Morphologically distinct P1 elements of Zieglerodina (Conodonta) at the Silurian- Devonian boundary: review and correlation

Abstract

In many parts of the world, the base of the Devonian is generally characterized by the prevailing onset of carbonate sedimentation. The index fossil for the base of the Lochkovian is the graptolite Monograptus uniformis Přibyl, 1940; however, because of dominating carbonates, the lowermost Devonian stratigraphy must rely on other faunal groups, especially conodonts. Owing to their abundance in carbonate successions and their global distribution, in many cases conodonts are the only faunal group that permits recognition of the Silurian-Devonian boundary (corresponds to the conodont hesperius-optima Zone). In many studies over the past decades conodont zonations for the uppermost Přídolí and the lowermost Lochkovian had been established (e.g.

Running across the Silurian/Devonian Boundary along Northern Gondwana: A Conodont Perspective

“…Poorly preserved casts of echinoderms and brachiopods are documented on bedding planes. According to brachiopods, the age is basal Devonian ("Gedinnian") [94]. Based on a personal communication by Havlíček in Feist (1985) [116], the brachiopod assemblage contains Glossinotoechia, Sicorhynchia, Iridistrophia, Strophonella, Cyrtina, Atrypa, Isorthis, Resserella, Parmothina and closely matches the characteristic fauna of the Bohemian Lochkovian.…”

“…Among spathognathodontids the most significant taxa are Z. petrea, Z. remscheidensis and "Oz." optima (Moskalenko) (see the summary in [21,94]). Zieglerodina petrea has a conspicuous gap in denticulation in P1 element near the cusp, similarly as taxa belonging to genus Cuspigrandiosa Murphy and Z. paucidentata (Murphy and Matti) (see discussion in [95]) and represents a promising "paucidentate" marker for the recognition of the Devonian base using the spathognathodontid clade [21]).…”