618


Journal of Paleontology 92(4):611–633


Figure 8. Comparisons of H. comalensis with H. knowltoni.(1) Distance of umbo from anterior margin versus valve length in millimeters. (2) Cross plot of valve height to thickness. (3) Cross plot of ratio of height to thickness versus ratio of umbo distance to height. The area of H. comalensis is separate from that of H. knowltoni. The outlier specimen is from the Comanche Peak Formation NPL44903. (4) Left lateral and dorsal outlines of H. comalensis illustrated by Whitney (1937, pl. 13, figs. 3, 4). (5) Left lateral and dorsal outlines of H. knowltoni holotype USNM145644. Scale bars=1 cm; dashed line marks the commissure; arrows indicate beaks.


Cohort Cardiomorphi Férussac, 1822 in Férussac 1821–1822 Subcohort Cardioni Férussac, 1822 in Férussac 1821–1822 Infrasubcohort Cardiidia Férussac, 1822 in Férussac 1821–1822 Megaorder Poromyata Ridewood, 1903 Order Poromyida Ridewood, 1903 Superfamily Poromyoidea Dall, 1886


Remarks.—This superfamily is composed of two families, Poromyidae Dall (1886) and Cetoconchidae Ridewood (1903), according to Carter et al. (2011).


Family Poromyidae Dall, 1886


Remarks.—Poromyidae genera are large, rounded to quadrate, most with radial costae, external ligament without a lithodesma, and at least one cardinal tooth in one valve (Keen in Newell, 1969). Modern Poromyidae are deep-water infaunal carnivores (Morton, 1981).


Genus Liopistha Meek, 1864


Type species.—Cardium elegantulum Roemer, 1852, p. 48–49, pl. 6, figs. 5a–c.


Diagnosis.—Features of the family.


Occurrence.—Early to Late Cretaceous. Subgenus Sergipemya Ayoub-Hannaa et al., 2015 Liopistha (Sergepimya) alta (Roemer, 1852)


Figure 11.5–11.8


1852 Homomya alta Roemer, p. 45, pl. 6, fig. 11. 1890 Homomya alta; Cragin, p. 76. 1895 Homomya alta; Cragin, p. 360. 1928 Homomya alta; Adkins, p. 141.


2002 Psilomya alta; Akers and Akers, p. 388, p. 389, fig. 372.


2015 Liopistha (Sergipemya) alta; Ayoub-Hannaa et al., p. 58.


Holotype.—STIPB-Roemer-79, Steinmann-Institut, Paläonto- logie, Geologisch-paleontologische Institute, University of Bonn.


Diagnosis.—Tall triangular shell, anterior margin truncated, posterior margin rounded; ornamented by irregular concentric ridges and grooves; minute, closely spaced nodes top concentric ridges and are vertically aligned in faint radial rows; posterior gape.


Occurrence.—Roemer (1852) collected the specimen of L. alta near Fredericksburg, central Texas, and Adkins (1928) reported it in the Fredericksburg Group. Cragin (1890, 1895) reported H. alta in the basal bed of the lower upper Albian Kiowa Formation in Kiowa County, southern Kansas. This 30cm thick bed is a transgressive lag deposit that yields two ammonite species of the upper Goodland Formation in Texas: Venezoliceras acutocarinatum (Shumard, 1854) and Vene- zoliceras kiowanum (Twenhofel, 1924) (Young, 1966; Scott, 1970).


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