Patella mahamensis Martín-González

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: 200-202

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-FFB6-E647-11B9-FBE8FC9CFE3F

treatment provided by

Plazi

scientific name

Patella mahamensis Martín-González
status

sp. nov.

Patella mahamensis Martín-González  sp. nov.

Figure 5 G, H, I View Figure

1976 Patella cf. intermedia (Jeffreys)  . Meco: pp. 78,83.

Type material. Holotype: Medium-size adult specimen with broken apex (L: 34.7 mm; W: 25.1 mm; H: 11.5 mm), record number TFMCFO-4605. Paratypes: Four samples, two of them very well conserved, with record numbers TFMCFO-4602 (L: 22.2 mm; W: 17.3 mm; H: 9.7 mm); TFMCFO-4 606 (L: 32 mm; W: 21.8; H: 13.2 mm); TFMCFO-4606b (L: 40.6 mm; W: 29.4 mm; H: 15.6 mm); TFMCFO-3527 (L: 22 mm; W: 14.9; H: 8.1 mm).

Type locality. Barranquillos Blancos ( Fuerteventura , Canary Islands). UTM 28 R 590819 m E 3156129 m N  , 15 m asl. The level is composed of cemented biogenic sandstones with basaltic boulders, approximately 1 m thick. Tortonian dating, defined by the gastropod association described above. The paratypes are from Playa del Valle and Barranco del Cuervito, both in Fuerteventura. 

Etymology. The species name derives from Maham, name of the subbmarine edifice common to the modern islands Lanzarote and Fuerteventura.

Description. Shell small (Lmax: 40.6 mm; Wmax: 29.4 mm; Hmax: 15.6 mm), slightly conical, longer than wide. Fragile apex, present in a single shell (although severely worn away), situated further towards anterior region. Very fluted sculpture (between 25 and 30 ribs) starting from the very apex, with three slightly pronounced ribs in the posterior region. Deep narrow flutes divide these ribs. All grooves display concentrically arranged nodules or scales. Growth lines barely visible. In ventral view, the shell profile is quadrangular and sinuous in contour. The mantle edge of the studied specimens leaves no impression.

Remarks. The shell of P. mahamensis  sp. nov. is very similar to that of P. intermedia Murray, 1857 in Knapp  , although the latter has a more rounded profile. Its radial ribs are more numerous and more evenly thick. However, in the fossil species P. mahamensis  sp. nov. from the Canary Islands, the posterior ribs are more robust than the anterior ribs. Furthermore, the apex of P. intermedia  is closer the center, whereas in P. mahamensis  sp. nov., it is located towards the anterior end.

The fossil taxon P. mahamensis  sp. nov. resembles P. vulgata Linnaeus, 1758  in shell shape and in the position of the apex closer to the anterior region; however, P. vulgata  has a higher shell. Patella mahamensis  sp. nov. has a more quadrangular profile with a rough margin, whereas the extant species P. vulgata  displays an oval profile and a smooth margin. Finally, the main ribs are located near the center of the posterior region in the fossil species P. mahamensis  sp. nov. while in P. vulgata  , they are more equally distributed. Patella rustica Linnaeus, 1758  , another taxon similar to P. mahamensis  sp. nov., is characterized by black tubercles in a spiral arrangement on the radial ribs. It is also higher and more conical than the fossil species P. mahamensis  sp. nov., with an apex in a notably posterior position, a fine edge and a rounded profile. These same features differentiate P. mahamensis  sp. nov. from P. piperata Gould, 1846  , a species closely related to P. vulgata  , but distributed across the Canary Islands and Madeira.

Patella mahamensis  sp. nov. resembles P. ulyssiponensis Röding, 1798  in some aspects. However, P. mahamensis  sp. nov. is smaller, has a more rounded profile and an apex situated in the posterior region. Patella mahamensis  sp. nov. shows groups of main ribs located close to each other with two intercalated moderatelydefined secondary ribs. However, in the extant species P. ulyssiponensis Röding, 1798  the main ribs are not well differentiated from the secondary ones and are arranged more towards the sides. Finally, Patella lugubris Gmelin, 1791  from Cape Verde has a more rounded profile, an anteriorly located apex and more evenly thick ribs than Patella mahamensis  sp. nov. Table 3 contains the biometric variables and descriptive statistics for P. mahamensis  sp. nov.

Distribution. Upper Miocene, Tortonian, Fuerteventura.

Kingdom

Animalia

Phylum

Mollusca

Class

Gastropoda

Order

Archaeogastropoda

Family

Patellidae

Genus

Patella

Loc

Patella mahamensis Martín-González

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

2018
Loc

Patella mahamensis

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

2018
Loc

P. mahamensis

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

2018
Loc

Patella mahamensis

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

2018
Loc

Patella mahamensis

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

2018
Loc

P. mahamensis

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

2018
Loc

P. ulyssiponensis Röding, 1798

Roding 1798

1798
Loc

P. ulyssiponensis Röding, 1798

Roding 1798

1798
Loc

Patella lugubris

Gmelin 1791

1791