temporal openings merge parietal bones move posteriorly zygomatic arch is all that remains of anapsid skull allows for bigger brain secondary hard palate masseter muscles differentiate and attachments change for better dentition, masseters, and eating apparatus
changes from primitive sprawling gate to directly beneath
Mammals evolved over which period?
after late permian into early triassic (~248mya)
Mammals radiated during which period?
after dinosaur extinction ~65mya
Most diverse - least diverse vertebrate groups 2018
Fish Birds Non-avian reptiles amphibians mammals
Age of mammals (right after cretaceous) includes tertiary and quaternary
reduction of temporal shield, differentiation of masseters heterodont dentition 2 occipital condyles maxillary and premaxillary bones into hard palate condyle of dentary fits into glenoid fossa of squamosal bone
early mammals in triassic that gave rise to monotremes