174


Journal of Paleontology 92(2):170–182 Comparison to Recent species.—Homarus americanus


and H. gammarus: the fossil specimen is clearly distinct from the American Lobster, Homarus americanus (and the extremely similar European lobster, Homarus gammarus), differing in aspects of carapace and pleon ornamentation and, especially, cutter claw shape. Homarus americanus has no hint of a ventral extension of the branchiocardiac groove. The postorbital spine seems stronger on the fossil specimen than on H. americanus. The cephalothorax of H. americanus is less granulose below the cervical groove, except for below the antennal groove, where both H. americanus and the fossil are granulose. Homarus americanus also has, below the prominence χ, a reticulate pat- tern that is absent on the fossil specimen. Homarus americanus lacks a large pore near the termination of pleura two–five (this pore is common on Hoploparia and on some modern nephropid genera, such as Nephrops, Metanephrops Jenkins, 1972, and Thymopides, but, strangely, not Homarus [nor on Nephropsis rosea Bate, 1888]). On H. americanus, on the carpus lower surface, the spine on the inner distal corner is smaller. The cutter claw of H. hungaricus n. sp. is very different


from that of H. americanus and is, by far, the easiest way to distinguish the two species. The cutter claw pollex on H. americanus is, proportionately, twice as wide as that of the fossil. The pollex on H. americanus is extremely wide, with a width/length ratio of 0.44 (width=26.17mm; length=59.81 mm) versus 0.21 on the fossil. There are no known fossil species of Homarus that have a pollex as wide as that on H. americanus. Homarus morrisi (with a broad crusher claw like that onH. americanus) has a cutter claw pollex (incomplete;


unable to compute a width/length ratio; Quayle, 1987, pl. 64, fig. 7) more closely similar to that of the fossil than to H. americanus. The manus is also shaped differently, being proportionately wider on H. americanus (e.g., 0.72; width= 34.71mm; length=48.07mm) than the fossil (0.61; width= 15mm; length=24.50mm). The dentition is also very different. The cutter claw of H. americanus has small, variably sized denticles that are cylindrical to subconical, and each is concave (crater-like) at its termination (versus the conical, pointed dentition on the fossil).


Genus Hoploparia M’Coy, 1849


Type species.—Astacus longimanus Sowerby, 1826, by sub- sequent designation of Rathbun, 1926.


Remarks.—Hoploparia was erected by M’Coy (1849) as a genus of fossil lobsters that generally resembles Homarus, but has a more sculptured (grooved, locally inflated, etc.) and ornamented carapace. In fact, the name Hoploparia (armagena) refers to the lobster’s “spiny cheeks,” the locally inflated and ornamented regions on the anteroventral sides of the cepha- lothorax. Homarus lacks these locally inflated “cheeks” and is less spiny.M’Coy’s diagnosis (1849, p. 175–176) distinguished the type species, Hoploparia longimana (Sowerby, 1826), from Homarus. Since 1849, the inclusion of more than 50 other fossil species has variously stretched and expanded the definition of Hoploparia to accommodate this or that spine, this or that car- ina, etc., to the point that Hoploparia is a genus that is difficult to characterize (Tshudy and Sorhannus, 2003).


redefined Hoploparia as follows: “Rostrum long, spinose. Postcervical groove well impressed over most of length; becomes subtler as it extends anteriorly toward cervical groove. Branchiocardiac groove (dorsally) usually present. Ventral extension of branchiocardiac groove typically extends to hepatic groove (see Tshudy, 1993, p. 463–464; Tshudy and Babcock, 1997, p. 257, for a discussion of the homologies of the branchiocardiac and postcervical grooves). The groove patterns on Triassic and Jurassic Erymidae Van Straelen, 1925 and the Jurassic chilenophoberids (now Stenochiridae Beurlen, 1928; see Karasawa et al., 2013), Chilenophoberus Chong and Förster, 1976, Palaeophoberus Glaessner, 1932, and Pseudastacus Oppel, 1861, show convincingly that the more ventrally directed branch of the postcervical groove (sensu Holthuis, 1974) is actually part of the branchiocardiac groove.


Redefinition by Tshudy (1993).—Tshudy (1993, p. 71–72)


Urogastric groove typically absent.—Cervical groove well


impressed; extends from level of orbit to junction of hepatic and antennal grooves. Median carina typically absent. Submedian carina present on a few species. Subdorsal carina present. Supraorbital spine present, typically followed by supraorbital carina. Postorbital spine typically present; gastrolateral and hepatic spine typically absent. Antennal carina absent, short, or extending to near cervical groove. Thoracic region lacks carinae. Pleonal terga unornamented, mostly unsculptured;


typically with a narrow transverse furrow along posterior margin. Pleura elongate, typically cordate, ending in a point. Telson surface with a pair of submedian ridges converging posteriorly. Telson without lateral spines, but with poster- olateral spines. Scaphocerite present. Claws typically unequal; upper and lower surfaces lacking carinae. Exoskeleton generally granulated.


Hoploparia: a wastebasket genus?.—Tshudy and


Sorhannus (2003) proposed that Hoploparia is a “wastebasket” genus, one with a broad range of variation and, in cladistic analyses, containing non-Hoploparia. They presented the following points: 1. Hoploparia has been expanded in a de facto fashion to


an extent that, today, there is so much variation among lobster species referred to Hoploparia that the genus is difficult to characterize and to code for cladistic analysis without using many polymorphic character states. Tshudy (1993) encountered this while attempting to write an emended diagnosis of the genus. His diagnosis (1993, p. 71–72; see above), by necessity, was rife with descriptions of how character states “typically” occur. Moreover, some of his other statements, such as “thoracic region lacks carinae,” are invali- dated by one or a few species (e.g., presence of thoracic carinae on Hoploparia antarctica Wilckens, 1907, and Hoploparia bearpawensis Feldmann in Feldmann, Bishop, and Kammer, 1977). 2. Hoploparia has been expanded in a de facto fashion to


an extent that, “the morphologies of some Recent genera (e.g., Eunephrops Smith, 1885 and Nephropides Manning, 1969) seem easily accommodated within the fossil genus Hoploparia” (Tshudy and Sorhannus, 2003, p. 700), and that, “if found in fossil form,”…“Nephropides and Eunephrops would very likely


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