Echovenator sandersi: a Toothed Whale Fossil Shows High Frequency Echo Location Hunting Evolved 10 Million Years Earlier Than Previously Thought

A newly-named fossil whale species had superior high-frequency hearing ability, helped in part by the unique shape of inner ear features that have given scientists new clues about the evolution of this specialized sense.

In a study published August 4 in Current Biology, researchers from New York Institute of Technology and colleagues from the National Museum of Natural History in France describe a new species of whale, Echovenator sandersi ("Echo Hunter"), an ancient relative of the modern dolphin, and its ability to hear frequencies well above the range of hearing in humans.

The research pushes the origin of high frequency hearing in whales farther back in time -- about 10-million years than previous studies have indicated.

"Previous studies have looked at hearing in whales but our study incorporates data from an animal with a very complete skull," says Morgan Churchill, a postdoctoral fellow at NYIT College of Osteopathic Medicine and the paper's lead author. "The data we gathered enabled us to conclude that it could hear at very high frequencies, and we can also say with a great degree of certainty where it fits in the tree of life for whales."

"This was a small, toothed whale that probably used its remarkable sense of hearing to find and pursue fish with echoes only," says Associate Professor Jonathan Geisler, a study co-author. "This would allow it to hunt at night, but more importantly, it could hunt at great depths in darkness, or in very sediment-choked environments."

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California Blue Whales Have Recovered to Near Historical Levels

The number of California blue whales has rebounded to near historical levels, according to new research by the University of Washington, and while the number of blue whales struck by ships is likely above allowable U.S. limits, such strikes do not immediately threaten that recovery.

This is the only population of blue whales known to have recovered from whaling – blue whales as a species having been hunted nearly to extinction.

Blue whales – nearly 100 feet in length and weighing 190 tons as adults – are the largest animals on earth. And they are the heaviest ever, weighing more than twice as much as the largest known dinosaur, the Argentinosaurus. They are an icon of the conservation movement and many people want to minimize harm to them, according to Trevor Branch, UW assistant professor of aquatic and fishery sciences.

"The recovery of California blue whales from whaling demonstrates the ability of blue whale populations to rebuild under careful management and conservation measures," said Cole Monnahan, a UW doctoral student in quantitative ecology and resource management and lead author of a paper on the subject posted online Sept. 5 by the journal Marine Mammal Science. Branch and André Punt, a UW professor of aquatic and fisheries sciences, are co-authors.

California blue whales ¬ are at their most visible while at feeding grounds 20 to 30 miles off the California coast, but are actually found along the eastern side of the Pacific Ocean from the equator up into the Gulf of Alaska.

Today they number about 2,200, according to monitoring by other research groups. That's likely 97 percent of the historical level according to the model the co-authors used. That may seem to some a surprisingly low number of whales, Monnahan said, but not when considering how many California blue whales were caught. According to new data Monnahan, Branch and another set of co-authors published earlier this summer in PLOS ONE, approximately 3,400 California blue whales were caught between 1905 and 1971.

"Considering the 3,400 caught in comparison to the 346,000 caught near Antarctica gives an idea how much smaller the population of California blue whales was likely to have been," Branch said.

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Orcas Went Through Population Bottleneck During the Tarantian Pleistocene Quaternary

Whole genome sequencing has revealed a global fall in the numbers of killer whales during the last Ice Age, at a time when ocean productivity may have been widely reduced, according to researchers at Durham University.

The scientists studied the DNA sequences of killer whale communities across the world.

They found a severe decline in whale numbers leading to a bottleneck and consequent loss of genetic diversity approximately 40,000 years ago when large parts of the Earth were covered in ice.

The only exception to this was found in a killer whale population off the coast of South Africa that retained high variations in genetic diversity.

As greater genetic diversity indicates larger population size, the researchers believe the South African community of killer whales escaped the bottleneck faced by other communities.

They said an important factor could have been the Bengeula upwelling system – which delivers nutrient rich cold water to the oceans off South Africa – remaining stable despite the last glacial period.

This nutrient rich water would have been able to sustain the supplies of fish and dolphins that killer whales in this part of the world feed on.

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Fossil Ambergris Found

Clumps of squid beaks sticking out of clay in Italy's Umbrian badlands may be the first fossilized ambergris, or whale poo, ever found.

Ambergris is a fatty, waxy-looking substance. Scientists believe sperm whales — the largest toothed predator on Earth — secrete ambergris inside their digestive tracts to protect themselves from sharp objects, like giant squid beaks and fish bones and teeth. And contrary to urban legend, ambergris is actually whale poo, not vomit. Sought after by perfume makers, aged ambergris is like umami for the nose, adding musky depth to scents.

Even though scientists have discovered fossilized feces, called coprolites, from dinosaurs, ichthyosaurs, mammoths and sharks, no one has reported finding ancient ambergris.

Good thing King Charles II isnt alive: might crack his teeth.  He'd have to use fossilized eggs to go with though.

A Pleistocene Cetothere Fossil From Northern California

Research from New Zealand's University of Otago detailing the fossil of a dwarf baleen whale from Northern California reveals that it avoided extinction far longer than previously thought.

Otago Department of Geology PhD student Robert Boessenecker has found that the fossil of the 4-5 meter long Herpetocetus, thought to be the last survivor of the primitive baleen whale family called cetotheres, may be as young as 700,000 years old.

Mr Boessenecker says the previously youngest-known fossils of this whale were from the pre-Ice Age Pliocene epoch; approximately 3 million years ago, a time before many modern marine mammals appeared. Baleen whales of this type were most common much earlier, about 10-15 million years ago.

"That this whale survived the great climatic and ecological upheavals of the Ice Age and almost into the modern era is very surprising as nearly all fossil marine mammals found after the end of the Pliocene appear identical to modern species.

"Other baleen whales underwent extreme body size increases in response to the new environment, but this dwarf whale must have still had a niche to inhabit which has only recently disappeared," he says.

The find indicates that the emergence of the modern marine mammals during the Ice Age may have happened more gradually than currently thought, he says.

The discovery also lends indirect support to a hypothesis about the modern pygmy right whale (Caperea marginata) recently published by Mr Boessenecker's colleagues Professor Ewan Fordyce and Dr Felix Marx. The pair posited that this enigmatic Southern Ocean whale is not a true right whale but actually a member of the cetothere family and one of the closest relatives of Herpetocetus.

"If their hypothesis is correct, this latest discovery indicates that other close relatives of the pygmy right whale nearly survived to modern times within the Northern Hemisphere.

"In this light, Herpetocetus can be viewed as a Northern Hemisphere equivalent of the pygmy right whale: both are small-bodied with peculiar anatomy, possibly closely related, with feeding habits that are seemingly divergent from other baleen whales."

Pyrgmy Right Whale Still Extant

News story.

Paper.

The Evolution of a Whale of a Tail

Brian and National Geographic have good articles on Georgiacetus, an archaeocetan.