Origin of monotreme
Examples from the Web for monotreme
Fig. 25 shows the male genito-urinary tract and the cloaca in the monotreme, Platypus anatinus.The Anatomy of the Human Peritoneum and Abdominal Cavity|George. S. Huntington
Pseu′dodont, having false teeth, as a monotreme; Pseu′dodox, false.
That bone is known in a separate state in reptiles and, I think, in monotreme mammals.Dragons of the Air|H. G. Seeley
One monotreme egg represents more economy and saving than a thousand eggs of a worm.
Moreover, it requires a large amount of material to form a mammalian egg, such as that of the monotreme.