Galene dashtbani, Khosravi & Sari & Mirziee-Ataabadi & Gholamalian & Hyžný, 2022

Khosravi, Erfan, Sari, Alireza, Mirziee-Ataabadi, Majid, Gholamalian, Hossein & Hyžný, Matúš, 2022, A new species of Galene de Haan, 1833 (Galenidae: Brachyura) from the middle Miocene of Zagros Mountains, Iran, Zootaxa 5124 (2), pp. 139-154 : 145-148

Galene dashtbani n. sp.

( Figs. 5 , 6 )

Type material. Holotype: ZUTC6881 , a carapace from the Honguyeh section, from the Middle Miocene (Langhian), Guri member of the Mishan Formation . Paratypes: HUIM195 , HUIM198-202 , carapaces from the Gohreh section, from the Middle Miocene (Langhian), Guri member of the Mishan Formation. Measurements of the carapace length and width are provided for each specimen in Table 1 .

Additional material. Non-types: HUIM 196-197, carapaces from the Gohreh section, the Middle Miocene (Langhian) of the Guri Member of the Mishan Formation. HUIM 203-205, chelipeds (one with fragmentary carapace), from the Gohreh section, the Middle Miocene (Langhian) of the Guri Member of the Mishan Formation.

Diagnosis. Carapace with smooth dorsal surface, no posterolateral spines, frontal and orbital lobes with swollen tuberosities, with no spines.

Description. Carapace subhexagonal, anterior margins more ovate; posterior margins with well-defined 45° angle between posterolateral and posterior margins; two anterolateral blunt teeth on epibranchial margins of carapace; not very sharp, but clearly distinguished ( Figs. 5E, F ), no posterolateral tuberosities ( Figs. 5A, C, E–I, K , 6A, D–F ); frontal margin bilobed. Dorsal surface of carapace smooth, longitudinally slightly convex; cardiac and mesogasteric regions defined with prominent fissures; lateral borders of anterior mesogastric region sub-parallel, extending close to the frontal lobe with narrow furrow ( Figs. 5A–D, I–K ); other regions of carapace not markedly prominent. Thoracic sternum and male pleon narrow (HUIM199, HUIM202, Figs. 6C, G ). Surface of cheliped manus smooth; palm with posterior tuberculated margin ( Fig. 6I ); dactylus shorter than pollex ( Fig. 6H ).

Occurrence. The species is known from the Middle Miocene (Langhian) of the Guri Member of the Mishan Formation exposed at Honguyeh and Gohreh sections, Hormozgan Province, southern Iran.

Etymology. This species is named in honor of Mr.Houshang Dashtban; a veteran paleontologist, who contributed deeply into the exploration and the study of Iranian fossils including crabs.

Remarks. Galene dashtbani sp. nov. is different from its congeners by having a combination of mixed characteristics. In having less prominent lateral spines, no posterolateral spines and a less protuberant cardiac region ( Figs. 5A, C, H, L ), Galene dashtbani sp. nov. is different from Galene bispinosa , including specimens previously documented as Gecarcinus trispinosus and Podopilumnus fittoni (also see Etheridge & McCulloch 1916: pl. III fig. 3; Valinassab et al. 2012: fig. 2a; Ng et al. 2017: fig. 5h), Galene stipata Morris & Collins, 1991 (see Morris & Collins 1991: 8, fig. 54a), Galene obscura A. Milne-Edwards, 1865 (see Collins et al. 2003: fig. 6a) and Galene litoralis Collins, Lee & Noad, 2003 (see Collins et al. 2003: 221, fig. 7a). The carapace frontal margin of G. dashtbani sp. nov. comprises half the orbitofrontal margin, compared to less than half in Galene granulifera Lin, 1947 (compare Hu & Tao 2004 L pl. V figs. 4,7) and G. obscura (see Collins et al. 2003: figs. 6a, 6c). Galene dashtbani sp. nov. has a smoother carapace surface, both in smaller and larger specimens ( Figs. 5A, C, I, K ), in contrast to G. bispinosa , which bears a more granular carapace in smaller specimens ( Ng et al. 2001: 31).

The most prominent character of Galene dashtbani sp. nov. is the spineless and globular form of the frontal margin and superior margin of the orbit, at the same time, bearing swollen tuberosities on these regions ( Figs. 5B, D, E ). Despite the size, this feature is prominent in all studied specimens with a well-preserved frontal margin. Even in the smallest specimen (HUIM195, Figs. 5C–F ), the globular form of frontal and orbital lobes is prominent.

Two small specimens (HUIM196, HUIM197) of Galene dashtbani sp. nov. appear to have a proportionally wider carapace ( Figs. 5I, K ). These specimens have less salient frontal and orbital margins and appear morphologically different from the others. These possess a flatter carapace, and deeper grooves between the mesogastric, cardiac and branchial lobes ( Figs. 5I–K ). In these specimens, the widest part of the mesogastric region is at the level between two lateral tuberosities of the carapace. The width of the posterior margin of the intestinal region equals the width of the front ( Fig. 5I, K ).

Figures

FIGURE 5. Galene dashtbani sp. nov.: A–B, dorsal (A) and front (B) stereo-pair views of holotype ZUTC6881, carapace; C–H, dorsal stereo-pair (C), front stereo-pair (D), left lateral (E), right lateral (F), ventral (G) and posterior (H) views of non-type HUIM195, carapace; I–J, dorsal (I) and front (J) views of non-type HUIM196, carapace; K, dorsal view of paratype HUIM197, carapace; L, dorsal view of paratype HUIM198, carapace. Scale bars = 10 mm.

FIGURE 6. Galene dashtbani sp. nov.: A–C, dorsal (A), right lateral (B) and ventral (C) views of paratype HUIM199, eroded carapace and partial cheliped; D, dorsal view of paratype HUIM200, eroded carapace; E, dorsal view of paratype HUIM201, eroded carapace; F–G, dorsal (F) and ventral (G) views of paratype HUIM202, eroded carapace and fragmentary cheliped; H–I, ventral (H) and left lateral (I) views of paratype HUIM203, cheliped; J–K, ventral (J) and dorsal (K) views of paratype HUIM204, cheliped and partial carapace. Scale bars = 10 mm.