Lobocarcinus sismondai ( von Meyer, 1843 )

Ossó, Àlex, Gagnaison, Cyril & Gain, Olivier, 2022, A re-appraisal of the middle-late Miocene fossil decapod crustaceans of the ‘ Faluns’ (Anjou-Touraine, France), Geodiversitas 44 (6), pp. 207-228 : 213-214

Lobocarcinus sismondai ( von Meyer, 1843)

( Fig. 4A-C )

Cancer sismondae von Meyer, 1843: 590 .

Cancer punctulatus – Desmarest 1822: 92, pl. 7, figs 3-4.

Platycarcinus antiquus – Sismonda 1846: 58-60, pl. 3, figs 1, 2. — Meneghini 1857: 528, pl. H, fig. 11.

Platycarcinus sismondai – Vinassa de Regny 1896: 124-127, pl. 2, fig. 1 a, b.

Cancer deshayesii – A. Milne-Edwards 1864: 74-76, pl. 4, figs 1, 2, pl. 5, fig. 2. — Couffon 1908: 5, pl. 2, fig. 11. — Van Straelen 1927: 87, pl. 3, fig. 2, pl. 4, figs 1, 2.

Cancer sismondai – A. Milne-Edwards 1864: 76-78, pl. 6, figs 1, 1a, pl. 7, fig. 1. — Ristori 1886: 95-99, pl. 2, fig. 1. — Varola 1981: 16-26, pl. 3, figs 5, 6, pl. 4, figs 1, 2, pl. 5, figs 1, 2, pl. 6, figs 2, 4. — Bonfiglio & Donadeo 1982: 270-291, figs 5-27, pls 33-44. — Bonfiglio 1982: 5-18, figs 1-4, pls 1-7. — Vía Boada et al. 1982: 245-254, pl.1, figs 1-3, pl. 2, figs 1, 2. — Moissette & Müller 1990: 739, 740, pl. 1, fig. 1, pl. 2, figs 1, 2. — Beschin & Santi 1997: 13, fig. 2, pl. 1, figs 1, 2. — Garassino & Fornaciari 2000: 29, fig. 1.

Lobocarcinus sismondai – Reuss 1858: 41, pl. 9, figs 1, 2. — Garassino & De Angeli 2004: 42, 43, figs 9-11. — Ferratges 2017: 58, pl. 16, figs A-B. — Baldanza et al. 2017: 59, fig. 15B. — Górka 2018: 523-522, text-fig. 5.1, 5.2.

Lobocarcinus sismondae – Maestre et al. 2005: 107-108. Lobocarcinus imperator – Reuss 1858: 41, pls 7, 8, pl. 9, fig. 1; Garassino, Hyžný & Pasini in Baldanza et al. 2013: 346, fig. 11.

Cancer sismondai var. antiatina – Maxia 1946: 134-147, fig. 1, pl. 1, figs 2-5.

MATERIAL EXAMINED AND MEASUREMENTS (in mm). — One carapace almost complete, cuticle partially preserved, ULB-IV-A (3): L = 42; W = 59.5; FOW = 23.

LOCALITY AND HORIZON. — ‘Noyant-la-Plaine’ quarry, Doué-la-Fontaine (Maine-et-Loire), Tortonian (upper Miocene).

