Marginalia

Speaking of newly found herps, an article by Frank Glow et al. in the latest PLoS One describes what may be the world’s smallest reptiles—indeed, among the world’s smallest amniotes.  They’re four species of leaf chameleons in the genus Brookesia from northern Madagascar.  Here they are, and note that the scale bar is 5 mm—about 0.2 inch! These are adults, and B. micra adults are about 15-27 mm long: about 0.6-1 inch long!  That’s a small lizard!

Here’s a baby on a matchstick from the BBC website, which gives more information but doesn’t identify the species.  Cute, eh?

And, as is often the case in animals, the diagnostic traits involve the shape of male genitalia, perhaps because those genitals evolve rapidly by sexual selection:

“In general, the hemipenes found in the B. minima group are remarkably dissimilar among species.”

Here’s a figure of the hemipenes (the bifurcated penis of many reptiles):

The photos show for each species, a general view of the organs and a close-up. For B. desperata, the inset picture shows a non-turgid everted hemipenis where the two apex projections are very prominent. Note that also several other of the shown preparations are not fully turgid, especially in B. ramanantsoai and B. micra. In two other species (B. confidens and B. tristis) the shown hemipenes might not be fully everted.

In other news, the Torygraph has reported that goats can develop different accents when moved to new social groups, so that their bleats come to resemble that of their companions, a form of cultural “inheritance”. There also appears to be a genetic component to among-family differences in bleats.  I haven’t read the paper, which was published in Animal Behaviour.

Finally, Larry, the official Chief Mouser to the Cabinet Office at 10 Downing Street (a rescue cat), has celebrated his first year in residence with a party. Details and photos are at the Prime Minister’s official website.

h/t: David and a couple of others whose emails I’ve lost.

15 Comments

  1. Harry Greene
    Posted February 16, 2012 at 10:59 am | Permalink

    Very cool discoveries indeed but one small correction: hemipenes is plural for hemipenis, some of which are bifurcated (many snakes) and some which are not–in those images of the tiny chameleons BOTH hemipenes are everted, tho they might look like a single bifurcated organ.

  2. GBJames
    Posted February 16, 2012 at 11:09 am | Permalink

    And I thought this was a family-friendly web site!

    • Dominic
      Posted February 17, 2012 at 9:55 am | Permalink

      There would be no human family without a penis!

  3. Posted February 16, 2012 at 11:12 am | Permalink

    Larry is the typical mixed breed alley cat, a healthy, epitome of a feline if I ever saw one. His markings exhibit his extensive mixed genetics. More beautiful to me than pure breeds.

  4. Posted February 16, 2012 at 11:26 am | Permalink

    Thanks for the info, very interesting. Have you done any online courses at all?

    • Dominic
      Posted February 17, 2012 at 9:59 am | Permalink

      There are a couple of Jerry’s talks freely available on iTunes, or iTunes U http://www.apple.com/education/itunes-u/
      The trouble is for some free talks (eg Open University) they want you to register a credit card.

  5. christopher
    Posted February 16, 2012 at 11:47 am | Permalink

    “three cheers for your willy or john thomas, hooray for your one-eyed trouser snake…” Darren Naish at Tetropod Zoology had a great post about terrifying turtle sex organs a few months ago that’s worth a look too, if you’re into that kind of thing.

  6. William
    Posted February 16, 2012 at 1:29 pm | Permalink

    The juvenile on the matchstick is Brookesia micra. (The same photo also appears in the PLoS One article.)

  7. Posted February 16, 2012 at 2:59 pm | Permalink

    So, here I am, looking a lizard dicks. Somebody get me a drink.

    • GBJames
      Posted February 16, 2012 at 3:15 pm | Permalink

      ROFL!!!

  8. GBJames
    Posted February 16, 2012 at 3:20 pm | Permalink

    I just notice that if I scroll my window up and down while looking at the image at the top of this post, the tails wag. Yet another reason for someone to bring drinks!

  9. Posted February 16, 2012 at 3:21 pm | Permalink

    This one is smaller, but it doesn’t have a tail…

    http://news.sciencemag.org/sciencenow/2012/01/scienceshot-smaller-than-a-dime-.html

  10. Renolds
    Posted February 16, 2012 at 5:00 pm | Permalink

    Larry has had a bumpy first year. He faced calls for his resignation after a mouse was spotted at a dinner.
    http://www.bbc.co.uk/news/uk-politics-15717341

  11. Posted February 17, 2012 at 6:59 am | Permalink

    One of the fascinating (and sad) things about these chameleons is they have distributions that are, like the animals, tiny: only a few square kilometers, apparently.

    I talk more about this, and how this factors into the names for these species, here:

    http://neurodojo.blogspot.com/2012/02/miniature-chameleons-beyond-squee.html

  12. Lars
    Posted February 17, 2012 at 1:21 pm | Permalink

    One of my proudest moments on a Madagascar field trip back in the 90s was finding one of these Brookesia all by myself. Even the larger species are extremely small and cryptic, and the first person to see any that were there was almost always the local guide.


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