Parachondria cordovanus (Pfeiffer, 1857)

Figure 9 A– O, 12 A

Type material. “Musée Cuming et dans ma collection;” MNHN (5), syntypes (only one referenced online: MNHN-IM-5418) (figs. 9 B, C); NHMUK unnumbered (3), specimens bearing Pfeiffer’s handwriting are probable syntypes; ZMB 65687 (1), possible syntype.

Type locality. “ Cordova Status Vera Cruz.”

Type figured. Pfeiffer, 1857: pl. 25, figs. 18, 19.

Cresonymy.

Chondropoma cordovanum Pfeiffer, 1857: 91 –92, pl. 25, figs. 18, 19; Reeve, 1863a: pl. 4, fig. 24; Martens, 1865: 6 –7; Pfeiffer, 1865: 154; Bland, 1866: 61; Bland, 1868: 179; Pfeiffer, 1876: 196; Martens, 1890: 15, 17; Fischer & Crosse, 1890: 207 –210, pl. 41, figs. 6, 6a, 6b; Crosse, 1890: 56; Solem, 1961: 204 –205, 211, pl. 11, figs. 15–17, map 2; Chevallier, 1965: 29 [in synonymy of Cyclostoma rubicundum Morelet, 1849]; Watters, 2006: 216.

Chondropoma (Chondropomium) cordovanum (Pfeiffer, 1857). Baker, 1928: 50; Thompson, 2011: 44, 295.

Chondropoma cordovanum (Pfeiffer, 1857). Chevallier, 1965: 29 [in synonymy of Cyclostoma rubicundum Morelet, 1849].

Halotudora cordovana (Pfeiffer, 1857). Watters, 2006: 73, 216.

Distribution and habitat. Limestone ridges on the Tabasco Plain above the northeast face of Sierra Madre Oriental and the southeast face of Sierra Chiconquiaco in Oaxaca and Veracruz states, usually from 75–1,200 m altitude. Parachondria cordovanus occurs farther north in México than any other species. Found in association with limestone outcrops. Locally abundant.

Conservation. Little of this species’ distribution occurs in protected areas.

Other material (specimens examined:>1,978). México. Oaxaca State: UF 211365 (3), 11.0 km WSW of Playa de Arroyo, 100 m; UF 216569 (3), Cueva Sin Fin 2.0 km S of Acatlán de Pérez Figueroa; UF 189736 (106), limestone hill 3.0 km S of Acatlán de Pérez Figueroa; UF 15932 (24), 4.0 km SW of Acatlán de Pérez Figueroa; UF 200450 (115), UF 211157 (5), 1.0 km SE of Aserradero; UF 19154 (13), UF 216568 (2), 9.2 km NE of San Juan Bautista Valle Nacional; UF 211238 (1), coffee grove on limestone ridge 1.0 km S of San Felipe Usila; UF 211245 (65), 1.0 km WNW of Bethania; UF 189793 (168), limestone ridge 3.5 km SW of Bethania; UF 200537 (16), limestone ridge 12.0 km NW of Bethania; UF 211269 (>200), limestone ridge 4.0 km SSE of Bethania, 100 m; UF 214024 (11), limestone ridge 3.0 km WNW of Mazín Grande; UF 211173 (17), limestone ridge 8.0 km ESE of Mazín Grande; UF 200486 (2), limestone ridge 1.5 km SE of Tembladera de la Selva # 1, 150 m; UF 337238 (2), limestone ridge 3.0 km NE of Tembladera de la Selva # 1, 140 m; UF 159475 (51), limestone ridge 1.0 km S of El Cedral; UF 159446 (2), 1.0 km S of Temascal; UF 337269 (17), 3.5 km NW of Temascal, 80 m; UF 159519 (43), 5.0 km NW of El Capillo; UF 200517 (196), limestone ridge 0.5 km N of La Joya de Santa María Jacatepec; UF 337214 (17), UF 337227 (17), limestone ridge 11.0 km SW of Tierra Blanca, 100 m; UF 337257 (62), 2.0 km S of Tembladeras de Castillo, 150 m; UF 211332 (63), 5.0 km ENE of Cuauhtémoc, 75 m. Veracruz State: UF 337127 (9), UF 337207 (4), hill above Santa Rosa 2.5 km ESE of San Rafael Calería, 1,200 m; UF 341557 (2), 2.0 km N of San Rafael Calería, 1,100 m; UF 337135 (75), limestone hill 2.0 km E of Colonia Nuevo Toxpan, Córdoba, 820 m; UF 337180 (14), limestone hill 4.0 km E of Colonia Nuevo Toxpan, Córdoba, 910 m; UF 190801 (23), Cerro de Las Palmas 1.0 km E of Berlin, 980 m; UF 190866 (>300), Cerro de Las Palmas 1.0 km N of San Mateo, 910 m; UF 77506 (5), Atlaakia de Sintempo; UF 81785 (73), UF 81808 (10), 1.0 km NE of Comalapa; UF 81874 (11), UF 81902 (15), 2.0 km NE of Comalapa; UF 81925 (21), 4 km NE of Comalapa; UF 81990 (3), 5.0 km NE of Comalapa; UF 81892 (11), UF 81961 (34), 6.0 km NE of Comalapa; UF 190951 (12), El Sumidero; UF 159327 (10), UF 216570 (18), 3.1 km SW of Fortín de las Flores; UF 190903 (22), limestone hill 3.0 km NE of Atoyac; UF 216571 (12), 4.7 km E of Córdoba; UF 159353 (24), limestone ridge 4.0 km ESE of Córdoba; UF 190917 (41), limestone hill 1.0 km NW of Atoyaquillo; UF 76424 (7), Ojo de Agua; UF 159294 (1), mountain crest 7.0 km NE of Orizaba.

