Quitinozoários Silurianos do Igarapé da Rainha, Estado do Pará

This paper describes Chitinozoa found in a gray, compact shale sample from an outcrop of the Igarapé da Rainha, a right margin tributary of the Tapajós River, Pará State, at about '4°26'38" latitude South and 56°07'16" longitude West.

Fifty-seven species, belonging to sixteen genera are recognized and analyzed qualitatively and quantitatively; of these, the following are described as new: Conochitina pedunculosa n.sp., C. pedunculosa n.subsp., C. flavioi n.sp., Tanuchitina paraensis n.sp., T. proeminenti n.sp., Angochitina amazonica n.sp., A. scorozai n.sp., Pogonochitina spinifera inornata n.subsp., Cyathochitina brasilica n.sp., and C. caputoi n.sp.

According to the systematic analyses, statistics and paleoecology of the microfossils examined, we suggest Lower Silurian age for the rock samples studied, correlating them with the Pitinga Member of the Trombetas Formation. The presence of a relatively substantial number of plant cuticles and microspores suggest neritic realm as zone of deposition.