Liocarcinus sp., Stimpson, 1871

Ossó, Àlex & Gagnaison, Cyril, 2019, An appraisal of the Middle-Late Miocene fossil decapod crustaceans of the ‘ Faluns’ (Anjou-Touraine, France), Geodiversitas 41 (9), pp. 367-383 : 374-376

publication ID

https://doi.org/10.5252/geodiversitas2019v41a9

publication LSID

urn:lsid:zoobank.org:pub:32E3623C-C47B-4D42-B2EB-E2594D031349

DOI

https://doi.org/10.5281/zenodo.3705482

persistent identifier

https://treatment.plazi.org/id/03D187F1-907F-FFB1-FBB7-9D230A234199

treatment provided by

Valdenar (2020-03-06 17:21:09, last updated 2024-11-27 18:54:43)

scientific name

Liocarcinus sp.
status

 

Liocarcinus sp.

( Fig. 5A, B View FIG )

MATERIAL EXAMINED AND MEASUREMENTS (in mm). — Partially preserved carapace, MS2012 0 172b: L = 10.5, W = 12, FOW = 8.5, F = 4.

LOCALITY AND HORIZON. — ‘La Sonneterie’ quarry, Meigné-le- Vicomte (Maine-et-Loire). ‘Savignean facies’, Langhian-Serravallian (Middle Miocene).

DESCRIPTION

Small sized carapace, subhexagonal, smooth, slightly wider than long. Regions weakly defined. Three longitudinally aligned tubercles at each side of carapace. Front incomplete, straight, but appears to be slightly produced medially. Orbits relatively large; supraorbital margin with two closed fissures. Anterolateral margin slightly arcuate, with four subtriangular teeth (excluding the outer orbital tooth), the last of them (epi- branchial tooth) the sharper. Posterolateral margin straight; reentrant of fifth pereiopod well marked. Posterior margin straight.Frontal region smooth, flattened.Gastric process poorly defined. Epigastric lobes slightly marked. Protogastric lobes slightly swollen with faintly marked transverse ridge at each lobe; marked tubercle near gastrohepatic groove. Mesogastric region weakly marked. Urogastric region depressed. Cardiac region large, slightly swollen. Intestinal region depressed. Hepatic region depressed. Epibranchial region sigmoidal, weakly marked, with medial tubercle. Mesobranchial region slightly swollen, with marked tubercle, Metabranchial region depressed. Cervical groove faintly marked. Branchiocardiac groove weakly marked. Ventral parts and appendages not preserved.

REMARKS

The features of the studied specimen fit with those of Liocarcinus , and its general outline matches well with the known Miocene Liocarcinus species (see Schweitzer et al. 2010). However, they differ in having a most decorated or rough surface of the carapace, as for instance L. rakosensis Lőrenthey in Lőrenthey & Beurlen, 1929 and L. kuehni (Bachmayer, 1953), whereas in the studied specimen the carapace surface is completely smooth; or in having more marked and raised regions as in the case of L. oroszyi (Bachmayer, 1953) and L. praearcuatus Müller, 1996 (see Bachmayer 1953a: pl. 2, figs 2, 5-5a; Müller 1984a: 83-84, pl. 69, figs 2-6, pl. 71, figs 1-4; 1996: 10, pl. 2, figs 2-3). Liocarcinus ottnangensis (Bachmayer, 1953) differs clearly in having a trifid front and a characteristic prominent transverse ridge running across the mesogastric and epibranchial regions, which is absent in the studied specimen (see Hyžný et al. 2015). Liocarcinus oligocenicus ( Paucă, 1929) and L. lancetidactylus ( Smirnov, 1929) present a different pattern of anterolateral margins and front, furthermore, their poor preservation makes difficult an accurate comparison (e.g. Jerzmańska 1967: fig. 1; Schweitzer et al. 2009: fig. 6; and Garassino & Novati 2001, respectively).

Regarding the extant species of Liocarcinus (see Ng et al. 2008), they have usually a more arched anterolateral margins than the studied specimen, and most of them have a trifid front, and/or a rough surface of carapace, which is smooth in the studied specimen. Liocarcinus pusillus ( Leach, 1815) and L. navigator (Herbst, 1794) have a similar blunt front medially produced, similar to the studied specimen, but they differ in having a rougher dorsal surface, and by the lack of the conspicuous protogastric ridges and three characteristic tubercles, longitudinally aligned, present in the French specimen possess (e.g. Froglia & Manning 1982; Koch & Ďuriš 2016)

The general outline and dorsal sculpture of the studied specimen also resemble that of Miopipus pygmaeus ( Brocchi, 1883) ( Brocchi 1883: 1, pl. 5, figs 4-4a). However, Müller (1984a: 84, pl. 72, figs 1-4), described the front of M. pygmaeus as trilobed, narrow and prominent, and the carapace regions as strongly inflated, which precludes a congeneric relationship with the specimen described herein.

Therefore, in spite that the aforementioned differences could lead us to propose a new species of Liocarcinus for this specimen, based on the poorly preserved sole specimen, we report it as Liocarcinus sp., until more specimens are available for study.

BACHMAYER F. 1953 a. - Die Dekapodenfauna des tortonischen Leithakalkes von Deutsch-Altenburg (Niederosterreich). Mitteilungen der Geologischen Gesellschaft in Wien 44: 237 - 262.

