[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

FW: Concavenator has two humps

Egad. I'm going to stick my neck out on this one. But ..... hmmmmm .....
I think we have to be very careful with our life-reconstructions here.
You know. Just because a certain patch/area of dinosaur skin displays
tubercles/scales doesn't necessarily equate that feathers don't cover
that area. Elongated feathers from an adjacent area could do just that.
In life, the entire beast may have looked completely feathered. 
Which brings me to another point.
Somewhere, years ago, I came across an article that suggested that ostriches
carried armor on their hips [upper thighs/top of the pelvis] in the form of
tubercles so that lions, attempting to bring them down, simply rake their
claws across the armor dislodging a few feathers. They attack from the rear
to avoid a frontal kick.
If anybody has a pdf on anything like this, I've got a good catchers glove 
I'm holding up. Thanks.             dale

> Date: Thu, 9 Sep 2010 03:01:03 +0200
> From: heinrich.mallison@googlemail.com
> To: GSP1954@aol.com
> CC: dinosaur@usc.edu; vrtpaleo@usc.edu
> Subject: Re: Concavenator has two humps
> I'd be very careful about jumping to conclusion about a "sail". The
> tail has higher neural arches than the back (but for the hump) - but
> given the fat tails of dinosaurs (yours, dear Greg, are always too
> thin, see, e.g., Persons's wonderful talk in Bristol) these high
> caudal neural arches may simply be related to the tail musculature,
> and not to any showy of other structure. So there may have been a
> sail, or there may not.
> If there was one extraordinarily high caudal spine - the way the
> dorsal one sticks out -, then one could reasonably assume that a sail
> was stretched between them. But as things are any sail talk is very
> speculative, and extending that to a generalization about dinosaur
> sails is bad practice.
> Best
> HM
> On Thu, Sep 9, 2010 at 2:53 AM, <GSP1954@aol.com> wrote:
>> Both the text and the life illustration of Concavenator show a single hump
>> just before the hips. But the tail base neural spines are also elongated
>> while those over the pelvis were apparently not, so there are two humps 
>> (there
>> may be a less extreme hip dip in Ouranosaurus). The arrangement tends to
>> favor that dinosaur sails were for display rather than supporting fat 
>> deposits
>> in at least some cases.
>> Hopefully this example will establish that the presence of scales on a
>> dinosaur specimen does not exclude the presence of feathers elsewhere on the
>> animal. And with bristles etc showing up hither and yon in the group it is
>> highly plausible that feathers go way back into basal theropods - as per the 
>> old
>> Sarah Landry feathered Coelophysis (=Syntarsus) in Bakker's 75 Sci Amer
>> article.
>> GSPaul</HTML>