Scutalus phaeocheilus
Encyclopedia
Scutalus phaeocheilus is a species
of tropical air-breathing land snail
, a pulmonate gastropod mollusk in the family Orthalicidae
.
Scutalus phaeocheilus phaeocheilus occurs in south of the Lambayeque Region
.
(1897), who copied the original description, the ‘granulation [is] confined to the last whorl’. However, Scutalus phaeocheilus altoensis is smaller and slightly stouter than Scutalus proteiformis and is also slightly more granulose than this species, especially visible in fresh specimens. Moreover, Scutalus proteiformis is said to have the aperture dark brown coloured. Scutalus proteiformis species, which has not been figured, was mentioned by Weyrauch (1967) from northern Peru without further information.
, the type locality.
Scutalus phaeocheilus altoensis is characterized by the whitish colour, the sculpture
of growth striae and inconspicuous granules on the last whorl, the broadly expanded lip and the orange colour of the aperture
inside.
The height of the shell is up to 38.1 mm, 1.71 times as long as wide, deeply perforated, conical, with slightly convex sides and solid. Colour is uniformly (greyish-)whitish, the upper whorls
somewhat lighter in greyish-white specimens. The surface is lustreless, with incrassate growth striae and inconspicuous granulation, under a strong lens visible as spiral rows of shallowly raised, short oblong granules; only in fresh specimens this granulation may be observed on the third and following whorls. Protoconch
is pit-reticulate. The shell has 5.7-6 whorls, that are somewhat convex. Suture is impressed, crenulated, at the aperture ascending in front. Aperture
is large, ovate, in fresh shells orange inside; margins converging; 1.33 times as long as wide, 0.73 times the total height. Peristome broadly expanded and reflexed, whitish. Columellar margin straight, broadly expanded and merging into the parietal callus, which is whitish and thickened in some specimens.
The width of the shell is 19.9 - 22.7 mm. The height of the shell is 34.3 - 38.1 mm. The width of the aperture is 14.2 – 17 mm. The height of the aperture is 19.3 - 22.8 mm. The height of the last whorl is 25.1 – 28 mm.
The holotype of Scutalus phaeocheilus altoensis has 5.8 whorls and dimension of holotype are as follows: The width of the shell is 21.4 mm. The height of the shell is 37.2 mm. The width of the aperture is 14.6 mm. The height of the aperture is 19.5 mm. The height of the last whorl is 25.9 mm.
Scutalus phaeocheilus altoensis differs from Scutalus phaeocheilus phaeocheilus by (1) being slightly smaller, (2) having the lip more broadly expanded and (3) having the aperture differently coloured (the nominate taxon has the aperture liver-coloured).
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of tropical air-breathing land snail
Land snail
A land snail is any of the many species of snail that live on land, as opposed to those that live in salt water and fresh water. Land snails are terrestrial gastropod mollusks that have shells, It is not always an easy matter to say which species are terrestrial, because some are more or less...
, a pulmonate gastropod mollusk in the family Orthalicidae
Orthalicidae
Orthalicidae are a family of tropical air-breathing land snails, terrestrial pulmonate gastropod mollusks are classified in the informal group Sigmurethra of the clade Stylommatophora...
.
Subspecies
- Scutalus phaeocheilus altoensis Breure & Mogollón Avila, 2010
Distribution
Scutalus phaeocheilus phaeocheilus occurs in south of the Lambayeque Region
Lambayeque Region
Lambayeque is a region in northwestern Peru known for its rich Moche and Chimú historical past. The region's name originates from the ancient pre-Inca civilization of the Lambayeque.-Etymology:...
.
Description
When describing the nominate taxon, Haas already noted the relationship with Scutalus proteiformis. He stated that this species ‘seems to lack the granules entirely’. According to PilsbryHenry Augustus Pilsbry
Henry Augustus Pilsbry was an American biologist, malacologist and carcinologist, among other areas of study. He was a dominant presence in many fields of invertebrate taxonomy for the better part of a century...
(1897), who copied the original description, the ‘granulation [is] confined to the last whorl’. However, Scutalus phaeocheilus altoensis is smaller and slightly stouter than Scutalus proteiformis and is also slightly more granulose than this species, especially visible in fresh specimens. Moreover, Scutalus proteiformis is said to have the aperture dark brown coloured. Scutalus proteiformis species, which has not been figured, was mentioned by Weyrauch (1967) from northern Peru without further information.
Scutalus phaeocheilus altoensis
The subspecific name altoensis refers to El AltoEl Alto
At one time merely a suburb of adjacent La Paz, Bolivia, on the Altiplano highlands, the city of El Alto is today one of Bolivia's largest and fastest-growing urban centers. As of the 2001 census, the population was 649,958. In 2010, the population may be nearly 900,000, or more. The city contains...
, the type locality.
Scutalus phaeocheilus altoensis is characterized by the whitish colour, the sculpture
Sculpture (mollusc)
The sculpture of a mollusc shell is the three-dimensional ornamentation on the outer surface, as distinct from the basic shape of the shell itself or colouration. Sculpture may be concave as well as convex. Sometimes it has microscopic detail. Sculpture refers to the calcareous outer layer, not the...
of growth striae and inconspicuous granules on the last whorl, the broadly expanded lip and the orange colour of the aperture
Aperture (mollusc)
The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where part of the body of the animal emerges for locomotion, feeding, etc....
inside.
The height of the shell is up to 38.1 mm, 1.71 times as long as wide, deeply perforated, conical, with slightly convex sides and solid. Colour is uniformly (greyish-)whitish, the upper whorls
Whorl (mollusc)
A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in of numerous gastropods, but it is also found in shelled cephalopods including Nautilus, Spirula and the large extinct subclass of cephalopods known as the...
somewhat lighter in greyish-white specimens. The surface is lustreless, with incrassate growth striae and inconspicuous granulation, under a strong lens visible as spiral rows of shallowly raised, short oblong granules; only in fresh specimens this granulation may be observed on the third and following whorls. Protoconch
Protoconch
A protoconch is an embryonic or larval shell of some classes of molluscs, e.g., the initial chamber of an ammonite or the larval shell of a gastropod...
is pit-reticulate. The shell has 5.7-6 whorls, that are somewhat convex. Suture is impressed, crenulated, at the aperture ascending in front. Aperture
Aperture (mollusc)
The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where part of the body of the animal emerges for locomotion, feeding, etc....
is large, ovate, in fresh shells orange inside; margins converging; 1.33 times as long as wide, 0.73 times the total height. Peristome broadly expanded and reflexed, whitish. Columellar margin straight, broadly expanded and merging into the parietal callus, which is whitish and thickened in some specimens.
The width of the shell is 19.9 - 22.7 mm. The height of the shell is 34.3 - 38.1 mm. The width of the aperture is 14.2 – 17 mm. The height of the aperture is 19.3 - 22.8 mm. The height of the last whorl is 25.1 – 28 mm.
The holotype of Scutalus phaeocheilus altoensis has 5.8 whorls and dimension of holotype are as follows: The width of the shell is 21.4 mm. The height of the shell is 37.2 mm. The width of the aperture is 14.6 mm. The height of the aperture is 19.5 mm. The height of the last whorl is 25.9 mm.
Scutalus phaeocheilus altoensis differs from Scutalus phaeocheilus phaeocheilus by (1) being slightly smaller, (2) having the lip more broadly expanded and (3) having the aperture differently coloured (the nominate taxon has the aperture liver-coloured).