A new species of the conodont genus Siphonodella Branson & Mehl (late Tournaisian)
DOI | 10.3176/earth.2017.15 |
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Aasta | 2017 |
Ajakiri | Estonian Journal of Earth Sciences |
Köide | 66 |
Number | 4 |
Leheküljed | 188-192 |
Tüüp | artikkel ajakirjas |
OpenAccess | |
Litsents | CC BY 4.0 |
Keel | inglise |
Id | 26987 |
Abstrakt
A new upper Tournaisian (Lower Carboniferous) siphonodellid conodont species Siphonodella carinata n. sp. is described. The material comes from the shallow-water carbonate sediments of the Pechora Swell (Timan-Pechora region or NE of European Russia). The co-occurrence of conodonts Hindeodus cristulus (Youngquist & Miller), Bispathodus stabilis (Branson & Mehl) Morphotype 1, Polygnathus longiposticus Branson & Mehl and Pseudopolygnathus nodomarginatus (Branson) suggests the late Tournaisian (Lower Siphonodella crenulata Zone) age of the deposits. Morphologically the new species is similar to Siphonodella semichatovae Kononova & Lipnjagov and S. ludmilae Zhuravlev & Plotitsyn, but differs in possessing three rostral ridges at the late stages of ontogeny and Class III symmetry. The presence of the shallow-water siphonodellids Siphonodella bella Kononova & Migdisova and S. quasinuda Gagiev, Kononova & Pazuhin in the upper part of the Tournaisian is detected for the first time.