檢視单孔目的原始碼

[[File:单孔目.jpg|缩略图|[https://image.baidu.com/search/detail?ct=503316480&z=0&ipn=d&word=%E5%8D%95%E5%AD%94%E7%9B%AE&step_word=&hs=0&pn=3&spn=0&di=1210&pi=0&rn=1&tn=baiduimagedetail&is=0%2C0&istype=0&ie=utf-8&oe=utf-8&in=&cl=2&lm=-1&st=undefined&cs=2359703705%2C3222959553&os=783980932%2C2903633246&simid=4231908391%2C721529791&adpicid=0&lpn=0&ln=219&fr=&fmq=1634508583454_R&fm=&ic=undefined&s=undefined&hd=undefined&latest=undefined&copyright=undefined&se=&sme=&tab=0&width=undefined&height=undefined&face=undefined&ist=&jit=&cg=&bdtype=0&oriquery=&objurl=https%3A%2F%2Fgimg2.baidu.com%2Fimage_search%2Fsrc%3Dhttp%3A%2F%2F5itupu.com%2Fpicture%2FuploadfileUser%2FUser190IMG1759%2F2020063002420785785.jpeg%26refer%3Dhttp%3A%2F%2F5itupu.com%26app%3D2002%26size%3Df9999%2C10000%26q%3Da80%26n%3D0%26g%3D0n%26fmt%3Djpeg%3Fsec%3D1637100897%26t%3Daa002a834b907465746d4502f706c7aa&fromurl=ippr_z2C%24qAzdH3FAzdH3Fctp7r7_z%26e3Bv54AzdH3FKg5osj12jSi5o-8la%2C80c0%2Ca%2C809a9%2Cd_z%26e3Bip4s&gsm=3&rpstart=0&rpnum=0&islist=&querylist=&nojc=undefined 原图链接][http://5itupu.com/KnowledgeShow-190,1757,0,17404,2.html 来自我爱图谱]]]
'''单孔目'''是哺乳纲动物中原兽亚纲的仅有的一目，因其直肠和泌尿生殖系统共同开口于一个肛门孔而得名。有2科3属3种，只分布在大洋洲地区，主要在澳大利亚东部及塔斯马尼亚岛以及新几内亚岛生活。历史上曾存在另外两个科，但都已灭绝。
单孔目动物没有分肛门、尿道及产道，而是由合一的总排出腔代替。与其他哺乳动物一样都是[[恒温性动物]]。