Question

Which of these is not a connecting link?

• A. Duck-billed platypus
• B. Spiny anteater
• C. Tortoise
• D. Lungfish

Answer 1

Answer: (C)

Tortoise

• The duck-billed platypus is an egg-laying mammal that has mammary glands, hair, diaphragm but resembles reptiles in having large carcinoids in the pectoral girdle and production of amniotic eggs.
• Spiny anteater is connecting link between reptiles and mammals that have mammary glands but resemble reptiles in the production of amniotic eggs.
• Protopterus (lungfish) is a living connecting link between fishes and amphibians; they resemble amphibians in presence of nostrils, lungs, and three-chambered hearts. Their fish-like characters are cylindrical bodies, filamentous paired fins, and the cartilaginous endoskeleton.
• Tortoise is a member of order Testudines under phylum Chordata and exhibits typical characters of its taxa i.e., it does not serve as connecting link between any two groups.

So, the correct answer is option C.