#skeletal morphology

• Actinolepis — Romanian name adapted from the taxonomic genus Actinolepis, representing an extinct genus of primitive placoderm fishes (arthrodires) that lived during the Early Devonian period. Structurally, these prehistoric fishes were characterized by a flat bony armor protecting their head and thorax, composed of bony plates ornamented with radiating striations or tubercles, adapted to benthic life on ancient seafloors.
• Actinopterygian — A fish belonging to the class Actinopterygii, structurally characterized by having fins supported by bony or cartilaginous rays (lepidotrichia) arranged radially, without fleshy lobes at the base. This vast group represents the dominant class of extant bony fishes, encompassing over 95% of all known fish species worldwide, adapted to diverse aquatic environments, from mountain freshwaters to abyssal ocean basins.