Bone histology. Evolution of growth pattern in birds.
Living (neornithine) birds grow up rapidly and without interruption, terminating their growth within one year and, with a few secondary exceptions, starting to fly only after or near the completion of growth. Bone histology has revealed that pre-avian theropods also grew fast for most of the postnatal period, but that this growth was usually intermittent and probably extended for more than one year. We have found surprising evidence for an early postnatal slowing-down of growth in two lineages of flying basal birds, which suggests that birds may have started their evolution as precocious fliers.
Chinsamy
A
A
Department of Zoology, University of Cape Town, Private Bag, Rondebosch 7700, South Africa.
Elzanowski
A
A
D000818:Animals; D005075:Biological Evolution; D001717:Birds / Q000033:anatomy & histology* / Q000254:growth & development; D001842:Bone and Bones / Q000033:anatomy & histology*; D005269:Femur / Q000033:anatomy & histology