Caudicriodus transiens ( Carls and Gandl, 1969 )

Drygant, Daniel & Szaniawski, Hubert, 2012, Lochkovian conodonts from Podolia, Ukraine, and their stratigraphic significance, Acta Palaeontologica Polonica 57 (4), pp. 833-861 : 848

Caudicriodus transiens ( Carls and Gandl, 1969)

Figs. 9C , 10E, I.

Pa element

1968 Icriodus eolatericrescens sp. n.; Mashkova 1968b: 942 [partim].

1969 Icriodus woschmidti transiens n. ssp.; Carls und Gandl 1969: 174, pl. 15: 1–7.

1970 Icriodus angustoides bidentatus Carls and Gandl, 1969 ; Mashkova 1970: fig. 1: 1–6 [form juv.].

1970 Icriodus woschmidti transiens Carls and Gandl, 1969 ; Mashkova 1970: fig. 1: 7–9 [form adult.].

1975 Icriodus postwoschmidti Mashkova ; Klapper in Ziegler 1975: 155 (partim), Icriodus plate 5: 5 (non 3, 4 = Caudicriodus postwoschmidti [Mashkova, 1968] and 6 = Caudicriodus hesperius [ Klapper and Murphy, 1975]).

1984 Icriodus woschmidti transiens Carls and Gandl,1969 ; Drygant 1984: 134 [partim], pl. 16: 5, 6, 8, 12–16 [non 7, 9–11 = Caudicriodus ruthmawsonae Drygant, 2010 ].

1984 Icriodus eolatericrescens Mashkova ; Drygant 1984: 135, pl. 16: 17–19.

non 1994 Icriodus woschmidti transiens Carls and Gandl, 1969 ; Valenzuela−Ríos 1994: 88, pl. 8: 20.

2010 Caudicriodus transiens ( Carls and Gandl, 1969) ; Drygant 2010: 60, pls. 2: 19, 3: 7–15.

Other (coniform) elements

1974 Rotundacodina dubia (Rhodes) ; Drygant 1974: pl. 2: 26–29. 1974 Acodina triquetra (Jentzsch) ; Drygant 1974; pl. 2: 13 [?12].

1974 Rotundacodina noguerensis Carls and Gandl ; Drygant 1974: pl. 2: 24, 25.

1974 Rotundacodina elegans Carls and Gandl ; Drygant 1974: pl. 2: 19–21.

1974 Rotundacodina quadratibasis sp. n.; Drygant 1974: 69, pl. 2: 9–11.

1974 Drepanodus ? curvatus (Rhodes); Drygant 1974: pl. 2: 18.

1984 Rotundacodina dubia Carls and Gandl ; Drygant 1984: 76, pl. 1: 48–52 [non pl. 1: 47].

1984 Acodina triquetra (Jentzsch) ; Drygant 1984; 75, pl. 1: 30 [?29].

1984 Rotundacodina noguerensis Carls and Gandl ; Drygant 1984: 77, pl. 1: 36, 37.

1984 Rotundacodina elegans Carls and Gandl ; Drygant 1984: 76, pl. 1: 40–42.

1984 Rotundacodina? quadratibasis Drygant ; Drygant 1984: 78, pl. 1: 43–45.

1984 Rotundacodina rotunda sp. n.; Drygant 1984: 77, pl. 1: 46.

For more extensive synonymy see Drygant (2010).

Material.—More than 120 Pa and about 300 (not separated from the elements of other Caudicriodus species) coniform elements from the Mytkiv Formation. Sections and samples: 12/1a, 2, 17/4v, 18/1, 5, 5d, 5e, 6, 18A/5, 45/180, and 170–180 m.

Remarks.—Juvenile Pa elements of the species possess narrow, wedge−shaped platform which in the later ontogeny become wider, mainly because of the better development of the spur. Number of the transverse ridges in adult specimens is up to six. Length of the spur 0.9–1.1 mm. Postero−lateral process triangular, more or less elongated, straight, laterally compressed, bears a single ridge of denticles. Inner and outer lobes undenticulated. Basal cavity lobe−like, expanded behind the second or third transverse ridge. Primary and secondary cusps high, approximately equal.The angle between anterior and postero−lateral processes not bigger than 120–140 ° in “right” elements and 105–125 ° in “left”. In stratigraphically older specimens “right” elements differ from the “left” by lack of the spur and longer postero−lateral process.

Representatives of the species differ from the related Caudicriodus woschmidti ( Ziegler, 1960) by the laterally expanded platform and possession of straight and narrow postero−lateral process. From C. hesperius ( Klapper and Murphy, 1975) they differ by triangular and shorter postero−lateral process, shorter inner posterior lobe and anteriorly expanded basal cavity.

All elements constructing apparatus of C. transiens from the Chortkiv deposits of Podolia (samples 18/5, 18/5d and 18/5e) were described and illustrated by Drygant (1974, 1984).

Stratigraphic and geographic range.— Caudicriodus transiens Zone in Podolia, Luesma Beds of Iberian Chains ( Spain).

Figures

Fig. 9. Ontogenetic development and morphological comparison of Pa elements of Podolian Caudicriodus species.