As synapsids continued to evolve during the Permian Period, however, they lost their belly ribs. Creatures like our cynodont ...

The Synapsid and Parareptile Collection includes both non-mammalian synapsids and Mesozoic mammaliaformes. The first collections at the Museum were acquired in 1853, with the transfer from the ...

The initial split was into synapsids (mammals and their relatives) and sauropsids (reptiles and birds). Mammals branched off from other amniotes very early. Several mammalian characteristics are ...