Textbook Problem

In 1798, a stuffed platypus specimen was delivered to the British Museum. Reports that it laid eggs created much confusion. To modem biologists, a platypus is clearly a mammal. It has fur and the females produce milk. Young animals have typical mammalian teeth that are replaced by hardened pads of the “bill” as the animal matures. Why do you think modem biologists can more easily accept that a mammal can have some reptilelike traits than scientists who were considering this animal in the late 1700s?