Re: Questions about dinosaur skin

[Derek Tearne <derek@nezsdc.fujitsu.co.nz>]

> 
> >Among the critters mentioned in the book were a "living fossil" called
> >tuatara.  This was the first that I heard the term "living fossil," and the
> >concept grabbed me.
> >
> >Unfortunately, I have seen very little else since about the tuatara or its
> >ilk.  I understand if memory serves that it is an ancient form of lizard or
> >lizard relative, that it is now found on some islands off New Zealand, that
> >it has been said to have a pineal eye, and that it is a surviving remnant
> >from dino days.

>From _before_ the dinosaur days.  They are now restricted to rat free 
islands around New Zealand, which have been specially prepared as 
a haven for some of our endangered indigenous species.  Tuatara used 
to be found over the New Zealand mainland until the arrival of rats and
other mammalian predators.

> The tuatara is a reptile of the genus Sphenodon, which currently lives only
> in New Zealand.  It is the last survivor of a once very common group,
> called the Sphenodontida (or sometimes the Rhynchocephalia).  Since it is
> the last survivor of a once more common group, it is considered a "living
> fossil".  

True.  although I feel it is important to point out that
the term 'living fossil' is slightly misleading as it implies that 
no evolutionary change has taken place since 220 million years ago and 
that a modern Tuatara would look identical to a fossilised one.  
  
> The tuatara appears, from first glance, to be the most primitive (i.e.,
> least derived) reptile alive.  In fact, recent discoveries show that it is
> a secondarily "primitive" animal, having ancestors with a more derived
> anatomical condition.

Exactly.

Here are some facts about this amazing creature which I found lying 
aroung on the machine at work (It's from the Wellington Zoo
pamphlet).  If anyone wants to know more, or anything specific I've got 
a fair amount of information about them at home.  

                          TUATARA FACTS

* The tuatara is native to New Zealand

* It is the sole survivor of the beak-heads (Sphenodontida) which is a 
  group of very ancient reptiles

* The tuatara is the most ancient of all living reptiles. It is 
  even older than the dinosaurs

* It has survived for almost 200 million years

* Tuatara can live up to 100 years

* The male is much bigger than the female

* Young tuatara have a third eye. It is on top of the brain 
  between it's other eyes. It becomes covered over when the 
  tuatara is an adult   


BABIES

The female lays 8 - 15 eggs in a shallow hole in the ground. The 
eggs are not cared for in any way by the parents. It takes 12 - 
15 months for the young to hatch. The female may only lay eggs 
every 3 - 4 years


FOOD

Tuataras are carnivores. They eat weta, moths and beetles. 
Sometimes they eat small lizards and even the eggs and chicks of 
petrels. At the zoo we feed them baby mice, huhu grubs, worms, 
meal worms and insects. They are fed twice a month. 


---
Derek Tearne.   --   derek@fujitsu.co.nz   --    Fujitsu New Zealand   --
Some of the more environmentally aware dinosaurs were worried about the
consequences of an accident with the new Iridium enriched fusion reactor.
"If it goes off only the cockroaches and mammals will survive..." they said.