Today, the bowhead

...probably the longest-lived mammal on the planet.

No, it wasn't the asteroid

Well, we had a definitive answer for about a week. Now a new paper in Palaeogeography, Palaeoclimatology, Palaeoecology points toward climate change as the driving force behind the Cretaceous-Paleogene boundary extinctions.

Long week..

...but some time to be real for a while. On the river this weekend. Tonight, night music with Guy Clark...

Aussie tyrannosaur

Another new slide for vertebrate zoo.

Bee brains

Bees and other hymenopterans have yielded some tremendous insights into insect behavior. Should probably just say behavior, period. Here's another interesting piece of work from a team at the Smithsonian Tropical Research Institute, appearing online in Proceedings of the Royal Society B. Queens of the bee Megalopta genalis can exist as a individuals which have to go out and provide for themselves, or as social queens. In the case of the social queen, one of the daughters, who does not become sexually mature, goes out and does the foraging while mom stays home and takes care of the place.

The work, done in STRI's new facility for studying insect neurobiology, indicates that a region of the brain (called the mushroom bodies, or corpora pedunculata) is larger in the social queens than in the solitary ones. Mushrooms bodies are present in the brain of many insects (that's Drosophila at left, with the mushroom bodies in blue), and have been shown to be related to learning and memory, especially as it relates to smell. This is groundbreaking work, in that it makes an intraspecific comparison between social and asocial queens. Similar studies have been done previously, but with insects of different species and the complicating factors that entails.

So, does this mean that "social interactions are cognitively challenging" as suggested by Adam Smith of the Smithsonian team? That's certainly a possible explanation - I've had more than my share of cognitively challenging social interactions and I don't think I'm alone in that. But it seems a fairly convenient explanation. Why for example, are the social interactions of the stay-at-home social queen more of a challenge than the food-finding activity of the solitary one, especially given what we know about the function of the mushroom bodies? I think I want to see a little more.

And finally...

This has nothing whatsoever to do with biology. I just had no idea that this great scene in a great movie...



...had anything to do with reality. My daughters are the anthropologists, and sometimes I'm jealous.

Loggerheads

All of the world's seven sea turtle species are endangered or threatened. Three, the Kemps ridley, the hawksbill, and the leatherback are considered to be critically endangered. The species that is currently least at risk is the loggerhead (Caretta caretta), which is only considered to be threatened. However, the loggerhead faces a bleak future as well, as anthropogenic influences continue to encroach on its domain.

The Mediterrean Sea has been an area of particular tragedy for loggerheads in recent years. As many as 20,000 are killed annually as bycatch by commerical fishermen. Spanish scientists are looking for ways to reduce that number. Many of the turtles are accidentally taken in the longline fishery for swordfish, and something as simple as changing baits from squid to fish might dramatically reduce the turtle bycatch. Of course, the fishermen are concerned about the potential impact on swordfish catch.

In with fire...

...and out too, although of a different nature. Everybody knows that the dinosaurs (most of them, anyway) died out suddenly about 65.5 million years ago, and the consensus, for now, is that it was an asteroid that did them in. Perhaps just as interesting as their sudden disappearance is their relatively sudden rise to prominence near the boundary of the Triassic and Jurassic Periods around 200 millon years ago.

New research led by Brown University's Jessica Whiteside suggests that it was volcanism that paved the way. During the Triassic, the early dinosaurs found were not the dominant form of carnivores in terrestrial habitats. That honor belonged to group known to paleontologists as the crurotarsans (that's one at right). These crocodilian relatives appeared early in the Triassic, rose to dominance, and were quite diverse by the latter part of the Period. Then, suddenly, all the large crurotarsans disappeared. That decline opened the door for the dinosaur dominance that would follow during the Jurassic Period. Whiteside's group have examined a number of lines of evidence to pinpont the cause of the crurotarsan fall.

The evidence points to massive, widespread volcanic eruptions, probably related to the beginning of the breakup of the supercontinent we call Pangea. Analysis of fossil pollen indicates that the changes associated with the volcanism led to the disappearance of perhaps 50% of the plant species present at the end of the Triassic. We also see that the crurotarsans, common and abundant before the period of volcanism, are gone afterward. This newly emptied niche, the large, terrestrial carnivore, was rapidly filled by the theropods, the group that would ultimately give rise to all of the carnivorous dinosaurs. And the rest is history.

