Anabarites biplicatus (Missarzhevsky, 1989)

Kouchinsky, Artem, Bengtson, Stefan, Landing, Ed, Steiner, Michael, Vendrasco, Michael & Ziegler, Karen, 2017, Terreneuvian stratigraphy and faunas from the Anabar Uplift, Siberia, Acta Palaeontologica Polonica 62 (2), pp. 311-440 : 420

Anabarites biplicatus (Missarzhevsky, 1989)

Fig. 75A–G .

Material.—Several thousand internal moulds, including figured SMNH X3707, 3712, 3713, 6020–6023, from samples 1/45 (section 1, Fig. 4 ), K2/21, K2/22, K2/23, K2/24, K2/25, 3/12, 3/12.2, 3/12.5 (section 3, Fig. 3), 5/10, 5/10B, 5a/1.2, 5a/5 (sections 96-5 and 96-5a, Fig. 2 ), Medvezhya and Emyaksin formations, Anabar Uplift, Siberian Platform, Russia (SOM 1). Correlated with the uppermost Fortunian Stage.

Description.—Thecae up to 2 mm long, laterally flattened and curved in one plane, with two shallow, wide longitudinal depressions. Cross-section ovoid in later growth stage but rounded triangular apically.

Remarks.—See Kouchinsky et al. (2009) for discussion of the validity of the species and Kouchinsky et al. (2015a) for probable lower part of Cambrian Stage 3 occurrence in the Emyaksin Formation.

Stratigraphic and geographic range.— Upper Fortunian Stage–Cambrian Stage 2 and probably lower part of Cambrian Stage 3, Siberian Platform (Kouchinsky et al. 2015a).

Figures

Fig. 75. Anabaritids Anabarites biplicatus (Missarzhevsky, 1989) (A–G) and A. kelleri Missarzhevsky, 1989 (H–J), calcium phosphatic internal moulds, from early Cambrian Medvezhya (A–E, H–J) and Emyaksin (F, G) formations, Anabar Uplift, Siberia, Russia; samples K2/21 (A–C, E, J), K2/26 (H), K2/13 (I), 3/12 (D), section 3; K5/10 (F), 5a/1.2 (G), sections 96-5 and 96-5a, respectively. A–J. SMNH X3713 (A; see also Kouchinsky et al. 2009: fig. 38R), SMNH X3712 (B; see also Kouchinsky et al. 2009, fig. 38P), SMNH X6020 (C), SMNH X6021 (D), SMNH X3707 (E; see also Kouchinsky et al. 2009: fig. F–G), SMNH X6022 (F), SMNH X6023 (G), SMNH X6024–6026 (H–J, respectively). A–C, D2, E–G, H–J, lateral views; D1, transverse view of apertural end. Scale bar 500 μm (A–F, H–J), 1 mm (G).

Fig. 4. The δ13Ccurve for Kotuj River section 1and sampled horizons with fossiliferous samples (arrows with numbers). Shift in stratigraphic column carb at Nemakit-Daldyn–Medvezhya formations contact indicates position of sequence boundary. Stratigraphic ranges and first appearances of fossils (see SOM 1): 2, Oelandiella korobkovi; 3, Securiconus cf. simus; 4, Bemella jacutica?; 8, Anabarella plana; 9, Watsonella crosbyi; 10, Pseudoyangtzespira selindeica; 11, Aldanella crassa; 13, Aldanella attleborensis; 15, Philoxenella spiralis; 16, Barskovia hemisymmetrica; 18, Khairkhania cf. evoluta; 19, Ceratoconus striatus; 21, Salanyella cf. costulata; 23, Purella cristata; 25, Yunnanopleura sp.; 26, Obscurania auriculata; 29, Protoconus cf. crestatus; 32, Siphogonuchites triangularis; 34, Lopochites sp.; 37, first appearance of Halkieria sp.; 39, first appearance of Chancelloria sp.; 40, Tianzhushanella sp.; 42, Khetatheca cotuiensis; 46, Turcutheca sp.; 48, Orthothecid operculum type A; 52, Fomitchella infundibuliformis; 57, Hyolithellus sp.; 62, Selindeochrea missarzhevskyi; 63, Selindeochrea ternaria; 64, Anabarites trisulcatus; 67, Anabarites kelleri; 68, Anabarites biplicatus; 71, Anabarites hexasulcatus; 74, Tiksitheca licis; 75, Cambrotubulus decurvatus; 76, Platysolenites antiquissimus; 77, Blastulospongia sp.

Fig. 2. Composite δ13Ccurve for the Bol’shaya Kuonamka River sections 96-4, 5, and 5a and sampled horizons with fossiliferous samples (arrows with carb numbers). Arrow 4/4 indicates “marker bed with angustiochreids” (Val’kov 1975; Kouchinsky et al. 1999). For section 96-6 see Kouchinsky et al. (2001, 2015a). Shift in stratigraphic column at Manykay–Emyaksin formations contact indicates position of sequence boundary. Stratigraphic ranges and first appearances of fossils (see SOM 1): 1, first appearance of helcionellid molluscs; 2, Oelandiella korobkovi; 3, Securiconus cf. simus; 6, Obtusoconus vostokovae; 7, Obtusoconus cf. mirabilis; 8, Anabarella plana; 13, Aldanella attleborensis; 14, Aldanella cf. sibirica; 22, Purella antiqua; 24, Yunnanopleura accurata; 34, Lopochites sp.; 35, Tianzhushania longa; 37, first appearance of Halkieria sp.; 38, Chancelloria symmetrica; 42, Khetatheca cotuiensis; 44, Conotheca cf. mammilata; 46, Turcutheca sp.; 47, Cupitheca sp.; 50, Orthothecid operculum type C; 51, Protohertzina anabarica; 52, Fomitchella infundibuliformis; 53, Fomitchella aff. infundibuliformis; 54, Fomitchella acinaciformis; 55, Fomitchella aff. acinaciformis; 56, Hyolithellus vladimirovae; 57, Hyolithellus sp.; 60, Selindeochrea cf. tecta; 61, Selindeochrea tripartita; 62, Selindeochrea missarzhevskyi; 63, Selindeochrea ternaria; 64, Anabarites trisulcatus; 65, Anabarites latus; 66, Anabarites natellus; 67, Anabarites kelleri; 68, Anabarites biplicatus; 69, Anabarites tristichus; 70, Anabarites compositus; 71, Anabarites hexasulcatus; 72, Anabarites hariolus; 73, Aculeochrea rugosa; 74, Tiksitheca licis; 75, Cambrotubulus decurvatus; 76, Platysolenites antiquissimus.