Criosarasinella cf. subheterocostata Reboulet, 1996

Vašíček, Zdeněk, Błażejowski, Błażej, Gaździcki, Andrzej, Król, Maria, Lefeld, Jerzy, Skupien, Petr & Wierzbowski, Andrzej, 2020, Early Cretaceous ammonites and dinoflagellates from the Western Tatra Mountains, Poland, Acta Palaeontologica Polonica 65 (4), pp. 799-810 : 803-804

Criosarasinella cf. subheterocostata Reboulet, 1996

Fig. 3A, C–E .

Material.—Four incomplete outer moulds (ZPAL 25/7, 14, 17, 19) with a preserved part of the ultimate whorl and preserved part of the penultimate whorl, with one exception (ZPAL 25/14). All from Cretaceous, Tatra Mountains, Poland.

Description.—The involute specimen with moderately low, slightly vaulted whorls. The ultimate whorl bears relatively strong, slightly arched ribs with inter­rib spaces broader than the ribs. Ribs running from the umbilicus in pairs can be sporadically found between simple ribs which do not start at tubercles near the line of coiling. The ribs are convexly bent near the umbilicus over a short section towards the aperture and then become slightly concavely curved on the flanks. Some ribs bifurcate close to the venter. Only on one specimen, a print can be found over a very short section of the penultimate whorl which bears distinct thin and dense subradial ribs. Simple ribs prevail over sporadically appearing shorter inserted ribs.

Measurements.—The most complete specimen ZPAL Am. 25/17 reaches a maximum diameter of 62 mm. In the penultimate whorl, at D = 39 mm, H is approximately 14.0 mm

H/D = 0.36), U approximately 15.0 mm (U/D = 0.38).

Remarks.—Preservation of the specimen from the Tatra Mountains is definitely unfavourable to an unambiguous identification. Criosarasinella furcillata Thieuloy, 1977 and Criosarasinella mandovi Thieuloy, 1977 seem to be relatives, not varying much from the studied material. The last species was mentioned by Lefeld (1974: 351, pl. 10: 1) from the Kościeliska Marl Formation of the Tatra Mountains identified as Crioceratites aff. sornayi ( Sarkar, 1955) , see Thieuloy (1977: 110). According to Reboulet (1996) Criosarasinella subheterocostata occurs in the uppermost Valanginian (together with the zonal species C. furcillata ). Typical C. subheterocostata is known from France as well as from the Ladce Formation ( Criosarasinella furcillata Zone ), the Butkov Quarry (Western Slovakia; see Vašíček 2005).

Figures

Fig. 3. The Lower Cretaceous ammonites from the Kościeliska Marl Formation in the Lejowa Valley, Tatra Mountains, Poland. A, C–E. Criosarasinella cf. subheterocostata Reboulet, 1996. A. ZPAL Am. 25/19. C. ZPAL Am. 25/7. D. ZPAL Am. 25/17. E. ZPAL Am. 25/14. B. Calcite valve of aptychus Didayilamellaptychus seranonis (Coquand, 1841), ZPAL Am. 25/12. F. Spitidiscus cf. cankovi Vašíček and Michalík, 1986, ZPAL Am. 25/9. G. Olcostephanus densicostatus (Wegner, 1909), ZPAL Am. 25/4.All in lateral view.