1126
Journal of Paleontology 91(6):1123–1147
Center (CMC-IP), Cincinnati, and Ohio State University (OSU), Columbus, Ohio. General collections are also stored in the GSC, with a number prefixed with “A” or “C” to denote the Paul Copper Collection from Anticosti Island.
Systematic paleontology Order Athyrida Boucot, Johnson and Staton, 1964
(
nom.transl. Athyridae Davidson, 1881; =Incerti ordinis Niki- forova and Rzhonsnitskaya, 1960, part; ex Athyridoidea Bou- cot, Johnson, and Staton, 1964, part)
Remarks.—Boucot et al. (1964) recognized that the family name Athyridae Phillips, 1841, used for a group of Leptaena species known at that time, was invalid because the genus Athyris M’Coy, 1844 was established later and, therefore, the family name could not have been derived from the genus Athyris. Boucot et al. (1964, 1965) accordingly assigned the authorship of the Athyridae to M’Coy (1844), but changed the family name to Athyrididae without any explanation. Later, Alvarez et al. (1980) identified the error in Boucot et al. (1964) (i.e., although M’Coy [1844] erected the genus Athyris,he assigned it to the family Delthyridae, but retained Phillips’ use of Athyridae for Leptaena and “Producta”). Alvarez et al. (1980) thereby assigned the authorship of Athyridae to David- son (1881), who was the first to include Athyris in the family Athyridae. As in Boucot et al. (1964, 1965), however, Alvarez et al. (1980) and Alvarez and Brunton (1993) recommended the use of Athyrididae instead of Athyridae. In terms of ICZN provisions, it should be noted that
Athyridae Phillips, 1841 and Athyridae Davidson, 1881 are effectively homonyms because the name was used for different genera of brachiopods. In this instance, the suppression of the senior homonym is warranted because neither Phillips (1841) norM’Coy (1844) derived the family name Athyridae from the genus Athyris (from the Greek, thyra, door, or its diminutive thyris, small opening, referring to the pedicle opening of the shell). As a result, Athyridae Davidson, 1881 becomes a valid name by default, and there is no justification to change the family name to Athyrididae, or to change the order name to Athyridida. According to ICZN (1999, Article 29.3.1.1), if the genitive singular stem of a noun ends in -id, these two letters should be elided bofore adding the family suffic -idae. An unelided form can be retained only if it has been in prevailing use. Therefore, even if the Greek word thyris is regarded as a latinized noun, and its genitive singlular stem is thyrid-, a proper family name is still Athyridae, as originally used by Phillips (1841) and Davidson (1881). Because Athyridae Davidson, 1881 is a valid family name that has been in use for over a century, we argue that its change to Athyrididae by Boucot et al. (1964) and subsequent use (Athyrididae, Athyridoidea, Athyr- idida, etc.) should be avoided. In light of the discussions above,we propose to retain the name
Athyridae (and hence Athyrida), as we have done in this study. A detailed discussion will be suitable for an ICZN Opinion note.
Family Hindellidae Schuchert, 1894
(nom. transl. Hindellinae Schuchert, 1894) Subfamily Hindellinae Schuchert, 1894
Genera assigned.—As emended in this study, the subfamily Hindellinae Schuchert, 1894 includes the genera listed below. Hindella, Davidson, 1882.—Hirnantian, Late Ordovician,
Anticosti, Canada. Cryptothyrella Cooper, 1942.—Aeronian, Llandovery,
mid-western USA. Tschatkalia Nikiforova, 1964.—Llandovery, Chatkal
Mountain Range, Siberia. Koigia Modzalevskaya, 1985.—early Rhuddanian, Esto-
nia, and Anticosti Island, Canada (simple brachidia as in Hindella).
Genera questionably assigned.—For most of the genera below, the precise nature of the jugum is not yet known, although some are superficially similar to Hindella, such as the genera from North China (Fu, 1982). Hyattidina Schuchert, 1913.—Aeronian, Llandovery,
North America; the genus has a brachidium similar to that of Hindella, and the subfamily Hyatidininae is considered a junior synonym of Hindellinae. Colongina Breivel and Breivel, 1970.—Early Devonian,
eastern slope of Urals; designated by Grunt (1986, p. 25) as a hindelline, but its brachidia are unknown; doubtful assignment considering its much younger age; possibly an atrypide. Apheathyris Fu, 1982.—Katian, Ningxia, North China
(smooth, biconvex, rectimarginate shell, brachidia unknown). Weibeia Fu, 1982.—Katian, Shaanxi, North China
(smooth shell, weak fold and sulcus, brachidia unknown). Argella Menakova and Nikiforova, 1986.—Pridoli, upper
Silurian, Zeravshan Range, Tadzhikistan; elongate smooth shell, with simple brachidia like Hindella and Hyattidina, but posterior internal structures unclear (Alvarez and Rongs, 2002). Cyclorhynchia Baranov, 1994.—Katian, Tscherkidium
Beds, Selennyakh Range, NE Siberia (jugum unknown, and requiring assessment, but with laterally directed spiralia of three whorls); Copper (2002, p. H1472) incorrectly synonymized it with the atrypoid Cyclospira, which lacks a jugum, but has medially directed spiralia, the opposite to that of Cyclorhynchia. Kellerella Nikitin and Popov in Nikitin et al.,
1996.—Anderken Formation, Dulandkara Stage (mid–late Katian), Chu-Ili, Kazakhstan; its short, disjunct jugal processes differ from those found in typical hindellides. Nikolaispira Nikitin and Popov in Nikitin et al.,
1996.—Anderken Formation, Dulandkara Stage (mid–late Katian), Chu-Ili, Kazakhstan; its short, disjunct jugum differs from that found in typical hindellides described in this study. Elkanathyris n. gen. (herein).—Jupiter Formation, Aero-
nian–Telychian, Anticosti Island.
Diagnosis (emended herein).—Smooth or gently plicate, com- monly with capillae, biconvex; small, distinct interarea, with minute deltidial plates, and apical to trans-apical foramen. Ventral valve mostly with relatively thick prismatic apical callus, deeply impressed muscle scars, and deep groove in the hinge plate. Dorsal valves with simple, arched jugum and medially aligned crura unconnected to the brachidium, with hooked terminations of the jugal blades. Laterally directed spiralia, <12 whorls. Loops, accessory lamellae, and extensions of the jugum absent.
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
