In the marine realm, the Carnian saw the first abundant occurrences of calcareous
nanoplankton, a morphological group including the
coccolithophores.
Invertebrates There are a few
invertebrates which are typical and characteristic of the Carnian. Among molluscs, the
ammonoid genus
Trachyceras is exclusive to the lower Carnian (i.e., Julian of the two-substages subdivision, see above). The family
Tropitidae and the genus
Tropites appear at the base of the upper Carnian (Tuvalian). The
bivalve genus
Halobia, a bottom-dweller of deep sea environments, differentiated from
Daonella at the beginning of this age.
Scleractinian coral reefs, i.e., reefs with corals of the modern type, became relatively common for the first time in the Carnian.
Vertebrates The earliest unequivocal
dinosaurs, such as those from the Ischigualasto Formation (e.g.
Herrerasaurus and
Eoraptor) and those from the
Santa Maria Formation (e.g.
Staurikosaurus and
Buriolestes) originated during the Carnian, around 230
Ma. In this stage the
archosaurs became the dominant animals in the world, evolving into groups such as the
phytosaurs,
rhynchosaurs,
aetosaurs, and
rauisuchians. The first dinosaurs (and the pterosaur
Carniadactylus) also appeared in this stage, and though at the time they were small and insignificant, they diversified rapidly and would dominate the fauna for the rest of the
Mesozoic. On the other hand, the
therapsids, which included the ancestors of
mammals, decreased in both size and diversity, and would remain relatively small until the extinction of the dinosaurs.
Conodonts were present in Triassic marine sediments.
Paragondolella polygnathiformis appeared at the base of the Carnian Stage, and is considered a characteristic species. A partial list of Carnian vertebrates is given below. Many Carnian vertebrates are found in
Santa Maria Formation rocks of the Paleorrota
geopark. == Classic localities and Lagerstätten ==