| Many of the comprehensive, algorithm-based analyses place multituberculates within the crown group of living mammals, in some cases tentatively united with monotremes. |
| They had a common ancestor more recently than either had with the monotremes or, probably, any other prototherian group. |
| But the monotremes probably split away from this main line of evolution early on, in the late Jurassic or early Cretaceous. |
| In some ways, monotremes are very primitive for mammals because, like reptiles and birds, they lay eggs rather than having live birth. |
| He designed a platypussary, in which one of the monotremes lived for months and was seen by thousands of people. |
| Triconodonts, monotremes and multituberculates have the primitive condylar arrangement for the radius. |
