Açu Formation

The Açu Formation is an Early Cretaceous (Albian) geologic formation of the Potiguar Basin in Ceará, northeastern Brazil. The formation comprises coarse-grained sandstones deposited in a fluvio-deltaic environment. The Açu Formation, belonging to the Apodi Group, has provided fossils of an indeterminate rebbachisaurid.

Description
The Açu Formation was deposited in a passive margin setting, overlying the Alagamar Formation and is overlain by the Jandaíra Formation. In the petroleum producing Potiguar Basin, the formation is a reservoir rock.

Fossil content
The following fossils were reported from the formation:
 * Reptiles
 * Dinosaurs
 * Carcharodontosauria indet.
 * Maniraptora indet.
 * Megaraptora indet.
 * Rebbachisauridae indet.
 * Spinosauridae indet.
 * Tiamat valdecii
 * Titanosauria Indet.
 * Fish
 * Cartilaginous fish
 * Tribodus limae
 * Ray-finned fis
 * Amiidae Indet.
 * Bawitius bartheli
 * Lepisosteiformes Indet.
 * Tharrhas araripis
 * Pycnodontiformes indet.
 * Lobe-finned fish
 * Arganodus cf. tinguidiensis
 * Ceratodus latissimus
 * Mawsonia cf. gigas