Ranina griesbachi Noetling, 1897

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 : 51-52

? Ranina griesbachi Noetling, 1897

Fig. 6

Ranina griesbachi Noetling, 1897 Series XVI, Part 3: 78, Pl. 22, fig. 4.

Raninella griesbachi - Glaessner 1929: 369. – Schweitzer et al. 2010: 74. – Van Bakel et al. 2012: 209.

Ranina griesbachi - Karasawa et al. 2014: 260.

Type material: holotype and repository unknown.

Type locality: neighborhood of Khattan , Mari Hills beds, Balochistán province ( Pakistan).

Geological age: Late Cretaceous (Maastrichtian).

Examined material: Noetling’s original plate (1897: Pl. 22, fig. 4).

Description by Noetling (1887): “ The greatest breadth of the anterior part, measured between the second lateral spines, is 58 mm; the front margin, taken as a whole from the base of the rostrum to the first lateral spine, is almost straight; the narrow rostrum, which is unfortunately a little damaged, must have been short, apparently three-pointed, and hollowed by a deep but short longitudinal furrow; the orbital margin is indented, at about the middle, by two strong incisions, converging in the posterior direction, the outer one of which is slightly longer but narrower than the inner one; between these two incisions the orbital margin forms a broad rounded lobe, provided with a short spine; a similar spine appears at either side of the two incisions; there are three lateral spines, of which the first is broad and long, projecting straight in front; this is separated by a deep and broad incision from the second one, which is narrower and obliquely directed; the latter is separated from the short third antero-lateral spine by a very short incision; the whole surface of the anterior part of the carapace is covered with numerous fine tubercles, which become somewhat coarser in the middle than at the margins; the specimen just shows the first of the fine transverse ridges which cover the posterior part of the carapace, which seems to have been covered also with extremely fine closely set punctures. ”

Discussion. Noetling (1897: 79) remarks that: ” It is possible that the species here described belongs to the genus Raninella, Milne-Edwards , but as the chief distinction of this genus from Ranina consist in the shape of the plastron, which is not visible in the specimen under examination, I refrain from expressing an opinion and take it as belonging to the genus Ranina , to which all the characters of the carapace point. ” Later this species was assigned by some authors ( Glaessner, 1929; Schweitzer et al., 2010; Van Bakel et al., 2012) to Raninella A. Milne Edwards, 1862 , perhaps because of its Late Cretaceous geological age ( Karasawa et al., 2014: 260). Nevertheless, according to Karasawa et al. (2014: 260), R. griesbachi seems to lack “ the narrower fronto-orbital width and postorbital ridge seen in Raninella ” ( Karasawa et al., 2014: 260). The anterior wide anterolateral margins, wide bifid outer orbital spine, scabrous carapace ornamentation (see Noetling, 1897: Pl. 22, fig. 4), are instead characters of Ranina apart from the suspicious Mesozoic age; for these characters the specimen “ can be accommodate in Ranina , which has all these characteristics ” ( Karasawa et al., 2014: 260). However, in our opinion, the morphological characters observables, such as the deep rostral groove, the presence of a dorsal “fine transverse granulate ridge”, the absence of both the anterolateral spines and the incompleteness of the specimen question the placement of this species within Ranina , but not in the Raninidae sensu stricto.

Figures

Fig. 6 -?Ranina griesbachi Noetling, 1897; Noetling’s original figure (Pl. 22, fig. 4).