BROCCHI P. 1883. - Notes sur les crustaces fossiles des terrains tertiaires de la Hongrie. Annales des Sciences geologiques 14 (2): 1 - 8.

FROGLIA C. & MANNING R. B. 1982. - Notes on Liocarcinus pusillus (Leach) and related species. Quaderni del Laboratorio di Tecnologia della Pesca 3 (2 - 5): 257 - 266.

GARASSINO A. & NOVATI M. 2001. - Liocarcinus lancetidactylus (Smirnov, 1929) and Platymaia lethaeus (Smirnov, 1929) from the Miocene of N Caucasus (Russia). Atti della Societa iItaliana di Scienze naturali e del Museo Civico di Storia naturale di Milano 141 (2): 269 - 281.

HYZNY M., HARZHAUSER M. & DANNINGER W. 2015. - Decapod Crustacea of the Central Paratethyan Ottnangian Stage (middle Burdigalian): implications for systematics and biogeography. Geologica Carpathica 66 (3): 217 - 233. https: // doi. org / 10.1515 / geoca- 2015 - 0021

JERZMANSKA A. 1967. - Crabs of the genus Portunus Weber from the Menilite Series of the Carpathians. Annales de la Societe geologique de Pologne 37: 539 - 545. (in Polish, with English summary).

LEACH W. E. 1815. - The Zoological Miscellany; being Descriptions of New, or Interesting Animals, Illustrated with Coloured Figures, Drawn from Nature, in NODDER R. P. et al. (eds). E. Nodder & Son, London, vol. 2: 145 - 154. https: // doi. org / 10.5962 / bhl. title. 41372

LORENTHEY I. 1897. - Adatok Magyarorszag harmadkoru rak faunajahoz. Mathematikai es Termeszettudomanyi Erttesito 15: 149 - 169

LORENTHEY E. & BEURLEN K. 1929. - Die fossilen Decapoden der Lander der Ungarischen Krone. Geologica Hungarica, Series Palaeontologica 3: 1 - 420.

MILLET DE LA TURTAUDIERE P. A. 1865. - Paleontographie ou Description des fossiles nouveaux du terrain tertiaire marin ou terrain miocene superieur du departement de Maine-et-Loire (Supplement). Indicateur de Maine et Loire. Cosnier et Lachese, Angers, vol. 2, 616 p.

MULLER P. 1984 a. - Decapod Crustacea of the Badenian. Geologica Hungarica, Series Palaeontologica 42: 25 - 317.

MULLER P. 1996. - Middle Miocene Decapod Crustacea from southern Poland. Prace Muzeum Ziemi, Prace paleozoologiczne 43: 3 - 14.

NG P. K. L., GUINOT D. & DAVIE P. J. F. 2008. - Systema Brachyurorum: Part I. An annotated checklist of extant brachyuran crabs of the world. The Raffles Bulletin of Zoology, Supplement 17: 1 - 286.

PAUCA M. 1929. - Zwei neue fossile Decapoden aus den Oligozanen Clupea crenata Schiefern von Suslaneski-Muscel und uber die Bildung der Menilitschiefer. Bulletin de la Section scientifique de l'Academie roumaine 12: 4, 5, 40 - 44.

SCHWEITZER C. E., FELDMANN R. M. & LAZA R I. 2009. - Fossil Crustacea (excluding Cirripedia and Ostracoda) in the University of Bucharest Collections, Romania, including two new species. Bulletin of the Mizunami Fossil Museum 35: 1 - 14.

SCHWEITZER C. E., FELDMANN R. M., GARASSINO A., KARASAWA H. & SCHWEIGERT G. 2010. - Systematic list of fossil decapod crustacean species. Crustaceana Monograph 10: 1 - 1222. https: // doi. org / 10.1163 / ej. 9789004178915. i- 222

SMIRNOV V. P. 1929. - Decapoda of the fish beds at Black river in the vicinity of Vladikavkaz. (Decapoda iz rybnykplastov na Chernoy rechke v okrastnostyakh Vladikavkaza). Arbeiten der Nord-Kaukasischen AssoziationWissenschaftlicher Institute 59: 1 - 49 (in Russian).

Gallery Image

FIG. 5. — A, B, Liocarcinus sp., MS2012 0 172b: A, dorsal view; B, frontal view; C, D, Necronectes michelini (A. Milne-Edwards, 1861): C, ULB-SO-9, right dactylus; D, ULB-SO-10, left dactylus; E, Paguristes gagnaisoni Gagnaison, 2012, MS2006 FS 134b, right chela; F-I, Xantho cf. moldavicus (Yanakevich, 1977): F, ULB-SO-11, left chela, inner lateral view; G, outer lateral view; H, ULB-SO-12, left chela, outer lateral view; I, frontolateral view; J-M, undetermined chelae: J, ULB-SO-13, lateral view of right chela; K, frontal view; L, ULB-SO-14, lateral view of left chela; M, close-up showing an encrusted colony of bryozoans. Scale bars: A, B, 5 mm; C-M, 10 mm. Photographs by À. Ossó.

Kingdom

Animalia

Phylum

Arthropoda

Class

Malacostraca

Order

Decapoda

Family

Polybiidae

Genus

Liocarcinus