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Re: Questions about dinosaur skin
>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.
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". Sphenodontida included both terrestrial and aquatic forms.
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
Thomas R. Holtz, Jr.
Vertebrate Paleontologist in Exile Phone: 703-648-5280
U.S. Geological Survey FAX: 703-648-5420
Branch of Paleontology & Stratigraphy
MS 970 National Center
Reston, VA 22092