Healdianella cf. subdistincta Wang, 1983

Fig. 8Q–R

Material examined

CHINA • 1 complete carapace (Fig. 8Q); Blue Snake section, Tangbagou Formation, sample 19BAI 02; P6M 3912 • 1 complete carapace (Fig. 8R); Blue Snake section, Tangbagou Formation, sample 19BAI 02; P6M 3913 • 8 complete carapaces; Blue Snake section, Tangbagou Formation, samples 19BAI 03, 19BAI 08, 19BAI 23. All from the Tournaisian, early Carboniferous.

Dimensions

RV: L = 359–697µm, H = 189–300µm, H/L = 0.42–0.52.

LV: L = 359–688µm, H = 200–291 µm, H/L = 0.42–0.56.

Remarks

This species is rare in the studied material. The specimens are morphologically close to Healdianella subdistincta Wang, 1983 from the Emsian, early Devonian of Guangxi, South China (Wang 1983a) but they have a more elongated morphology, a straight DB with Hmax developed all along DB and a straight PDB with distinct AD angulation. Healdianella subdistincta is larger, with L ranging from 1440 to 1760 µm, H from 880 to 1000µm and H/L between 0.57 and 0.61, while it is between 0.47 and 0.56 here. Our material has a small size and may correspond to juveniles so that we only compare them to Healdianella subdistincta until more material is found to clarify this issue.

Occurrence

Samples 19BAI 02, 19BAI 03, 19BAI 08, 19BAI 23, Tangbagou Formation, Blue Snake section, Tournaisian, early Carboniferous (this work).