When scientists first laid eyes on the duckbilled platypus and the echidnas in the late 18th century, they were so baffled by these bizarre egg-laying mammals that some considered the specimens a hoax. Modern researchers have uncovered other implausible features, including 40,000 tiny glands in the broad bill that sense electric currents, which may help the platypus catch prey underwater. The ant-eating echidna has about 100 in its tiny snout. The platypus and echidna are so unusual that they were assigned an order-the Monotremata-separate from the more common marsupial and placental mammals.
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