…with a guest appearance by Charles Darwin

Marine iguana hands, Galápagos Islands. Photo E. Shock.

Pentadactyly, from Greek πέντε “five” plus δάκτυλος “finger”, is the condition of having five digits on each limb.

I make a lot of TOES. Gila monster toes. Crane toes. Jaguar toes. Hummingbird toes, owl toes, and roadrunner toes. Toad toes. A lot of TOES.

For the last week, I’ve been detailing Horned Lizard effigy bowls. This involves rendering a lot of small features like scales, horns, cloacal slits, pineal glands, and TOES. So it takes a long time, and that length of time is repeated for each horned lizard bowl, leaving plenty of opportunity for wistful thought about such subjects as, how can I finesse five toes on each tiny, fragile, rapidly hardening clay foot, and would anyone notice if there were only four?

“What could be more curious than that the hand of man formed for grasping, that of a mole, for digging, the leg of a horse, the paddle of a porpoise and the wing of a bat, should all be constructed on the same pattern and should include similar bones and in the same relative positions?” –Charles Darwin, On the Origin of Species

Okay, so Charles Darwin would notice. Darwin suggested pentadactyly was strong evidence in support of evolution. So, five digits is significant. A horned lizard has five digits on each limb, just like us, and just like many other animals, whether they are lizards, bats, or whales. With some exasperation, I realized I had no idea why this was — why five?

Needing a break from TOES, I headed to the computer: this is what the Internet is for. A quick search on the web produced the slick answer that we all have five digits because the ancestor of all tetrapods (four-limbed organisms) had five digits, and any modern organism that doesn’t (snakes, horses, most birds, etc) has lost digits through evolution. Well, alright so far as it goes — although it’s more of a description than an explanation — but why didn’t the ancestral tetrapod have 8 digits, or 4, or some other number?

It turns out they did: 8, and 6 and 7, among others. In the last few decades, paleontologists have found some fascinating tetrapod ancestors with a variety of phalangic arrangement probably related to the shift from fins to feet, at least partially connected with the shift from aquatic life to life on solid land. Does all this sound inconclusive? That’s because the significance of “Why Five?” is still being manhandled, pinched and slapped around with the discovery of each new ancient tetrapod, mostly in the North Atlantic land areas like Greenland and Scandinavia, which used to be swampy and warm, prime habitat for critters who wallowed in and out of muddy shallows on iffy substraits. Think Muddy Mudskipper, but Big, and with weird feet. Lots has been written about this, if you crave more detail than can be supplied here, check out an older but seminal essay by Stephen Jay Gould, “Eight (or Fewer) Little Piggies” and Jenny Clack’s website. She’s a professor at Cambridge University in the UK, and seems to be the reigning Queen of Early Tetrapod Research Especially As It Relates to Limb Development. (The image above of Acanthostega is from her site.)

Which brings me back to toad TOES (regular toad, not horned “toad”). As sometimes happens while riffling though the internet, I didn’t find an exact answer to my original question. But a lot of useful info accrued along the way. Like, now I know something I’d had a hard time finding out from pictorial sources, and forgot to count on the Couch’s spadefootlets: how many toes does a toad sport on its front feet? The answer is four (five on the back feet, the opposite of cats), and the next time I make a toad, I’ll have the right number. And be thankful, because it could have been eight.

The last pieces for Three Star Owl‘s Southwest Wings Birding and Nature Festival date slid into the kiln thursday, so no more pinching, coiling, stamping, slipping, scoring, or glazing nares, coverts, hooves, beaks, talons, or TOES again, until after the event.  Meanwhile, here’s a peek at a few things lurking informally around the studio now, waiting to be photo’d, priced, and packed:

New for this event are Javelina salt & pepper shakers and owl whistles.  And there’s a Plethora of Owls in all forms this time, even more than usual.

The Festival is in Sierra Vista (Arizona) at the Windemere Hotel, 5 – 9 August — that’s next week.  If you’d like to drop in, the vendor’s hours are: Thursday, August 6, 10:00 a.m. to 8:00 p.m.; Friday, August 7, 10:00 a.m. to 7:00 p.m.; and Saturday, August 8, 10:00 a.m. to 6:00 p.m.  Admission is FREE to the vending and exposition area in the hotel Lobby and Conference Rooms.  And, there’s still some room in several of the birding and natural history field trips, too.  Come by and say Hello!

The Stacked Toad Teapot Effigy is alive and well, so far.

