Barreirinha Formation
# Barreirinha Formation

The Barreirinha Formation is a late Frasnian geologic formation of the Amazon Basin in the state of Amazonas of northern Brazil. The group comprises deep marine black shales and sandstones.

## Fossil content

The formation has provided conodont fossils of:

* Mehlina gradata
* Ozarkodina aff. sannemanni
* Cryptotaxis sp.
* Polygnathus sp.
* ?Prioniodina sp.
