Originally mistaken as Homo Ergaster or Neanderthal, Heidelbergensis was an early form of H. sapiens. They possessed more advanced tools than earlier species.
Yet there is few, if any, traces of innovation and cultural innovations. Again, no art or other artefacts have been found.
Intriguingly, there is evidence they possessed a modern humanlike hyoid bone that could have supported human speech. So it’s possible this early hominid did possess some rudimentary language system.