Small, toothed mammals represent the most unusual of all whales. If they were still around today, they would be as symbolically Australian as kangaroos. A new paper published this week in The Linnaean Society’s Journal of Zoology details a recently identified species named Janjucetus lullardi, derived from a 25 million-year-old specimen unearthed in Victoria, Australia.
Janjucetus lullardi — 25 million years ago, a calf and its mother swam in the shallow waters off the coast of Victoria. Image credit: Ruairidh Duncan.
“Currently, some of the most iconic species of whales, including blue and humpback whales, are whale veil.” I noted, said LeAilid Duncan, a paleontologist from Monash University.
“These marine giants utilize a hairy filter in their mouths called Baleen to sift through plankton.
“In contrast, these mammals had bodies measuring less than 3 meters, with large eyes and short jaws filled with teeth.”
“Despite this description, we know that mammalian whales lacked Baleen.”
“They appeared to be derived from the major evolutionary lines leading to today’s toothless giants.”
All known mammalian species thrived during the late Oligocene epoch, approximately 27 to 23 million years ago.
Interestingly, three of the four identified species were found along the Victoria Surf Coast, southeast of Melbourne.
“The first mammal was uncovered in 1932 and was named in 1939 Mammalian Coraliber,” the paleontologist remarked.
“It featured a blunt jaw bone with a rich supply of blood and nerves for its facial and lip muscles.”
“Notably, the teeth show signs of wear on the gums, indicating they foraged for abrasive prey (along with gritty substances) from the seafloor.”
“In 2006, a local naturalist discovered the first fossil of a species named after him, Janjucetus hunderi.
“This whale had a sturdy triangular snout with sharp teeth and strong muscles to close its powerful jaw.”
“However, the exact differences in the lifestyle of Mammalian Coraliber and Janjucetus hunderi compared to other whales remain largely unclear, hinting at a diverse range of behaviors.”
The fossilized remains of Janjucetus lullardi, dating back 25 million years, were found in 2019 by school principal Ross Dallard along the coast of Yang JUC in Victoria.
“Janjucetus lullardi measured about 2 meters in length. It’s compact enough to fit in a standard single bed,” the researcher noted.
“This may be the first fossilized whale discovered in Australia, and potentially the first fossils of a juvenile whale found in this region.”
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Ruairidh J. Duncan et al. 2025. Insights into the mystiology of immature teeth from the Australian Oligocene and mammals (Cetacea: Mysticeti) morphology, phylogenetics, and ontogeny. The Linnaean Society’s Journal of Zoology 204 (4): ZLAF090; doi: 10.1093/zoolinnean/zlaf090
Source: www.sci.news
