Caudicriodus schoenlaubi, Drygant & Szaniawski, 2012

Drygant, Daniel & Szaniawski, Hubert, 2012, Lochkovian conodonts from Podolia, Ukraine, and their stratigraphic significance, Acta Palaeontologica Polonica 57 (4), pp. 833-861 : 849-850

Caudicriodus schoenlaubi sp. nov.

Fig. 11C–I.

1985 Icriodus sp. n. A; Schönlaub 1985 a: pl. 2: 17, 20 [only].

http://dx.doi.org/10.4202/app.2011.0124

2002 Icriodus vinearum Carls ; García−López et al. 2002: pl. 2: 5.

?2007 Icriodus steinachensis Al−Rawi eta morphotype Klapper and Johnson; Slavík et al. 2007: fig. 3: 4 [only].

?2012 Icriodus angustoides alcoleae Carls ; Slavík et al. (in press): fig. 6: 16.

Etymology: In honor of the Austrian geologist Hans Schönlaub, who first illustrated specimens of this species.

Type material: Holotype: well−preserved “left” Pa element ZPAL C.20/ 8.5 ( Fig. 11D). Paratypes: “right” Pa element ZPAL C.20/8.6 ( Fig. 11E).

Type locality: Outcrop 81, left side of the Dniester, above the village Vynohradiv ( Fig. 1 , Table 1), sample 81/ 380 m.

Type horizon: Upper part of Chortkiv Formation, middle– upper Lochkovian .

Material.—Eight (including holotype) complete Pa elements from the Chortkiv Formation. Sections and samples: 5/320 340, 81/ 360 m, 380 m, 11/ 375 m.

Diagnosis.—Platform of Pa element wide and comparatively short with the drop−like outline of basal cavity. Spindle with maximum six straight or slightly curved transverse ridges. Postero−lateral process short. Spur developed only in adult forms. Description.—Platform of Pa elements very wide and comparatively short, expanded in posterior part of the spindle. “Right” forms differ from the “left” by gradual widening of basal cavity and its drop−like outline. Platform of the “left” forms suddenly gets wider approximately behind the fourth transverse ridge. Spindle about 0.71–1.22 mm long, straight or slightly curved, with maximum six transverse ridges. Spur developed only in the mature forms. Postero−lateral process short, with rounded tip. Denticles of the transverse ridges and the median row joined. Those of the lateral rows are bigger and have circular base. Primary and secondary cusps equal in size and not higher than the denticles of the transverse ridges. Angle between the median row and postero−lateral process about 110–120 °.

Remarks.—New species differs from the closest Caudicriodus serus ( Drygant, 1984) by expanded, drop−like platform, less developed spur in the “left” forms and convex outer bor− der of the platform opposite to the second transverse ridge.

Some specimens of the new species ( Figs. 5 , 11I) are similar to the specimen from the middle Lochkovian of Northwestern Spain, determined as Icriodus vinearum Carls, 1975 ( García−López et al. 2002: pl. 2: 5), which differs from the typical forms by narrower and longer platform (compare with Carls 1975: pls. 2: 22–28, 3: 31–33).

The specimen from the uppermost Lochkovian, illustrated by Slavík et al. (2007: figs. 3, 4) as “ Icriodus steinachensis Al−Raw eta morphotype Klapper and Johnson, 1980 ” and characterized by straight spindle, wide platform in front of the postero−lateral process and spur merged with the inner posterior lobe is probably not an “eta morphotype” of Caudicriodus? steinachensis but close to the new species.

Stratigraphic and geographic range.— Caudicriodus postwoschmidti Zone and lower part of Caudicriodus serus Zone (middle–upper Lochkovian) in Podolia, Lebanza Formation

(middle Lochkovian) of Northwestern Spain,?upper Lochkovian in Barrandian.

Figures

Fig. 1. A. General location of the study area. B. Distribution of the subsurface Silurian and Devonian deposits in Podolia and geological setting of the area. 1, Eastern extent of the Silurian deposits; 2, Eastern extent of the Devonian Tyver Group (see Fig. 2); 3, Eastern extent of Dniester Member (Old Red Formation); 4, Western extent of the Devonian deposits. 5. Extent of the Middle Devonian deposits (area of the Lviv Depression); 6, Location of the studied borings. C. Location and numbers of the studied outcrops (see also Table 1).

Fig. 5. A. Probable phyletic relationships within Caudicriodus, based on the evidence of the Podolian collection. B. Similar forms in other regions. D., Devonian; S., Silurian; Fm., Formation. For legend see Fig. 3.