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.

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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.

Good Australian dolphin news


This video from South Australia says about itself:

18 September 2012

The Adelaide Dolphin Sanctuary is one of the gems of metropolitan Adelaide. Located in the Port River and Barker Inlet, the sanctuary is just 20 minutes from the city centre and features a 10,000-year-old mangrove forest. A resident pod of about 30 bottlenose dolphins call the river home, while another 300 visit the area regularly.

To learn more about the Adelaide Dolphin Sanctuary, visit here.

Video filmed and produced by Hartwig Heller.

From Science News:

City dolphins get a boost from better protection and cleaner waters

by Sarah Zielinski

11:08am, November 3, 2016

There are many places in the world where you can see bottlenose dolphins, but the dolphins swimming in the Port River estuary near Adelaide, Australia, are special. They gambol about in waters surrounded by factories, power stations and other signs of human habitation.

For much of the 20th century, there were no dolphin sightings in the inner estuary. Prior to European settlement in 1858, bottlenose dolphins were commonly seen by the local Kaurna aboriginal tribal group. But as the city of Adelaide was built, the dolphins disappeared. What changed that enabled their return? A combination of improved environmental conditions, a little bit of protection and some public education, researchers report October 24 in Marine Mammal Science.

“The future of these dolphins would appear to be as secure as any population of any species can be in this era of climate change,” says the study’s lead author, Mike Bossley of Whale and Dolphin Conservation Australasia in Port Adelaide, who has studied the area’s dolphins for 25 years.

As the city of Adelaide grew, the Port River grew to be an unfriendly spot for marine wildlife. People cleared away the marshes and mangroves, replacing them with sulfuric acid and soda ash producers, sugar refineries and power stations. Sewage and storm water flowed into the river. Boats and ships traversed the estuary, which had become the main shipping port for the state of South Australia. And no one reported a dolphin sighting between 1940 and 1980.

Scientists began field studies in 1989 and started finding bottlenose dolphins — and documenting threats to them. In addition to pollution, any dolphins brave enough to traverse the Port River had to deal with boat strikes, infections, entanglement with nets and other marine trash and even deliberate attacks. In response, the Adelaide Dolphin Sanctuary was established by law in 2005, setting aside a small patch of river for the resident dolphin population (about 30 live in the river; another 300 visit the area regularly) and establishing resources for public education about the dolphins. And over the last few decades, water quality has improved as some of the least environmentally friendly activities — such as sulfuric acid production, salt evaporation and coal-fired power production — have ended.

In 1990, Bossley and his colleagues started surveying the Port River dolphins. The researchers would take their boat out on a 40-kilometer journey through the estuary, following the same path each time and photographing any dolphins they saw. They used distinguishing marks, such as shape or notches, on a dolphin’s dorsal fin to identify the animal and ensure each was only counted once.

From January 1990 to December 2013, the researchers made a total of 735 complete journeys, averaging one survey every 11.7 days. Based on those surveys, and the near absence of dolphins in the 1980s, the team estimates that bottlenose dolphin sightings are increasing by about 6 percent a year.

“The trends in sightings provide compelling evidence of a large change in some aspect of relative abundance and occupancy and usage of the Port River estuary,” the researchers write. The increase could be the result of an increase in the resident population, in the number of visiting dolphins or a combination of both.

Improved water quality may be better for the dolphins or their prey. Plus, the establishment of the sanctuary gave the dolphins some protection against human activities. In addition, Bossley notes, “by designating the area as a sanctuary, the public is both more aware and more protective of the dolphins.” The dolphins still have to deal with human impacts — the river is not pollution free, an attack occurred as recently as 2014 and there’s a growing new potential threat in the form of tourism — but the dolphins appear to be able to cope.

The Adelaide dolphins offer a lesson in conservation, Bossley and his colleagues note. Corralling off large areas for wildlife from human activities isn’t always necessary. “People have to learn to live with wildlife,” Bossley says. And that “requires taking into account both the wildlife itself and its habitats.”

Baltic sea dolphin swims with humans, video


This 11 September 2016 video from Kiel, Germany, shows a bottlenose dolphin swimming with humans in the Baltic sea.

Humpback whale in Baltic sea: here.