Janjucetus dullardi sheds light on predatory origins of baleen whales

A newly described fossil of Janjucetus dullardi sheds new light on the early evolution of baleen whales, revealing a small, fast predator that roamed warm, shallow seas off southern Australia about 26 million years ago. The juvenile mammalodontid, roughly two meters in length, boasted large forward-facing eyes and a mouth lined with sharp, slicing teeth, a combination that underscores a more aggressive feeding style than that of modern filter feeders. The partial skull, including ear bones and teeth, was found on the Victorian coast in 2019, donated to Museums Victoria, and is now the basis for a study published in the Zoological Journal of the Linnean Society. The species is named in honor of the local finder, Ross Dullard, whose discovery has helped illuminate a pivotal chapter in whale history.

The fossil’s discovery near Jan Juc, along Victoria’s Surf Coast, is part of a broader pattern in the Jan Juc Formation, a geologic unit famed for preserving remnants of early whales during the Oligocene epoch, a period of global warmth and rising sea levels. The specimen’s preservation—especially the newly analyzed inner ear structures—has allowed researchers to infer aspects of how...