Ancient dolphin species discovery in Ecuador


This video says about itself:

21 December 2017

A well-preserved juvenile skull recently discovered in Ecuador belongs to a new species of ancient dolphin, which researchers are calling Urkudelphis chawpipacha. The fossil was discovered near Montañita in Santa Elena Province, a tropical region of Ecuador, and is believed to be between 24 to 26 million years old.

From PLOS:

Ancient dolphin species Urkudelphis chawpipacha discovered in Ecuador

Small dolphin skull may have belonged to river dolphin ancestor from the Oligocene

December 22, 2017

Summary: An extinct dolphin species likely from the Oligocene has been discovered. The fossil is one of the few fossil dolphins from the equator, and is a reminder that Oligocene cetaceans may have ranged widely in tropical waters.

A new dolphin species likely from the Oligocene was discovered and described in Ecuador, according to a study published December 20, 2017 in the open-access journal PLOS ONE by Yoshihiro Tanaka from the Osaka Museum of Natural History, Japan, and colleagues.

Many marine fossils described in previous research have been from long-recognized temperate regions such as South Carolina, off the coast of Oregon, Hokkaido and New Zealand. Few equatorial and polar fossils are currently known.

While in the tropical region of Santa Elena Province, Ecuador, the authors of this study found a small dolphin skull, which they identified as representing a new species, Urkudelphis chawpipacha, based on facial features. The dolphin skull had a bone crest front and center on its face, above the eye sockets. This species stands apart from other Oligocene dolphins with its shorter and wider frontal bones located near the top of the head and the parallel-sided posterior part of its jaw. The authors also conducted a phylogenetic analysis which revealed that the new species may be the ancestor of the nearly-extinct Platanistoidea, or river dolphin, and may have lived during the Oligocene era.

The fossil is one of the few fossil dolphins from the equator, and is a reminder that Oligocene cetaceans may have ranged widely in tropical waters.

This study was supported by an UPSE project IN-P5-2016-1 for equipment at UPSE, and YT thanks support of a trip to Ecuador. This work has also been supported by the Agencia Estatal de Investigación (AEI) from Spain and the European Regional Development Fund of the European Union (CGL2016-76431-P) and the project CGL2015-68333 (MINECO/FEDER, UE).

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Narwhal, dolphin news


This video says about itself:

Listen to a narwhal’s resting heartbeat | Science News

7 December 2017

Narwhals have a resting heart rate of about 60 beats per minute. Now researchers have observed narwhals’ heart rate dropping precipitously low when diving to escape from humans. As melting sea ice opens up the Arctic to more human activity, the mammals, known as “unicorns of the sea” for their single tusk, may be more exposed to the potentially harmful escape response, scientists say.

Narwhals react to certain dangers in a really strange way. ‘Unicorns of the sea’ fleeing humans show the physiological signs of also being frozen in fear. By Mariah Quintanilla, 2:41pm, December 7, 2017.

This video says about itself:

Science News – Whales & Dolphins Have “Human-Like” Societies

19 October 2017

AI eavesdrops on dolphins and discovers six unknown click types. Computer program picked out the noises from underwater recordings of 52 million echolocation signals. By Maria Temming, 2:00pm, December 7, 2017.

Dwarf dolphin fossil discovery


This video says about itself:

23 August 2017

Researchers have uncovered a fossil of an extinct dolphin species along the South Carolina coast. The toothless dolphin, which lived 28-30 million years ago, used suction-feeding and preyed on fish and squid.

From the New York Institute of Technology in the USA:

Dolphin that existed along South Carolina coast long ago

August 23, 2017

Continuing to uncover fossil evidence along the coast of South Carolina, researchers, led by a faculty member at College of Charleston, have discovered a species of extinct dolphin. The toothless dolphin, which lived about 28-30 million years ago, provides new evidence of the evolution of feeding behavior in whales (which includes dolphins).

The species, named Inermorostrum xenops, lived during the same period as Coronodon havensteini, a species of ancient whale announced recently by investigators at New York Institute of Technology College of Osteopathic Medicine and College of Charleston in Current Biology.

