Fenestrate Bryozoa of the Moniello Formation (Lower-Middle Devonian, NW Spain)

摘要

Lower-Middle Devonian non-fenestellid fenestrate bryozoans of NW Spain are reported, from two coastal sections of the upper Emsian-lower Eifelian Moniello Formation, the type locality at Moniello Inlet and at Arnao. Eighteen species of non-Fenestellidae fenestrates belonging to thirteen genera and six families have been identified; nine species are new: Bashkirella arnaoense, Utropora parva, Bigeyina cantabrica, B. spinosa, Fenestrapora elegans, Paraseptopora geometrica, P. irregularis, Kalvariella antiqua and Filites robustus. Fenestrates described herein, together with earlier reported taxa of the Family Fenestellidae from the Moniello Formation show palaeobiogeographic affinities with those of neighbouring Gondwanan regions, especially with Bohemia, but also with Middle Devonian assemblages from Eastern North America. The fenestrate fauna fromNWSpain comprises seven species common with the Lower Devonian of the Prague Basin (Bohemia, Czech Republic) and genera with relatively limited geographic distributions, such as Utropora and Filites. A remarkable feature of the studied fauna is the presence of several species that represent the earliest and westernmost reported occurrence of their genera, Bashkirella, Paraseptopora and Kalvariella, as well as previously reported Cavernella asturica. The occurrence of these species together with the stratigraphic and geographic position of previously reported ones indicate the existence of large gaps in the distribution of these Lazarus genera.