#cartilaginous fish

Out of the Blue: How Animals Evolved from Prehistoric Seas

Devonian period (419 to 359 mya): the age of fish! Bony fish, jawless fish, placoderms, sharks, etc.

By Elizabeth Shreeve and illustrated by Frann Preston-Gannon

Southeast Asia//Vulnerable// Cartilaginous Fish//image source

Fun Fact: The giant freshwater stingray is one of the largest freshwater fish. There have been reports of them weighing up to 600 kg.

(fossils found in) North America, Europe//Early Carboniferous (360 million years ago) // Cartilaginous Fish//image source

Fun Fact: Stethacanthus had enlarged denticles (small spikes found on all shark skin, akin to scales) on its head and unique, flat-topped dorsal fin.