Pygmy whale sighting raises questions over history
An elusive pygmy whale sighting has prompted questions over whether it may be the last living relative of an ancient group of whales, believed to be extinct for around two million years.
The pygmy whale has only been seen just a handful of times and scientists know little about this creature, only that its appearance is very different to the whales around today. A new study, published in the Proceedings of the Royal Society B, may help to explain why the mysterious marine mammals look so different from any other living whale.
The relatively small pygmy right whale, which grows to just 6.5 metres long, lives out in the open ocean and inhabits the Southern Hemisphere. The strange creature's arched, frownlike snout makes it look different from other living whales.
DNA analysis suggested pygmy whales diverged from modern baleen whales, such as the blue whale and the humpback whale between 17 million and 25 million years ago. However, the pygmy whales' snouts suggested they were more closely related to the family of whales that includes the bowhead whale. Yet there were no studies of fossils showing how the pygmy whale had evolved.
Paleontologist Felix Marx, and his colleagues at the University of Otago in New Zealand, carefully analysed the skull bones and other fossil fragments from pygmy whales and several other ancient cetaceans.
The pygmy whale's skull most closely resembled that of an ancient family of whales called cetotheres that were thought to have gone extinct around two million years ago, the researchers found. Cetotheres emerged about 15 million years ago and once occupied oceans across the globe.
The findings help explain how pygmy whales evolved and may also help shed light on how these ancient "lost" whales lived. The new information is also a first step in reconstructing the ancient lineage all the way back to the point when all members of this group first diverged.
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