"It's not like they were sitting in the burrow and a flooding
event filled the chamber with sediment and they were entombed. They
must have died, undergone decay and then the burrow was filled."
Commenting on the discovery, Professor Kevin Padian from the
Museum of Palaeontology, University of California-Berkeley, said the
Montana team should be commended for the detailed way in which it
went about its work.
Many would have missed the significance of the tunnel, he said.
"This discovery is first and foremost a testament to the value
of keeping one's eyes open in the field and noticing everything, and
it took a special group of scientists to realise the meaning of the
discovery that they made," he added.
Professor Padian bemoaned the impact of commercial fossil
hunting which, he claimed, sought to get specimens out of the ground
as fast as possible, often destroying valuable scientific
information in the process.