Friday 23 January 2015, an Aurizon (ex-QR National) train of coal empties having crested the pass in the Ardglen tunnel through the Liverpool Range northwest of Murrurundi NSW, races down towards Willow Tree on the Main North. An echidna hunts for lunch among the ants by the track. The echidna and platypus, both unique to Australia, are the world's only egg-laying mammals.