Sunday, June 18, 2017

[Gastropoda • 2017] Luzonocoptis antenna & L. angulata • A New Diplommatinid Genus and Two New Species (Caenogastropoda, Cyclophoroidea) from the Philippines


Luzonocoptis antenna  Páll-Gergely & Hunyadi, 2017


Abstract
A new diplommatinid genusLuzonocoptis Páll-Gergely & Hunyadi, gen. n. is erected for two new speciesLuzonocoptis antenna Páll-Gergely & Hunyadi, sp. n. and L. angulata Páll-Gergely & Hunyadi, sp. n. Both species inhabit the northeastern part of Luzon Island, Philippines. The genus Luzonocoptis gen. n. is mostly characterized by a very slender shell with 14–18 whorls, a strongly expanded peristome, an interrupted, weak columellar lamella, the absence of any additional plicae or lamellae, and a rachidian tooth having five cusps.

Keywords: Land snail, Luzon, rock habitat, systematics, taxonomy




Diplommatinidae Pfeiffer, 1856

Genus Luzonocoptis Páll-Gergely & Hunyadi, gen. n.

 Diagnosis: Shell sinistral; apex blunt, club-like; shell very slender with 14–18 whorls, rather regularly, finely ribbed; aperture round with a weak columellar lamella visible from standard apertural view; columellar lamella interrupted, its inner, short portion blunt thorn or tubercle-like, situated inside post-constriction bay; other inner plicae and lamellae absent; outer surface of operculum matt, smooth; inner surface with a very slightly elevated arcuate ridge; rachidian tooth with five cusps (central one blunt, larger than other four cusps), marginal teeth with four pointed cusps.

Differential diagnosis: Luzonocoptis gen. n. differs from Palaina Semper, 1865 (type species: Diplommatina macgillivrayi Pfeiffer, 1854) by the unique shell shape, the strongly expanded peristome, and most importantly, the presence of a columellar tooth, which continues to a strongly developed lamella (see Yamazaki et al. 2013 and Neubert and Bouchet 2013). The most similar diplommatinid genus in terms of shell characters is Hungerfordia. Luzonocoptis gen. n. differs from Hungerfordia by the presence of an interrupted columellar lamella, and the rachidian tooth, which possess five well-developed cusps. In contrast, the columellar lamella of Hungerfordia is not interrupted, and the rachidian tooth is simpler, with a single, or three cusps.

Etymology: The first part of the name derives from the name of the island (Luzon), where the included new species have been found. The second part (“-coptis”) refers to the similarity with Middle American urocoptid taxa in terms of shell size, shape, colour and habitat. Gender feminine.

Type species: Luzonocoptis antenna sp. n.
Content: Luzonocoptis antenna sp. n. and L. angulata sp. n.

Distribution: This genus is known so far from northeastern Luzon Island. The distance between the type localities of the two species is approximately 34 km in a straight line.


Luzonocoptis antenna Páll-Gergely & Hunyadi, sp. n.

Diagnosis: A tall, yellowish, very slender diplommatinid with club-shaped apex, dense, low ribs on the last whorl, rounded lower whorls, strongly expanded and reflected peristome that is strongly oblique to the shell axis, and a weak interrupted columellar lamella.

Etymology: The shell shape of this new species (wide aperture, very slender upper whorls, and a club-shaped apex) resembles a radio antenna. The specific epithet antenna to be used as a noun in apposition.

Habitat and distribution: Living specimens were found on a limestone rock wall. This species is known from the type locality only, which is situated ca. 34 km in a straight line from the type locality of L. angulata sp. n.


Luzonocoptis angulata Páll-Gergely & Hunyadi, sp. n.

Diagnosis: A tall, yellowish, moderately slender diplommatinid with club-shaped apex, widely spaced, sharp ribs on the last whorl, angled lower whorls, strongly expanded peristome that is slightly oblique to the shell axis, and a weak interrupted columellar lamella.

Etymology: The specific epithet angulata (Latin: angled) refers to the keeled lower whorls, which distinguishes this species from L. antenna sp. n.

Habitat and distribution: Empty shells were found at the base of a limestone rock wall. This species is known from the type locality only, which is situated ca. 34 km in a straight line from the type locality of L. antenna sp. n.


 Barna Páll-Gergely, András Hunyadi and Takahiro Asami. 2017. A New Diplommatinid Genus and Two New Species from the Philippines (Gastropoda, Caenogastropoda, Cyclophoroidea). ZooKeys.  678; 1-10.  DOI: 10.3897/zookeys.678.13059


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