Say goodbye to another great fish

The actions (or, more correctly, lack of action) at the triennial meeting of the Convention on International Trade in Endangered Species of Wild Fauna and Flora in Qatar has likely sent the magnificent Atlantic bluefin tuna (Thunnus thynnus) down the path to extinction. A secret ballot allowed for nations to place commercial interests over the long-term preservation of the species.

Thunnus stocks have dropped by 97% over the last 50 years, and a CITES ban on marketing the fish may well have been the last, best chance to save them. You see, the Japanese have quite a taste for bluefin, and a large individual can bring as much as $200,000.

The Atlantic bluefin can live to be 30 years old, although none are allowed to reach that age. The largest on record as 14 feet long and weighed nearly 3/4 of a ton. They are, along with the great marlins, the largest of the marine bony fish. They have a pronounced ability to thermoregulate, one of the few fish that do so. This allows them to feed actively in the cold waters of the North Atlantic, and to cruise a half mile below the surface.

Enjoy your sashimi.

Time to update the notes...

...and, I guess, most of the textbooks, too. It appears that the old "birds have lighter bones" is just not true. This is, apparently, something that people working with birds have long be aware of, but it certainly has not made it's way into most of the texts I see. It hasn't been long since I was pointing out to students the remarkable lightness of the skeleton of the magnificent frigatebird. Regardless, bat researcher Elizabeth Dumont of the University of Massachusetts Amherst, has demonstrated in a new paper coming out in the Proceedings of the Royal Society B that, even though the bones of birds are often thin and hollow, they are, in fact, denser than those of mammals. Dr. Dumont points out that "this is a new way to think about how bird skeletons are specialized for flying and solves the riddle of why bird skeletons appear so lightweight and are still relatively heavy." She goes on to say that these facts have not made it into textbooks, and she'd like to see that rectified. I would too.

It's too early for...

...more night music, but this guy deserves some attention.

Big fish, again

One of the world's great fish is in even more trouble than we realized. The IUCN has reclassified the beluga sturgeon (Huso huso) as critically endangered. A new study appearing in Conservation Biology, based on data obtained from sturgeon captured in the Ural River population of Caspian Sea beluga sturgeon, suggests that the current conservation strategy is flawed. Rather than depending on the release of hatchery-raised juveniles, the authors feel that the sturgeon can only be saved if current overfishing of the adult stock is ended. They feel that the current take of adult sturgeon is perhaps five times that that the population can support.

Sturgeon, in general, may be the world's most critically endangered vertebrates. Virtually all of the 27 sturgeon species are in need of enhanced protection. Locally, our Alabama sturgeon may be the most endangered vertebrate in the U.S.

Interesting, on several levels...

We were talking just the other day about the South's giant prehistoric crocodile, Deionosuchus, which has lived in the Late Cretaceous some 80 million years ago. Deinosuchus, which reached lengths of 30 feet and weighed perhaps 8 or 9 tons, was first discovered in North Carolina but has been found across the southern states.

An analysis of petrified feces has revealed that the big guy may have had a sweet tooth for dinosaurs. Paleontologist David Schwimmer (more on that later) from THE Ohio State University and his grad student Samantha Harrell recently presented results at a meeting of the Geological Society of America in which they discussed evidence from bite marks on dinosaur fossils and from coprolites (that's fossilized poop, for the uninitiated) that they feel link Deinosuchus to attacks on relatively large dinosaurs. One potential prey was a T. rex relative known as Appalachiosaurus montgomeriensis, discovered near Montgomery. In addition, Harrell has analyzed coprolites indentified as belonging to Deinosuchus and discovered that they contain sand and shell fragments, indicating that the big crocs lived in shallow, brackish environments that likely contained an abundance of their preferred prey - sea turtles.

So, now for the more intriguing fact. David Schwimmer, OSU paleontologist really does exist. It's not some sort of weird Friends alternative reality. Really.

On the road again...

...well, the campus loop, anyway. All the activities of the last couple of weeks have made it tough for Bess and me to get out and run. A little less on our plate now. Ran yesterday, but the IPod was dead (among the more frustrating feelings out there to get Bess harnessed up, stretch out, push play, and have nothing happen). This morning we ran in the rain, and had to get reacquainted with Philip Hoare and his whales. Guess what we're talking about now...



Had to assume that we'd get around to narwhals, discussed with other holarctic whales like belugas and bowheads. Along with the sperm whales and the orcas, they've got to be the most charismatic of the cetaceans. Here's another, less entertaining look.



Have to take issue with the comment that the horn "doesn't seem to serve any evolutionary purpose." Not true. In fact, the more we learn about it, the more purposes we uncover.