Research paper

Devonian brachiopods of the Cantabrian Mountains (Northern spain). 12) Ferronirhynchia new genus, an upper Emsian rhynchonellid (Trigonirhynchiidae)


JENARO L. GARCÍA-ALCALDE
Retired Professor, Department of Geology, University of Oviedo, c/ Jesús Arias de Velasco, s/n, 33005 Oviedo, Spain. jalcalde@geol.uniovi.es
Corresponding author


ABSTRACT

The taxonomic status of the subfamily Trigonirhynchiinae is discussed based on the morphological features, together with the geographic and the stratigraphic distribution of the type genus Trigonirhynchia Cooper. The new genus, Ferronirhynchia n. gen., including the type species F. pulgari n. sp., is proposed. The new taxon, close to Trigonirhynchia, occurs in upper Emsian beds of the Moniello Formation, in Asturias, serotinus/patulus conodont zones, Faunal Intervals 14 to 16a. The ontogeny and palaeoecology of F. pulgari are analyzed. Growth of the new species is bicyclic. Juvenile forms are low and biconvex displaying sharp commissures. Adult forms are high, dorsi-biconvex, geniculate, with abrupt anterior and lateral margins. Ferronirhynchia pulgari is an opportunistic species, often found in paraautochtonous rhynchonellid assemblages that occur in quiet and muddy deposits formed below the wave-base level near or in reefal environments in the Cantabrian platfom. Shells of the new species supported a variety of small epizoans, commensalists or mutualists, mostly reticulate bryozoans, serpulid and other tubeworms, and auloporids. This life habit favoured the epizoans to escape from burial in muddy bottoms.


Key words: Ferronirhynchia n. gen., brachiopods, Trigonirhynchiinae, biostratigraphy, palaeoecology.

How to cite: García-Alcalde, J.L.  2021. Devonian brachiopods of the Cantabrian Mountains (Northern spain). 12) Ferronirhynchia new genus, an upper Emsian rhynchonellid (Trigonirhynchiidae). Spanish Journal of Palaeontology, 36 (2).

Received 30 October 2020, Accepted 3 March 2021, Published online: 22 June 2021

https://doi.org/10.7203/sjp.36.2.20574