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Temporal range: Upper Triassic–Recent
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
(unranked): Amniota
Class: Synapsida
Order: Therapsida
Suborder: Cynodontia
(unranked): Mammaliaformes
Rowe, 1988

Mammaliaformes ("mammal-like") is a clade which contains the mammals and their closest extinct relatives.

Living members of the clade include the monotremes (Monotremata), marsupials (Marsupialia) and the eutherians (Placentalia).[1][2]

Mammaliforms have highly specialized molar teeth, with cusps and flat regions for grinding food. This is a single inherited system in present mammals, but it seems to have evolved convergently in pre-mammals more than once. Instead of having many teeth that are frequently replaced, mammals have one set of baby teeth and later one set of adult teeth which fit together precisely. This may help to grind food, and make it easier to digest.

Lactation (milk) and fur, along with other features, also characterize the Mammaliaformes, though these traits are difficult to study in the fossil record. The fossilized remains of Castorocauda lutrasimilis are an exception to this.

Taxonomy[change | change source]

In some sources Class Mammalia takes the place of Mammaliaformes, and includes all members of that clade.

References[change | change source]

  1. Kielan-Jaworowska, Zofia; Cifelli, Richard L. and Luo, Zhe-Xi 2004. Mammals from the age of dinosaurs. Columbia N.Y. ISBN 0-231-11918-6
  2. Kemp T.S. 2005. The origin & evolution of mammals. Oxford.