Arandaspis

Arandaspis prionotolepis is an extinct species of jawless fish that lived in the Ordovician period, about 480 to 470 million years ago. Its remains were found in the Stairway Sandstone near Alice Springs, Australia in 1959, but it was not determined that they were the oldest known vertebrates until the late 1960s. Arandaspis is named after a local Indigenous Australian people, the Aranda (now currently called Arrernte).

Description
Arandaspis is estimated to reach around 12-14 cm long, with a body covered in rows of knobbly armoured scutes. The front of the body and the head were protected by hard plates with openings for the eyes, nostrils and gills. It probably was a filter-feeder. Morphology of trunk and tail is unknown. According to comparison with other early ostracoderms, it would lacked paired fins and caudal fin would be simple shape, although another arandaspid Sacabambaspis had the tail that consist dorsal and ventral webs and an elongated notochordal lobe.