Type Material
Holotype: “Male holotype from Boquillas, Texas, USA, 7 June 1948, coll. C. and P. Vaurie (AMNH). We were able to examine the type” (Cushing et al., 2018, p. 457).
Measurements: “Males (n=8). TL 28.0-42.0; CL 9.5-14.0; CH 4.0-6.0; FNL NA; FNH 0.5; FFH 1.0-1.3; PL 29.5-40.5; PT 1.7-4.0; PMT 5.4-9.0; PT 3.0-4.5; LI 20.0-28.0; LIV 33.0-43.0; PPL 35.0-43.0; A/CP 4.7-5.5; FNL/FNH NA; FFH/FNH NA; FFH/CH 0.2-0.3” (Cushing et al., 2018, p. 458).
“Females (n=7). TL 39.0-50.0; CL 10.7-16.0; CH 4.3-6.0; PL 29.0-35.0; PT 1.7-3.5; PMT 7.0-7.9; LI 20.5-30.0; LIV 31.0-45.0; A/CP 4.6-5.0” (Cushing et al., 2018, p. 458).
Operculum Description: “Genital operculum club shaped with slender anterior arms, posterior rounded with inner edge slightly hooked posteriorly. No visible pits laterally. Genital operculum not as in fig. 31 in Muma (1951). More like E. titania fig. 38 in Muma (1951) but with wider, shorter anterior arms and larger more rounded club shape posteriorly (Fig. 4D)” (Cushing et al., 2018, p. 458).
Chelicerae Description: “Male. VDC occupies approximately half the length of fixed finger; deep, with a thin carina on the interior extending half the length of the cavity (Fig. 1E, arrow). Fixed finger broad proximally, sinuate dorsally with no median dentition. Movable finger: large MP-2 MSM the proximal larger-MM a long ridge with notch in the middle; MD also a ridge; MPL distinct (Figs. 2O & P). Fondal notch indistinct. Two distinct RFA in the notch and two tiny RFA on ventral edge of fixed finger; fondal teeth graded retrolaterally I & II (equal), III, tiny IV; prolaterally I, III, IV, tiny IV (Fig. 3E)” (Cushing et al., 2018, p. 458).
“Female. Fixed finger: FP-2 FSM-FM-FSD-FD. Movable finger: MP-2 MSM-MM; large MPL (Figs. 2Q & R). One large RFA; fondal teeth I, III, II, IV (III almost the same size as I) retrolaterally and prolaterally” (Cushing et al., 2018, p. 458).
Diagnosis: “Eremocosta gigasella is distinguished by the lack of a fondal notch on the male fixed finger (Figs. 2O & P). All other species in the genus have a moderate fondal notch to distinct fondal notch. On the male fixed finger, the relatively flattened MM is also distinctive as well as the presence of an apparent MD or a tooth-like structure at the distal location of the movable finger (Fig. 20, arrow). The female genital operculum is similar to that of E. titania; however, the two species can be easily distinguished with the posterior part of arms of E. gigasella more rounded and the inner edge slightly hooked (compare Figs. 4D & F)” (Cushing et al., 2018, p. 458).
Other Information: “This species was described by Muma (1951) as E. gigas. This species is a Chihuahuan Desert inhabitant extending from New Mexico (Brookhart & Brantley 2000) into the Big Bend region of Texas and south into the Mexican states of Chihuahua, and Coahuila. The collection of this species by David Footle (personal comm.) from 20 pitfall arrays in Big Bend National Park resulted in 24 males, 24 females from April to August. They were collected in 5 of the 20 arrays set up by the collector in the park. Brookhart & Brantley (2000) identified this species as far north and west as Socorro, New Mexico, USA” (Cushing et al., 2018, p. 458).
Eremocosta gigasella – male holotype
AMNH
Originally IDd as Eremorhax gigasellus n. sp. By Martin H. Muma, 1968
TEXAS: Boquillas; June 7, 1948; coll. C. & P. Vauries
Measurements:
| Char | Char description | M (mm) |
| CL | chelicerae length | 10.29 |
| CH | Chelcera height | 4.71 |
| FNL | Fondal notch length | 0.22 |
| FNH | Fondal notch height | 0.56 |
| FFH | Fixed finger height | 1.16 |
| LI | First leg length | 27.86 |
| LIV | Fourth leg length | 43.00 |
| PPL | Propeltidium length | 1.15 |
| PPW | Propeltidium width (from bottom edge where “ears” begin) | 7.40 |
| PL | Palpus length | 35.29 |
| PMT | Palpal metatarsus length | 8.30 |
| PT | Palpal tarsal length | 2.15 |
| TL | Total length | 36.50 |
Notes:
Pedipalp – no color
Pedipalp – no papillae
Notes: took photo of left chelicerae fondal teeth because I was unable to pull right (removed) cheliceral fingers open enough.
