New interpretations of the phylogeny and taxonomy of delthyridoid spiriferids (Brachiopoda, Lower and Middle Devonian)

Abstract

A new phylogeny is introduced for Lower and Middle Devonian delthyridoid spiriferids with plicated fold and sulcus and bifurcating and trifurcating ribs. The new interpretation is based on side-by-side comparison of the type species of the genera with special focus on the micro-ornamentation and the style of ribbing, especially in the sulcus. During the revision of this group the following taxa are proposed: Multispiriferidae fam. nov, Ovetensispirifer novascotianus gen. et sp. nov., Turcispirifer turciae gen. et. sp. nov.; three taxa are described in open nomenclature: gen. nov. A, ?Turcispirifer sp. A, and Ovetensispirifer cf. ovetensium. In the systematic part, each genus is described including its type species of the studied group. Emended diagnoses from family to species level are given. As a consequence of this study, the geographic distribution of the taxa of each evolutionary branch emphasizes the endemicity present during Early Devonian time and its decline at the beginning of the Middle Devonian. However, on the other hand, faunal pathways are shown from Western Europe to Nova Scotia, from North Africa over Turkey to Eastern Asia and to Arctic Canada, and probably from Venezuela to North Africa. • Key words: Delthyridoidea, Spiriferida, Brachiopoda, phylogeny, palaeobiogeography, Devonian.SCHEMM-GREGORY, M. 2008. New interpretations of the phylogeny and taxonomy of delthyridoid spiriferids (Brachiopoda, Lower and Middle Devonian).

A new species of Neopaulinella (Brachiopoda, Terebratulida) from the Eastern Iberian Chains, Spain (Lower Devonian)

“…Boucot & Wilson (1994 pointed out that the Early Devonian provincialism is reflected by the European terebratulid forms Xana and Paulinella (now Neopaulinella). I agree with these authors and consider these forms as Gondwanan forms because Spain and France belong to former Gondwana (today's North Africa and Western Europe) which are distinct from today's Central Europe (Jansen 2001, Schemm-Gregory 2008a). However, forms described as Neopaulinella guerangeri from Central Europe and Turkey have to be revised in order to prove the Gondwanan endemism of Xana and Neopaulinella.…”

“…It has to be stressed that the Istanbul Basin from where guerangeri forms are reported belongs to the northern Gondwanan terrane, too, as already discussed by Schemm-Gregory (2008b). On the other hand a migration pathway between Central and Western Europe existed during the Middle Siegenian and the Siegenian/Emsian boundary interval reflected by the terebratulid genus Rhenorensselaeria (Schemm-Gregory 2008a). Faunal affinities between the Armorican Massif and the Eastern Iberian Chains were shown by Carls (1987) Figure 7.…”

“…However, forms described as Neopaulinella guerangeri from Central Europe and Turkey have to be revised in order to prove the Gondwanan endemism of Xana and Neopaulinella. It has to be stressed that the Istanbul Basin from where guerangeri forms are reported belongs to the northern Gondwanan terrane, too, as already discussed by Schemm-Gregory (2008b). On the other hand a migration pathway between Central and Western Europe existed during the Middle Siegenian and the Siegenian/Emsian boundary interval reflected by the terebratulid genus Rhenorensselaeria (Schemm-Gregory 2008a).…”

“…(Giebel, 1858) proves that the Erbslochgrauwacke is part of the northern Gondwana terranes and presents a block that probably slipped northward (Jansen 2001, Schemm-Gregory 2008c. The Lower Devonian of Western Europe can also be correlated with the Meguma Zone (Nova Scotia) with the presence of Vandercammenina Boucot, 1975 andOvetensispirifer Schemm-Gregory, 2008b in both regions, however, Neopaulinella has not yet been reported from Nova Scotia (Bouyx et al 1992;Boucot 1960Boucot , 1975Schemm-Gregory 2008b). Neopaulinella appears in Siegenian and Emsian strata.…”

“…In contrast to the strata in Morocco, strata of the Eastern Iberian Chains have undergone a complicate tectonic deformation. The intercalation of strata representing the hercynian (pelagic) facies and the rhenish (neritic) facies in the Eastern Iberian Chains allows correlation of Lower Devonian rocks between North Africa, Central and Western Europe, and Bohemia (e.g., Jansen 2001, Schemm-Gregory 2008a. Subsequently, the Subcommission on Devonian Stratigraphy (SDS) is paying special attention to their research.…”