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Post Info TOPIC: Fossil Whale


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RE: Fossil Whale
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Whale Predecessors Had 100-Million-Year Run

A study in the journal Science shows that bony fish filter-feeders spent 100 million years developing and occupying the niche that baleen whales do now. Another Science study finds that whale diversity has been determined by the types of tiny organisms they eat.
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An ancient "dwarf" whale appears to have fed by sucking small animals out of the seafloor mud with its short snout and tongue, experts say.
Researchers say the 25 million-year-old fossil is related to today's blue whales - the largest animals on Earth.
The ancient animal's mud slurping may have been a precursor to the filter feeding seen in modern baleen whales.


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Mammalodon colliveri
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Museum Victoria palaeobiologist Dr Erich Fitzgerald has made new groundbreaking discoveries into the origin of baleen whales, based on a 25 million year old fossil found near Torquay in Victoria.
Dr Fitzgerald's study, which is published in the Zoological Journal of the Linnean Society, is centred on Mammalodon colliveri, a primitive toothed baleen whale, one of a group of whales that includes the largest animal ever to have lived, the blue whale. Although Mammalodon was discovered in 1932 and named in 1939, it has remained relatively unknown until now.

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Desvelan la historia de una ballena de 4,5 millones de años de antigüedad en Huelva

En 2006, un equipo de científicos españoles y estadounidenses encontró en Bonares (Huelva) los restos fósiles de una ballena de 4,5 millones de antigüedad. Ahora publican por primera vez el proceso de degradación y fosilización ocurrido desde la muerte del joven cetáceo, posiblemente del grupo de ballenas barbadas Misticetos.
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The path to the whales was clearly marked out by rows of red rocks. I followed them to the first exhibit which displayed the fossilised lower jaw bone, ribs and vertebrae of an ancient whale known as Basilosaurus Isis, a type of whale that still had functional hind limbs from an earlier phase as a land-based mammal. It was marked by a circle of small red stones, followed by an inner circle of rope held by stumpy posts. The fossils lay on the surface; while being impressive due to their antiquity, they were at the same time unimposing, as if they had been sitting there sunbathing within their little circle and Id disturbed them.
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Partial remains of ancient toothed whale discovered on California beach
A 1,000-pound slab of sandstone lifted off a beach in Santa Cruz County, California, Wednesday may provide a better glimpse of what plied the seas 5 million years ago.
Within the rock, says a county-contracted excavation crew, are the partial remains of an ancient toothed whale, dating to a time when a shallow ocean covered most of the region and sea life was not what it is today.

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Two newly described fossil whales - a pregnant female and a male of the same species--reveal how primitive whales gave birth and provide new insights into how whales made the transition from land to sea.
The 47.5 million-year-old fossils, discovered in Pakistan in 2000 and 2004 and studied at the University of Michigan, are described in a paper published Feb. 4 in the online journal PLoS.
U-M paleontologist Philip Gingerich, who led the team that made the discoveries, was at first perplexed by the assortment of adult female and fetal bones found together.

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Maiacetus_skel1_sm.jpg

Artist's conception of male Maiacetus inuus with transparent overlay of skeleton. Credit: John Klausmeyer and Bonnie Miljour, University of Michigan Museums of Natural History


Fossils_sm.jpg

Fossils of female Maiacetus inuus with near-term fetus in utero, as found in the field. The female's skull is shaded white (teeth brown), and other parts of her skeleton are shaded red. The single fetus, in birth position inside the mother whale, is shaded blue (teeth orange). The specimen was collected in three plaster jackets (blue dashed lines), and additional bones were picked up separately. The red dashed line indicates the edge exposed by erosion. Copyright: University of Michigan Museum of Paleontology.



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The crashing of the enormous fluked tail on the surface of the ocean is a calling card of modern whales. Living whales have no back legs, and their front legs take the form of flippers that allow them to steer. Their special tails provide the powerful thrust necessary to move their huge bulk. Yet this has not always been the case. Reporting in the latest issue of the Journal of Vertebrate Paleontology, paleontologist Mark D. Uhen of the Alabama Museum of Natural History describes new fossils from Alabama and Mississippi that pinpoint where tail flukes developed in the evolution of whales.

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A man finds large bone in a lake in northern Sweden.

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Whale Ancestors
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Scientists have long known that cetaceans (whales, dolphins, and porpoises) descended from four-footed land mammals.  Cetaceans still have some features of land mammals; they use lungs to breathe air and give birth to young that are nursed by milk produced by the mother.  Modern cetaceans cannot live on land, and look very different from land mammals in most respects.
Cetaceans evolved rapidly, and the entire transition from land mammal to obligate marine whale took less than 8 million years.  These Eocene cetaceans are often called archaeocetes, and they can be divided into six families: Pakicetidae, Ambulocetidae, Remingtonocetidae, Protocetidae, Dorudontidae, and Basilosauridae.  It is only since the 1990s that relatively complete skeletons of the archaeocetes have been found in abundance and that the transition from land-to-water could be studied in detail.
Until the early years of the 21st century, most palaeontologists thought that cetaceans were most closely related to mesonychians (The Mesonychian Hypothesis). Mesonychians are an extinct (Palaeocene-Oligocene) group of hoofed mammals from the Northern Hemisphere. They varied in size from that of a weasel to a grizzly bear, and may have eaten carrion or meat. Unlike palaeontologists, most scientists studying DNA were of a different opinion. They considered hippopotamids as the closest relatives to cetaceans (The Hippopotamid Hypothesis). Hippopotamids (including the recent Hippo and the Pygmy Hippo) are included in a group of mammals called even-toed ungulates or artiodactyls. Other artiodactyls are: pigs, peccaries, camels, llamas, giraffes, deer, goats, sheep, cattle, and antelopes.

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