* Dingoes are native to mainland Australia. They are a type of wild dog that has been present on the mainland for thousands of years.
* Tasmania has its own unique native marsupial predator, the Tasmanian devil. This creature is a carnivorous marsupial that serves a similar ecological role to the dingo on the mainland.
* Tasmania was separated from the mainland by rising sea levels around 10,000 years ago, long after the dingoes were established in mainland Australia.
It is possible that you are thinking of a different animal, or perhaps you are thinking of the fact that there have been some attempts to introduce dingoes to Tasmania for conservation purposes. However, these attempts have not been successful and there is no established population of dingoes on the island.