Thursday, October 25, 2007

"Where's the beef?"

There's a mystery paleontologists have been puzzling over for decades that's pretty well summed up by everyone's favorite Wendy's ad.

Dimetrodon vertebrae found at HMNS site; additional object present for scale.

The Permian Red Beds in North Texas have turned up hundreds of Dimetrodons - the top predator of the era - but only a few fossils of the plant eaters they would have munched on. Without evidence of enough meat for this species to survive, how did they flourish for so long?



Dimetrodon ribs found by HMNS team.



In other words, Where's the beef?

About 50 years ago, E.C. Ulson, UCLA, hypothesized that Dimetrodons didn't eat plant eaters very often - because they were eating sharks.

Xenacanthus sharks of the era were unlike anything we've seen today. While the front of this prehistoric shark resembles modern species, it's back was shaped like an eel, and it had a long, poisonous spine coming out of its head. Most importantly, these were freshwater sharks that lived in the shallow, swamp-like habitat that was also populated by Dimetrodon 290 million years ago.

Evidence found by the HMNS paleo dig team supports this theory. For example, the team has found lots of Xenacathus teeth and poison spines at the site - but comparatively few examples of Xenacanthus coprolite (or shark poop). If the teeth were lost in the act of eating something, there would be coprolite around to prove it. Instead, the team has found lots of chewed-up shark skull.

An example of coprolite found at the site.

Something was eating the Xenacanthus at this site. Dimetrodon is the only species in the same weight class.

So, mystery solved?


17 comments:

Anonymous said...

Could the sharks have been canibals?

Houston Museum of Natural Science said...

Hi Tarrington and Matt,

Xenacanthus had tiny teeth and a small jaw - which were designed "more for snagging small fry," according to Dr. Bakker. They probably couldn't hae eaten anything as large as another Xenacanthus.

Good question - thanks for posting!

Erin

Levitra Online said...

I don't believe that this kind of creature be cannibal. He should eat little microorganisms or not.

buy generic levitra online said...

Great info.. Thanks

alan said...

I like to read this kind of data.


Smith Alan
http://www.raymeds.com

canadian pharmacy online viagra said...

hey buddy,this is one of the best posts that I�ve ever seen; you may include some more ideas in the same theme. I�m still waiting for some interesting thoughts from your side in your next post.

Edegra Online said...

Hi...
I keep thinking about it. Thanks for the information...

viagra generic said...

hey buddy,this is one of the best posts that I�ve ever seen; you may include some more ideas in the same theme. I�m still waiting for some interesting thoughts from your side in your next post.

Unknown said...

its really a nice one.Thanks for sharing.


forzest Online

Buy Generic Levitra said...

Very nice site and article. Amazing one, i appreciate this work.... This is a wonderful post Hey I see smart blog

Generic Levitra said...

Great Post and Nice Article.I like it.Thanks for sharing.

elliot thomas said...

Great article. First found difficult but interesting when read got some new information. thanks.

Unknown said...

Ektarao- Our Agency provides the High Class and the Elite independent Escorts in Chennai to the customer for enjoying the pleasure of our Escorts

escorts in Chennai

escorts service in Chennai

call girls in Chennai

Chennai call girls

Unknown said...



Chennai Escorts provide independent Busty escorts service in Chennai


Chennai independent escorts

collage girls in Chennai escorts

Chennai escorts models

Best Escort Service in Chennai

High Profile Escorts in Chennai

Nancy Oberoi said...

vip Hyderabad escorts
Busty Hyderabad escorts Girls
Hyderabad escorts Girls
Hyderabad escorts Models
Hyderabad High Profile escorts

Nancy Oberoi said...

escorts service in Hyderabad
Hyderabad independent escorts
Hyderabad escort
Hyderabad call girls
call girls in Hyderabad

KAJOL ROY said...

if we are all visit in the bangalore city is best good company .the high skill and high hotel reserved of the college girls and hot girls
https://www.payalpandya.com
https://www.payalpandya.com/about.html
https://www.payalpandya.com/services.html
https://www.payalpandya.com/gallery.html
https://www.payalpandya.com/blog.html
bangalore escorts
escorts in Bangalore
bangalore escorts service
call girls in bangalore
bangalore escorts agency
https://www.payalpandya.com