He would be questioned at Ecuador's embassy in London, where he has been for more than three years.
Environmentalists say Ecuador's leftist leader, Rafael Correa, gives a greater priority to business.
The dragon-like wood-lizards were discovered in the Andes in Ecuador and Northern Peru.
WikiLeaks have accused authorities in Sweden of holding up the trial, but have welcomed the news.
Assange, who has spent two years inside the Ecuadorian embassy, said he planned to leave, but only if he wasn't arrested, his spokesman added
The WikiLeaks editor fled to the South American country's embassy in June 2012 to avoid extradition to Sweden to face allegations of sexual assault and rape
A federal judge says mafia-like racketeering was used against the oil giant