In: Biology
Explain the evolutionary characters and similarities that exist among Docodonts, Triconodonts, Symmetrodonts, Multituberculates, Monotremes, Pantotheres, Placentals and Marsupials
Docodonta is an order of extinct mammaliaforms They are distinguished from other early mammaliaforms by their relatively complex molar teeth, from which the order gets its name.
Symmetrodonta is a group of Mesozoic mammals and mammal-like synapsids characterized by the triangular aspect of the molars when viewed from above and the absence of a well-developed talonid.
Multituberculata (commonly known as multituberculates, named for the multiple tubercles of their teeth) is an extinct taxon of rodent-like allotherian mammals that existed for approximately 166 million years, the longest fossil history of any mammal lineage.
The monotremes are typified by structural differences in their brains, jaws, digestive tract, reproductive tract, and other body parts compared to the more common mammalian types.
Pantotheres-is an abandoned taxon of Mesozoic mammals. This group is now considered an informal "wastebasket" taxon and has been replaced by Dryolestida as well as other groups. It is sometimes treated as an infraclass and older books refer to it as being related to symmetrodonts.
Placentalia is one of the three extant subdivisions of the class of animals Mammalia; the other two are Monotremata and Marsupialia. The placentals are partly distinguished from other mammals in that the fetus is carried in the uterus of its mother to a relatively late stage of development.
Marsupials are any members of the mammalian infraclass Marsupialia. All extant marsupials are endemic to Australasia and the Americas. A distinctive characteristic common to these species is that most of the young are carried in a pouch.