[C.S.] Testament Background III

[mythusmage]

On The Cause of Dinosaurian Extinction

From all I know there was no one cause. There were 'contributory events'. A change in planetary climate, the series of volcanic events known as the Deccan Traps, an asteroid strike. The last of which put the final kibosh on the whole thing. But no 'smoking gun'.

I pick up my information in bits and pieces, from here and there. I don't follow academic standards. This is not an academic journal.

Before you send in a heated reply ask yourself this, "How would I feel if someone else was saying this to my face?" If the answer is, "I'd be ticked." don't post it.

 

[Desdichado]

For dinosaurs, Josh, dinosaurs. BTW, those titanosaurids you reference were found in South America, not the southern U.S.

Both of the species I referenced were found in Texas and New Mexico, actually. There were other titanosaurs in South America, Africa, Europe, and most of Asia.

Now, nodosaurs may have been descended from stegosaurs, but I doubt anyone would call them stegosaurs. Though one is descended from the other they are different types of critters.

That's a fair statement. However, the fauna you call typical isn't merely Mk II of late Jurassic fauna, like nodosaurs are to stegosaurs; they are from completely different lineages. And, like I said, they weren't typical.

As to ceratopsians and T Rexes etc. They were normal for their time. You're about the only person I've run across who calls them 'aberrant'. May as well refer to horses as aberrant since they evolved in North America and later migrated to the Old World

Ceratopsians and tyrannosaurs only appear in Mongolia and northern North America. That's not typical, that's geographically constrained. And the quintessential ceratopsians were only in North America. I call them aberrant, because I've read that in plenty of professional publications. Dr. Paul Serreno said as much, if I remember correctly. Of course, he's also one of the ones who's uncovered the previously little known fauna of areas like Late Cretaceous South America, North Africa, India, etc.

When's the last time you checked out Discover and Scientific American? Or looked into Cretaceous faunas other than the dinosaurs? From all I've seen, most everything was undergoing stress before the asteroid hit.

I prefer to go straight to the source -- Nature and Science articles were written by paleontologists, not journalists, and tend to be more rigorous rather than speculative. Not that speculation isn't good -- I also like to get the more unofficial views of dinosaur professionals on the Cleveland Museum of Natural History hosts the mailing list most frequented by practicing paleontologists, and is great for getting the scoop on stuff they don't print professionally because they don't have the evidence to support what they believe yet. But, like I said, I haven't seen anything new in terms of evidence for dino waning before the Yucatan asteroid hit, assuming that's what killed them off. Bakker published the idea fifteen? years ago, and it wasn't new then. But the idea still hasn't amassed enough evidence to be entirely convincing. Preservational bias and the small sample size makes "fossil counting" evidence extremely suspect anyway. Most paleontologists don't use it.

In a pop piece I'm supposed to get all academic on people? Sorry, I don't work that way. There's tons of data available that people can go look up if they feel the urge. What I present is based on tons of reading over the years. Filtered through this mass of neurons and glial cells that forms my brain. Besides, it's better for you to go and look yourself, for only that way can you be convinced.

What you get in this series is my take on things. All you're doing is a version of, "No it aint.". Giving me no evidence to support your take. How do you know that North American ceratopsians were aberrant? Or that titanosaurids were found in the southern U.S.?

One more thing, please calm down. My essay at the top of this thread aint going to drive wombats extinct or make naked mole rats any balder than they already are. It's intellectual fluff for crying out loud. Light reading that may (I do hope) lead folks into researching the subject for themselves.

Only so far as it 'inspires' someone to make a study of the subject will it have any meaning what-so-ever. Beyond that it means nothing and is certainly not worth the effort you're putting into your replies. Let it go.

Oh, I'm not uncalm. Can't I disagree without it being an argument? I should think I hardly need to present references to titanosaurids being in the Southern US, though -- the most famous dinosaur footprint series in the world, found by Roy Chapman Andrews in a Texas riverbed, was made by a titanosaurid and carcharodontosaurid. The type speciman for Alamosaurus was found in Ojo Alamo, New Mexico. That's easily available public knowledge. As is the presence of carcharodontosaurid and allosaurid top carnivores everywhere except Mongolia and the northern part of North America.

 

[mythusmage]

Both of the species I referenced were found in Texas and New Mexico, actually. There were other titanosaurs in South America, Africa, Europe, and most of Asia.

