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.