Primitive oviparous mammals found only in australia tasmania and new guinea .
只在澳大利亚塔斯马尼亚岛和新几内亚发现的原始卵生哺乳动物。
Worms and insects : oviparous , viviparous , aquatic .
虫:卵生、化生、湿生。
In 1843 , friedrich engels saw an egg of a duckbill in england . People told him that it was a mammal animal from australia . He broke into laughter after hearing it and said : " all the mammal animals were viviparous . The duckbill was oviparous , so it could not be a mammal animal " .
