Two new Peregrinella species (P. garganica and P. fascicostellata) from the Lower Cretaceous Maiolica Formation of the Gargano Promontory (southern Italy) are proposed. The shells are allochthonous and occur in densely packed, gravity displaced accumulations that are intercalated within pelagic sediments. Preliminary data on the palaeoecology and palaeoenvironment of the Peregrinella beds confirm the suggestion that these brachiopods were the dominant component of cold-seep assemblages. The occurrence of ‘Rhynchonella’ peregrina (Buch) [junior synonym of Peregrinella multicarinata (Lamarck)], cited in the past literature on the area investigated, located NW of Mattinata, is not confirmed. The specimens collected present several features which are different from Lamarck’s species: the majority of them have a more convex shell, alae clearly separated from the lateral regions, and large deltidial plates. These specimens are here classified as P. garganica sp. nov. Other specimens, all collected from a single exposure, are characterized by having several orders of ribs forming a fascicostellate ornamentation, particularly accentuated in the central part of the valve; they are attributed to P. fascicostellata sp. nov.
New species of Peregrinella (Brachiopoda) from the Lower Cretaceous of the Gargano Promontory (southern Italy)
POSENATO, Renato;MORSILLI, Michele
1999
Abstract
Two new Peregrinella species (P. garganica and P. fascicostellata) from the Lower Cretaceous Maiolica Formation of the Gargano Promontory (southern Italy) are proposed. The shells are allochthonous and occur in densely packed, gravity displaced accumulations that are intercalated within pelagic sediments. Preliminary data on the palaeoecology and palaeoenvironment of the Peregrinella beds confirm the suggestion that these brachiopods were the dominant component of cold-seep assemblages. The occurrence of ‘Rhynchonella’ peregrina (Buch) [junior synonym of Peregrinella multicarinata (Lamarck)], cited in the past literature on the area investigated, located NW of Mattinata, is not confirmed. The specimens collected present several features which are different from Lamarck’s species: the majority of them have a more convex shell, alae clearly separated from the lateral regions, and large deltidial plates. These specimens are here classified as P. garganica sp. nov. Other specimens, all collected from a single exposure, are characterized by having several orders of ribs forming a fascicostellate ornamentation, particularly accentuated in the central part of the valve; they are attributed to P. fascicostellata sp. nov.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
