Tectarius isletaensis Vera-Peláez

Martín-González, Esther, Vera-Peláez, José Luis, Castillo, Carolina & Lozano-Francisco, M. Carmen, 2018, New fossil gastropod species (Mollusca: Gastropoda) from the upper Miocene of the Canary Islands (Spain), Zootaxa 4422 (2), pp. 191-218: 209

publication ID

https://doi.org/10.11646/zootaxa.4422.2.3

publication LSID

lsid:zoobank.org:pub:4182A649-56E2-448D-B130-06FE28DEC013

persistent identifier

http://treatment.plazi.org/id/BB7C87F4-FFAD-E65E-11B9-FE7AFC72F806

treatment provided by

Plazi

scientific name

Tectarius isletaensis Vera-Peláez
status

sp. nov.

Tectarius isletaensis Vera-Peláez  sp. nov.

Figure 8 D, E View Figure

Type material. Holotype: shell of an adult specimen (H: 5.3 mm; W: 4.2 mm), with record number TFMCFO- 6335c/1. Paratypes: two adult specimens with record numbers TFMCFO-6335c/2 (H: 5.5 mm; W: 4.2 mm) and TFMCFO-6535c/3 (H: 5.2 mm; W: 4.6 mm).

Other material examined. Six specimens, all from the type locality. Biometric data are displayed in Table 8.

Type locality. La Esfinge ( Gran Canaria , Canary Islands), UTM 28 R 459801m E 3115759 m N  , 30 m asl. The level is composed of a poorly consolidated sandy matrix approximately 30 cm in thickness, with great abundance of bioclasts. Tortonian dating defined by the gastropod association described above. The paratypes are from the same type locality.

Etymology. The species name refers to La Isleta, linked to Gran Canaria by an isthmus where La Esfinge quarry is located.

Description. Shell small (Hmax: 6.3 mm; Wmax: 5.1 mm), conical-turbiniform, pyramidal. Five spire whorls. Protoconch missing or much worn. Studied specimens well preserved but slightly eroded, still displaying original color. First whorls almost twice as wide as high. The suture is strongly undulating and not very deep. Thick spiral cord on first two whorls, with rounded nodules nearly half the height of each whorl. During ontogeny, cord unfolds into two on the penultimate whorl. Growth lines well defined, strongly prosocline, and clearly visible on the last whorl. Last whorl makes up 75% of total shell height and is slightly wider than high. Spire whorls with subsutural ramp occupying 1/3 of its height, slightly concave, smooth and oblique. Below ramp, two spiral cords run parallel to each other, bearing 12–15 rounded and protruding tubercles each. Tubercles may be linked by an axial costula or alternatively separated by a very narrow space. Base flat with a very thin circular white band. A small siphonal fasciola can be seen in some specimens. Aperture holostomatous, completely circular with a weak siphonal notch, rotated adaxially. Columellar, parietal, and basal edges covered by a thin white callus. Outer lip unthickened, smooth and simple. Non-umbilicate. Intense red color. Tubercles can be red or display white ends.

Remarks. We assign Tectarius isletaensis  sp. nov. to the genus Tectarius Valenciennes, 1832  because of the conical-pyramidal shell shape with its base perpendicular to the axis (not rounded as in Littorina Fèrussac, 1822  , Melarhaphe Menke, 1828  or Nodilittorina Martens, 1897  ), the circular aperture and the indistinct short siphonal channel which is absent in these three genera.

Tectarius isletaensis  sp. nov. presents some similarity with Tectarius striatus ( King, 1832)  from which it can be separated by its thick last-whorl tubercles and by the conical-pyramidal shell shape, which is far from the typical more rounded-turbiniform shape of the latter species. The new species differs from Echinolittorina tuberculata ( Menke, 1828)  , with an amphiatlantic distribution according to García-Talavera (1986), in its greater number of tubercled cords that decorate the entire shell, its larger size and the globular profile of its last whorl. Tectarius isletaensis  sp. nov. shows great similarity to Echinolittorina granosa Philippi, 1845  from the coasts of Gabon and western equatorial Africa, but T. granosus  is distinguished by its greater size (17 mm) and by the two much finer and wider-spaced spiral cords, with very small granules that develop between them.

Regarding other forms from the European Neogene, specifically from the Bartonian of the Paris Basin, Nodilittorina guaspallensis Dolin & Pacaud, 2000  differs from T. isletaensis  sp. nov. by having spiral cords with very small nodules and from Nodilittorina lozoueti Dolin & Pacaud, 2000  by its more rounded shape and small nodules evenly scattered throughout the shell, as shown by Dolin & Pacaud (2000).

Joksimowitsch (1910) reported Tectarius  cf. nodulosus Gmelin from the Miocene of the Selvagens Islands; this material probably represents Tectarius isletaensis  sp. nov.

Distribution. Upper Miocene, Tortonian: La Isleta, Gran Canaria.

Kingdom

Animalia

Phylum

Mollusca

Class

Gastropoda

Order

Littorinimorpha

Family

Littorinidae

Genus

Tectarius

Loc

Tectarius isletaensis Vera-Peláez

Martín-González, Esther, Vera-Peláez, José Luis, Castillo, Carolina & Lozano-Francisco, M. Carmen 2018

2018
Loc

Tectarius isletaensis

Martín-González & Vera-Peláez & Castillo & Lozano-Francisco 2018

2018
Loc

Tectarius isletaensis

Martín-González & Vera-Peláez & Castillo & Lozano-Francisco 2018

2018
Loc

T. isletaensis

Martín-González & Vera-Peláez & Castillo & Lozano-Francisco 2018

2018
Loc

Nodilittorina guaspallensis

Dolin & Pacaud 2000

2000
Loc

Nodilittorina lozoueti

Dolin & Pacaud 2000

2000
Loc

Echinolittorina granosa

Philippi 1845

1845
Loc

Tectarius striatus (

King 1832

1832
Loc

Echinolittorina tuberculata (

Menke 1828

1828