Homo heidelbergensis
Homo antecessor and H. heidelbergensis may have had the same ancestor: Homo ergaster from Africa.  Mostly, H. ergaster was not very different from H. heidelbergensis.  However, H. heidelbergensis had a larger brain-case.  On average, their skulls had a volume of 1100 – 1400 cm³ of space inside.  (The average modern human has 1350 cm³ of space inside his or her skull.)  H. heidelbergensis also had more advanced tools and behavior than H. ergaster.  For these reasons, H. heidelbergensis has been classified as a separate species.