Question about the evolution of the Pteranodons

[Bill Nye Guy]

alright i was reading from the Chicago Tribune how a museum in EUREKA SPRINGS, Ark was putting up creationist explainations on some fossils that were being exhibited. They gave a example of a dinosaur, Pteranodons, saying that it was ""a pointy-headed flying reptile with a 33-foot wingspan, hollow bones and a bony ruffle on its skull. Visitors are told: "Each of these unique design features indicate that Pteranodons were created to fly, not that they slowly evolved into flying creatures."""

 

I am currently trying to come up with a evolutionist based response to explain the appearance of the dinosaur ( be warned i didn't have a good picture of the beast or the time period when i thought of this ), I thought that the dino might have appeared if there was a rapid change in the environment that could possible in some way have mutated the dna of the larva or oppsring, thus changing its appearance.

 

I think this idea is not really explicate nor very reasonable and probably did not occur. Can any of you guys help me out with this explanation. Thanks alot.

[LucidDreamer]

I think if you want to examine the origin of flying creatures you should look at creatures like flying squirrels. Flying squirrels don't fly but they glide long distances from tree to tree. The transition from a ground creature to a flying creature can be explained when you consider how a creature that leaps from tree to tree might benefit from developing traits that help in gliding, such as a flying squirrel. It's easy to see how a creature that glides might benefit from learning to stay in the air longer.

[Bill Nye Guy]

ahh you are right that does make alot of sense. I should have thought of it that way.

 

however are "hollow bones and a bony ruffle on its skull" common to Pteranodons? Because from what i read, it sounded like those 2 qualities were unique to the pteranodons and not found in its ancestors.

 

By the way the link for the site is here, http://www.chicagotribune.com/news/nationworld/chi-0508070365aug07,1,474799.story?coll=chi-newsnationworld-hed&ctrack=1&cset=true .

 

Thanks for the help.

[Mokele]

Hollow bones are, in fact, common to all pterosaurs (of which pteranodon is one, and which are not actually dinosaurs but rather a close relative), as well as to numerous fossil species that have flown or even just seen the need for lighter bones in other contexts. For instance, theropods had hollow bones in the neck and some degree of hollowing in the skull (presumably to make strikes faster), while sauropods had hollow neck bones, so that it took less effort to keep their necks up. Numerous living animals that glide (such as Draco lizards, flying squirrels, lemurs, etc) also have hollow bones.

 

As for the crest, that's probably not for aerodynamics, or you'd see it in all pterosaurs. In fact, most were crestless, and within genus Pteranodon, you see many distinct crest shapes: P. ingens is the one you always see, with the long, backwards crest, while P. sternbergi had an upright, almost square crest.

 

More info on them is here: http://www.ucmp.berkeley.edu/diapsids/pterosauria.html

 

Mokele

[CPL.Luke]

isn't it likely that the size and or shape of the crest and other "facial features" were signs of verility and forwarded the evolution of large and or interestingly shaped crests

[Mokele]

Yes, most likely they were shaped by sexual selection, specifically the competition among males for mates.