Sacambambaspis Plush

Sacabambaspis was an extinct jawless fish that lived in the Ordovician period, inhabiting shallow waters along the continental margins of Gondwana. It is the best-known arandaspid, with many specimens discovered. Its head was covered by a shield made of a large dorsal plate with a slight ridge and a deep curved ventral plate, both adorned with characteristic oak-leaf or tear-drop-shaped tubercles. The eyes were positioned far forward, near what are believed to be nostrils, a defining feature of arandaspids. Behind the head, its body was covered in long, strap-like scales.

The fish had a distinct tail with large dorsal and ventral webs and an elongated notochordal lobe, differing from the symmetrical tails of related groups. Fossils were first discovered in Sacabamba, Bolivia, with the type species, S. janvieri, found in the Anzaldo Formation. Over 30 specimens were clustered together, likely due to a mass death event from sudden freshwater inflow. Additional fossils have been found in Australia, Argentina, and Oman, indicating a wide distribution around Gondwana. Despite lacking jaws, Sacabambaspis used rows of small bony oral plates to aid in suction feeding. It also possessed a lateral line system, helping it detect movement in the water, possibly to evade predators.