The skull of Inermorostrum was discovered by a diver in the Wando River in Charleston, just miles from the location where Coronodon’s remains were found, and presents the first clear evidence of suction feeding in echolocating sea mammals. The researchers estimate that the dolphin grew to be only four feet long, smaller than its closest relatives, and significantly smaller than today’s bottlenose dolphins, which measure seven to twelve feet in length.

The study has been released in the journal Proceedings of the Royal Society B.

According to College of Charleston adjunct geology professor Robert W. Boessenecker, Ph.D., the dwarf dolphin had a short snout and entirely lacked teeth. The genus name, Inermorostrum xenops, means “defenseless snout,” referring to its toothless condition. Boessenecker, the lead author of the study, believes that the suction-feeding dolphin fed primarily on fish, squid, and other soft-bodied invertebrates from the seafloor, similar to the feeding behavior of a walrus. Furthermore, a series of deep channels and holes for arteries on the snout indicate the presence of extensive soft tissues, likely enlarged lips, and also perhaps even whiskers.

“We studied the evolution of snout length in cetaceans, and found that during the Oligocene (25-35 million years ago) and early Miocene epochs (20-25 million years ago), the echolocating whales rapidly evolved extremely short snouts and extremely long snouts, representing an adaptive radiation in feeding behavior and specializations,” says Boessenecker. “We also found that short snouts and long snouts have both evolved numerous times on different parts of the evolutionary tree — and that modern dolphins like the bottlenose dolphin, which have a snout twice as long as it is wide, represent the optimum length as it permits both fish catching and suction feeding.”

Research team member, Jonathan Geisler, Ph.D., chair of the Anatomy Department and associate professor at NYITCOM, says the discovery is an important step in understanding why the South Carolina Coast provides unique insights into cetacean evolution.

“Coronodon, a filter feeder whale, and Inermorostrum, a suction feeding dolphin, may well have fed on the same prey. Their feeding behaviors not only help us understand their vastly different body sizes, but also shed light on the ecology of habitats that led to Charleston’s present-day fossil riches,” says Geisler.

Dr. Danielle Fraser, a paleontologist at the Canadian Museum of Nature and also part of the research team, notes that the identification of Inermorostrum opens up new questions about the evolution of early whales. “The discovery of a suction feeding whale this early in their evolution is forcing us to revise what we know about how quickly new forms appeared, and what may have been driving early whale evolution” she explains. “Increased ocean productivity may have been one important factor,” she says.

Many species of Oligocene whales have been described from South Carolina, with several discovered in and around Charleston. The area is among a few in the world, including others in New Zealand, Japan, and the Pacific Northwest, to offer a window into early toothed whale evolution.

Inermorostrum xenops is now on display in the Mace Brown Museum of Natural History at College of Charleston, reunited with its prehistoric neighbor Coronodon havensteini.

Dolphins beaching to feed, video


This video, recorded in the USA, says about itself:

Dolphins Beach Themselves To Feed – The Hunt – BBC Earth

21 July 2017

These amazing Bottlenose Dolphins have adopted a unique way of hunting fish. Taking advantage of the low tide, these super smart mammals are able to beach themselves on mud banks, and attack in perfect synchrony.

Hydroplaning dolphins in Australia


This video says about itself:

Hydroplaning Dolphins – Planet Earth – BBC Earth

2 May 2017

These remarkable Dolphins in Western Australia display incredible ingenuity when hunting for fish in the shallows. With little room for error, it would appear fortune does indeed favour the brave.

Bahamas wild spotted dolphins


This video says about itself:

27 January 2017

In the Bahamas, a group of wild Spotted Dolphins play “keep away” with a bandana–a game they invented with seaweed and people started playing with them. Jonathan travels to the Bahamas with dolphin expert Wayne Scott Smith to meet these playful animals and try playing the Bandana Game with them.

How a dolphin eats an octopus without dying, by Sarah Zielinski. 1:00pm, April 25, 2017: here.