Tujiaaspis

Tujiaaspis is an extinct genus of eugaleaspidiform, a group of armored jawless fish, from the Huixingshao Formation of China. It contains one species, Tujiaaspis vividus, which lived 436 million years ago, during the Telychian age of the Silurian period.

Around 7 cm (2.8 in) in length, Tujiaaspis was protected by a bony headshield covered in a pattern of sensory canals. It also possessed a pair of ventrolateral fins, elongate fins running across the body wall from the gills to the base of the tail, which would have helped it passively generate lift. The first galeaspid known from articulated specimens, Tujiaaspis provided evidence that they possessed ventrolateral fins, which may have been the precursors to paired pectoral and pelvic appendages in gnathostomes. In life, Tujiaaspis was likely an active swimmer, living in a coastal, nutrient-rich environment.