Vertebrate Zoology - V. M. Konstantinov 2011

Chordates
Gnathostomes
Class Bony Fishes - Subclass Sarcopterygii

Lobe-finned Fishes are known from the middle Early Devonian, i.e., approximately 400–300 million BC. These fish combine archaic features with progressive traits.

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Fig. 43. Pelvic Girdle and pelvic fins of the ceratodus:

1 — pelvis; 2 — basalia; 3 — radialia

The notochord serves as The basis of the Axial Skeleton. There are no vertebral centra, only upper and lower arches; the body is covered with cosmoid scales, the intestine features a spiral valve, and The Heart possesses an conus arteriosus.

At the same time, they are characterized by progressive features: pulmonary sacs, open nostrils, and fleshy (muscular) lobes of the paired fins (Fig. 43).

It has been established that already at the dawn of this fish group's formation, they began to specialize in two distinct directions: relatively peaceful mollusk-eaters — superorder Lungfishes (Dipnoi or Dipneustomorpha), and active predators — superorder Crossopterygians (Crossopterygii).



Last update: 13/08/2026

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