Isogramma Meek & Worthe, 1870 (Dictyonellida, Brachiopoda) from the Pennsylvanian of the Cantabrian Mountains (N Spain)
M. LUISA MARTÍNEZ CHACÓN
Departamento de Geología, Universidad de Oviedo, Jesús Arias de Velasco s/n, 33005 Oviedo, Spain. firstname.lastname@example.org
COR F. WINKLER PRINS
Department of Geology, NCB Naturalis, Postbus 9517, NL-2300 RA, Leiden, Netherlands. email@example.com
Isogramma is one of the strangest and easiest to recognize brachiopod genera. Its shells is very transverse, flattened, oval, ornamented with strong concentric ridges which cover the whole exterior of both valves, apart from a smooth triangular depressed area, extending from the beak of the ventral valve forward to beyond the umbo, the colleplax. The sell is strongly punctate which gives it a spongy structure. In this paper, the morphology and shell structure of the genus are discussed, and the species from the Catabrian Mountains assigned to the genus are revised. The species Isogramlma davidsoni, the only one thus far described for the region, is discussed and three new species are described for the Pennsylvanian of Asturian and León: Isogramma wagneri, I. casina and I. demuesensis.
Keywords: Isogramma, Brachiopoda, Pennsylvanian, Cantabrian Mountains, Spain.
How to cite: Martínez Chacón, M.L. & Winkler Prins, C.F. 2016. Isogramma Meek & Worthen, 1870 (Dictyonellida, Brachiopoda) from the Pennsylvanian of the Cantabrian Mountains (N Spain). Spanish Journal of Palaeontology, 31 (1), 115-130.
Received 12 November 2016, Accepted 6 March 2016, Published 30 June 2016