| 1. |
- Holmer, Lars E, et al.
(författare)
-
Early Ordovician organophosphatic brachiopods with Baltoscandian affinities from the Alay Range, southern Kyrgyzstan
- 2000
-
Ingår i: GFF. - : Informa UK Limited. - 1103-5897 .- 2000-0863. ; 122:4, s. 367-375
-
Tidskriftsartikel (refereegranskat)abstract
- Organophosphatic-shelled brachiopods (Subphylum Linguliformea, Class Lingulata) of early Ordovician (Arenig) age are described for the first time from carbonate olistoliths within the Silurian Pulgon Formation of the Kichik Alay Range, southern Kyrgyzstan. The assemblages include Paterula? naukatensis sp. nov., Rowellella sp., Orbithele ceratopygarum (Brgger), Acrotreta korynevskii Holmer & Popov, Ombergia mirabilis gen. et sp. nov., Eoconulus cf.primus Popov & Holmer, and Palaeoglossa? aff. razumovskii (Lermontova). The Kyrgyzstanian faunas appear to correlate mainly with assemblages from the upper Hunnebergian or lower Billingenian regional stages of Baltoscandia. Taxa in common with those from the early Arenig of Baltoscandia and the South Urals include O. ceratopygarum and A. korynevskii. Ombergia mirabilis is known otherwise only from coeval strata in Baltoscandia. It is probable that the Kyrgyzstanian olistoliths originated from early Ordovician intra-oceanic volcanic island arcs in the proximity of Gondwana, and the microbrachiopod faunas around these islands may have given rise to the more widespread and richer faunas that spread across Baltica during the rest of the Ordovician, as the island complexes drifted towards Baltica.
|
|
| 2. |
- Tolmacheva, Tatiana, et al.
(författare)
-
Conodont biostratigraphy and faunal assemblages in radiolarian ribbon-banded cherts of the Burubaital Formation, West Balkhash Region, Kazakhstan
- 2004
-
Ingår i: Geological Magazine. - 0016-7568 .- 1469-5081. ; 141:6, s. 699-715
-
Tidskriftsartikel (refereegranskat)abstract
- Biostratigraphical study of the early to mid-Ordovician conodont fauna from ribbon-banded radiolarian cherts of the middle Burubaital Formation in Central Kazakhstan reveals an almost complete succession of conodont biozones from the late Tremadocian to the early Darriwilian. During this interval, biosiliceous sediments were deposited in basinal environments, inhabited by lingulate brachiopods, sponges, pterobranchs and caryocaridids in conditions of high fertility and primary productivity of surface water. The community structure of taxonomically diverse conodont assemblages typifying open oceanic environments is not significantly different from that of epicratonic basins of the North Atlantic conodont province. The regional increase of oxygenated bottom waters at the base of the Oepikodus evae Biozone is possibly related to considerable changes in palaeo-oceanographical circulation patterns. The finds of three natural clusters of Prioniodus oepiki (McTavish) enable us to propose an emended diagnosis of this species.
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
- Popov, Leonid, et al.
(författare)
-
Lingulate brachiopods from the Cambrian-Ordovician boundary beds of Utah
- 2002
-
Ingår i: Journal of Paleontology. - 0022-3360 .- 1937-2337. ; 76:2, s. 211-228
-
Tidskriftsartikel (refereegranskat)abstract
- Seven genera and eight species of lingulate brachiopods are described from the Cambrian-Ordovician boundary beds (Cambrooistodus minutus Conodont Subzone to Rossodus manitouensis Conodont Zone) at the Lawson Cove and Lava Dam North sections, Ibex area, Utah, USA. The fauna includes one new linguloid genus, Wahwahlingula, and four new species, Lingulella? incurvata, Zhanatella utahensis, Conotreta millardensis, and Quadrisonia? lavadamensis. Lingulate brachiopods from this interval are very poorly known from Laurentia, but the recorded fauna is very similar to that described from coeval beds at Malyi Karatau, Kazakhstan, and both areas contain Eurytreta cf. bisecta (Matthew, 1901); E. sublata Popov, 1988; ZhanatellaKoneva, 1986; SchizambonWalcott, 1889; and Wahwahlingula. Eurytreta cf. bisecta is also known from the Lower Ordovician of Avalonian Canada, Britain, and Scandinavia.
|
|
