monotreme

How To Use monotreme In A Sentence

• The Australian fossil record of monotremes also includes some quite good Miocene and Pleistocene fossils of giant echidnas.
• monotremes and marsupials are aplacental mammals
• The platypus and the echidna - a nocturnal, burrowing mammal with a spiny coat, long claws, and no teeth - are the only known living members of a type of animal known as monotremes.
• But what the newly sequenced genome reveals is that the platypus's male-determining gene, the monotreme equivalent of primates' SRY gene, is not located on any of those five pairs of sex chromosomes. Archive 2008-05-01
• Like the eggs of birds, monotreme eggs are incubated and hatched outside the body of the mother.
• An unquestioned monotreme, Steropodon has molars that are surprisingly similar to those of marsupials and placentals, suggesting a closer relationship to living therians than had generally been thought.
• But the monotremes probably split away from this main line of evolution early on, in the late Jurassic or early Cretaceous.
• We are familiar with the monotremes, marsupials and placentals of today, but there were also other kinds, such as multituberculates, which are now extinct.
• But in the monotremes the formation of the cenogenetic entoderm does not precede the invagination; hence in this case the construction of the germinal layers is less modified than in the other amniota. The Evolution of Man — Volume 1
• However, the bone is rather persistent otherwise, and has been identified, for example, in tritylodontids, Morganucodon, Gobiconodon, and monotremes, although it is absent in multituberculates.