Dignomia munsterii (Brachiopoda, Lingulata) from the Ordovician of Bolivia, with redescription of the genus

Specimens of Dignomia have been recorded in the Anzaldo Formation (Upper Ordovician) in three localities in the Cochabamba area of the Cordillera Oriental, Bolivia. Th ey had been attributed to Lingula munsterii d'Orbigny, 1842 found in company with L. submarginata d'Orbigny, 1850, both are indubitable Dignomia. Th ese species were collected in the Cordillera Oriental in the Cochabamba region and in the Chuquisaca area, near Zudanez the type locality and belong in fact to Dignomia. Dignomia munsterii is described and a new generic diagnosis is proposed. The emended diagnosis is based on characters of the shell and anatomic traits that permit its recognition as a discrete genus of the Lingulidae, the family to which it belongs. Th e type species is Lingula alveata Hall, 1863. Dignomia is found in strata ranging in age from Lower Silurian to Middle Devonian in North and South America. At least six previously described species can be referred to Dignomia but all are inadequately described without reference to the scars indicating the sites of attachment of the visceral organs.Original Abstract: Dignomia munsterii (Brachiopoda, Lingulata) de l'Ordovicien de Bolivie, et redescription du genre. Des exemplaires de Dignomia ont ete recoltes dans la Formation Anzaldo (Ordovicien superieur) dans trois localites de la region de Cochabamba (Bolivie) dans la Cordillere Orientale des Andes. Ils ont ete attribues a Lingula munsterii d'Orbigny, 1842 qui appartient sans conteste au genre Dignomia, de meme que L. submarginata d'Orbigny, 1850: ces deux especes ont ete decrites de la region de Cochabamba (Cordillere Orientale) et de celle de Chuquisaca (a Zudanez qui est la localite type). Une redescription de Dignomia munsterii et une nouvelle diagnose generique sont proposees. Grace a l'etude des caracteres de la coquille et des caracteristiques anatomiques, le genre Dignomia, dont la diagnose a ete amendee, a ete reclasse dans la famille des Lingulidae et se distingue bien des autres genres de cette famille. L'espece type est Lingula alveata Hall, 1863. L'extension geologique du genre va du Silurien inferieur au Devonien moyen et la distribution geographique se situe en Amerique du Nord et du Sud. Au moins six especes peuvent etre rapportees au genre Dignomia, mais toutes ont ete decrites de facon inadequate car sans reference aux traces donnant la disposition des caracteres anatomiques du corps.