Mr Lynch effectively ruled that out, saying the skull was large and leaned toward that of an adult.
The skull and "a number of bones'' were found at a depth of about 70cm as builders dug a trench for fencing. They were about 3m from the footpath.
"We have an archaeologist looking at the site today,'' Mr Lynch said, adding they hoped to have a result in the next couple of days.
Mr Lynch said initial investigations showed the state of the teeth within the skull did not tie in with anyone who may have been buried there a century or more ago.
"But it is not a fresh skeleton. It is aged - we're just not sure of the age of it.''
The discovery was made about 11.15am on the site of an old villa which was removed last year. The replacement building was close to completion but work had been postponed at this stage.
Mr Lynch said a blessing of the site had been carried out before the scene examination on the chance it could have been a burial site.
The work was being carried out by Simkin Construction.
Manager Terry Simkin said the crew on site had been forced to dig a little deeper for the fencing foundations as they had come across rubble.
"They came across a couple of smaller bones and thought they may have been buried there by a dog.''
But one man came across what looked like a skull and used his hand to carefully brush dirt away.
When he realised it was a skull he called Mr Simkin with a "what do we do now?''
Mr Simkin told the crew not to touch anything, get off the site and call the police.
He said the worker who found the skull was "not too shaken'' and was back at work, on another site, today.
One neighbour said when she heard what had been found just metres from her house she was at first mystified and intrigued by the arrival of police crews and kaumatua who carried out the blessing.
But today, as the situation unfolded, she felt "unsettled.''
"It is a bit creepy,'' she said, before adding she was relieved to hear the remains were not recent.
She had never heard of anything happening in the past, or whether there were old burial sites in the area.