Cyrtospirifer Research Articles

A NEW SPECIES OF CYRTOSPIRIFER (BRACHIOPODA) FROM THE MIDDLE DEVONIAN OF THE WESTERN SAHARA (NORTHWESTERN AFRICA)

A new species of Cyrtospirifer is described from the Middle to Upper Givetian of the Western Sahara (Northwest Africa). Cyrtospirifer tindoufensis new species differs in its smaller number and coarser medial and flank plications and equibiconvex shell profile from the other Givetian species of Cyrtospirifer that all occur in Europe and to which the new species probably gives rise. The new implications of the proposed phylogeny of the earliest cyrtospiriferids and their origin from the Western Sahara are discussed. The palaeogeographic distribution of the cyrtospiriferids during the Givetian and Frasnian is shown and its migration ways are described considering the global transgression and regression cycles.

Frasnian Brachiopoda Fauna From The Late Devonian Gümüşali Formation In The Saimbeyli Region (Adana-Eastern Taurides)

In this study, Frasnian brachiopoda fauna of the Gumuþali formation in the Saimbeyli area (Eastern Taurides) has been identified and described for the first time in Turkey. The measured section, located near Naltaþ village, Gumuþali formation is well exposed and very rich in macrofossils. This macrofossils occur in local accumulations within the limestones and sandstones. The section which represents lower part of the formation is formed by fossiliferous limestones at the basal part, by sandy limestone-shale alternation at the middle part and by sandstones interbedded with thin shales at the top. The sequence was deposited in a shallow marine environment. It contains brachiopods, corals and subordinate bryozoa and crinoidal elements. The detemined brachiopoda assemblage includes Douvillina dutertrei (Murchison), Cyphoterorhynchus arpaensis (Abramian), Desquamatia sp., Cyrtospirifer bisinus (Lehon), Cyrtospirifer schelonicus Nalivkin, Cyrtospirifer sp., Apousiella bouchardi (Murchison), Spinatrypina chitralensis (Reed), Uchtospirifer multiplicatus Brice. This assemblage can be correlated with those from the Frasnian of Iran, Afghanistan and Western Europe.

Brachiopoda of the Melville Island Group (Upper Devonian), Banks Island, N.W.T.

ABSTRACT On northeastern Banks Island, N.W.T., a total of 3700 feet of late Devonian clastics are exposed. In the lower 2600 feet of section occur rich benthonic faunas consisting primarily of brachiopods, pelecypods and corals. Thirteen brachiopod species are illustrated. One genus, Retichonetes, has not been previously reported from the Arctic Islands. Of particular importance is the presence of the rhynchonelloid zone fossils, Ladogioides pax and Calvinaria albertensis, and recognition of the overlap in stratigraphic ranges of Eleutherokomma and Cyrtospirifer. Analysis of the brachiopod faunas yields an age of from earliest Frasnian (zone of Ladogioides pax = Waterways and basal Hay River Formations) to late Frasnian (zone of Calvinaria albertensis = lower Mount Hawk and Ireton formations).