136 |
Page 137 |
Page 138 |
Page 139 |
Page 140 |
Page 141 |
Page 142 |
Page 143 |
Page 144 |
Page 145 |
Page 146 |
Page 147 |
Page 148 |
Page 149 |
Page 150 |
Page 151 |
Page 152 |
Page 153 |
Page 154 |
Page 155 |
Page 156 |
Page 157 |
Page 158 |
Page 159 |
Page 160 |
Page 161 |
Page 162 |
Page 163 |
Page 164 |
Page 165 |
Page 166 |
Page 167 |
Page 168 |
Page 169 |
Page 170 |
Page 171 |
Page 172 |
Page 173 |
Page 174 |
Page 175 |
Page 176 |
Page 177 |
Page 178 |
Page 179 |
Page 180 |
Page 181 |
Page 182 |
Page 183 |
Page 184 |
Page 185 |
Page 186 |
Page 187 |
Page 188 |
Page 189 |
Page 190 |
Page 191 |
Page 192 |
Page 193 |
Page 194 |
Page 195 |
Page 196 |
Page 197 |
Page 198 |
Page 199 |
Page 200 |
Page 201 |
Page 202 |
Page 203 |
Page 204 |
Page 205 |
Page 206 |
Page 207 |
Page 208 |
Page 209 |
Page 210 |
Page 211 |
Page 212 |
Page 213 |
Page 214 |
Page 215 |
Page 216 |
Page 217 |
Page 218 |
Page 219 |
Page 220 |
Page 221 |
Page 222 |
Page 223 |
Page 224 |
Page 225 |
Page 226 |
Page 227 |
Page 228 |
Page 229 |
Page 230 |
Page 231 |
Page 232 |
Page 233 |
Page 234 |
Page 235 |
Page 236 |
Page 237 |
Page 238 |
Page 239 |
Page 240 |
Page 241 |
Page 242 |
Page 243 |
Page 244 |
Page 245 |
Page 246 |
Page 247 |
Page 248 |
Page 249 |
Page 250 |
Page 251 |
Page 252 |
Page 253 |
Page 254 |
Page 255 |
Page 256 |
Page 257 |
Page 258 |
Page 259 |
Page 260 |
Page 261 |
Page 262 |
Page 263 |
Page 264 |
Page 265 |
Page 266 |
Page 267 |
Page 268 |
Page 269 |
Page 270 |
Page 271 |
Page 272 |
Page 273 |
Page 274 |
Page 275 |
Page 276
