652
Journal of Paleontology 91(4):643–661
Table 2. Ichnogenera diagnoses. According to the last ichnotaxonomic discussions, only diagnoses of those broadly accepted ichnogenera have been included. ICHNOTAXA
Ichnogenus DIAGNOSES ECHINOID TRACES Bioturbation Bichordites
Plaziat and Mahmoudi, 1988 meniscate, complex burrow with a central bilobate core.” (emended by Demírcan and Uchman, 2012)
Cardioichnus Smith and Crimes, 1983 Scolicia de Quatrefagues, 1849 “Predominantly horizontal, cylindrical or subcylindrical, straight to winding, unbranched,
“Resting trace preserved as positive features sandstone soles. Ovate to sub-quadrate in outline consisting of two curved lateral lobes which merge anteriorly and may be faintly marked with fine, impersistent lineations, and a central depressed, V-shaped area sometimes surrounded by a weak rim. The central region is covered in strong prod marks. May be continuous with the repichnia Scolicia or isolate.” (after Mayoral and Muñiz, 2001)
“Variable and commonly selectively preserved, simple, winding, meandering to coiling bilobate or trilobate back-filled trace fossil with two parallel, locally discontinuous, sediment strings along their underside. Cross-section approximately oval in outline. Underside between the strings flat or slightly convex up. Backfill laminae composite, may be biserial on the upper side. Washed-out variants preserved as hypichnial bilobate ridges.” (emended by Uchman, 1998)
Bioerosion Circolites
Mikuláš, 1992 Ericichnus
Santos et al., 2015
Bromley, 1975 Planavolites
Gnathichnus Mikuláš, 1992
HOLOTHURIAN TRACES
Bioturbation Artichnus
“Shallow, roughly circular pits in carbonate substrates. The peripheral edge of the pit is sharp, the walls of the pit are perpendicular to or overhanging the substrate surface. The edges of some pits are undulated, the pit bottom is moderately concave.” (after Mikuláš, 1992)
“Grooves relatively deep, with sinuous pathway, with a width fairly uniform along its trajectory. Often they show points where the path is bifurcated reaching, in these cases, a width which can be the double of the normal diameter. Inside there are a number of lines or marks, more or less pronounced, with a concavity oriented in the animal’s direction of movement.” (Santos et al., 2015)
“Biogenic sculpture consisting of grooves, pits, and scratches on hard substrate.” (Bromley, 1975)
“Flat, considerably large depressions of irregular oval or very elongated form, occurring on the surface of a firm limestone substrate, The outline is undulated, sometimes lobate, even with
pointed prejections. The bottom is rounded, more or less smooth, in some individuals with flat protrusions or depressions. The walls are usually steep, perpendicular or slightly overhanging; borings often occur in large groups.” (after Mikuláš, 1992)
Zhang et al., 2008
“Wide J-shaped, generally cylindrical structure, turbinate in the distal part towards the blind termination, and tapering in the proximal part. The proximal part comprises a steeply upward bent, narrowing shaft, tapering upwards. The burrow lumen lies within a thickly laminated, short, vertical, mostly retrusive spreite, which is best developed in the lower part of the structure. The outer margin is longitudinally striated in some specimens.” (Zhang et al., 2008)
ASTEROZOAN TRACES
Bioturbation Arcichnus
von Schlotheim, 1820 Biformites
Sutcliffe, 1997 Asteriacites
Maerz et al., 1976
Linck, 1949 Pentichnus
CRINOID TRACES Bioturbation Krinodromos MITRATE TRACES Bioturbation Vadichnites Neto de Carvalho et al., 2016 Rahman et al., 2009
“Horizontally oriented horseshoe- to U-shaped tracks opening in a constant direction.” (Sutcliffe, 1997)
“Star-shaped, commonly pentamerous impressions with arms grading from a central area and continuously tapering distally.” (Knaust and Neumann, 2016 after Seilacher, 1953)
“Narrow, bedding-parallel vermiform, hook-shaped and sinuous imprints with slightly tapering terminations, unbranched or with secondary successive branching, with or without ornament.” (emended by Knaust and Neumann, 2016)
“Subcylindrical to subconical burrows with poorly to well-developed pentameral symetry.” (emended by Knaust and Neumann, 2016)
“Trails composed of a narrow and flat central area with an irregular winding furrow, or almost no sedimentary disruption, bordered by shallow and large grooves externally limited by irregular piles of sediment.” (Neto de Carvalho et al., 2016)
“Horizontal straight to curved traces characterized by low relief protuberances or closely spaced fine ridges transversely oriented across a shallow groove.” (Rahman et al., 2009)
boring (i.e., removal of stereom), on echinoderms (mainly crinoids; Fig. 6.8) (see also, Brett, 1978; Eckert, 1988; Feldman and Brett, 1998; Wilson et al., 2014; Donovan, 2015; Vinn et al., 2015). Brett (1985) proposed parasites or commensal filter feeders as possible tracemakers. The stratigraphic record of Tremichnus ranges from the Middle Ordovician to the Middle Jurassic. In addition, an important ichnotaxonomic discussion has been developed around this ichnogenus together with Oichnus Bromley, 1981, Sedilichnus Müller, 1977 and Fossichnus Nielsen, Nielsen and Bromley, 2003. Pickerill and
Donovan (1998) regarded Tremichnus as junior synonym of Oichnus. Bromley (2004) followed this synonymy and in turn considered Sedilichnus as their possible senior synonym; nevertheless Bromley (2004) kept using Oichnus. Subsequently, Zonneveld and Gingras (2014) formalized all these proposals and established Tremichnus, Oichnus and Fossichnus as junior synonyms of Sedilichnus. Finally, Wisshak et al. (2015) noted that Sedilichnus is an atelonym and has no nomenclatural value. Consequently, they retained Oichnus and Tremichnus as valid ichnogenera and pointed out their
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 |
Page 277 |
Page 278 |
Page 279 |
Page 280 |
Page 281 |
Page 282 |
Page 283 |
Page 284 |
Page 285 |
Page 286 |
Page 287 |
Page 288
