Ranina bouilleana A. Milne Edwards, 1872

Pasini, Giovanni & Garassino, Alessandro, 2017, A preliminary review of the fossil species of Ranina Lamarck, 1801 (Decapoda, Brachyura, Raninidae), with systematic remarks, Natural History Sciences 4 (1), pp. 43-72 : 47-48

? Ranina bouilleana A. Milne Edwards, 1872

Fig. 3

Ranina bouilleana A. Milne Edwards, 1872: 6 , 9, Pl. 8, figs. 2, 2a-c.

Ranina bouilleana - A. Milne Edwards 1873: 8, Pl. 4, fig. 55. – Bittner 1883: 303, 304. – Fabiani 1910: 90, 91. – Glaessner 1929: 361. – De Angeli & Beschin 2001: 20. – De Angeli et al. 2009: 120, 121. – Schweitzer et al. 2010: 74. – De Angeli & Beschin 2011: 13, 15, 16, Tab. 1 . – Van Bakel et al. 2012: 208. – Karasawa et al. 2014: 260. – Baldanza et al. 2014: 274, 275, fig. 7.

Hela bouilleana - Lőrenthey in Lőrenthey & Beurlen 1929: 109.

Type material: lost (S. Charbonnier pers. comm., 2015).

Type locality: Biarritz (Pyrénées Atlantique, Aquitaine, France) .

Geological age: ‟Couches à Nummulites de Biarritz”, early Oligocene ( SW France);?early Oligocene (NE Italy).

Examined material: two specimens MNHM R03540 “ Coll. Duperier ” .

Description by A. Milne Edwards (1872): “ Plusieurs exemplaires de cette espèce ont été trouvés par M. le comte R. de Bouillé aux environs de Biarritz, et je dois à l’obligeance de ce géologue d’avoir pu les étudier et de les décrire; la carapace est moins large que chez R. palmea ; cependant, par les progrès du développement, elle s’élargit surtour dans sa portion antérieure; des changements semblables dans les proportions générales du corps s’observent d’ailleurs chez l’espèce des mers de l’Inde, et il suffit, pour s’en convaincre, de jeter les yeux sur les figures que de Haan en a données dans la Fauna japonica ; on voit que non-seulement la carapace s’élargit beaucoup en avant chez les vieux individus, mais que les lobes du bord antérieur tendent à se découper et à se digiter de plus en plus, de telle sorte qu’il est impossible d’attribuer une grande importance aux changements de forme que présentent ces parties; de même que chez le R. granulata , le bord latéro-antérieur se découpe en trois lobes grands et très-rapprochés, en dedans desquels existent deux lobes sus-orbitaires plus petits, séparés entre eux par d’étroites scissures; la surface du bouclier céphalothoracique ne porte pas de véritables granulations; elle est au contraire comme corrodée, et l’on y remarque une infinité de petites dépressions ovalaires, souvent rapprochées par groupes de deux ou trois, et plus espacées en avant que sur les parties postérieures et latérales; sur les côtés, il esiste una petite crête linéaire très-finement granuleuse; les sillons branchio-cardiaques sont peu profonds, et on ne les aperçoit que parce que, sur ce point, les petites dépressions ovalaires du test disparaissent presque complétement; la face externe du bras des pattes antérieures est couverte d’un certain nombre de crêtes arquées en avant, paralléles et très-finement granuleuses; des ornaments du même genre garnissent l’avant-bras; la main est très-comprimée, très-haute; son bord inférieur est découpé en dents de scie; l’écusson sternal est grand et lisse. ”

Literal translation: many specimens of this species were found by the count R. de Bouillé in Biarritz area, giving me the opportunity to study them; the carapace is less wide than that of R. palmea though wider anteriorly; changes in the body proportions are also observable in the species living in the Indian Ocean and to look at de Haan’s figures in the Fauna japonica ; the carapace is wider frontally in the oldest (mature) individuals in which the frontal lobes split in more and more bifid and serrate accessorial points; as in R. granulata , the anterorlateral margin has three big lobes, close each other and two small suborbital lobes, separated by narrow fissures; dorsal surface of carapace with ovoid pits, uniformely arranged along posterior and lateral margins, less anteriorly; lateral margins with a granulate ridge; shallow branchiocardiac grooves; outer surface of cheliped with transverse granulate ridges curved forward; carpus with transverse granulate ridges; propodus very flat with serrate inferior margin; wide and smooth sternum.

Discussion. The type series described and figured by A. Milne Edwards (1872) probably housed in the Muséum national d’Histoire naturelle in Paris ( France) is today lost. These specimens were very poorly preserved frontally with both the anterolateral spines broken, and from the original description and figures it is not possible to recognize adeguate characters to confirm their assignment. Van Bakel et al. (2012: 208) reported a generic Oligocene age for this species, whereas previously Boussac (1911), carried on a palaeostratigraphic study on the” nummulitique de Biarritz ” outcrops, assigning the layers preserving the echinoderm Eupatangus ornatus and including the raninid decapods remains, to the early Oligocene.

Only two specimens have been traced in the Paris Museum collections ( MNHM R03540 ) as belonging to R. bouilleana and collected from the same locality ( Phare de Biarritz ) of the type series. One specimen preserves first and second anterolateral spines ( Fig. 3B ), important main characters for specific level. The dorsal carapace shape and general ornamentation fit with the original description by A. Milne Edwards (1872). The rostrum is not preserved .

However, as previously pointed out by Pasini, Garassino & De Angeli in Baldanza et al. (2014: 276), “ these specimens cannot be considered as syntypes because the attached label clearly reported Coll. Duperier, whereas the type specimens had been collected by the Count R. de Bouillé ”, as attested by A. Milne Edwards (1872: 6). Moreover it’s also impossible to establish a lectotype for the poorly preserved front and anterolateral margins of the type series. In conclusion the inability to recognize the diagnostic characters of Ranina questions the placement of bouilleana within this genus.

The two specimens from Duperier’s collection were partially discussed by Pasini & Garassino (2017: 92) in order to clarify their assignment. Indeed, the second anterolateral spine shape, strongly directed outward and serrate dorsally, is not a typical character of Ranina , but allows us to assign these specimens only to the Raninidae sensu stricto.

Finally, we were unable to revise the specimen reported by Bittner (1883) from the Oligocene of Vicenza (NE Italy) originally housed in the Geological Museum of the Vienna University, and most probably today lost, for a close comparison.

Figures

Fig. 3 -?Ranina bouilleana A. Milne Edwards, 1872.A) Milne Edwards’s original figures (Pl. 8, figs. 2, 2a-c). B-C) Two specimens, MNHM R03540, collected from the same locality (Phare de Biarritz) of the type series (natural size).