The corpus callosum (CC), a large axon bundle connecting the telencephalon, is formed exclusively in Eutheria (placental mammals). Here we demonstrate that interhemispheric remodeling, a prior developmental step for CC formation, is highly conserved in nonmammalian amniotes.

BMP signaling regulates ROS generation and scavenging to control interdigital cell death in the developing chicken limb, highlighting a balance between oxidative stress and tissue regression.