Palaeastacus sussexiensis ( Mantell, 1824 )

Devillez, Julien, Charbonnier, Sylvain, Hyžný, Matúš & Leroy, Lucien, 2016, Review of the Early Cretaceous erymid lobsters (Crustacea: Decapoda) from the Western Tethys, Geodiversitas 38 (4), pp. 515-541 : 526-528

Palaeastacus sussexiensis ( Mantell, 1824)

( Figs 6 ; 7 A-E)

Astacus sussexiensis Mantell, 1824: 11 , pl. 29, fig. 15; 1833: 124, 373, 379, fig. 2; 1844: 238, fig.4. — Quenstedt 1852: 269; 1885: 411, fig. 129.

Enoploclytia imagei M’Coy, 1849: 331 ; 1854: 136. — Reuss 1854: 3. — Woodward 1877: 9. — Glaessner 1929: 146. — Schweitzer et al. 2010: 22.

Enoploclytia brevimana M’Coy, 1849: 332 ; 1854: 137. — Reuss 1854: 3. — Bronn 1852: 352. — Woodward 1877: 9. — Schweitzer et al. 2010: 22.

Palaeastacus dixoni Bell, 1850: 344 , 345, pl. 38, figs 1-5. — Geinitz 1875: 292. — Schlüter 1879: 602. — Schweitzer et al. 2010: 25.

Hoploparia scabra Bell, 1863: 28 , pl. 7, fig. 3-7. — Glaessner 1929: 221.

Phlyctisoma granulatum Bell, 1863: 36 , pl. 11, fig. 9-10. — Glaessner 1929: 314. — Monaco & Garassino 2000: 297.

Palaeastacus plauensis Geinitz, 1875: 291 , pl. 64, fig. 9.

Astacus leachii (pars) – Mantell 1822: 223, pl. 30, fig. 3.

Glyphea sussexiensis – Roemer 1841: 105.

Enoploclytia sussexiensis – Morris 1854: 108. — Willet 1871: 42-43. — Woodward 1877: 10; 1878: 377, pl. 38, figs 1-4. — Schlüter 1879: 602. — Van Straelen 1936: 12.

Palaeastacus sussexiensis – Glaessner 1929: 200. — Rathbun 1935: 23. — Förster 1966: 133, fig.24, pl.17, fig.6.—Aguirre-Urreta& Ramos 1981: 609, fig. 4c; 1989: 510, figs 8-10 — Morris 1987: 196, pl. 42, figs 4-5. — Wittler 1998: 18, fig. 5. — Garassino & Schweigert 2006: 11. — Schweitzer et al. 2010: 26. — Karasawa et al. 2013: 79, 102.

Palaeastacus? plauensis – Glaessner 1929: 290.

Enoploclytia dixoni – Woods 1930: 83, pl. 23, figs 9-12, pl. 24, figs 1-3. — Van Straelen 1936: 11.

Enoploclytia (Palaeastacus) sussexiensis – Mertin 1941: 161, fig. 4a.

Enoploclytia (Palaeastacus) imagei – Roberts 1962: 164.

Palaeastacus scaber – Förster 1966: 132, fig. 26, pl. 17, fig. 7-9. — Schweitzer & Feldmann 2001: 174. — Garassino & Schweigert 2006: 11. — Schweitzer et al. 2010: 25. — Karasawa et al. 2013: 102.

Palaeastacus cf. sussexiensis – Taylor 1979: 30, fig. 10e, pl. 4 fig. d-f.

Palaeastacus? plavensis – Schweitzer et al. 2010: 25.

Pustulina granulata – Schweitzer et al. 2010: 26.

Pustulina scabra – Schweitzer et al. 2010: 26.

TYPE MATERIAL. — According to Morris (1980), Förster (1966: 134) selected as a lectotype of Palaeastacus sussexiensis one of the syntypes of Palaeastacus dixoni Bell, 1850 ; obviously the selection should have been made on the original type material of Mantell (1824). So the specimen NHMUK 5601, from the original type material of Mantell, is herein designated as lectotype. Thirteen paralectotypes are also considered: NHMUK 5024, 5584, 5586, 5589, 5600, 5602, 5608, 5613, 5618, 5624, 5626, 5629, 10760.

