Chordate Zoology - Textbook - Y. V. Tsaryk - 2013
Chapter 4. DIVISION GNATHOSTOMATA, or ECTOBRANCHIATA. SUPERCLASS PISCES
4.2. CLASS BONY FISHES OSTEICHTHYES
4.2.3. Classification of Bony Fishes and Characteristics of Representatives of Selected Orders
4.2.3.2. Subclass Ray-finned Fishes Actinopterygii
4.2.3.2.1. Superorder Palaeonisci
Ganoid scales. Vertebral centra are absent or rudimentary. The Skull contains numerous dermal bones. The Maxilla is tightly fused with the ectopterygoid and preopercular bones. The caudal fin is heterocercal, and its upper lobe is covered with ganoid scales. Body shape is diverse; sizes are small to medium. They existed from the Middle Devonian to the early Cretaceous. All other groups of ray-finned Fishes originated from palaeoniscids.
Last update: 19/08/2026
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