• Tag Archives monitor lizard
  • Land lubbing crocs get their day in the sun. Also, there’s a varanid special on NOVA.

    Dr. Paul Sereno stands with others at a meeting for the American Association for the Advancement of Science in Chicago. Note the wheelbarrow like retroarticular processes on the "boar croc."
    Dr. Paul Sereno stands with others at a meeting for the American Association for the Advancement of Science in Chicago. Note the wheelbarrow like retroarticular processes on the "boar croc."

    After spending? a few years collecting and looking at the weirdness that is Gondwanan crocodyliformes, Dr. Paul Sereno has finally started to unveil stuff. With the help of National Geographic comes When Crocs Ate Dinosaurs. It appears to be a special that focuses on the remarkable – and often underrated – diversity seen within this group of animals. The highlight of the program (at least in my opinion) is the focus on all the very un-crocodile like crocodyliformes.

    The National Geographic website has a special section that shows off the various, apparently unnamed, taxa. For now, there are just placeholder names that will likely hurt the eyes and ears of anyone who had to deal with the aftermath of The Land Before Time.

    The artwork is by artist Todd Marshall. I’ve always enjoyed his portrayals of prehistoric reptiles (he tends to get almost too fanciful with dewlaps and spikes though). Sadly the accompanying animations do not do Marshall’s incredible artwork justice.? It will be interesting to see how it all gets integrated into the television show.

    Also airing tonight is a special on NOVA entitled: Lizard Kings. It features the work of Dr. Eric Pianka; a well known and respected lizard ecologist who has focused on monitors for much of his career.? The special looks to be very interesting. Especially given that it appears to have taken years for the film crew to get the footage they needed. As you read this the special has already aired. However, PBS does make their shows avaialable to watch online for free, on their website. The show should also be viewable on Hulu by tomorrow.

    A perentie monitor (_Varanus giganteus_) poses for the camera.
    A perentie monitor (_Varanus giganteus_) poses for the camera.

    I realize that both of these options are only available in the states. To date there seems to be no international options. At best there are some workarounds.

    Still, for those that can get them, both shows should prove to be entertaining.


  • New study finds that numbers are inherent to humans…and…

    I came across this study today from The New Yorker.

    It’s a long (for the internet) read, so I’ll only do a few verbatim copies here. The gist of the study, by French scientist Stanislas Dehaene, is that the concept of integers (1,2,3 etc) is something that is hard wired in our brains. We have a natural ability to do rudimentary addition, and we can tell when one number is larger than another. Well, as long as the gap is large enough.

    According to the article:

    If you are asked to choose which of a pair of Arabic numerals?4 and 7, say?stands for the bigger number, you respond ?seven? in a split second, and one might think that any two digits could be compared in the same very brief period of time. Yet in Dehaene?s experiments, while subjects answered quickly and accurately when the digits were far apart, like 2 and 9, they slowed down when the digits were closer together, like 5 and 6. Performance also got worse as the digits grew larger: 2 and 3 were much easier to compare than 7 and 8. When Dehaene tested some of the best mathematics students at the ?cole Normale, the students were amazed to find themselves slowing down and making errors when asked whether 8 or 9 was the larger number.

    Dehaene conjectured that, when we see numerals or hear number words, our brains automatically map them onto a number line that grows increasingly fuzzy above 3 or 4. He found that no amount of training can change this. ?It is a basic structural property of how our brains represent number, not just a lack of facility,? he told me.

    This is fascinating. Especially the discovery of a “hard wired” number line (which goes right to left, apparently. See the article), which works really well up to about 4. The fascination comes not from the discovery of this in humans, but the fact that this degree of rudimentary math has been found in a wide variety of animals. The most recent being fish.

    In that study, scientist found mosquito fish (Gambusia affinis) females were able to count up to four (right at the end of the number line). Also, like in human studies, the fish were able to tell which group of fish was larger, as long as the discrepancy was big enough (approximately 2:1).

    Keeping with the theme of my site, the most famous example of reptilian counting would be that of varanids. Studies on the white throated monitor (Varanus albigularis), found that they can reliably count to six (King & Greene, 1999).

    So it seems that the concept of math is so important that it has been hard wired in our genes for at least 400 million years.

    Think about that the next time you ignore a mathematical equation.

    Also, give the article a read through. It is very intriguing. It’s the closest that psychology has ever come to being a hard science, and the ramifications for education cannot be understated.


    King, D. & Green, B. 1999. Goannas: The Biology of Varanid Lizards. University of New South Wales Press. ISBN 0-86840-456-X, p. 43.