"The bush is not a good place for the preservation of bones as rain and stream water is slightly acidic so they will only be preserved if they are in a relatively dry site," he said.
The bone, which was formally blessed by a contingent from Ngati Pahauwera, has been analysed and recorded, but it has not been formally dated and been left in situ.
The trust's property at Maungataniwha is where palaeontologist Joan Wiffen first discovered evidence of land dinosaur fossils in New Zealand.
"If any one place is the epicentre of New Zealand palaeontology, Maungataniwha is probably it," Shaw added.
In March 2015, Shaw discovered the fossilised jaw of a mosasaur - a large marine reptile that was the dominant marine predator during the last 20 million years of the Cretaceous period.
The jaw contained the largest mosasaur tooth on record in the country.
In 2019, Shaw was recognised by the Geoscience Society of New Zealand for his work on fossils in the forest.
He was awarded the Harold Wellman Prize for the discovery of important fossil material in New Zealand.
The Forest Lifeforce Restoration Trust was established in 2006 to provide funding for the restoration of threatened species of fauna and flora and to restore the ngahere mauri in native forests within the Central North Island.