Mastanesosus

Mastanesosus is an extinct genus of ostracoderm, a group of armored jawless fishes that lived during the Silurian period. Fossils of Mastanesosus have been found in North America.

Mastanesosus is characterized by its distinctive headshield ornamentation, consisting of tubercles and ridges. The overall shape of the headshield is typically rounded or oval. Like other ostracoderms, it lacked paired fins and possessed a bony external skeleton.

The genus Mastanesosus contributes to our understanding of early vertebrate evolution and the diversification of armored jawless fishes. Further research into Mastanesosus and related genera continues to shed light on the paleoecology and phylogenetic relationships within this important group of extinct organisms.