A group of mammals that comprises the monotremes and their extinct relatives. Compare with Theria.
- Subclass Prototheria, class Mammalia
More example sentences
- They are often placed in a separate subclass from other mammals, Prototheria.
- Triconodonta were viewed as broadly ancestral to the extinct Docodonta and to living monotremes, collectively grouped (often with Multituberculata) as Prototheria.
- As noted, recognition of skull resemblances to monotremes and triconodonts led to later referral to ‘Prototheria,’ within a monophyletic Mammalia.
Definition of Prototheria in:
- The British & World English dictionary