Question

Which of these is not a connecting link?
A. Duck billed platypus
B. Spiny anteater
C. Tortoise
D. Lungfish

Answer 1

A connecting link between two precise classes of species is a halfway or temporary state. The other name of connecting links is missing connections. It bears characters normal to both these gatherings on either side of its position. Along these lines it speaks to a developmental line.Connecting link is a living being having qualities of two diverse gatherings of creatures.

Complete answer:

Duck billed platypus is an egg laying vertebrate that have mammary organs, hair, stomach however take after reptiles in having enormous coracoid in pectoral support and creation of amniotic eggs.
Spiny anteater is an association among reptiles and well evolved creatures.e. mammals that have mammary organs however look like reptiles underway of amniotic eggs.
Protopterus (lungfish) is a living association among fishes and creatures of land and water; they take after creatures of land and water in presence of nostrils, lungs and three chambered hearts. Their fish-like characters are tube shaped body, filamentous combined fins and cartilaginous endoskeleton.
Turtle is individual from order Testudines under phylum Chordata and shows run of the characters of its taxa i.e., it doesn't fill in as a connecting link between any two gatherings.

So, the correct answer is option C.

Note:
Platypus are interfaces among Mammals and Reptiles since they have taking after attributes to both the gatherings. Platypus isolated from Mammals around 165-166 million years back and held some reptilian attributes, for example, laying eggs. It took up some mammalian qualities like having mammary organs and stomach. Echnidia (spiny anteater) and Ornithorhynchus (platypus) are the associating links between reptiles and mammals.A class of lungfish is considered as the interfacing link between the fishes and amphibians. It has fish-like appearance, combined blades and furthermore has creatures of land and water like characters like inside nostrils, lungs and heart.