Livro de Resumos - Dinossauros do Maranhão

Paleontologia 40
1
Universidade do Vale do Rio dos Sinos (UNISINOS), Avenida Unisinos, 950 - Cristo Rei - 93022-000, São
Leopoldo, RS, Brasil.
2
Departamento de Paleontologia e Estratigrafia, Instituto de Geociências, Universidade Federal do Rio Grande
do Sul (UFRGS), Campus do Vale, Avenida Bento Gonçalves, 9500, Caixa postal 15001, 91501-970, Porto
Alegre, RS, Brasil.
3
Bolsista de Produtividade em Pesquisa do CNPq.
4
Instituto de Geologia, Universidad Nacional Autónoma de México (UNAM), Delegación de Coyoacán 04510,
DF, México.
Holocene ostracodes from the Brazilian eastern and northeastern
continental shelves, SW Atlantic: A zoogeographical approach
Cláudia Pinto Machado 1 , João Carlos Coimbra 2,4 & Ana Luisa Carreño 3
The studies concerning Recent and Sub-recent ostracodes from the Brazilian continental
shelf have been so far devoted mainly to the Equatorial and to the South/Southeast
shelves. The region between these two shelves, consisting of the area between Cabo de
São Roque (05°09‟S/35°04‟W) and Cabo Frio (23°07‟S/42°55‟W), has not been
appropriately studied and displays several gaps in Ostracoda taxonomy and zoogeography.
In order to improve these deficiencies, the present study approaches the taxonomy of
ostracodes form the eastern and the northeastern Brazilian shelves, aiming at the
understanding of its origin and zoogeographical distribution. One hundred twenty-eigth
species have been identified. 34% of the species found in the studied area are typical of
temperate water, 42% of warm water and 5% are eurythermal. The remaining 19% of the
species could not be evaluated due to the scattered occurrence. The review of the fauna
of the northern portion of the Brazilian continental shelf from Cabo Orange
(4°24‟N/51°30‟W) to Cabo Frio recognized 213 species, 32% of which are endemic. A new
zoogeographical province (the Brazilian Province) has been proposed on the basis of
endemism, faunal distribution and environmental characteristics. Its southern limit is
located in the Lat. 15º/16º S. The northern limit remains indeterminate, due to the
inexistence of ostracode studies in the region from French Guyana to Guyana. Fossil
representatives for the Brazilian Province display specimens that are as old as the Upper
Tertiary. The presence of different water masses is the factor that more appropriately
explains the present distribution pattern of shallow marine ostracodes along the Brazilian
continental shelf. Apoio: CNPq.
E-mails: claudinhacpm@yahoo.com.br, joao.coimbra@ufrgs.br, anacar@servidor.unam.mx
Micropaleontologia