General Question

jdegrazia's avatar

What ever happened (evolutionarily) to the spikes on the stegasaurus tail?

Asked by jdegrazia (266 points ) September 9th, 2008

Any living reptiles have weapons on their tails? Are there any other dinosaurs that used to have them? Seems weird that there doesn’t exist a whole evolutionary line of reptiles with spiky tails. I mean carrying that weight around is a pretty serious cost. For those things to have grown stega-size, they must have been around for a long time on stega-ancestors, no?

Observing members: 0 Composing members: 0

6 Answers

bodyhead's avatar

When the dinosaurs when extinct, there was no need for the next generations of lizards to have this particular defense mechanism. They have other traits that compensate for this type of thing.

Some reptiles are poisonous. Some shoot blood out of their eyes to scare away predators. Some have huge teeth and/or claws. If any of the new generation of lizards needed spiky weapon tails, they would either have them (I don’t know of any) or they wouldn’t because it’s not necessary to survive.

delirium's avatar

There are plenty of lizards who have spiky tails. (But its important to note that the saurians went extinct… There aren’t ancestors of the stegosaurus in particular because they didn’t make it that far.)

http://i4.photobucket.com/albums/y127/Delightedly/urourourouro/85865656-L.jpg
There’s a spikey modern tail for you. Trust me when I tell you that those hurt like a bitch when he’s whipping it around, all angry.

I’ll find you a few more. There are plenty of agamids that have spines on their tails.
Even iguanas have back spikes.

ht1979's avatar

This article argues that the spikes were not really for defense most likely. Instead, they suggest that the spikes and plates on the stegosaur were basically evolved to help the creatures identify their own kind among the other dinosaurs (like the helmets of the pachycephalosaurs and the crests of the duck-billed hadrosaurs)... Not sure if this is bunk or not, but it kindof explains why this trait didn’t result in a class of similar large creatures in modern times…
http://tinyurl.com/6hwrfx

syz's avatar

That first photo is lovely, del. Very cool.

delirium's avatar

Thank you, syz. The first photo is actually my little guy. I can’t wait to get back home to him!

Answer this question

Login

or

Join

to answer.

This question is in the General Section. Responses must be helpful and on-topic.

Your answer will be saved while you login or join.

Have a question? Ask Fluther!

What do you know more about?
or
Knowledge Networking @ Fluther