Tryonia julimesensis, Hershler, Robert, Liu, Hsiu-Ping & Landye, Jerry, 2011

Hershler, Robert, Liu, Hsiu-Ping & Landye, Jerry, 2011, New species and records of springsnails (Caenogastropoda: Cochliopidae: Tryonia) from the Chihuahuan Desert (Mexico and United States), an imperiled biodiversity hotspot, Zootaxa 3001, pp. 1-32 : 24

publication ID	https://doi.org/ 10.5281/zenodo.278442
DOI	https://doi.org/10.5281/zenodo.5629211
persistent identifier	https://treatment.plazi.org/id/03E687C5-BF60-8319-FF2E-15AEFE981E95
treatment provided by	Plazi
scientific name	Tryonia julimesensis
status	sp. nov.

Treatment

Tryonia julimesensis new species

( Figs 5 View FIGURE 5 L, 11A–C, F–G, J–L)

Types. Holotype, USNM 874130, unnamed springs along east side of Río Conchos, south-southeast of Julimes, Chihuahua, 28º24'37.2" N, 105º25'21.6 " W, leg. J.J.L. et al., 5/v/1991. Paratypes (from same lot), USNM 1153671.

Etymology. A geographic epithet referring to the distribution of this species near the town of Julimes, Chihuahua.

Referred material. CHIHUAHUA. USNM 854940, topotype, R.H. and J.J.L., 9/xii/1998.

Diagnosis. Shell small, broad- or ovate-conic; penis having two distal papillae on the inner edge. Contrasted with T. chuviscarae and T. minckleyi above.

Description. Shell ( Fig. 11 View FIGURE 11 A–C) up to 2.0 mm tall, large females having 4.00–4.50 whorls, spire height 80–99% width of shell, male shells smaller than those of females. Teleoconch whorls high convex, frequently shouldered, sutures impressed, last 0.25 whorl sometimes loosened. Aperture usually rounded adapically, rarely weakly angled, inner lip complete, slightly thickened, adnate or disjunct, umbilicus narrow or open. Outer lip thin, orthocline or prosocline, weakly sinuate. Sculpture of strong growth lines, weak spiral thread also sometimes present. Periostracum light tan.

Shell measurements (mean in parentheses): height 1.54–1.98 mm (1.69), width 1.03–1.21 mm (1.09), body whorl height 1.15–1.34 mm (1.21), body whorl width 0.92–1.07 mm (0.97), aperture height 0.66–0.79 mm (0.71), aperture width 0.61–0.71 mm (0.65), total number of whorls 4.00–4.50 (4.18) (USNM 1153671, n = 15).

Measurements of holotype: height 1.90 mm, width 1.24 mm, body whorl height 1.34 mm, body whorl width 1.07 mm, aperture height 0.81 mm, aperture width 0.69 mm, 4.25 whorls.

Inner and outer sides of operculum smooth ( Fig. 11 View FIGURE 11 F–G). Radula ( Fig. 11 View FIGURE 11 J-L): dorsal edge of central radular teeth strongly concave, basal tongue rounded or V-shaped, median cusps distally pointed, parallel-sided proximally, lateral cusps four–five, basal cusps one–three (roughly equal-sized) ( Fig. 11 View FIGURE 11 K). Lateral teeth having three–four cusps on inner and four–five cusps on outer sides, length of outer wing about 160% width of cutting edge, central cusp pointed ( Fig. 11 View FIGURE 11 L). Inner marginal teeth having 16–21 cusps, outer marginal teeth having 15–20 cusps. Radula data are from USNM 1153671.

Animal darkly pigmented. Penis ( Fig. 5 View FIGURE 5 L) having two distal papillae on the inner edge (26 of 30 specimens), four specimens differed in having a single distal papilla. Distal bulb of penis expanded laterally on inner side, black; stylet large. Penial duct weakly undulating in medial section. Penial data are from USNM 1153671.

Distribution and habitat. Endemic to the type locality, a warm spring complex along the east side of the Río Conchos ( Fig. 1 View FIGURE 1 , locality 10). Tryonia julimesensis was abundant (on hard substrate and in detritus) in the main spring runs (44°C) ( Fig. 6 View FIGURE 6 N) when first discovered in 1991. It was also found in a small rheocrene just to the west of the main spring pools (44°C) as well as in semi-aquatic habitats on exposed rootlets and stones. When visited in 2001 the springs had been draglined (excavated) and T. julimensis could not be found. We presume that this species is now extinct.

Figures

FIGURE 6. Photographs of habitats of species treated in this paper. A. Ojo Vareleño, Chihuahua, type locality of T. peregrina sp. nov. (photograph taken on 16 / ix / 1990). B. Main spring in Yepomera, Chihuahua, T. peregrina habitat (18 / ix / 1990). C. Springs northeast of Ignacio Zaragoza, Chihuaua, type locality of T. zaragozae sp. nov. (8 / xii / 1998). D. Western-most head spring, Ojos de Arrey, Chihuahua, type locality of T. angosturae sp. nov. and T. ovata sp. nov. (7 / xii / 1998). E. Spring in northern part of El Molino, Chihuahua, type locality of T. molinae sp. nov. (26 / iv / 2010). F. Ojo del Apache, Chihuahua, type locality of T. contrerasi sp. nov. (14 / xii / 1998). G. Ojo Carbonero, Chihuahua, T. contrerasi habitat (2 / iv / 1991). H. Outflow of Ojo Caliente, Chihuahua, type locality of T. taylori sp. nov. (7 / xii / 1998). I – J. El Ojo de Servin, Chihuahua, T. taylori habitat (27 - viii- 1971, 7 / xii / 1998, respectively). K. Seeps in La Cienega, Texas, type locality of T. metcalfi sp. nov. (6 / xii / 2001). L – M. Balneario de San Diego de Alcala, Chihuahua, type locality of T. chuviscarae sp. nov. and T. minckleyi sp. nov. (4 / xii / 2001). N. Springs southeast of Julimes, Chihuahua, type locality of T. julimesensis sp. nov. (5 / iv / 1991). O. El Ojito (outflow), southwest of Talamantes, Chihuahua, type locality of T. allendae sp. nov. (10 / xii / 1998). P. Caroline Spring, Oasis Ranch, Texas, type locality of T. oasiensis sp. nov. (30 / iii / 2009). Q. Spring in Nombre de Dios, Durango, T. seemani habitat (2 / ix / 1971). R. Spring in Amado Nervo, Durango, T. seemani habitat (7 / iv / 1991).