814
Journal of Paleontology 92(5):804–837
México from deposits that both Woodring (1966, 1970) and Beu (2009) reported as middle Miocene in age. An artificial cast (PRI 70566) of the type specimen (IGM 170; Fig. 4.1, 4.2) was kindly provided by Dr. Perrilliat at the Colección Nacional de
Paleontología, Instituto de Geología. Woodring (1970) was the first to apply the name C. burckhardti to material from the Gatun Formation, and his circumscription of the material he examined from the Gatun Formation is consistent with the features of IGM 170. Conasprella burckhardti was the second most commonly collected species at UF locality YN020. Woodring (1970) treated Conus harrisi Olsson, 1922
the eastern Pacific species Conasprella (Ximeniconus) tornata (Sowerby I, 1833), which ranges from Baja California, Mexico to Peru (for a detailed overview of this species, see Tenorio et al., 2012). Both taxa have similar shell shapes, multispiral protoconchs, sutural ramps lacking spiral ornamentation, and moderately deep subsutural flexures. The coloration patterns of both taxa are also consistent: a primary pattern of axial blotches overlain by spiral rows of dots or dashes.Anotable difference is that tubercles are present on the first postnuclear whorl of C. burckhardti, but are reportedly absent from C. tornata (Tenorio et al., 2012). Among fossil species, C. burckhardti is similar to the recently described species C. ageri Hendricks, 2015 from the lower Pliocene Gurabo Formation of the Dominican Republic. Like C. tornata, C. ageri also lacks tubercles on its early postnuclear whorls. Shells ofC. ageri also typically have lowervalues ofPMD (0.83–0.89, x=0:86; Hendricks, 2015) than C. burckhardti (0.86–0.96, x=0:91), corresponding with the fact that they are usually widest below the shoulder, while specimens of C. burckhardti are usually widest at the shoulder. Finally, shells of C. burckhardti usually have higher spires (RSH 0.20–0.31, x=0:25) than shells ofC. ageri (RSH 0.18–0.23, x 0.20; Hendricks, 2015). Presuming, as suggested here, that C. burckhardti is closely related to extant C. tornata, the occurrence of the fossil taxon in the lower Gatun Formation provides a useful minimum age of origination for the subgenus Ximeniconus at ca. 10 Ma.
Genus Conus Linnaeus, 1758
Type species.—Conus marmoreus Linnaeus, 1758 by sub- sequent designation (Children, 1823). Species is extant and occurs in the Indo-Pacific.
Remarks.—Conus was recently subdivided by Puillandre et al. (2014, 2015) into 44 extant subgenera. Species of modern western Atlantic and eastern Pacific species belong, respec- tively, to 11 and 12 of these clades. The genus includes
(Fig. 4.5) as a subspecies of Conus burckhardti. The specimen (USNM 645754; Fig. 4.4) figured by Woodring (1970) differs from typical C. burckhardti in the very narrow width of its shell (RD 0.44), but it is otherwise consistent in shell characteristics with other C. burckhardti. Conasprella burckhardti harrisi is thus treated here simply as C. burckhardti. While Woodring (1970) only reported C. burckhardti burckhardti from the middle and upper Gatun Formation, most of the shells found at UF locality YN020 (lower Gatun Formation) are more consistent with this wider form than they are with the narrower Conasprella burckhardti harrisi morphology. Bothmorphologies span the Gatun Formation. Among extant taxa, Conasprella burckhardti is most similar to
Figure 5. Specimens from the Gatun Formation questionably assigned to Conus symmetricus Sowerby I, 1850: (1, 3) photographed under regular light; (2) photographed under UV light. (1, 2) USNM 645747, specimen figured by Woodring (1970, pl. 57, figs. 13, 14), Panama Canal Zone, Woodring locality 155a, middle Gatun Formation, SL 20.3mm; (3) UF 271037, UF locality YN020 (lower Gatun Formation), SL 21.0mm. Scale bar to left of (1)is 1 cm and pertains to all specimens.
vermivores, molluscivores, and piscivores, though only two tropical American species, C. purpurascens Sowerby I, 1833 (eastern Pacific) and C. ermineus Born, 1778 (western Atlantic), eat fish (e.g., Puillandre et al., 2014).
Conus symmetricus? Sowerby I, 1850 Figure 5.1–5.3
1850 Conus symmetricus Sowerby I, p. 44, pl. 9, fig. 1. 1917 Conus symmetricus; Maury, pl. 7, fig. 7, 7a. 1921 Conus symmetricus; Pilsbry, pl. 20, fig. 2, 2a, 2b.
1961 Conus (Leptoconus) symmetricus;Pflug, p. 63, pl. 18, figs. 1–11.
2009 Purpuriconus symmetricus (Sowerby I); Tucker and Tenorio, p. 116.
2015 Conus symmetricus; Hendricks, p. 22, fig. 9a–g.
Lectotype.—NHMUK PI BM G 83969 (designated by Pflug, 1961); label reports specimen from the Miocene of the Yaque River, St. Domingo.
Occurrence.—Conus symmetricus is a very common taxon in some Neogene assemblages in the Dominican Republic (see Pflug, 1961; Hendricks, 2015). Its occurrence in the Gatun Formation of Panama is regarded as tentative (see below) and its occurrence at UF locality YN020 is considered questionable.
Materials.—USNM645747 (one specimen, figured by Woodring, 1970; Fig. 5.1, 5.2); UF 271037 (one specimen, Fig. 5.3).
Remarks.—On the basis of two specimens from the middle Gatun Formation (one of which is USNM 645747; Fig. 5.1, 5.2), Woodring (1970, p. 353) declared a “first unequivocal record for” Conus symmetricus “beyond the Dominican Republic, where it is abundant in the Gurabo Formation.” While USNM 645747 appears consistent in shell form with C. symmetricus from the Dominican Republic, its coloration pattern is different. Hendricks (2015, p. 25) noted that specimens of C. symmetricus from the Dominican Republic “show a wide range of variability in coloration pattern,” which
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
