by CKR
I pull articles out of magazines or bookmark them on the computer for future post-writing. The file of dead-tree articles is getting quite large; I purge the bookmarks more frequently.
But I get distracted. I was in Wisconsin last weekend; the snow and cold here wasn’t enough for me. I am working on a book, with colleagues, on how to get to zero nuclear weapons, or many fewer than we have now, anyway, and not doing enough work on that. The bird feeder needs replenishing. And, of course, we have the presidential race and the never-ending outrages of the Bush administration.
I think it’s good for me to look at something other than politics from time to time. I’ve got quite a few articles on fossils. Let’s see if I can find links and pictures. As I go through these clippings, I realize that you may have seen these stories already. But they’re good ones, worth repeating.
Bottom-Feeding Plesiosaurs
Plesiosaurs are those long-necked, finned dinosaurs that floated the Mesozoic oceans. Their teeth were sharp, and it was mostly thought that they snapped up swimming fish and squid, sneaking around with those snaky necks. But some fossil plesiosaurs in Queensland, Australia, were found to have snails and clams in their stomachs, no fish or squid. Others, found in Kansas, have indeed contained fish and squid, along with stomach stones like the gravel that birds swallow to grind their food in their stomachs rather than their mouths. The conclusion is that plesiosaurs ate a great many kinds of food, depending on where they were. Not all that earth-shaking, but a nice drawing from the University of Sydney. (OMG, the article is from the 7 October 2005 Science; that’s how long I’ve been saving some of this stuff!)
Velociraptor Had Feathers
The Jurassic Park speedsters had feathers. Paleontologists from the American Museum of Natural History and Chicago’s Field Museum found a velociraptor bone with knobs of the kind that are found in turkey vultures and other birds to hold the feathers on. The feathers probably didn’t allow the dinosaur to fly, but they may have been used for controlling their temperatures and that of their nests, for creating a bit of lift to help in running, or to look pretty to prospective mates. The quill knobs were on the ulna, part of the forearm/leg. [Photo Caption: (A) View of right ulna of Velociraptor IGM 100/981. (B) Detail from cast of red box in (A), with arrows showing six evenly spaced feather quill knobs. (C) View of right ulna of a turkey vulture (Cathartes). (D) Same view of Cathartes as in (C) but with soft tissue dissected to reveal placement of the secondary feathers relative to the quill knobs. (E) Detail of Cathartes, with one quill completely removed to reveal quill knob. (F) Same view as in (E) but with quill moved to the left to show placement of quill, knob, and follicular ligament. Follicular ligament indicated with arrow. (Credit: Mick Ellison; from Science Daily)] (Science, 21 September 2007)
Some Neandertals Had Red Hair
I found this particularly interesting, since I have red hair myself and consider it an essential mark of human populations that small and select group have red hair. At about the same time, it was also found that Neandertals had a gene that is believed to give us our loquaciousness. Both of these findings came out of sequencing Neandertal DNA, recovered from their bones and amplified. The genes are the same for modern humans in both cases, but probably evolved independently. For red hair (and light skin, as well), a particular protein is inactivated, and it is inactivated in different ways in human and Neandertal redhead DNA. (Science, 26 October 2007)
The Oldest Horseshoe Crab
Horseshoe crabs have been around just about forever. Or at least since the Ordovician age, 445 million years ago. A recent find puts them back that far, 100 million years older than the previous oldest from Montana. (BTW, there’s a really nice timeline of biodiversity, in terms of number of genera (biological families) since the Cambrian in that link. Evidently the horseshoe crabs are doing something right: they haven’t changed their body plan in almost half a billion years. Here’s more about horseshoe crabs today, from NOAA and the Ecological Research and Development Group. (Science, 1 February 2008)