Choose your answer: Is "The line following the stem group Sphenacodontia split-off several diverse groups of non-mammalian synapsidssometimes referred to as mammal-like reptilesbefore giving rise to the proto-mammals (Therapsida) in the early Mesozoic era." a good answer to the question "From which time period did birds and reptiles began to appear from?"
Available options: (a). yes (b). no
(b).