Cribrospira paradenticulata, Liu & Vachard & Cózar & Coronado, 2023

Liu, Chao, Vachard, Daniel, Cózar, Pedro & Coronado, Ismael, 2023, New species and evolution of the foraminiferal family Janischewskinidae in the middle-upper Mississippian of South China, Palaeontologia Electronica (a 2) 26 (1), pp. 1-27 : 11-12

Cribrospira paradenticulata sp. nov.

Figure 6G‒H

zoobank.org/ 090413BF-19F5-4E87-B059-D1B7BA103028

Derivation of the Name. For its similarity with C. denticulata .

Material. Holotype ( HPU-SDB114-2 , Figure 6G ) and four paratypes ( Table 1 ).

Repository. School of Resources and Environment, Henan polytechnic University ( HPU).

Type Locality and Horizon. Shuidong section, Mikhailovian (late Viséan).

Occurrence. Middle Viséan to early Serpukhovian in the Shuidong section, and early Serpukhovian in the Kacai section.

Diagnosis. Cribrospira of moderate-small size with tooth-like septa and moderate evolution rate between whorls.

Description. Test free, composed of 2‒2.5 whorls, of which, coiling initially irregular in a different plane, and the final or final 1.5 are planispiral, with a diameter (D) between 670 and 1200 μm. Wall granular, calcareous. Septa slightly directed backward, short, pointed to swollen. The evolution rate increases between whorls slowly and uniformly. Height (H) of the lumen in the final chamber is 130‒280 μm, with a low H/D ratio of 0.14‒0.29. Number of chambers is moderate, ranging in the last whorl between 9 and 11. Thickness of the wall in the last chamber is 20‒45 μm. Rudimentary cribrate aperture composed of a few holes concentrated in the lower part of the apertural face.

Remarks. The species differs from C. denticulata by a higher number of chambers for similar number of whorls, larger diameter, more rudimentary aperture, thicker wall, and the occurrence of some swollen septa. It differs from other species of the genus by the shape of the septa and the granular wall.

Figures

FIGURE 6. A. Typical representatives of the genus Cribrospira recorded in South China. Cribrospira mikhailovi Rauser-Chernousova, 1948c, HPU-SDB140-5. B. Cribrospira mira Rauser-Chernousova, 1948c, HPU-KC10-2. C. Cribrospira panderi Möller, 1878, HPU-SDB137-3. D. Cribrospira baliamadeni Pille, Vachard and Argyriadis in Pille et al., 2010, HPU-KC66-2. E. Cribrospira orbiculata (Ganelina, 1956), HPU-SDB144-9. F. Cribrospira lianxianensis Lin, 1981, HPU-SDB147-528. G‒H. Cribrospira paradenticulata sp. nov., G. HPU-SDB114-2 (holotype), H. HPU-SDB144- 1. (Scale bar equals 1 mm, except for Figure G equals 0.5 mm).

Tables

TABLE 1. Measurements of the types in Cribrospira paradenticulata sp. nov. (in microns). Abbreviations: D — diameter of the test; W — width of the tests; Iprol — inner diameter of the proloculum; Nw — number of whorls; NcLw — number of chambers in the last whorl; Hlc — height of the last chamber; Wt — Wall thickness in the last whorl.

		Specimen	D	W	Iprol	Nw	NcLw	Hlc	Wt	Hlc/D
83	SDB17(5)-3	HPU-SDB17-3	670	—	—	>2	9	190	20	0.283
84	SDB114(5)-2	HPU-SDB114-2	770	—	—	>2	10	130	30	0.168
88	SDB144(2.5)-1	HPU-SDB144-1	1210	605	—	2	10.5	200	45	0.165
90	SDB173(5)-5	HPU-SDB173-5	950	—	60	>2	11	280	25	0.294
148	KC76(5)-1	HPU-KC76-1	1225	—	—	2.5	10.5	175	35	0.143