After languishing at the back of a shelf in the studio for many weeks wrapped in damp paper towels and layers and layers of plastic film, the Stacked Toad Teapot Effigy has finally been fully sculpted and is drying, awaiting further surface treatment (terra sigillata and slips) and firings.  Between the last episode and now, I’ve added a new under-toad hanging upside down off of the main toad’s belly, and refined the detail of the piece, textured all the toads, and cleaned up the crannies.

If you’re having a tough time seeing why it’s a teapot effigy (and it is Toadlier than Teapotly), here’s a visual aid:

Remember the issue of pentadactyly in the studio and the fact that unlike the majority of tetrapods toads have only 4 digits on their front pair of limbs?  Here are the final numbers:  Potential (actual biological) toe count: 7 (# of toads) x 18 (# of toes each toad has) = 126!!  One hundred and twenty six toes on a piece that’s less than 12″ tall!  Yikes!  Does it have 126 toad toes?  No: Actual toe count = 108:   This is known as artistic license which can also be expressed as Biological digit defecit: 14.3%.  A close call! — it’s generally considered that greater than 15% and it becomes Grossly Inaccurate (over 25% and it’s just Wrong). There are, however, the requisite number of paratoid glands — 14 — in case you were wondering.  And, the flying insect “finial” has no toes at all — too tiny.

There have been many delays and distractions for the Stacked Toad Effigy Teapot: computer failure and restoration, other deadlines, and Thanksgiving, including a tragic Saguaro Plunge, details to be posted later.

But here is the next phase: the “lid” of the “teapot” is in place, and also the “finial” (knob), with Hector Halfsquid for scale.

This involved the addition of more toads — the final toads — to represent the top of the “teapot”.  The visual theme is toads-upon-toads, stacks of toads, piles of toads.  During the Couch’s spadefootlet episode, I was reminded of the toadly practice of Climbing On Your Neighbors.  When kept in captivity in large numbers, toads (and other amphibians and reptiles) will climb on each other with no regard for personal space, or any politeness at all.  I wanted to capture this “toe-in-the-eye” sense of physical involvement in the Toad Stack.  So on went two more toads, atop the base grouping of four toads.  Despite more than a week having elapsed this was not a problem, because even in the desert clay can be kept workable if enough dry-cleaners’ plastic and moist towels are employed. On the right is a shot of damp paper towels swathing the heads of the toads; they will need to be textured at some point, and if they’re too hard, it won’t work and the moist towels keeps the clay pliable and soft enough to receive an impression.

The effect of the two new toads, striving against each other on top of the pile, was what I wanted, but they needed a focal point — a flying insect they’re both trying to swallow.  This was the finial, or knob, of the “teapot” “lid”:

At this point, I always feel a piece is almost finished: the basic elements are sculpted and in place, there are at the moment no structural crises to solve.  But it’s far from the truth: a lot still remains to be done — texturing, refining shape detail (toes!), cleaning up stray clay bits and meaningless marks, applying decorative slip, etc.  For instance, I’ve forgotten until now about parotoid glands, which will have to be added.  And, other time-consuming details like compound eyes on the flying prey item.  So stay tuned for the next post on the effigy teapot: Texturing the Toad.

(Potential Toe Count: 104; Actual Toe Count: 49 so far; current Biological Digit Deficit, 53%)

Increments so far:

Why is a toad not a frog?

You almost certainly know this, but a toad isn’t a frog.

If that came as a surprise, it’s time for a speedy round-up of amphibian facts:

In general: toads have dry warty skin, frogs have moist slick skin. Toads need little or no water except to breed; frogs are usually amphibious. Toads have large kidney-shaped swellings behind each eye called parotoid glands; frogs have round hearing-related structures called tympani behind each eye. Most people think toads are gross but frogs are cute. That isn’t science; it’s just bad taste. Frogs croak, but many toads like  Woodhouse’s toads have beautiful muscial trills. ( If you were a Woodhouse’s toad, you’d think that was beautiful…) Toads have stout compact bodies with short legs for hopping; frogs are often svelte and long-legged for leaping.  Most frogs have webbed feet, most toads are not or only partially web-footed.  Frogs are more inclined to climb; toads are more inclined to dig.  Both can secrete irritating or even poisonous compounds that deter predators.

To the right above is a photo of a Ramsey Canyon Leopard Frog being aquatic.  Contrast it with the photo below it, a tropical toad from Belize. (photos, A. Shock)

In fact, these distinctions are generalizations and don’t hold true for every frog or toad. For more detail, I recommend the Dorling-Kindersley Eyewitness book Amphibian, by Dr. Barry Clarke.  It’s meant for kids, but it’s really all anyone but a real herpetologist needs to get the gist of of toads, frogs, and caecilians.