Spinopyrgus luismaedai Czaja, Covich, Neubauer & Estrada-Rodríguez, 2022
|
publication ID |
https://doi.org/ 10.11646/zootaxa.5169.5.5 |
|
publication LSID |
lsid:zoobank.org:pub:77339EEB-28FC-4D5A-AB22-9AACA4DF3050 |
|
DOI |
https://doi.org/10.5281/zenodo.7305277 |
|
persistent identifier |
https://treatment.plazi.org/id/03C4F212-A303-FF81-A6AD-FA8D9267D628 |
|
treatment provided by |
Plazi |
|
scientific name |
Spinopyrgus luismaedai Czaja, Covich, Neubauer & Estrada-Rodríguez |
| status |
n. gen. et n. sp. |
Spinopyrgus luismaedai Czaja, Covich, Neubauer & Estrada-Rodríguez View in CoL n. gen. et n. sp.
( Figures 2A View FIGURE 2 to 3P)
ZooBank registration number: urn:lsid:zoobank.org:act:385187F6-986B-4200-84D1-91147F22F4D1
Etymology. The new species is named in honor of Dr. Luis Maeda Villalobos, Torreón, Coahuila, who was the first collector of fossil snails at Viesca.
Holotype. Specimen UJMC-250 ( Fig. 2A, B View FIGURE 2 ).
Type locality. Superficial sediments in the desiccated Juan Guerra spring, ca. 1 km south of Viesca, Coahuila, Mexico. Collected by Alexander Czaja and José Luis Estrada-Rodríguez, 2014 ( Figure 1 View FIGURE 1 ).
Type material. Holotype ( Fig. 2A, B View FIGURE 2 ), UJMC-250 from Juan Guerra spring, Viesca, 25° 19’ 17’’N, 102° 49’ 08’’W, paratypes ( Figs. 2C–F View FIGURE 2 ), UJMC 251 , UJMC 252 , UJMC 252 a GoogleMaps . Paratypes 1, 2 and 3 from the same lot as the holotype.
Type horizon. Holocene (sub-fossil).
Studied material. 154 specimens from the type locality ( UJMC 250-252 b, 254) , 45 specimens from El Molino spring ( UJMC 253-253 c) and 50 specimens from Hacienda de Hornos y Carranza spring ( UJMC 257-257 c) .
Occurrence. Endemic to Juan Guerra, Hacienda de Hornos y Carranza and El Molino springs near Viesca, Coahuila, Mexico.
Diagnosis. Shell medium-sized, usually light brown or (when blanched) white, narrow-conic, variably umbilicate to imperforate. Aperture round polygonal, inner lip adnate. Teleoconch whorls having one to three distinct keels sculptured with broad, strong, conical spines.
Description. Shell medium-sized, thickened, imperforate, and conical, up to 7.25 whorls, the holotype has 6.25 whorls, first two rounded. The apex is acute and inclined, protoconch consisting of about one whorl, smooth or slightly wrinkled, measuring 160–180 µm in diameter. A shoulder frequently develops on early teleoconch whorls. The slightly corrugate nucleus is narrow and immersed and has 40–50 μm in diameter. Protoconch-teleoconch boundary is clearly discernable, characterized by the onset of fine, axial growth lines, which are prosocline on first whorls and later become almost orthocline. Teleoconch whorls have fine or often more pronounced irregular axial ribs ( Fig. 2J View FIGURE 2 , 3O View FIGURE 3 ), as well as two to three spiral carinae. Because of the strong carinae the whorls appear more angular than rounded ( Fig. 2A–H View FIGURE 2 , 3L View FIGURE 3 ). Along the central carina, many axial ribs extend into strong spines on the periphery. The spines are regularly spaced and always in the middle part of the whorl. The last three or four whorls are geniculate, angled at location of carina. Body whorl large, almost always having a second carina with spines on the lower side, sometimes with a third carina ( Fig. 2E, F View FIGURE 2 ). Whorls mostly with very pointed, shovel-shaped spines, with up to 30 spines on the body whorls, spines very pointed. The spines like all other shell ornamentations are part of the calcareous shell material. Suture slightly impressed. Many shells conserve still their thin light-brown periostracal layer ( Figs. 2C–J View FIGURE 2 ). Aperture polygonal, mostly pentagonal in shape ( Figs. 2A, E, G View FIGURE 2 ), slightly longer than wide. Parietal lip adnate, the basal and outer lip rounded and thin. Opercula were not preserved.
Shell measurements (mean ± standard deviation in parentheses; n = 20). SH 4.64 (0.46) mm, SW 2.19 (0.31) mm, WN 6.05 (0.49) whorls (shells from Juan Guerra spring).
Measurements of Holotype. SH 4.91 mm, SW 2.72 mm, AH 1.89 mm, AW 1.83 mm, AH/SH 0.39, WN 6.25 whorls.
Remarks. The prominent spine ornamentations of S. luismaedai with extremely long and almost “marinelike” spines are not seen in any other North American gastropod species. All spines are built completely of shell material and are not made of a combination of shell material and periostracal projections, like in some other spiny Pyrgophorus Ancey (Cochliopidae) or Potamopyrgus Stimpson (Tateidae) species. The variability of the shell ornamentations is remarkable especially regarding the number and form of the spines ( Fig. 2C–K View FIGURE 2 ). Most of the shells are turriform with 5–7 elongated whorls ( Fig. 2A–H View FIGURE 2 ), but there are also in all springs a sub-population with a more rounded general form and less than 5 whorls. This variability could be an indication of different ecophenotypes within the S. luismaedai populations.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
|
Kingdom |
|
|
Phylum |
|
|
Class |
|
|
Order |
|
|
Family |
|
|
Genus |