TYPE LOCALITY. — Sussex, United Kingdom (precise type locality not indicated on the original labels).

TYPE AGE. — Cenomanian, Late Cretaceous.

DESCRIPTION

Carapace sub-cylindrical (lectotype: CL = 82 mm, CH = 41 mm); long spiny rostrum; fusiform and tuberculate intercalated plate; ridge on dorsal margin of branchial region; deep cervical groove, joined to dorsal margin and to antennal groove; deep antennal groove; short gastroorbital groove originating as a slight median inflexion of cervical groove; postcervical and branchiocardiac grooves subparallel; dorsally deep, sinuous postcervical groove, shallowing ventrally, not joined to dorsal margin, joined to hepatic groove; narrow branchiocardiac groove, strongly inclined, shallower than postcervical groove, not joined to dorsal margin, joined to hepatic groove; concavo-convex, narrow hepatic groove, joined to cervical groove; inflated ω bulge; flat χ area; deep inferior groove, joined to hepatic groove; carapace densely covered with rounded tubercles in branchial region and widely spaced coarse tubercles in gastric, hepatic and cephalic regions; row of coarse tubercles parallel to dorsal margin in cardiac and branchial regions; two oblique rows of coarse tubercles in cardiac region; two rows of tubercles parallel to the intercalated plate in gastric region; pleonal somites with terga ornamented by three pairs of strong dorsal spines and by rounded, coarse tubercles on the remaining surface; subtriangular pleura, with pointed ventral margin, ornamented with strong spines; telson with rounded extremity; telson with longitudinal median ridge flanked by two wide lateral ridges interrupted at telson mid-length; telson covered with coarse rounded tubercles; uropods as long as telson, covered by tubercles; uropodal endopod with longitudinal carina; uropodal exopod with diaeresis; chelate P1; short, trapezoidal, slightly globose P1 propodus, with two divergent rows of spines on ventral and dorsal surfaces; inner margin with strong spines; wide fingers, slightly longer than propodus; occlusal margins with short, spaced teeth; index wider than dactylus; dactylus adorned with spines; spiny P1 carpus and merus.

DISCUSSION

The original type material of Astacus leachii Mantell, 1822 was heterogeneous and composed of a set of P1 chelae and fragments of carapaces. Among these chelae, Mantell (1824) distinguished Astacus sussexiensis (short, spiny chelae with short fingers) from A. leachii (chelae with long fingers). Later, numerous authors regarded A. sussexiensis as a representative of Enoploclytia ( Morris 1854; Willet 1871; Woodward 1877, 1878; Van Straelen 1936; Mertin 1941). Bell (1850) described Palaeastacus dixoni which type material is composed of an isolated pair of P1 chelae, some P1 chelae connected with carapaces and a complete carapace preserved in connection with a complete pleon ( Fig. 6F ; Bell 1850: pl. 38, fig. 1). The latter specimen was designated by Woods (1930) as the lectotype of Enoploclytia dixoni ( Bell, 1850) . Woods (1930) also considered A. sussexiensis , Enoploclytia brevimana M’Coy, 1849 , Hoploparia scabra Bell, 1863 ( Fig. 7B, C ), and Phlyctisoma granulatum Bell, 1863 ( Fig. 7D, E ) as junior synonyms of E. dixoni . Förster (1966), recently followed by Karasawa et al. (2013), distinguished Palaeastacus sussexiensis ( Mantell, 1824) (including as synonyms: A. sussexiensis , Enoploclytia imagei M’Coy, 1849 , E. brevimana , P. dixoni and Palaeastacus plauensis Geinitz, 1875 ) and Palaeastacus scaber ( Bell, 1863) (including as synonyms: H. scabra and P. granulatum ). Lastly Schweitzer et al. (2010) re-established the distinction between E. brevimana , E. imagei , P. granulatum , P. plauensis , P. dixoni , P. scaber and P. sussexiensis .

