The non-mammalian members are described as mammal-like reptiles in classical systematics; they can also be called stem mammals or proto-mammals. Synapsids evolved from basal amniotes and are one of the two major groups of the later amniotes; the other is the sauropsids, a group that includes modern reptiles and birds. The distinctive temporal fenestra developed in the ancestral synapsid about 312 million years ago (mya), during the Late Carboniferous period. Synapsids were the largest terrestrial vertebrates in the Permian period, 299 to 251 million years ago. As with almost all groups then extant, their numbers and variety were severely reduced by the Permian–Triassic extinction. Though some species survived into the Triassic period, archosaursbecame the largest and most numerous land vertebrates in the course of this period. Few of the nonmammalian synapsids outlasted the Triassic, although survivors persisted into the Cretaceous. However, as a phylogenetic unit, they included the mammals as descendants, and in this sense synapsids are still very much a living group of vertebrates. After the Cretaceous–Paleogene extinction event, the synapsids (in the form of mammals) again became the largest land animals. The only extant synapsids today are mammals.
Permian. Anomodontian Accumulated Many Skeleton Plaque. Suminia getmanovi. From Russia. Anomodontia is an extinct group of non-mammalian therapsids containing many species from the Permian and Triassic periods (possibly continuing into the Early Cretaceous) most of which were toothless herbivores. A..
Dicynodontian Skeleton Mounted. Austalobarbarus kotelnichi. From the collection of: Koltelnich Peleontological Museum in Russia. Polyurethane Cast. Time 255 MYA - Upper Permian. * Size: 28" x 17.4" x 6.8" (71cm x 45cm x 17cm) * Museum quality replica * Made in Lancaster, Ca USA .
Dimetrodon Skeleton. Replica. MOUNTED AND CRATED. Mammal-like reptile of Permian Texas. Hayashibara Science Museum.
* Size: 117in. length x 4 ft. height
* Museum quality Dimetrodon skeleton is cast in durable polyurethane resins. * Made in USA
Dimetrodon linbatus.,Dimetrodon was an apex predator, among the largest of its day. It grew to up to 3 metres (9.8 ft) in length. The name Dimetrodon means 'two-measures of teeth', so named because it had a large skull with two different types of teeth (shearing teeth and sharp canine teeth), unlike..