PALEOECOLOGIA DOS BIVALVES E BRAQUIÓPODES DA FORMAÇÃO INAJÁ (DEVONIANO), BACIA DO JATOBÁ (PE), BRASIL. (original) (raw)

The Inajá Formation documents the first depositional cycle under continental shelf conditions during the Devonian in the intracratonic Jatoba Basin, Pernambuco, with a predominance of marine depositional environment of shallow platform. Its lithology of thin laminated sandstones, with ferruginous sandy intercalations and levels of organic matter preserved relevant molluscan fauna and brachiopods as well as diverse trace fossil record. The work presents paleoecological inferences for the invertebrate fauna based on quantitative analysis, taphonomic and functional morphology. The material studied belongs to the scientific collection of the Department of Geology-UFPE. The fauna is studied bivalve orders - Pterioida (Leptodesma (Leptodesma) langei), Modiomorphoida (Spathella brevis), Pholadomyoida (Sanguinolites pernambucensis; S. rochacamposi e Edmondia philipi), Nuculoidea (Nuculites aff. oblongatus), Carditoida (Cypricardella petrolandensis), Pectinoida (Streblopteria antiqua) brachiopods and of the orders – Lingulida (Lingula aff. scalprum e Orbiculoidea), Terebratullida (Hamburguia ? sp.) e Rhynchonellida (Camarotoechia jatobensis). 761 specimens were analyzed preserved as mould and by substitution, which allowed us to infer the habit semi-infaunal and infaunal preferred among bivalves and epifaunal for the brachiopods with powered suspension-feeders dominant in the community, reinforcing shallow marine waters environment with moderately warm normal saline water for the deposition of the Inaja Foramtion (Upper Devonian) of the Jatoba Basin. The taphonomic data suggest an autochthonous/parautochthonous assembly.