paleontology
laelaps | February 3, 2009The extinct whale Dorudon, from the new PLoS One paper.When the English anatomist William H. Flower proposed that whales had evolved from terrestrial ungulates in 1883 he cast doubt upon the notion that the direct ancestors of early whales chiefly used their limbs for swimming. If they did, Flower reasoned, whales would not have evolved their distinctive method of aquatic locomotion, typified by vertical oscillations of their fluked tails. Instead Flower suggested that the stock that gave rise to whales would have had broad, flat tails that paved the way for cetacean locomotion as we know it…
laelaps | February 2, 2009The right hip of Basilosaurus as seen in Lucas' 1900 description.If you were a 19th century American paleontologist and you wanted a Basilosaurus skeleton there was only one place to look; Alabama. Even though fossils of the ancient whale had been found elsewhere their bones were most abundant in Alabama, and S.B. Buckley, Albert Koch, and others exhumed multiple specimens of the extinct whale from the southern state. Unfortunately, however, most of the skeletons were fragmentary. Even though long chains of vertebrae were often found intact other parts of the skeleton, most notably the head…
jwhitfield | February 2, 2009We left Darwin in a troubled frame of mind. The fossil record seemed to offer little support to his theory (then again, it offered little support to any other theory). By the time we reach the end of chapter 10, 'On the geological succession of organic beings', he's feeling far more chipper:
"[A]ll the chief laws of palaeontology plainly proclaim, as it seems to me, that species have been produced by ordinary generation: old forms having been supplanted by new and improved forms of life, produced by the laws of variation still acting round us, and preserved by Natural Selection."
What…
jwhitfield | January 31, 2009Thomas Kuhn -- the one philosopher of science that even ignorami like me have heard of -- said that during periods of 'normal science', researchers only take on problems that they know they can solve. 'Paradigm' is an overused word, but it's a measure of the paradigm-shifting nature of the Origin that in much of it, such as in chapter 9 'On the imperfection of the geological record', Darwin flies blind.
This creates almost as much trouble for the reader as it does for Darwin, as we saw in the previous chapter. The less you can explain, the more you need to describe; where Darwin has cracked a…
laelaps | January 27, 2009It is another busy day, and since I am again left with little time to write here I have decided to post another "follow-up" excerpt from my book.**
A few days ago I mentioned that many paleontologists were skeptical that humans had lived alongside extinct mammals until discoveries made in Europe between 1858-1859 convinced them otherwise. Below is a brief summary of how the scientific consensus began to change on this issue;
The plan of Brixham Cave, from Geology: Chemical, Physical, and Stratigraphical by Joseph Prestwich.Several months after Koch's presentation, and over 4,000 miles away,…
laelaps | January 25, 2009The AMNH mount of the Warren Mastodon. From The American Museum Journal.Glendon's session on Art & Science last weekend inspired me to intensify my search for bits of paleontological art, and I have been fortunate enough to uncover some more verses about a prehistoric beast. Here is Hannah F. Gould's "The Mastodon", published in the prosaically-titled New Poems in 1850;
THE MASTODON.
Thou ponderous truth, from thy long night's sleep
Through the unrecorded eras
Awaked, and come from their darkness deep
To this day of light chimeras! --
What wast thou, when thy mountain form
Stood forth in…
laelaps | January 22, 2009A restoration of the Warren mastodon entombed in sediment, from Popular Science.In 1841 S.B. Buckley was the first to mount a skeletal restoration of Basilosaurus, but his efforts to do so have generally been forgotten. The skeleton changed hands several times during the 1840's and Buckley's more accurate restoration was overshadowed by Albert Koch's monstrous "Hydrarchos", a fantastical creature made from Basilosaurus bones.*
*[I have to admit that that I have not seen any illustrations of Buckley's restoration. My statement regarding its accuracy is based upon his technical papers in which…
laelaps | January 14, 2009
In considering the history of science, it is easy to think of scientific discovery and debate as distinct from the rest of culture. Academics picked away at fossils and squinted at the eyepieces of microscopes in isolation, and only in exceptional cases did science jump the cultural barrier to challenge cherished beliefs. This is nonsense, and even though arguments over scientific minutiae may have been restricted to journals and learned societies, there have been many times when scientific discoveries have stirred great public interest.
One way to get at the interaction between science…
clock | January 12, 2009From SCONC:
The next Sigma Xi Pizza Lunch is noon, THURSDAY. Jan. 22. The title: "Dinosaurs under the microscope: New ways to look at old bones."
Come hear NC State University paleontologist Mary Schweitzer explain why she rocked science not long ago with evidence that soft tissue survived in a 68-million-year-old dinosaur fossil. Not all fossil experts accept it, but many do. If Schweitzer is correct, she's found a whole new route to explore the biology and evolutionary lineage of extinct life.