Learn something new.

That's a fair statement. However, the fauna you call typical isn't merely Mk II of late Jurassic fauna, like nodosaurs are to stegosaurs; they are from completely different lineages. And, like I said, they weren't typical.

So the Virginia Opossum is aberrant because it's descended from a South American lineage? Or have I got that wrong? Sounds like anti immigrant bias here.

Ceratopsians and tyrannosaurs only appear in Mongolia and northern North America. That's not typical, that's geographically constrained. And the quintessential ceratopsians were only in North America. I call them aberrant, because I've read that in plenty of professional publications. Dr. Paul Serreno said as much, if I remember correctly. Of course, he's also one of the ones who's uncovered the previously little known fauna of areas like Late Cretaceous South America, North Africa, India, etc.

Considering geographical conditions during most of the Cretaceous, I find it unsurprising that such late appearing animals such as ceratopsians and tryannosaurids are found in only one or two areas. For that matter, wasn't there a dromaeasaurid analog from the Jurassic found only in South America? (It starts with an 's', but danged if I can remember the name.) With the break-up of Pangea and the subsequent break up of Laurasia and Gondwana of course faunal assemblages were going to diverge. Some regions more than others.

I prefer to go straight to the source -- Nature and Science articles were written by paleontologists, not journalists, and tend to be more rigorous rather than speculative. Not that speculation isn't good -- I also like to get the more unofficial views of dinosaur professionals on the Cleveland Museum of Natural History hosts the mailing list most frequented by practicing paleontologists, and is great for getting the scoop on stuff they don't print professionally because they don't have the evidence to support what they believe yet. But, like I said, I haven't seen anything new in terms of evidence for dino waning before the Yucatan asteroid hit, assuming that's what killed them off. Bakker published the idea fifteen? years ago, and it wasn't new then. But the idea still hasn't amassed enough evidence to be entirely convincing. Preservational bias and the small sample size makes "fossil counting" evidence extremely suspect anyway. Most paleontologists don't use it.

Evidence doesn't have to be new. Sometimes all it needs is a reconsideration. Much as a reconsideration of the Burgess Shale fauna gave rise to a rethinking of early Cambrian life. It also helps if the involved parties are willing to give the evidence an honest appraisal in the first place, especially when said evidence could upset what they learned years before. The controvery regarding paleontologital evidence versus genetic evidence regarding mammalian relationships going on today for instance. The nigh pathological reluctance of the bulk of the zoological and primatological communities to even look at readily available evidence supporting the existence of the yeti and bigfoot is another example. Scientist are not immune to being close minded.

Oh, I'm not uncalm. Can't I disagree without it being an argument? I should think I hardly need to present references to titanosaurids being in the Southern US, though -- the most famous dinosaur footprint series in the world, found by Roy Chapman Andrews in a Texas riverbed, was made by a titanosaurid and carcharodontosaurid. The type speciman for Alamosaurus was found in Ojo Alamo, New Mexico. That's easily available public knowledge. As is the presence of carcharodontosaurid and allosaurid top carnivores everywhere except Mongolia and the northern part of North America.

Didn't sound like it to me. It sounded like an argument. It pays to be attentive to the tone of your writing. BTW, much of what I wrote is also based on publically available writing.

As to the mailing list you mentioned, does it have an edress and how does one go about subscribing to it?

Mr. Dyal, consider not only what you say, but how you say it. No need for euphemisms that wind up offending all by trying to offend none, but something much akin to, "I've heard differently, and here's what I've heard." That should help.

Forgot this part: FYI, Scientific American articles are not written by journalists, but by scientists. It is a popular science magazine, but more rigorous than the typical specimen. It is the scientific community's way of communicating new and interesting things to the general public. At least that segment of the general public interested in such matters. My mom was a trained biologist, she subscribed. That's good enough for me.

 

[Desdichado]

Fair enough -- I'm not trying to come across as mean-spirited, just that some of those things you're writing are specifically addressed as speculative in papers I've read that discount them -- or at least discount taking them seriously without better evidence, even if they might well be right.

I don't remember the exact address to subscribe the dinosaur mailing list (although there are public html archives, so I've actually unsubscribed myself to just lurk that way.) I know the host server is cmnh.org, and I've been able to find them with simple yahoo and google searches as dinosaur mailing list and looking for the cmnh.org URL.