Isisfordia duncani was about 1.1 metres long, no monster, but evolutionarily it was a giant. Recovered from the Cretaceous Winton Formation, it is one of the most primitive members of the lineage that gave rise to all modern crocodilians - the closest thing yet found to their common ancestor. Where older crocodile relatives were sprawling, varied experiments, Isisfordia already carried the streamlined, fish-catching body plan that would prove so durable it survives, barely altered, in the saltwater crocs of today's northern rivers. Seven individuals have been unearthed, making it the best-represented Cretaceous crocodyliform in Australia. To stand on the Isisford plains is to stand where the crocodile's deep-time story turned a corner.

The Barcoo River curls past the town, and that name carries weight in Australian letters. Banjo Paterson spent time in this country, and the flat, churchless distances fed his verse. "A Bush Christening" opens "On the outer Barcoo where the churches are few, / And men of religion are scanty" - lines drawn from exactly this stretch of saltbush and red dirt. The town leans into the connection: its grand two-storey pub trades as Clancy's Overflow Hotel, a nod to another Paterson poem. There is something fitting in a place this remote inspiring poetry about remoteness itself, where a man could ride for days and meet no one but the folk that are lost.

The name is a knot of history. The Indigenous people of this region are the Kuungkari, who lived along the river when Thomas Mitchell's expedition passed through in September 1846, describing a large camp of permanent huts and well-worn paths. The town that grew here was first called Whittown, after the publican James Whitman who opened a hotel, store, and smithy in 1875. By 1878 it had been renamed Isisford - for the nearby Isis Downs pastoral run and a ford across the Barcoo. The early decades were marked by frontier violence as pastoralists took up the land and the Kuungkari were dispossessed and, too often, killed.

Isisford has never held more than about 300 people, yet its footnotes keep surprising you. In April 1910 it became the first town in Australia served by motorised mail, the cars running 90 kilometres from Ilfracombe to the north; a plaque on the post office still marks it. The 1885 courthouse stands as a relic of the wool boom that built the town. Today the Outer Barcoo Interpretation Centre anchors the main street, where a life-sized model of Isisfordia greets visitors who have driven a very long way to meet a very old crocodile. Idalia and Welford National Parks lie within reach, their gorges and dunes folding away to the south.