Pizza Lunch is free and open to science journalists and science communicators of all stripes.…
gregladen | January 11, 2009One of the most interesting and exciting stories in science is that of the Younger Dryas. The Younger Dryas was a climate event that had important effects on human history, and that has been reasonably linked to some of our most important cultural changes, and ultimately some evolutionary changes as well. That is one reason why it is interesting. In addition, the Younger Dryas was a pretty big deal ... a climate change or something like a climate change that caused massive changes all around the earth, and fairly recently. But the cause of the Younger Dryas is at present unknown, although…
gregladen | December 30, 2008... and other matters.
The following list represents widely held beliefs, either first order beliefs (things you hear people say) or second order beliefs (things implied directly by what people say):
Evolution is very slow.
It takes millions of years for a species to evolve into another species.
Evolution has stopped for humans.
Evolution occurs over "geological time scales."
Geological time scales are very long ... millions of years.
Geological and evolutionary time scales are similar to each other.
Evolution = Natural Selection.
"Macro evolution" is slow, "Micro evolution" is fast but tiny…
grrlscientist | December 19, 2008tags: evolution, behavioral ecology, parental care, egg incubation, dinosaurs, birds
The Oviraptorid dinosaur, Citipati osmolskae,
on a nest of eggs that was unearthed in the Gobi desert
of Mongolia by the American Museum of Natural History.
Image: Mick Ellison, American Museum of Natural History.
Oviraptors ("egg seizer") were given their name because their fossil remains were first discovered on top of a pile of eggs. Because of their close proximity to clutches of dinosaur eggs, it was initially assumed that these dinosaurs were eating them. However, in his 1924 paper, their…
grrlscientist | December 18, 2008tags: Austroraptor cabazai, dinosaurs, Dromaeosauridae, birds, fossils, taxonomy, evolution
The newly unveiled Austroraptor cabazai (left) attacks a juvenile sauropod dinosaur in an artist's interpretation.
The giant raptor, found in Argentina, measured between 16.5 and 21 feet (5 to 6.5 meters) long, making it one of the largest raptors to roam Earth 70 million years ago, a new study finds.
A dramatic new carnivorous dinosaur that was bigger than a car was unveiled yesterday in public at the Museo Argentino de Ciencias Naturales (the Argentine, or Bernardino Rivadavia, Museum of Natural…
clock | November 26, 2008Now I finally understand the lyrics! Joan Baez was really singing to Bob about prehistoric turtles!
gregladen | November 26, 2008Personally, I think we should start with a dodo, and then work our way up the ethical ladder from there.
... We know roughly how the sequence of life ran forward in time. What about running it backward? ...
Last week in Nature, scientists reported major progress in sequencing the genome of woolly mammoths. [see this] ... Now, according to Nicholas Wade of the New York Times, biologists are discussing "how to modify the DNA in an elephant's egg so that after each round of changes it would progressively resemble the DNA in a mammoth egg. The final-stage egg could then be brought to term in…
gregladen | November 23, 2008The genome of the extinct woolley mammoth (Mammuthus primigenius) has been sequenced, and reported in Nature. This confirms that elephant genomes are large, like the elephants themselves. It confirms previously proposed relationships amongst the elephants (see phylogeny below) and refines the known phylogeny. Interpopulation differences among mammoths were also demonstrated.
Here's the phylogeny:Comparison of phylogenies of elephants and hominoids. "We show estimated divergence times, that is, times to the common ancestor averaged across autosomes (see Methods). Red circles at the leaves…
laelaps | November 20, 2008... and Traumador, it's host, has something special in mind;
So my thinking for this themed boneyard is for anyone and everyone out on the innerweb to put up a post about their favourite museum... it doesn't have to be a really "smart" or sciencey one, cause afterall it's me the archosaur without enough grey matter to fill a walnut running the show! rather i'd like to get to know other museums of the world through the eyes and words of other palaeo lovers who have been to them.
Other posts about paleo will be accepted, of course, but it would be fun if everyone could contribute something…
laelaps | November 7, 2008After a few delays, The Boneyard #25 has gone up at The Great Dinosaur Mystery and the Big Lie. Check it out.
The next edition is due to go up on December 2, 2008. If you're interested in hosting, speak up in the comments.
laelaps | November 6, 2008Maybe Toumai (or the first known skull of Sahelanthropus, if you like) doesn't represent a true human ancestor, but this documentary is still pretty interesting. Called Pre-Human: Riddle of the Toumai Skull, I missed it when it originally aired, but thankfully the glory of the inter-tubes has allowed me to see it.
The most curious thing about this particular show is that Toumai narrates its own story, and in a British accent no less! What do you think of this sort of narrative style?;
laelaps | October 29, 2008The 25th edition of The Boneyard is coming up next Tuesday over at The Big Dinosaur Lie. You can send your submissions directly to me (evogeek AT gmail DOT com) or to the blog where they will be posted, and let's try to get some of the new paleo-bloggers in on this one!