Samuel Mayo, 4, prefers to be called Sammy and will tell you so.
He just started pre-kindergarten and loves learning, the color green, pizza and building things. He is smart and has a tender heart, according to his mother, Meagan Mayo.
His brother, Barrett, 2, known as Bear, goes full speed ahead in all things. He loves the color orange, hot dogs and driving his toy tractor. He is silly and fun to be around, his mother said.
But the Jacksonville siblings also have a few things in common: a love of dinosaurs and a birth defect called sagittal craniosynostosis where the skull bones fuse prematurely before the baby s brain is fully formed. The condition can run in families.