Mid-week Reptilian #23: Tuatara

Friday, September 17, 2010 at 12:39 PM Bookmark and Share
I recently came across an excellent short film on a most fascinating reptile - the Tuatara (Sphenodon sp.) - so I've embedded the film below for your viewing pleasure.

Figure 1: Tuatara (Sphenodon punctatus).
Click image for source.

But first, some background on the tuatara is in order...

Native only to some of the cooler islands of New Zealand, the long lived tuatara are rather unique among reptiles as contrary to their looks, they are NOT lizards. Why? Lizards belong to the order Squamata, along with snakes, which is one of the four orders in the class Reptilia: Squamata, Testudines (turtles, tortoises), Crocodilia, and the order containing only 1 surviving genus, Sphenodontia - the Tuataras.  That is, snakes and lizards are more closely related to one another than are any of them to the tuatara.

The evolutionary relationships between squamates and tuataras looks something like the cladogram to the right.  The numbers and icons correspond to

  1. Tuatara, order Sphenodontia.
  2. Lizards along with...
  3. Snakes form the order Squamata.
  4. Order Crocodilia
  5. Birds form the classical class Aves, though clearly that status is becoming dated.

In the wild, tuatara are considered threatened and some populations may have already been lost. The primary threat comes from introduced rats, which on some islands have been eradicated(!) specifically to protect local tuatara populations.

The short film Love in Cold Blood (official website), by Carla Braun-Elwert and Jane Adcroft, is part of the 2010 Reel Earth film festival and retells the story of how a tuatara named Henry (age 111-ish) came to hook up with a Ms. Mildred (age 80-ish) in a small zoo in New Zealand. To watch this low resolution version, use the password tuatara.

Love in Cold Blood from Love in Cold Blood on Vimeo.

Post Script:  Ok, so this awesome little film got me thinking -- how do they know the age of these two tuataras? After all, Henry was wild caught only a few decades ago!

According to this article, a few Tuatara were individually marked in 1957 and their growth tracked over subsequent years. Since then, the current age guesstimates appear to be based on size and growth rates but (as above) come unaccompanied by any confidence intervals or other information indicating how certain we are of those age estimates.

I'm tempted to dig into the article for details, but for now I'm going to force myself to let it go and get back to thesis writing! ;)


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