Guess who’s next in line to get a certain famous fossil? The Pacific Science Center will be exhibiting Lucy between October and March. Even if I can’t arrange it, I expect you lucky Pacific Northwest residents to all make the pilgrimage.
The paleontologists are going too far. This is getting ridiculous. They keep digging up these collections of bones that illuminate tetrapod origins, and they keep making finer and finer distinctions. On one earlier side we have a bunch of tetrapod-like fish — Tiktaalik and Panderichthys, for instance — and on the later side we have fish-like tetrapods, such as Acanthostega and Ichthyostega. Now they’re talking about shades of fishiness or tetrapodiness within those groups! You’d almost think they were documenting a pattern of gradual evolutionary change.
The latest addition is a description of Ventastega curonica, a creature that falls within the domain of the fish-like tetrapods, but is a bit fishier than other forms, so it actually bridges the gap between something like Tiktaalik and Acanthostega. We look forward to the imminent discovery of yet more fossils that bridge the gap between Ventastega and Tiktaalik, and between Ventastega and Acanthostega, and all the intermediates between them.
Sometimes, the politics of science can get ugly, and they don’t get much uglier than this ghastly mess going on among paleontologists. I’ve read a couple of accounts of this story so far, and it sounds to this outsider like a few senior scientists riding roughshod over their junior colleagues and students and appropriating as their own the interpretations and details of others’ explanations. There seem to be shenanigans all over the place, and it seems to be in the interests of all parties involved to resolve the issues.
The sensible thing to do would be to have an impartial review of both sides of the story by neutral but knowledgeable observers — as a non-paleontologist, someone like me would certainly defer to the judgment of such a panel. Well, the New Mexico Museum of Natural History and Science put together a review, supposedly, and did so in such a bumbling, biased, and stupid way that although they decided there was no wrongdoing, I’m persuaded otherwise. Why else make such an effort to assemble a kangaroo court?
Spencer Lucas and his colleagues at the NMMNHS were accused of using the work of William Parker, Jerzy Dzik, and Jeff Martz without proper attribution. To judge this accusation, the NMMNHS put together a committee of external experts that consisted of people who had published with Lucas, one of whom declared his summary judgment before the hearings were held.
Unbelievable.
They’re accused of a serious impropriety, so they blatantly fix the review, packing the jury and even declaring innocence before the trial? That’s compounding a major ethical lapse on top of an accusation of an ethical lapse, and only makes the problem worse. What were they thinking?
It’s not often that something as delicate as details of the reproductive tract get preserved, but here’s a phenomenal fossil of a Devonian placoderm containing the fragile bones of an embryo inside, along with the tracery of an umbilical cord and yolk sac.
This is cool: it says that true viviparity, something more than just retention of an egg internally, but also the formation of specialized maternal/embryonic structures, is at least 380 million years old. Hooray for motherhood!
Here’s a reconstruction of what the animal would have looked like in life, as it is giving birth to its young.
Long JA, Trinajstic K, Young GC, Senden T (2008) Live birth in the Devonian period. Nature 453:650-652.
It’s another transitional form, this time an amphibian from the Permian that shares characteristics of both frogs and salamanders — in life, it would have looked like a short-tailed, wide-headed salamander with frog-like ears, which is why it’s being called a “frogamander”.
Check it out: it’s yet another transitional form, a 92 million year old snake with two hindlimbs. Cool! Just last week I was told that none of these things exist.
It means “devil toad,” and it was a 10 pound monster that lived 70 million years ago, in what is now Madagascar. It’s huge, and judging by its living cousins, was a voracious predator. If it were alive today, it would probably be eating your cats and puppies.
In other words, this was an awesome toad, and I wish I had one for a pet.
Here’s what it looks like, with some very large extant toads for comparison.
There are some biogeographical puzzles associated with this beast. It’s found in Madagascar, but it’s closest extant relatives are South American…and since frogs and toads do a poor job of crossing salt water, that implies the existence of land bridges between those continents around the Cretaceous. It’s not a major puzzle, though, although some of the news reports I’ve seen play up the concern, as if it were a significant controversy. As the authors explain,
We suggest that extant ceratophryines are remnants
of a Gondwanan hyloid clade that once ranged from at least
South America to Indo-Madagascar. Whether this clade was
more broadly distributed and on which Gondwanan landmass it
originated cannot be determined on current evidence. However,
as the Late Cretaceous fauna of the Maevarano Fm,
including its ceratophryine anuran, bears little resemblance to
that of modern Madagascar, major biotic changes clearly occurred on the island in the intervening period. When and how the ancestors of the endemic mantellid and microhylid anurans arrived on Madagascar remains controversial,
but there is general agreement that these frogs did not diversify
significantly until the Paleogene. Their radiation
has been linked, at least in part, to the expansion of rainforests,
but may also have been facilitated by the extinction of archaic
faunal elements, including ceratophryines.
It was a diverse, widespread group once upon a time, and it’s not at all challenging to report that the continents have shifted in 70 million years. It’s just very cool that anurans achieved the status of charismatic megafauna*, once upon a time.
*For a generous definition of “mega”.
Evans SE, Jones MEH, Krause DW (2008) A giant frog with South American affinities from the Late Cretaceous of Madagascar. Proc Nat Acad Sci USA 105(8):2951-2956.
The capybara is the current champion for rodents of unusual size — it weighs about 60kg (about 130 pounds); another large rodent is the pakarana, which weighs about a quarter of that. Either one is far too much rattiness for most people to want hanging around.
Now there’s another king of the rodents: Josephoartigasia monesi, which is estimated to have tipped the scales at about 1000kg, over a ton. Don’t worry about getting bigger rat traps; these beasties have been extinct for perhaps 2 million years. I’ve put a few pictures from the paper describing this new species below the fold.
(hat tip to RBH)
We’ve got a splendid new analysis of a southeast Asian artiodactyl from the Thewissen lab that reveals that these little deer-like animals are a sister taxon to whales — so this pushes our understanding of the ancestry of whales yet further back. Carl Zimmer has already described the essentials — I’ll just show a few pictures of the fossils.
