: Unlike the overlapping "shingle-like" scales of common fish, ganoid scales are rhomboidal and connect via peg-and-socket joints . This creates an interlocking, nearly impenetrable surface that is highly resistant to predators.

The defining feature of these fish is their scales, which act like a suit of chainmail.

A is a type of primitive bony fish characterized by its heavy, diamond-shaped ganoid scales . Often referred to as "living fossils," these fish retain ancient skeletal features and armor-like protection that have largely been lost in more modern fish species. Key Characteristics of Ganoid Scales

: Species like the Alligator Gar are famous for their diamond-shaped armor.

: Due to their thick, bony nature, these scales make the fish's body relatively rigid compared to more modern teleost fish. Representative Living Species

Today, only a few groups of fish still possess these primitive scales: