Scott M. Huse in his 1983 book The Collapse of Evolution (Grand Rapids: Baker Book House) wrote in a chapter called “Commonly Cited ‘Proofs’ of Evolution”:
Evolutionists insist that the duck-billed platypus is an evolutionary link between mammals and birds. The platypus is an Australian mammal which has fur and nourishes its young with milk, like mammals. Their young hatch from eggs like reptiles, and they have webbed feet and a flat bill like a duck. It has pockets in its jaws to carry food and a spur on its rear legs which, like a snake’s fang, is poisonous. And, amazingly enough, the platypus even uses echo location like dolphins! Admitedly [sic] the platypus does combine a curious mixture of features and traits (Figure 21). But does this unusual combination of characteristics necessarily mean that the platypus is a transitional creature? Creationists reply, “absolutely not” and argue that the platypus is simply a kind of organism whose design includes a mosaic of traits.
[pp. 109-10; I am using the 17th printing from 1993]
The simple fact is that no biologist proposes that mammals are descended from birds and no biologist proposes that platypus is a link between mammals and birds. And yet he stated on page 43 that the theory of evolution proposes that mammals are descended from birds.
So how can he be claiming that evolutionist commonly claim that the platypus is the link between birds and mammals? Keep in mind that anyone who has made even the most superficial study of science of evolution knows Huse said is not true. Given that he often cites creationists sources for what an evolutionist said instead of the evolutionists directly makes me suspect that at the time he wrote the book he had not actually read books by professional evolutionary biologists.
Finally, I will note that I am not picking on some obscure creationist. The book in question is widely distributed and often cited by creationists as a book that “proves” that evolution is false. The moment any one of them cites Huse’s book they automatically label themselves as being a person who does not know the first thing about evolution and such not be taken seriously when he is discussing it.
Also note that the platypus does not use echo location like dolphins.
Also see: “Creationism and the Platypus”