Rosenfeldia Garassino, Teruzzi & Dalla Vecchia, 1996

Audo, Denis, Schweigert, Günter, Charbonnier, Sylvain & Haug, Joachim T., 2017, Systematic revision and palaeobiology of Rosenfeldia triasica and Rogeryon oppeli gen. et comb. nov. (Eucrustacea, Polychelida), European Journal of Taxonomy 367, pp. 1-23 : 3-4

Genus Rosenfeldia Garassino, Teruzzi & Dalla Vecchia, 1996

Rosenfeldia Garassino, Teruzzi & Dalla Vecchia, 1996: 33–41 , figs 6–10, 17–20.

Rosenfeldia – Garassino & Schweigert 2006: 30. — Ahyong 2009: 380. — De Grave et al. 2009: 23. — Schweitzer et al. 2010: 43. — Audo et al. 2014a: 464, fig. 2E; 2014c: 500; 2016: 13, figs 1h–k; 2017: 5, fig. 3M. — Feldmann et al. 2013: 3. — Audo 2016: 291, fig. 3M.

Type species

Rosenfeldia triasica Garassino, Teruzzi & Dalla Vecchia, 1996 , by monotypy.

Included species

Rosenfeldia triasica .

Original diagnosis

Subround carapace, with longitudinal median carina originating from the posterior margin; two thin carinae run parallel to the median carina; two parallel rows of tubercles are located in the median portion of the cephalic region; chela of pereiopod I with the dactylus longer than the index and bent at the distal extremity; subrectangular telson; exopodite without diaeresis.

Emended diagnosis

Subquadrate yet slightly rounded carapace (in dorsal view); inner angle of ocular incision blunt, not forming a spine; ocular incision fringed laterally by an expansion of carapace; cervical incision shallower than postcervical incision; posterolateral angle short, not projecting along pleonite 1; very rounded telson and strengthened by a media carina; third maxilliped ischium kidney-shaped; uropodal exopod not articulated (no diaeresis).

Remarks

Rosenfeldia was assigned to Eryonidae de Haan, 1841 , because (1) it did not fit in other families then described ( Coleiidae Van Straelen, 1925 , Tetrachelidae Beurlen, 1930 , Polychelidae Wood-Mason, 1874 ), and (2) based upon of its longitudinal median carina, two thin lateral carinae, elongate P1 propodus, subrectangular shape of pleonal somites and uropodal exopod without a diaeresis ( Garassino et al. 1996). This opinion was followed by Ahyong (2009), De Grave et al. (2009), Schweitzer et al. (2010) and Feldmann et al. (2013), who did not discuss further the familial assignment. Our reinvestigation questions this familial assignment. Indeed, as noted by Garassino et al. (1996), the telson of Rosenfeldia is rounded in dorsal view, contrary to that of Eryonidae , which is triangular. Other important differences include: the scaphocerite is rounded with a median carina, a disposition well known in Coleiidae , but not in Eryonidae (fusiform, without median carina); the third maxilliped ischium is kidney-shaped, once again a character well known in Coleiidae , contrary to Eryonidae , in which it is subtriangular. Garassino et al. (1996) argued that the “lack of cervical and branchiocardiac grooves” was also typical of Eryonidae , however, the cervical and postcervical grooves at least are present, although poorly preserved. In fact, these grooves occur in all Polychelida ( Fig. 2 ), but are often restricted to the median part of the carapace in Eryonidae . This is not the case in Rosenfeldia . Finally, the lack of diaeresis is a poor indicator since it is present in Coleiidae , Tetrachelidae and in Hellerocaris Van Straelen, 1925 , which was considered as being close to Polychelidae ( Audo et al. 2014c) . A diaeresis is absent (= uropodal exopod in one part) in all other polychelidan lobsters. Taking into account these characters, the assignment of Rosenfeldia to Eryonidae is equivocal, and will be tested in a future work, the phylogenetic analysis of Polychelida .

Figures

Fig. 2. Comparison of the general outline of carapaces (right sides omitted, adapted from Audo 2016 and Audo et al. 2017) of the type species of each genus of fossil Polychelida. A. Adamanteryon fourneti Audo, Schweigert, Saint Martin & Charbonnier, 2014. B. Antarcticheles antarcticus Aguirre-Urreta, Buatois, Chernoglasov & Medina 1990. C. Coleia antiqua Broderip, 1835. D. Cycleryon propinquus (Schlotheim, 1822). E. Eryon cuvieri Desmarest, 1817. F. Gabaleryon coquelae Audo, Williams, Charbonnier & Schweigert, 2017. G. Hellerocaris falloti (Van Straelen, 1923). H. Knebelia bilobata (Münster, 1839). I. Palaeopentacheles roettenbacheri (Münster, 1839). J. Palaeopolycheles longipes (Fraas, 1855). K. Proeryon hartmanni (Meyer, 1836). L. Pseudocoleia mazzolenii Garassino & Teruzzi, 1993. M. Rogeryon oppeli (Woodward, 1866) gen. et comb. nov. N. Rosenfeldia triasica Garassino, Teruzzi & Dalla Vecchia, 1996. O. Soleryon amicalis Audo, Charbonnier, Schweigert & Saint Martin, 2014. P. Tethyseryon campanicus Bravi, Garassino, Bartiromo, Audo, Charbonnier, Schweigert, Thévenard & Longobardi, 2014. Q. Tetrachela raiblana (Bronn, 1858). R. Tonneleryon schweigerti Audo, 2016. S. Tropifer laevis Gould, 1857. T. Voulteryon parvulus Audo, Schweigert, Saint Martin & Charbonnier, 2014. U. Willemoesiocaris ovalis (Van Straelen, 1923). V. Wrangelleryon perates Feldmann, Schweitzer & Haggart, 2013. Illustrations not to scale.