INVESTIGADORES
VACCARI Norberto Emilio
artículos
Título:
New raphiophorid trilobites from the Ordovician of Argentina and their biogeographic implications
Autor/es:
VACCARI, N.E., WAISFELD, B.G., CHATTERTON, B.D.E. &. EDGECOMBE, G.D
Revista:
Memoir of Association of Australasian Palaeontologists
Editorial:
Association of Australasian Paleontologists
Referencias:
Lugar: Camberra; Año: 2006 vol. 32 p. 353 - 374
ISSN:
0810-8889
Resumen:
The raphiophorid trilobites Lehnertia nawisapa gen. et sp. nov. and Pytine wirayasqa sp. nov. are
described from the Lower and Middle Ordovician of Argentina. Lehnertia gen. nov. is a member
of Endymioniinae that includes L. nawisapa, from the Las Chacritas Formation (Darriwilian) in
the Precordillera of San Juan Province, and L. embolion, from the Nora Formation (Darriwilian)
in the Georgina Basin, Australia. An extension of the cephalic doublure as a long, pointed spine in
Lehnertia is regarded as convergent with a similar spine in Alsataspididae. Silicified material of
L. nawisapa includes a growth series from protaspides to holaspides, recording the development
of the ocular structures and an increase in the relative size of the eyes late in ontogeny. Lehnertia
is most closely allied to Pytine Fortey, 1975; both genera include species with and without
ocular structures. Pytine wirayasqa sp. nov. is found in the Acoite Formation (early Arenig) in
the Cordillera Oriental, Jujuy Province. In addition to its type from Spitsbergen and the new
species from Argentina, Pytine includes early Arenig-Darriwilian species from the North and
South China blocks, Baltica, and East Gondwana (Canning Basin, Australia). Lehnertia provides
further evidence for East Gondwanan influence on Precordilleran faunas in the Darriwilian. A
reevaluation of the trilobite fauna of the Cordillera Oriental suggests East Gondwanan connections
since the Early Tremadocian