Question

Lobefins evolved into?
A. Jawed cartilaginous fishes
B. Jawed bony fishes
C. Jawless fishes
D. Amphibian

Answer 1

Hint: Vertebrates that need water or moist environment to survive, characterized as both aquatic and terrestrial organisms.

Complete answer:
Lobe finned fish constitute a class of the bony fish. A strict cladistic view shows that some lobe fins evolved into tetrapods, including amphibians, reptiles, and mammals.

Additional information
- Early lobe- finned fishes are bony fish with fleshy, lobes, and paired fins, which are joined to the body by a single bone.
- The morphology of these fishes that are similar looking to tetrapods gives indications of the transition from water to terrestrial life.
- The first amphibians were found to have evolved around 370 million years ago during the Devonian period.
- The articulations similar to the limbs of tetrapods are found in the pectoral and pelvic fins of these fishes.
- Those fins evolved into the legs of the first tetrapod land vertebrates, amphibians.
- The fin limbs of lobe- finned fishes show a strong similarity to the expected ancestral form of tetrapod limbs.
- Most of the lobe- finned fishes are extinct.
- The largest known lobe finned fish was Rhizodus hibberti from the carboniferous period of Scotland which may have exceeded 7 meters in length.
- It is believed that lobe fins evolved into tetrapod limbs during the Devonian period when amphibians evolved.

So, the correct answer is ‘Amphibian'.

Note: The lobe-finned fish is also called Sarcopterygii which is derived from a Greek word sarx meaning flesh and pteryx meaning fin. It is sometimes considered synonyms with Crossopterygii which means fringe- finned fish, it is also derived from a Greek word krossos meaning fringe. Amphibious is the Greek term from which the word amphibian is derived which is referred to as ‘both kinds of life’.