Description. Shell conical, moderately high-spired, rather solid. Smallest adult specimen seen 7.6 mm in length, largest 14.5 mm, average 10.7 mm (non-decollate). Protoconch retained, 1.5 large, rounded, smooth whorls, dark brown or banded, earliest portion paler, not clearly demarcated from teleoconch. Teleoconch of 4.5–5 rounded whorls. Umbilicus open, wide. Spiral sculpture absent except for 1–3 weak cords in the umbilicus. Axial sculpture of erect, regularly spaced, thin, blade-like lamellae, spacing varying from close-set to widely separated. Suture strongly indented. Tufts absent but the axial lamellae may render the suture serrate. Aperture nearly circular. Inner lip smooth, narrowly exserted. Outer lip lamellate, reflected rather widely perpendicular to whorl, more or less evenly expanded, somewhat narrower facing umbilicus, slightly auriculate posteriorly, adnate to previous whorl. Base color tan, spire may be darker than final whorls. Unicolor or spotted or banded with brown, continuous over adapertural face of peristome, visible inside aperture. Peristome white or red. Operculum paucispiral, flat, with a thin calcareous deposit. Radula and anatomy unknown.

Variation in specimens. Strength of and distance between axial lamellae vary within the same population (figs. 9 M– O.). Color varies considerably, from unicolor to spotted.

Comparison with other species. Parachondria cordovanus is obviously closely related to P. rubicundus. Parachondria rubicundus differs in having a generally shorter spire, less inflated whorls, and a narrower outer lip. The color bands often appear on the face of the outer lip in P. cordovanus but rarely do so in P. rubicundus. In shell characteristics both species are similar to G. chiapasense and G. sumichrasti but are readily distinguished by the multispiral, lamellate operculum found in those species.

Remarks: Historically two taxa have been discussed as either distinct or as variations of one species: a northwestern species (Chondropoma cordovanum Pfeiffer, 1857) in Oaxaca and Veracruz states, México, and a southeastern species (Cyclostoma rubicundum Morelet, 1849, including Cyclostoma acerbulum Morelet, 1851) in Guatemala and southern Belize. Both were known to have the same two intergrading color morphs, a reddish form and a white form, with or without spots. Solem (1961) considered them distinct while acknowledging that further collections could prove them all synonymous. Thompson (2011) also maintained them as distinct. Chevallier (1965) listed C. cordovanum as a synonym of C. rubicundum without comment.

While Solem (1961) had a good sample size of P. rubicundus, he apparently had very few examples of P. cordovanus. This study, based primarily on the UF collections, greatly increases the number of specimens available for study of these taxa (>2,300 specimens from ca. 100 lots) and expands the known range of both species, including into the important intervening area of Palenque in Chiapas State. The results here suggest that Solem’s and Thompson’s separation into two species seems correct. Solem (1961) suggested that P. cordovanus and P. rubicundus could be distinguished by the former having a more widely expanded outer lip, finer sculpture, and more strongly rounded whorls than the latter; this appears to be the case. Nevertheless, both species are obviously closely related and share many of the same characteristics, including having the same range in color and banding.

Original description (translated here from Latin). “Shell narrowly perforated, turreted, entire, thin, with crowded longitudinal plications, slightly shiny, pale brown, colored with interrupted brown bands; spire regularly turreted, top often violet, apex shining submammilate, corneous; 7–7.5 very convex whorls, last not solute; aperture vertical, oval; peristome double: inner white, briefly erect, outer rather narrow, horizontally continuous, concentrically striate, brown spotted, top produced, nearly cut at penultimate whorl.—Operculum white.” 13–15.5 mm.

Etymology. Cordoba, México.