Sacabambaspis

Sacabambaspis is an extinct genus of armored jawless fish which lived in the Ordovician period. Sacabambaspis inhabited shallow waters on the continental margins of the southern supercontinent Gondwana. The most complete specimens have been found in Bolivia, while armor fragments are also known from Argentina, Australia, and Oman. Sacabambaspis vaguely resembles a slender tadpole, with an oversized armor-plated head, flat body, and no discernible fins outside of its narrow tail. The eyes are closely spaced and positioned at the very front of the head, akin to car headlamps. It was about 35 cm (13+3⁄4 inches) long in total, including its distinctively thin scaly tail. With many well-preserved specimens, Sacabambaspis is the best-known member of Arandaspida, a group of jawless fish found only in the Ordovician of Gondwana. Arandaspids were among the earliest members of the class Pteraspidomorpha, alongside a far more diverse group of jawless fish, the Silurian–Devonian heterostracans.