Paraparchites pecosensis Crasquin, 2021

Tarnac, Anaëlle, Forel, Marie-Béatrice, Nestell, Galina, Nestell, Merlynd & Crasquin, Sylvie, 2021, Middle Permian ostracods (Crustacea) from the Guadalupe Mountains, West Texas, USA, European Journal of Taxonomy 770, pp. 1-60 : 26-27

Paraparchites pecosensis Crasquin sp. nov.

urn:lsid:zoobank.org:act:E76693E7-FD8A-4E7B-9328-6D3248AC584F

Figs 5D , 7D–H

Diagnosis

A species of Paraparchites with a small hemi-circular ridge at mid-H of PB on both valves and a weak overreach of RV above hinge-line.

Etymology

In reference to the Pecos River, West Texas, USA.

Material examined

Holotype USA • complete carapace, ( Fig. 7D ); Guadalupe Mountains , West Texas, Williams Ranch Member , Cutoff Formation , Quarry section, sample GM1; Roadian, Middle Permian; MNHN.F. F63404 .

Paratype USA • 1 complete carapace, ( Fig. 7H ); Guadalupe Mountains , West Texas, Williams Ranch Member , Cutoff Formation , Quarry section, sample GM1; Roadian, Middle Permian; MNHN.F. F63408 .

Additional material

USA • 1 complete carapace; Guadalupe Mountains , West Texas, Williams Ranch Member , Cutoff Formation , Quarry section, sample GM1; Roadian, Middle Permian; MNHN.F. F63405 • 1 right valve; same locality as for preceding; Roadian, Middle Permian; MNHN.F. F63407 • 1 right valve; Guadalupe Mountains , West Texas, ‘ McKittrick Canyon’ Member, Bell Canyon Formation, MKCS1 section, sample GM6; Capitanian, Middle Permian; MNHN.F. F63406 • 1 complete carapace, 52 valves; Guadalupe Mountains , West Texas, Williams Ranch Member, Cutoff Formation, Quarry section, samples GM1, GM2, GM3; Roadian; MNHN.F. F63656 • 15 valves; same locality as for preceding; ‘ McKittrick Canyon’ Member , Bell Canyon Formation , MKCS1 section, sample 2 (GM6), Capitanian; Middle Permian; MNHN.F. F63486 .

Dimensions

L= 503–2100 µm; H= 341–1467 µm ( Fig. 5D ).

Description

Carapace stocky (H/L=0.69–0.75) sub-rectangular in lateral outline; DB straight at LV; DB a little convex with weak overreach of RV above hinge-line; AB and PB quite equivalent with large radius of curvature, maximum of curvature around mid-H; VB nearly straight; LV overlaps RV all around free margins; presence of small hemi-circular ridge at mid-H of PB on both valves.

Occurrence

Samples GM1, GM2, and GM3, Quarry section, Williams Ranch Member, Cutoff Formation, Roadian; sample 2 (GM6), MKCS1 section, ‘McKittrick Canyon’ Member, Bell Canyon Formation, Capitanian; Guadalupe Mountains, West Texas, USA, Middle Permian (this work).

Remarks

Paraparchites pecosensis sp. nov. has a lateral outline similar to that of Paraparchites texanus Ulrich & Bassler, 1906 emend. Scott, 1959 from the Early Permian of Texas ( Scott 1959). The main difference between the two species is the small hemi-circular ridge at PB in the new species.

Figures

Fig. 5. Height/length scatter plots of species from the Middle Permian (Roadian, Capitanian) of the Guadalupe Mountains (West Texas, USA). A-1, A-2, A-3. Three last juvenile stages before adult.

Fig. 7 (next page). SEM micrographs of ostracods from the Middle Permian (Roadian, Quarry section, samples GM1 and GM2; Capitanian, MKCS1 section, samples 4 (GM5) and 2 (GM6)) of the Guadalupe Mountains (West Texas, USA). All specimens are temporarily housed in the collections of the Muséum national d’histoire naturelle, Paris, France (MNHN). A. Libumella cf. athabascensis Green, 1963, left lateral view of a carapace, sample GM1 (MNHN.F.F63401). – B. Fellerites? sp., external view of a right valve, sample GM1 (MNHN.F.F63402). – C. Paraparchites texanus Delo, 1930, right lateral view of a carapace, sample 4 (GM5) (MNHN.F.F63403). – D–H. Paraparchites pecosensis Crasquin sp. nov. D. Holotype, right lateral view of a carapace, sample GM1 (MNHN.F.F63404). E. Right lateral view of a carapace, sample GM1 (MNHN.F.F63405). F. External view of a right valve, sample 2 (GM6) (MNHN.F.F63406). G. External view of a right valve, sample GM1 (MNHN.F.F63407). H. Paratype, left lateral view of a carapace, sample GM1 (MNHN.F.F63408). – I. Acratia sp., right lateral view of a carapace, sample GM2 (MNHN.F.F63409). – J. Acratia cf. sinuata (Kozur, 1991), external view of a left valve, sample GM1 (MNHN.F.F63410). – K. Acratia sinuata (Kozur, 1991), external view of a left valve, sample GM1 (MNHN.F.F63411). – L–M. Bairdia radlerae Kellett, 1934. L. External view of a left valve, sample GM1 (MNHN.F.F63412). M. Right lateral view of a carapace, sample GM1 (MNHN.F.F63413). – N. Bairdia rhomboidalis Hamilton, 1942, right lateral view of a carapace, sample 2 (GM6) (MNHN.F.F63414). – O. Bairdia subfusiformis Hamilton, 1942, external view of a left valve, sample GM1 (MNHN.F.F63415). – P–R. Bairdia elcapitanensis Forel sp. nov. P. Right lateral view of a carapace, sample GM1 (MNHN.F.F63416). Q. Right lateral view of a carapace, sample GM1 (MNHN.F.F63417). R. Paratype, external view of a right valve, sample GM1 (MNHN.F.F63418). Scale bars: 100 µm.