Tindaria ruru, Simone, 2024

Family Tindariidae View in CoL Genus Tindaria Bellardi, 1875

Tindaria ruru , new species ( Fig. 40 View Figure 40 ) https://zoobank.org/ 0A989925-9FDC-415B-AB18-C414E660B129

Types: Holotype MZSP 166688 View Materials ,left valve . Paratypes: MZSP 104207 View Materials , 60 View Materials valvesfromtypelocality. BRAZIL. EspíritoSanto ; ItaÚnas,off,abyssal platform, 19°08.8′S 37°34.8′W, 3,450 m, MZSP 166679 View Materials , 10 View Materials valves, 1 shell, MNHN-IM-2000-39811, 6 valves ( MD55 sta. DS66, 25.v.1987) GoogleMaps .

Type locality: BRAZIL. Espírito Santo ; Linhares , off, abyssal platform S of Vitória-Trindade Mountain Chain, 21°09.3′S 34°50.5′W, 4,120 m [ MD55 sta. SY38, 16.v.1987] GoogleMaps .

Diagnosis: Abyssal species from off SE Brazil with shell of ~ 7 mm; inflation ~80% of length. Sculptured by commarginal, uniform lines. Hinge with anterior set of teeth slightly longer than posterior; posterior set of teeth with horizontal posterior end.

Description: Shell of ~ 7 mm; shape oval; slightly longer than height; walls thick. Umbo rounded, prominent; almost central-slightly dislocated posteriorly. Anterior and posterior umbonal edges almost symmetrical, posterior edge slightly shorter and concave; anterior edge longer and straight; ventral edge widely rounded ( Fig. 40E, F View Figure 40 ,I-K) or with weak, blunt anterior beak ( Fig. 40 View Figure 40 A-B). Maximum inflation ~80% of length ( Fig. 40D, G View Figure 40 ). Sculptured by uniform commarginal cords, from umbo up to margin; interspaces equivalent to half of each cord width. Hinge occupying entire dorsal edge ( Fig. 40A, C, F, H, I, K View Figure 40 ), thicker regions occupying ~10% of shell height; short sub-umbonal potion lacking teeth; from this region both anterior and posterior series of teeth gradually growing towards edges, becoming wider in subterminal region in both sides; 11-14 teeth in straight, longer anterior set; 9-10 teeth in slightly shorter posterior set, with small curved, horizontal portion in posterior end ( Fig. 40C, F, I View Figure 40 ). Inner muscle scars of difficult visualization; both adductor muscle scars rounded, located ventrally to both ends of hinge; no individualizable pallial line.

Etymology: The specific epithet is derived from the Guarani language ruru , meaning swollen, an allusion to the inflated shape of the shell ( Fig. 40D, G View Figure 40 ).

Distribution: So far known off Espírito Santo coast.

Habitat: Abyssal platform, 3,450 -4,120 m. Measurements (in mm): Holotype MZSP 166688 garding the hinge, T.ruru lacks teeth in the sub-umbonal ( Fig. 40 View Figure 40 A-D): 6.4 by 5.2. Paratype: MZSP 104207#1 region, while T. cytherea possesses teeth in the sub-um- ( Fig. 40 View Figure 40 E-H): 6.9 by 5.5; MZSP 104207#2 ( Fig. 40I View Figure 40 ): 5.9 by bonal area, albeit much smaller in size.

5.2; MZSP 104207#3 ( Fig. 40 View Figure 40 J-K): 5.8 by 5.2. The habitat of T.ruru appears to be significantly different, occurring at much greater depths (3,450 -4,120 m), Remarks: Tindaria ruru is only known from collect- whereas T.cytherea is known to occur in shallower depths ed valves found on the abyssal platform south of the ranging from 537-1,140 m.

Vitória-Trindade mountain chain. A single articulated specimen, MZSP 166679, is present in the sample, but it is a young specimen measuring 3.5 mm. Nonetheless, its Tindaria cytherea ( Dall, 1881)

presence indicates the species′ habitat in that environ- ( Fig. 41 View Figure 41 )

ment.

The shell of T.ruru differs from that of T.cytherea (Dall, Synonymy check Sanders & Allen (1977: 35). Comple- 1881), the only congeneric species occurring in the West- ment:

ern Atlantic, in several aspects: it is smaller, has a more rounded outline (compared to the more antero-posteri- Nucula cytherea Dall, 1881: 123 .

orly elongated shape of T. cytherea ), exhibits a more del- Malletia veneriformis Smith, 1885: 246-247 (pl. 20, icate commarginal sculpture (as opposed to the coarser figs. 9, 9a).

sculpture of T. cytherea ), and is much more inflated. Re- Malletia (Tindaria) cytherea : Dall, 1889: 438.

Malletia amabilis Dall, 1889: 438 (pl. 40, fig. 8).

Tindaria amabilis View in CoL : Dall, 1889: pl. 40 legend; Abbott, 1974: 413 (fig. 4833); Díaz & Puyana, 1994: 43.

Tindaria cytherea View in CoL : Abbott,1974:413 (fig. 4835); Sanders & Allen, 1977: 35-42 (figs. 17-22); Rios, 1994: 226 (pl. 78, fig. 1116), 2009: 469 (fig. 1323); MolluscaBase, 2024.

Type localities: Off Cape San Antonio, 413-424 fms.; Yucatan Strait , 640 fms. Malletia amabilis : Off Cape San Antonio, 413-424 fms .; Yucatan Strait , 640 fms .; Sta. 226, near St. Vincent, 424 fms .; Sta. 2392 US Fish. Comm. Gulf of Mexico, 28°45′N 87°30′W, 724 fms. ( Dall, 1886) GoogleMaps ; M. veneriformis : sta. 33, off Bermuda, 435 fms; Sta. 24, off Culebra Is., W Indies, 390 fms .

Distribution: Florida to Rio de Janeiro.