Our re-examination of the type specimens reveals that the P1 chelae of P. sussexiensis and P. dixoni are similar (short, spiny P1 propodus with narrow dactylar bulge and bearing wide fingers). Moreover, the carapaces of P. dixoni , P. granulatum and H. scabra show the same groove pattern (nearly parallel postcervical and branchiocardiac grooves joined to hepatic groove and not joined to dorsal margin) and the same ornamentation (branchial region densely covered with tubercles; widely spaced tubercles in gastric, hepatic and cephalic regions; row of coarse tubercles parallel to dorsal margin in cardiac and branchial regions; oblique rows of coarse tubercles in cardiac region). Thus, we follow Woods (1930) and consider A. sussexiensis , P. dixoni , H. scabra and P. granulatum as a unique species: Palaeastacus sussexiensis ( Mantell, 1824) . Enoploclytia brevimana ( Fig. 6E ) and E. imagei ( Fig. 7A ) have not been figured until now. Both have spiny P1 chelipeds; short P1 propodus with short and wide fingers as P. sussexiensis . Moreover, a syntype of E. imagei includes a carapace ( Fig. 7A ) with a long rostrum, a groove pattern and an ornamentation close to P. sussexiensis . The type material of P. plauensis is an incomplete P1 propodus and fragments of wide fingers coarsely ornamented close to those of P. sussexiensis . Finally our review leads us to recognise P. dixoni , E. imagei , E. brevimana , H. scabra , P. granulatum and P. plauensis as junior synonyms of P. sussexiensis .

In addition, Palaeastacus sussexiensis ( Mantell, 1824) had a wide geographic distribution and a stratigraphic range from the Aptian to the Turonian. Indeed, this species has been reported: 1) from the Aptian of Alexander Island (Antarctic; Taylor 1979) and Patagonia ( Argentina; Aguirre-Urreta 1989); 2) the Albian of England ( Bell 1863; Woods 1930; Förster 1966); 3) the Cenomanian of England ( Bell 1850; Förster 1966; Morris 1987), Germany ( Mertin 1941) and France ( Van Straelen 1936; Förster 1966); and 4) the Turonian of England ( Mantell 1822, 1833, 1844; Morris 1987) and Germany ( Wittler 1998).

Figures

FIG. 6. — Palaeastacus sussexiensis (Mantell, 1824) from the Cretaceous of the United Kingdom: A, B, lectotype herein designated (NHMUK 5601, Mantell coll.) from the Cenomanian of Sussex: right side of carapace with parts of pereiopods (A) and line drawing of carapace (B); C, D, paralectotype NHMUK 5624 (Mantell coll.) from the Late Cretaceous of Southerham: dorsal view of left P1 chela (C) and line drawing (D); E, syntype SM B8885 of Enoploclytia brevimana M’Coy, 1849 from the Cenomanian of Cherryhinton: dorsal view of left P1 chela; F, lectotype BM 007750 (Willet coll.) of Palaeastacus dixoni Bell,1850 from the Cenomanian of Glynde: dorsal view. Abbreviations, a, branchiocardiac groove; b, antennal groove; b1, hepatic groove; c, postcervical groove; d, gastro-orbital groove; e1e, cervical groove; i, inferior groove. Photographs and line drawings: J. Devillez. Scale bars: A-E, 10 mm, F, 20 mm.

FIG. 7. — Palaeastacus sussexiensis (Mantell, 1824) from the United Kingdom (A-E) and Palaeastacus loryi (Van Straelen, 1923) n. comb. from France (F, G): A, syntype SM B8892 of Enoploclytia imagei M’Coy, 1849 from the Cenomanian of Maidstone: part of carapace with right P1 chelae; B, C, lectotype NHMUK 41938 of Hoploparia scabra Bell, 1863 from the Albian of Folkestone: right lateral view (B) and line drawing (C); D, E, syntype SM B22448 (Carter coll.) of Phlyctisoma granulatum Bell, 1863 from the Albian of Cambridge: right lateral view (D) and line drawing (E); F, G, holotype (probably lost) of Palaeastacus loryi from the Valanginian of Malleval: original figure of carapace by Van Straelen (1936: pl. 1, fig. 6) (C) and line drawing (D). Abbreviations: a, branchiocardiac groove; b, antennal groove; b1, hepatic groove; c, postcervical groove; d, gastro-orbital groove; e1e, cervical groove; i, inferior groove; ω, attachment site of mandibular muscle. Photographs and line drawings: J. Devillez. Scale bars: A, 20 mm, B-G, 10 mm.