Japonacteon longissimus, Helwerda, Renate A., 2015

Helwerda, Renate A., 2015, Acteonidae, Bullinidae and Ringiculidae (Gastropoda: Heterobranchia) from the Plio-Pleistocene of the Philippines, Zootaxa 3990 (2), pp. 197-220 : 204

publication ID	https://doi.org/ 10.11646/zootaxa.3990.2.2
publication LSID	lsid:zoobank.org:pub:BDF1BC11-4848-4858-99DC-0336A5FBEE2B
DOI	https://doi.org/10.5281/zenodo.6116509
persistent identifier	https://treatment.plazi.org/id/03FA878C-9517-FE4D-FF26-E7C6004CCF35
treatment provided by	Plazi
scientific name	Japonacteon longissimus
status

Treatment

Acteon View in CoL spec 5 aff. Japonacteon longissimus Valdés, 2008

( Figure 13 View FIGURE 8 – 13. 8 )

Aff. 2008 Japonacteon longissimus n. sp. —Valdés: p. 604–605, figs. 6E–G, 7, 8B.

Material. Anda4 (1) RGM 961.743.

Characterization. Shell small, juvenile; H 1.29 mm, W 0.99 mm; protoconch slightly elevated, large, 1.3 whorl, DP 0.79 mm; nucleus small, DN 0.24 mm; teleoconch 0.8 whorl; teleoconch whorls sculpted with punctuated spiral grooves, becoming stronger towards base; strong groove near suture; interspaces large, becoming smaller towards base; suture weakly channeled with weak punctuated spiral groove; aperture narrow; columella with weak single fold; umbilicus very narrow.

Remarks. Only one juvenile specimen with the sculptural details described above, is available. It is similar to the paratype of Japonacteon longissimus Valdés, 2008 from the Philippines, as shown in figure 6F in Valdés (2008), but this species has two strong punctuated spiral grooves near the suture which grow much wider within the first teleoconch whorl than they do in the specimen RGM 961.743. All other species within Acteonidae , of which material is well described and illustrated, differ from the specimen discussed here in their sculptural details. Yet, many species do not have their protoconch and first teleoconch described, because it is often not preserved on larger shells and juvenile specimens are often overlooked.