Museum Victoria's Jane Melville was asked to study the lizard, originally classified as Tympanocryptis pinguicolla, which have featured on the endangered species list since 1996.
During a year-long review, Dr Melville found instead of a single species, there were four distinct classifications with different characteristics.
Dr Melville said the discovery of the new species will be vital to manage the conservation of the dragons.
"The single species was already listed as a threatened species at a federal level. Now that they are four separate species the conservation recovery teams will be working to re-evaluate the status of the species."
Her study, published in Royal Society Open Science, found the action plan to preserve the dragons was a decade old and assessing the conservation status of each of the four species was an immediate priority.
One species of the tiny dragon has not been seen since 1969, raising fears it could be the first extinction of a reptile on mainland Australia.
However, Dr Melville has not lost hope for the Victorian population with a survey by Zoo Victoria continuing the search.
"You have to be pretty confident to call a species extinct and we don' feel that we have reached that point yet. Having said that, it is concerning that we have not seen them since 1969 - there is no doubt they are in trouble."
The Grassland Earless Dragon was once widespread, found throughout western Victoria, NSW and ACT, from Geelong to Bathurst.
It reaches 15cm from head to tail when fully-grown and lacks external ear openings, unlike most other lizards.
Habitat loss and fragmentation are thought to be the main causes of the decline in the species, she said.