DESCRIPTION

Medium sized carapace, transversely ovate, clearly wider than long, gently convex transversely and longitudinally; regions weakly marked, axial regions more elevated; endocuticle preserved, exocuticle partially preserved; surface smooth. Maximum width about two thirds posteriorly of carapace. Front slightly raised and produced, armed with three sharp triangular teeth, the mesial one smaller, at lower level than the others. Orbits small, rounded, deep. Supraorbital margin raised; inner orbital tooth trifid, produced, adjacent to the frontal teeth; two pointed mesial teeth at higher level than the supraorbital teeth; closed fissures that ending in a small hole, separate these mesial teeth. Infraorbital margin concave, serrate, bearing an inner tooth, dorsally visible, coalescent with basal antennal article, fissure separating them is visible internally; and an outer tooth separated laterally from the outer orbital tooth by a notch. Anterolateral margins widely convex. Right margin preserves six subrectangular lobes bearing three triangular teeth, the mesial the larger; closed fissures that ending in a small hole separate the lobes. Left margin with not preserved lobes or teeth. Left posterolateral margin concave, bearing two post epibranchial teeth, subtriangular, serrated, decreasing in size; rest of the margin rimmed by a row of granules. Posterior margin short, broken, rim of granules partially preserved. Gastric process slightly swollen, faintly raised over adjacent regions. Mesogastric anterior lobe slender, at lower level than protogastric lobes; posterior portion of region broader, subtrapezoidal, undifferentiated from meta- and urogastric regions. Protogastric lobes swollen, anterior portion confluent with distal frontal and inner orbital teeth. Cardiac region subhexagonal, swollen. Intestinal region subrectangular, not well defined, narrower than cardiac region. Epi-, meso-, and metabranchial regions, slightly swollen, weakly differentiated. Hepatic regions subtriangular, slightly swollen. Sternopleonal features and appendages not preserved.

REMARKS

The specimen of Noyant-la-Plaine, is herein attributed to Lobocarcinus sismondai with confidence. In despite of the partial incompleteness of its margins, it matches perfectly with the descriptions or figures seen in the literature (see synonymies list above). For instance, although the lateral margins are partially incomplete, it is possible to see the ten anterolateral lobes (included the outer orbital tooth), or scars of them, diagnostic character of the species as it is stated, in particular in the description of A. Milne-Edwards (1864) or in the exhaustive and detailed work by Bonfiglio & Donadeo (1982) (see also the specimen MNHN.F.A24543).

Couffon (1908: 5, pl. 1, fig. 11), reported a palm of a left chela from Le Haguineau (Maine-et Loire), and assigned it to Cancer deshayesii (syn. of Lobocarcinus sismondai ; cf. specimen MNHN.F.B39264). Ossó & Gagnaison (2019: 379, fig. 6G) in face of the absence of known carapaces of that species from the ‘Faluns’ outcrops, and neither in the Miocene of the Atlantic of Europe, left this chela tentatively as Lobocarcinus sp. in view of the similarity with the chelae of L. sismondai .

Lobocarcinus sismondai , is widespread in deposits from the Miocene to the Pleistocene in the Mediterranean Sea and related basins (see Garassino, Hyžný & Pasini in Baldanza et al. 2013: 346). However, in the Miocene of the Atlantic margin of Europe, Lobocarcinus sismondai it is reported based upon only isolated dactyli from the Miocene-Lower Pleistocene of the Netherlands ( Holthuis 1949). Therefore, its presence in the Atlantic margin of Europe from the Miocene, is completely confirmed by the report of the carapace described herein.

Figures

FIG. 4. — Decapod from the Tortonian of the ‘ Noyant-la-Plaine’ quarry, Doué-la-Fontaine (Maine-et-Loire): A-C, Lobocarcinus sismondai (von Meyer, 1843), ULB-IV-A (3): A, dorsal view; B, close-up of front in dorsal view; C, close-up of front and orbits in frontal view. Decapods from the ‘ Savignean facies‘ (Langhian) of the ‘Blandinerie’ quarry, Breil (Maine-et-Loire): D, E, Hebertides jurassica Guinot, De Angeli & Garassino, 2007, ULB-IV-A (5): D, left lateral view; E, dorsal view; F, G, ‘Ebalia’ cf. hungarica Müller, 1974a, ULB-IV-A (7): F, frontal view; G, dorsal view; H-M, Maja orbignyana Millet de la Turtaudière, 1865: H, ULB-IV-A (1), dorsal view; I, ULB-IV-A (2), left lateral view; J dorsal view; K, ULB-IV-A (23), frontal view; L, dorsal view; M, ventral view. Abbreviations: ab, basal antennal article; dsab, distal spines of basal article; ias, interantennular spine; iot, infraorbital tooth. Scale bars: A-E, H-M, 10 mm; F, G, 5 mm. Photographs by À. Ossó.