PvM posted Entry 2054 on February 23, 2006 02:55 PM.
Trackback URL: http://www.pandasthumb.org/cgi-bin/mt/mt-tb.fcgi/2049

‘Jurassic beaver’ unearthed in China: Fossil overturns ideas about mammals’ lowly status in dinosaur era

Another evolutionary Icon ‘bites the dust’

For years, the mammals living in the era of dinosaurs have been thought of as tiny shrewlike creatures scurrying through the underbrush. Now the discovery of a furry aquatic creature with seallike teeth and a flat tail like a beaver has demolished that image.

Ji Q., Luo Z.-X., Yuan C.-X.& Tabrum A. R. . Science, 311. 1123 - 1127 (2006).

See also Jurrassic Beaver swims into view Nature News, Michael Hopkin

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Comment #81825

Posted by Doc Bill on February 23, 2006 3:41 PM (e)

Another evolutionary Icon ‘bites the dust’

Leave it to beaver.

Comment #81832

Posted by wamba on February 23, 2006 4:42 PM (e)

The linked MS-NBC article didn’t say whether it was placental, monotreme or marsupial. I guess I’ll have to dig it out of Science.

Comment #81837

Posted by Ginger Yellow on February 23, 2006 4:54 PM (e)

If that’s not a porn film title in the making, I don’t know what is.

Comment #81848

Posted by Thomas R. Holtz, Jr. on February 23, 2006 5:36 PM (e)

It is neither monotreme, multituberculate, marsupial, or placental. It’s a docodont: a mid-Mesozoic group of mammaliaforms (the larger clade of mammals and their closest relatives).

About the only other time docodonts have made it into the news was the discovery of the burrowing Fruitafossor last year.

Comment #81849

Posted by Thomas R. Holtz, Jr. on February 23, 2006 5:40 PM (e)

Scratch that last comment: Fruitafossor was actually a true mammal, nested between monotremes and their extinct kin on one branch, and triconodonts, multis, marsupials, and placentals on the other. Sorry about that.

Comment #81854

Posted by 'Rev Dr' Lenny Flank on February 23, 2006 6:25 PM (e)

Leave it to beaver.

Must . . resist . . urge . . to make… joke ….

Must … resist …. .

Arrrggghhhh!!!!!!!!!!

Comment #81858

Posted by Peter Henderson on February 23, 2006 6:36 PM (e)

I wonder if creationists will claim that this is yet another so-called living fossil which will disprove evolution ?

They’ll probably just classify it as another “kind” of beaver !

Comment #81883

Posted by John Marley on February 23, 2006 8:08 PM (e)

Cool article.

Comment #81926

Posted by Pete Dunkelberg on February 24, 2006 1:35 AM (e)

I prefer the news link to New Scientist. The Nature article has this irritating nonsense:

mistaken wrote:

The evolutionary history of mammals is a long and complex one. The earliest mammals evolved from primitive terrestrial reptiles called therapsids, which lived some 200 million years ago.

No, synapsids and sauropsids were separate lines.

Comment #81936

Posted by Jacob on February 24, 2006 4:21 AM (e)

Ever notice how much of this stuff comes out of China.

The Commie atheists have a real handle on fossil making.

Google it.

Comment #81952

Posted by Jaime Headden on February 24, 2006 6:05 AM (e)

Note that several 2004 and 2005 studies have redated the sediments at Daohugaou where the fossils were recovered to the Lower Cretaceous, not the Middle Jurassic.

“Jacob” wrote:

Ever notice how much of this stuff comes out of China.

Ever notice how much this stuff comes from one type of fossil bed, a lake bottom environment? So called lagerstätten, or lake-beds, are ideal preserves of a low-oxygen slow-deposition region where accumulated detritus can be resolved into crepe-thin layers of sandstone and limestone and shale. These regions are IDEAL for preserving fine details in animals, and are known at the Quercy site in France (not a commie country), Messel and Solnhofen in Germany (also, not a commie country), the London Clay in England (commies!!!), the Green River beds in Wyoming, USA (Is the USA a commie country?), and places in Russia, Denmark, the eastern US seaboard such as at Newark, New Jersey, and so forth. So quit whining.

The Commie atheists have a real handle on fossil making.

Indeed they are so busy faking these fossils that they forgot such finds have been known in other countries for centuries. The fossil beds in China are both more extensive, and less-developed, than in other countries, and there are tons of villages spending old-time hard work mining and quarrying to make roofing slates and housing materials and thus, as in Solnhofen, coming across these fossils more readily than the scientists at the other sites, who work on their own, and never fake fossils. The last faked fossil in the West was, if I recall correctly, either Creationists hoaxes at Paluxy, and the Piltdown forgery, which was falsified – not by creationists disproving evolution – but by scientists who had accepted it for 50 years before making a detailed study to find the fakery involved … and may have implicated famed author Sr Arthur Conan Doyle, a “christian” and an “occultist”.

