1951, Alan Devoe, This Fascinating Animal World, page 4:The whole of this vast mammaldom which so dwarfs us is itself no more than a tenth of the entirety of the vertebrates (the backboned animals).
2007, February 20, Natalie Angier, A Mammal in Winter With a Furnace of Her Own, At the museum, visitors are reminded that mammaldom did not confer any major advantages on its earliest practitioners.
2009, Christopher McDougall, Born to Run, page 214:But why, in all mammaldom, would a jackrabbit need a spring-loaded belly?
