Provanna dongshaensis, Wu & Chen & Tian & Amano & Su, 2025

Wu, Cong, Chen, Fang, Tian, Ying, Amano, Kazutaka & Su, Xin, 2025, A new species of genus Provanna (Gastropoda, Abyssochrysoidea) from gas hydrate-bearing sediments of the northern South China Sea, Zoosystematics and Evolution 101 (1), pp. 45-54 : 45-54

publication ID	https://doi.org/10.3897/zse.101.137176
publication LSID	lsid:zoobank.org:pub:4CB8A2ED-7082-4BB1-8641-473C90A8B00B
DOI	https://doi.org/10.5281/zenodo.14589159
persistent identifier	https://treatment.plazi.org/id/E4BE6EC5-559A-587C-95AB-A8418026A106
treatment provided by	Zoosystematics and Evolution by Pensoft
scientific name	Provanna dongshaensis
status	sp. nov.

Treatment

Provanna dongshaensis sp. nov.

Fig. 2 A – O View Figure 2

Etymology.

This new species is the only appearance of genus Provanna in SCS to date. We use the specific epithet “ dongsha ” to present the place where it is discovered.

Type material.

Holotype: GMGS 2-09 B-C 15-2 . Paratype: GMGS 2-07 B-A 1 .

Type locality.

Site GMGS 2-07 B, GMGS 2-09 B, Dongsha area, northern SCS (Fig. 1 View Figure 1 ).

Buried depth and type horizon.

3.50, 3.60, 6.07 mbsf (meter below sea floor) at core GMGS 2-09 B, 33.85 mbsf at core GMGS 2-07 B; Carbonate layers, Late Pleistocene (Table 1 View Table 1 ).

Material.

Type material and other fragment specimens. All specimens are deposited in China Deep Sea Drilling Core Repository, Guangzhou City, China.

Dimensions.

Holotype is approximately 7.80 mm in height and 5.02 mm in width of the whole whorl, 3.66 mm in apertural height and up to 0.58 mm thick at the apertural wall. Apical angle of approximately 54 ° reaching at least 3.66 mm in height and 3.02 mm in width.

Diagnosis.

A medium-sized Provanna , sturdy, shell with prominent, angular whorls with nodes at intersection of the axial and spiral ribs.

Description.

Protoconch: at least one whorl, but poor preservation in all specimens; maximum diameter about 0.58 mm (Fig. 2 C View Figure 2 ); sculptured pattern not clear; transition to teleoconch unknown. Teleoconch: shell height 7.8 to more than 10 mm. Diameter of the last whorl 5.02 to 7.13 mm. Shell thick, 0.41 to 0.58 mm in the thickness of last whorl. Shell four to five whorls, sculptured by reticulate pattern. 15 to 16 strongly orthocline axial ribs (Fig. 2 C, H, L View Figure 2 ) on both the penultimate and last whorls. Three prominent and equally strong spiral ribs with blunt, strong and swollen tubercles at intersections on the penultimate whorl, and up to 7 on the last whorl. Tubercles more prominent on lower whorls, like strings of pearls. Basal margin marked by the distinct with strength-decreasing spiral rib. Axial ribs start at the upper suture and fade below the lower spiral rib. Regularly and closely spaced, fine spiral treads on whorl flank, fine axial growth increments. Aperture broadly oval, siphonal canal bordered by low ridge.

Remarks.

(Table 2 View Table 2 ) P. dongshaensis sp. nov. is differentiated from those provannids with smooth shell surface and simple sculpture by its prominent angulate appearance, particularly including the extant species living in Japan seeps and vents (e. g., P. abyssalis , P. glabra , also see " Shell microstructures of Provanna "). It exhibits a smaller number of the spiral ribs but more pronounced axial structure compared to P. cingulata and P. macleani . P. dongshaensis sp. nov. shares with P. sculpta the strong and inflated tubercles, which makes them different from those spiny species like P. goniata , P. ios , P. stephanos , etc, but differs in its shelf-structure. Compared to another similar species, P. fortis , it has more robust axial structures on the body-whorl, which are generating the inflated tubercles and bead-like appearance.