So who’s doing the harm here? When we, as scientists, find falsification, lies, and corruption in our institutions and our collections, we are as avid to be rid of these problems and expose them as any one else, and will be the first to do so, as history has shown for centuries, and will continue to do. So far, creation apologetics has FAILED to provide evidence that has not been quacked or misinterpreted out of context.

This fossil itself shows the detail of variability in many early non-mammals, long before they became true mammals, and expands our knowledge, not decreases it. This should be embraced, not rejected. Creationists seem almost rabid to proclaim questions on where our “transitional fossils” are, and when we point to animals like Castorocauda, or Archaeopteryx, they wave their arms, or call them “beavers” and “birds”, and decided to stop listening. The truth is, should anyone decide to hear it, is that nearly all animals are “transitional” between ancestors and descendants, and this is true of fossils back to time immemorial.

Comment #81955

Posted by the pro from dover on February 24, 2006 6:24 AM (e)

I was under the impression that “therapsid” always referred to a kind of synapsid reptile and was distinct from “pelycosaur” another kind of synapsid (think dimetrodon). Perhaps the confusion here is the similarity to the term “theropod” which always refers to a diapsid (except when it refers to Lenny).

Comment #81957

Posted by ben on February 24, 2006 6:49 AM (e)

Ever notice how much of this stuff comes out of China.

The Commie atheists have a real handle on fossil making.

Ever notice how much of this stuff comes out of ignorant hit-and-run IDiots who have nothing of substance to say.

The creationists have a real handle on unsubstantiated claim-making.

Google it.

Comment #81971

Posted by GT(N)T on February 24, 2006 7:50 AM (e)

Okay, this is marginally off topic, but we are talking about primative mammals. I have a question that has intrigued me for years and have never found the answer in a comparative physiology text.

What form does nitrogenous waste excretion take in monotremes?

This is an important evolutionary question, plus it bugs the heck out of me that I don’t know.

Comment #81972

Posted by 'Rev Dr' Lenny Flank on February 24, 2006 7:57 AM (e)

The last faked fossil in the West was, if I recall correctly, either Creationists hoaxes at Paluxy, and the Piltdown forgery

Well, there was also Archaeoraptor, but this wasn’t really a fake — it was just two different fossils that had been artificially fitted together by the finder to inflate the price (one a Microraptor, and the other a previously unknown avian now named Yanornis).

Comment #81980

Posted by W. Kevin Vicklund on February 24, 2006 8:49 AM (e)

What form does nitrogenous waste excretion take in monotremes?

I’m not entirely sure if this answers your question, but monotreme means one-holed, referring to the use of a single orifice for excrement (both urinary and digestive tract) and reproduction. In other words, they have a cloaca.

Comment #81984

Posted by J-Dog on February 24, 2006 9:04 AM (e)

re: Monotremes
Mr. Vicklund - Wow! What a poor design! Why would anyone put an amusement park and a waste treatment facility in the same location? It must be The Unintelligent Designer.

Comment #82003

Posted by GT(N)T on February 24, 2006 11:25 AM (e)

Kevin, I didn’t ask the question well. Do they excrete uric acid or urea? There that’s clearer!

Comment #82104

Posted by vandalhooch on February 24, 2006 7:49 PM (e)

Kevin, I didn’t ask the question well. Do they excrete uric acid or urea? There that’s clearer!

Going through my Functional Anatomy of the Vertebrates text, I found no reference to differences between the three major mammal groups in regards to kidney functions. There is a great deal of variance in nephron structure between species but the excretion of nitrogenous waste is always referred to as urea. Some variance in concentration depending on habitat/niche though.

Vandalhooch

Comment #82161

Posted by GT(N)T on February 25, 2006 1:46 PM (e)

The reason I ask is that birds secrete uric acid. The explanation usually given is that being egg-layers birds require a nitrogenous waste that isn’t water soluble. Since monotremes are egg-layers I wonder how, if they produce urea, they manage to not poison their developing young.

Comment #82355

Posted by Chris Nedin on February 26, 2006 7:37 PM (e)

Posted by J-Dog on February 24, 2006 09:04 AM

“re: Monotremes
Mr. Vicklund - Wow! What a poor design! Why would anyone put an amusement park and a waste treatment facility in the same location? It must be The Unintelligent Designer.”

The single external entry/exit condition is inherited from their reptile-like ancestors and is shared with many modern reptiles and birds. Call it an unholy alliance.

Comment #103331

Posted by Brandy on June 1, 2006 8:29 AM (e)

this is the worst web page i’ve ever been to.