The title is factually incorrect and is not what the research actually found:

https://www.nature.com/articles/s41593-026-02433-7

Title: "Two parallel neural ectoderm progenitors contribute to the developing brain".

"Hence, we postulate the brain is a composite organ emanating from two lineage-restricted progenitors; these dual progenitors may be evolutionarily conserved across 550 million years from hemichordates to mammals."