Condylopyge cf. rex ( BARRANDE, 1846 )

Fatka, Oldřich, Knížek, František & Kozák, Vladislav, 2015, Condylopyge Hawle Et Corda, 1847 In The Příbram-Jince Basin (Barrandian Area, The Czech Republic, Agnostida), Acta Musei Nationalis Pragae Series B 71 (1 - 2), pp. 103-109 : 106-107

Condylopyge cf. rex ( BARRANDE, 1846)

Text-fig. 2a–c

1992 Condylopyge cf. rex ; Fatka and Korule, p. 50. 2004 Condylopyge cf. rex ; Fatka et al., p. 377.

M a t e r i a l a n d l o c a l i t y. The internal mould of a broken cephalon (CGS CW 17, Text-fig. 2a ) and an external mould of a pygidium (CGS FK 63, Text-fig. 2b ), preserved in purple-brown fine greywacke. Both specimens were collected at the locality Potůček near Rejkovice (= locality 12 in Fatka and Kordule 1992) in lower levels of the Paradoxides (Eccaparadoxides) pusillus Zone sensu Fatka and Szabad (2014) .

The internal mould of a cephalon (CGS CW 18, Text-fig. 2c ) preserved in green-grey mudstone and collected by one of the authors (V.K.) from the man-made excavation at the foot of the slope known as Vinice near Jince (locality 20 in Fatka and Kordule 1992) in lower levels of the Onymagnostus hybridus Zone sensu Fatka and Szabad (2014) .

D e s c r i p t i o n. Cephalon roughly rectangular, gently rounded in front with slightly medially flattened surface. Postero-lateral sides slightly diverging. Axis convex, well vaulted, reaching about 80 percent of the total cephalic length and more than half the cephalon width. Anteroglabella triangular in outline with rounded anterior and postero-lateral margins, sagittal length of anteroglabella about three-quarters of the width. Posteroglabella slightly longer (sag.) than wide (tr.), reaching slightly more than two-thirds the width of the anteroglabella. A small median tubercle developed in the centre of the posteroglabella, a more massive spine is present at the posterior end of the posteroglabella. Border furrow relatively wide, shallow, border moderately wide.

Pygidium without marginal spines, slightly longer than wide. The convex border of uniform width, anteriorly narrower. The axis long with an expanded rounded posterior lobe. Axis bears a distinct elongated keel ending at the posterior lobe. F1 and F2 orientated forward, F3 bent slightly backward.

Thoracic segments unknown.

D i s c u s s i o n. The lectotype of Condylopyge rex was selected by Šnajdr (1958, p. 52) from Barrande’s original collection housed in the National Museum Prague (coll. Barrande ČC 237, No. 1034, NM-L16556), and was figured by Barrande (1852, pl. 49, fig. 5a, b), Šnajdr (1958, pl. 2, fig. 1), Horný and Bastl (1970, pl. 1, fig. 2), Shergold et al. (1990, fig. 19.2) and Shergold and Laurie (1997, fig. 240.3).

For comparison, three specimens of Condylopyge rex from the Skryje-Týřovice Basin are presented here ( Text-fig. 2d–2f ). The C. cf. rex pygidium is morphologically identical to that of the type species (compare Text-fig. 2b and 2e ). Morphology of both cephala from the Jince Formation of the Příbram-Jince Basin agree with topotype specimens of C. rex from the Buchava Formation of the Skryje-Týřovice Basin. However, the median tubercle is situated in the middle of the posteroglabella, while in specimens of C. rex from the Skryje-Týřovice Basin this tubercle is located more anteriorly (compare Text-fig. 2a and 2c with 2d and 2f). This morphological feature excludes a definitive assignment to the type species.

D i s t r i b u t i o n. Condylopyge rex ( BARRANDE, 1846) was originally described from the “Pod hruškou” locality near Týřovice ( Šnajdr 1958, Fatka 2005). It is one of the abundant agnostids occurring in the higher stratigraphical levels of the Buchava Formation in the Skryje-Týřovice Basin of the Barrandian area ( Šnajdr 1958, Fatka 2005). This large agnostid has subsequently been found in Baltica, Avalonia and several areas in West Gondwana.

Baltica. C. rex has been reported from southern Sweden ( Tullberg 1880, Westergård 1946, Ahlberg et al. 2009, Weidner and Nielsen 2014), the Oslo area of Norway ( Høyberget and Bruton 2008) and from Pleistocene erratic boulders of northern Germany ( Rudolph 1990, 1994, Buchholz 2004).

Avalonia. C. rex has been known from Britain ( Illing 1916, Rushton 1979, Rees et al. 2013) and from south-eastern Newfoundland ( Howell 1925, Hutchinson 1962, Fletcher 2007).

West Gondwana. This agnostid species is documented from areas assigned to the Armorican Terrain Assemblage, namely in the Iberian Chains of Spain ( Sdzuy 1961, Liñan and Gozalo 1986, Chirivella et al. 2009, Gozalo et al. 2011), in Montagne Noire of France ( Courtesolle 1973, Álvaro et al. 1998), and in the Franconian Forest and Leipzig area of Germany ( Elicki 1997, Sdzuy 2000, Elicki and Geyer in Heuse et al. 2010, Geyer 2010).

Figures

Text-fig. 2. Condylopyge cf. rex (BARRANDE, 1846), middle Cambrian, latest Cambrian Stage 5 and lower Drumian, Jince Formation, Příbram-Jince Basin. a. internal mould of isolated cephalon (Specimen CGS CW 17), Potůček near Rejkovice locality (= locality 12 in Fatka and Kordule 1992) in lower levels of the Paradoxides (Eccaparadoxides) pusillus Zone. b. latex cast of external mould of isolated pygidium (Specimen CGS FK 63), Potůček near Rejkovice locality (= locality 12 in Fatka and Kordule 1992) in lower levels of the Paradoxides (Eccaparadoxides) pusillus Zone. c. internal mould of isolated cephalon (Specimen CGS CW 18), foot of the slope known as Vinice near Jince (locality 20 in Fatka and Kordule 1992) in lower levels of the Onymagnostus hybridus Zone. Condylopyge rex (BARRANDE, 1846), middle Cambrian, lower Drumian, Buchava Formation, Paradoxides (Eccaparadoxides) pusillus Zone, Skryje-Týřovice Basin. d. internal mould of isolated cephalon (NM-L43011a), Karáskovská rokle - nad chatami. e. internal mould of isolated pygidium (NM-L43014), Lůmek u Týřovic. f. internal mould of isolated cephalon (NM-L43013), Lůmek u Týřovic. Whitened with ammonium chloride sublimate. All scale bars are 1 mm. Photographs by Martin Valent (National Museum Prague).