Zachos—Paleocene echinoids
Smith and Jeffery (2000) treated E. ovalis as a junior synonym of E. scutata Leske, 1778, which is not accepted here.
Order Spatangoida Agassiz, 1840 Family Hemiasteridae Clark, 1917
Genus Hemiaster Desor in Agassiz and Desor, 1847
Hemiaster parastatus (Morton, 1833) Figure 9.1
1833 Spatangus parastatus Morton, p. 294. 1834 Spatangus parastatus; Morton, p. 77, pl. 3, fig. 21. 1847 Hemiaster parastatus; Agassiz and Desor, p. 141. 1853– Hemiaster parastatus;d’Orbigny, p. 265, pl. 894, 1856 figs. 3, 4.
1858 Hemiaster parastatus; Desor, p. 373. 1859 Hemiaster parastatus; Gabb, p. 19. 1893 Hemiaster parastatus; Clark, p. 83, pl. 44, figs. 1a–m. 1907 Hemiaster parastatus; Weller, p. 298, pl. 15, figs. 1–3. 1915 Hemiaster parastatus; Clark in Clark and Twitchell, p. 92, pl. 48, figs. 1a–n.
1924 Hemiaster (Leymeriaster) parastatus; Lambert and Thiéry, p. 501.
1942 Hemiaster parastatus; Cooke, p. 43. 1959 Hemiaster parastatus; Cooke, p. 67, pl. 28, figs. 15–20. 2000 Hemiaster parastatus; Smith and Jeffery, p. 326.
Type.—Holotype ANSP 1487, from the Vincentown Formation, Timber Creek, New Jersey.
Description.—Medium, ovate, rounded, widest and slightly emarginate anteriorly, apex near posterior end. Apical disc posterior of center, ethmophract, four genital pores, lateral pairs closer. Anterior ambulacrum shallowly depressed, uniserial series of paired zygopores to just above peripetalous fasciole, outer pores larger than inner, separated by large tubercle or bead, interporiferous surface covered with fine granulation.
Anterior petals about three times length of posterior, broadly flaring near distal tips, nearly closed, slight anterior flexure, diverge at 90º; posterior petals short and broad, also diverge at 90º. All petals shallowly depressed, pores elongate, nearly equal, conjugate, interporiferous zones slightly wider than por- iferous. Periproct oval, vertical. Peristome is anterior third, reniform, distinctly lipped. Complete peripetalous fasciole, no lateral fasciole. Ambulacral plates are slightly reduced where crossed by the fasciole, but not pinched to the degree char- acteristic of Holanthus. Primary tubercles small aborally, larger and less dense orally; posterior paired ambulacra naked. Labrum short, contacting sternal plates.
Additional material.—USNM 29472, from the Vincentown Formation, Burlington County, New Jersey.
Occurrence.—Vincentown Formation, Timber Creek, Glouce- ster County, New Jersey (exact locality unknown). Rancocas Creek, Vincentown, Burlington County, New Jersey (UTM Zone 18, E 520,995 m, N 4,421,446 m, NAD83).
Remarks.—Description is based on the original description. Hemiaster parastatus is readily distinguished from H. stella,
1015
a sympatric hemiasterid in the Vincentown Formation, by its larger size and anterior emargination (which is not deep enough to merit the term notch).
Hemiaster stella (Morton, 1830a) Figures 9.2, 9.4, 10
1830a Spatangus stella Morton, p. 245, pl. 3, fig. 11. 1830b Spatangus stella; Morton, p. 200. 1834 Spatangus stella; Morton, p. 78, pl. 3, fig. 18. 1847 Hemiaster stella; Agassiz and Desor, p. 141. 1853– Hemiaster stella;d’Orbigny, p. 245. 1856
1858 Hemiaster stella; Desor, p. 373. 1891 Hemiaster incrassatus; Clark, p. 77. 1893 Hemiaster stella; Clark, p. 84, pl. 46, figs. 1a–d. 1907 Hemiaster stella; Weller, p. 300, pl. 16, figs. 1–4. 1915 Hemiaster stella; Clark in Clark and Twitchell, p. 93, pl. 48, figs. 2a–d.
1924 Hemiaster (Integraster) stella; Lambert and Thiéry, p. 504.
1942 Hemiaster stella; Cooke, p. 44. 1959 Hemiaster stella; Cooke, p. 67, pl. 28, figs. 10–14. 2000 ?Hemiaster stella; Smith and Jeffery, p. 323, text-fig. 134a, b, f.
2001 ?Hemiaster stella; Kroh, p. 410, figs. 25, 26, pl. 12, figs. 1–8.
Type.—Holotype ANSP 1491, from the Vincentown Formation, Timber Creek, New Jersey.
Description.—Small, ovate to nearly circular, apex near posterior end, sloping anteriorly, posterior truncated, no anterior emargination. Apical disc posterior of center, ethmophract, four genital pores, all evenly spaced. Anterior ambulacrum very shallowly depressed, narrower than petals, paired zygopores above peripetalous fasciole, pore nearly equal size, separated by wall-like bead. Petals broad and very shallowly depressed, anterior petals more than twice length of posterior, straight, anterior pair diverge at 120º, posterior pair diverge at 90º,pores elongate, nearly equal size, interporiferous zone narrower than poriferous. Periproct small, barely visible from above. Peristome in anterior third of test, semicircular, elongate, lipped. Peripetalous fasciole complete, somewhat irregular, unindented. Labrum long, expanding posteriorly, contacts asymmetric, obliquely sutured sternal plates (Fig. 10). Primary tubercles small aborally, larger and less dense orally, posterior ambulacra naked orally.
Additional material.—MMNS 5095, from the Clayton Formation, Furman, Wilcox County, Alabama.
Occurrence.—Vincentown Formation, Timber Creek, Gloucester County, New Jersey (exact locality unknown). Timber Creek, Camden County and Rancocas Creek (exact locality unknown), Vincentown, Burlington County, New Jersey (UTM Zone 18, E 520,995m, N 4,421,446m, NAD83). Clayton Formation (McBryde Member), Resource Management Services Palmyra tract, west of StateHighway 263, 2miles north of Butler-Lowndes County line, Lowndes County, Alabama. County Rd 11 near
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