Comments on: Irish elk of the Jurassic http://blogs.discovermagazine.com/loom/2006/02/08/irish-elk-of-the-jurassic/ A blog about life, past and future. Written by DISCOVER contributing editor and columnist Carl Zimmer. Sat, 26 May 2012 01:25:59 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: Sordes http://blogs.discovermagazine.com/loom/2006/02/08/irish-elk-of-the-jurassic/comment-page-1/#comment-2478 Sordes Fri, 26 Oct 2007 13:25:18 +0000 http://blogs.discovermagazine.com/loom/2006/02/08/irish-elk-of-the-jurassic/#comment-2478 What I find interesting enough is the fact that Guanlong had a prominent crest, no matter what actual purpose it had. Among modern predators neither mammals nor birds evovled similar structures. Some carnivores like lions and hyeneas evolved more or less big manes, but they are in general only hair which is longer on some bodyparts. But the complex bony structures at the heads of different theropods are actually weird. The crest and comparably weak jaws of Dilophosaurus were (and are) often used as an argument for a scavenging behavior. As I am a strict opponent of such ideas about specialications towards scavenging in big carnivores, I took a closer look at Dilophosaurus´ skull. The shape of the teeth and especially the dent in the upper jaws resembled a bit those of crocodiles, spinosaurids and some other piscivorous reptiles. The whole body with the long neck and the comparably gracile body would also fit well the idea that Dilophosaurus was some kind of super-heron. It was really interesting that a short time ago evidence was discovered that a relative of Dilophosaurus did wade into the water to catch fish. So what does this mean´ Perhaps the crests on the heads do indicate also for Guanlong an unusual way of life, which was not typical for a theropod of its size. I?m not saying it was a fish-eater, but perhaps there was another kind of special ecological niche which was occupied by this dinosaur. What I find interesting enough is the fact that Guanlong had a prominent crest, no matter what actual purpose it had. Among modern predators neither mammals nor birds evovled similar structures. Some carnivores like lions and hyeneas evolved more or less big manes, but they are in general only hair which is longer on some bodyparts. But the complex bony structures at the heads of different theropods are actually weird.
The crest and comparably weak jaws of Dilophosaurus were (and are) often used as an argument for a scavenging behavior. As I am a strict opponent of such ideas about specialications towards scavenging in big carnivores, I took a closer look at Dilophosaurus´ skull. The shape of the teeth and especially the dent in the upper jaws resembled a bit those of crocodiles, spinosaurids and some other piscivorous reptiles. The whole body with the long neck and the comparably gracile body would also fit well the idea that Dilophosaurus was some kind of super-heron. It was really interesting that a short time ago evidence was discovered that a relative of Dilophosaurus did wade into the water to catch fish. So what does this mean´ Perhaps the crests on the heads do indicate also for Guanlong an unusual way of life, which was not typical for a theropod of its size. I?m not saying it was a fish-eater, but perhaps there was another kind of special ecological niche which was occupied by this dinosaur.

]]> By: Richard Hamilton http://blogs.discovermagazine.com/loom/2006/02/08/irish-elk-of-the-jurassic/comment-page-1/#comment-2477 Richard Hamilton Wed, 20 Dec 2006 20:20:42 +0000 http://blogs.discovermagazine.com/loom/2006/02/08/irish-elk-of-the-jurassic/#comment-2477 So does that mean that some birds have ancestors from Maniraptora and some have ancestors from Tyrannisauriodea? I thought that all birds evolved from Maniraptora. And as far as headgear in dinosaurs go, excluding Ceratopsians, Stygmoloch takes the cake without a doubt. So does that mean that some birds have ancestors from Maniraptora and some have ancestors from Tyrannisauriodea?
I thought that all birds evolved from Maniraptora.

And as far as headgear in dinosaurs go, excluding Ceratopsians, Stygmoloch takes the cake without a doubt.

]]> By: Hank Roberts http://blogs.discovermagazine.com/loom/2006/02/08/irish-elk-of-the-jurassic/comment-page-1/#comment-2476 Hank Roberts Sat, 11 Feb 2006 23:14:20 +0000 http://blogs.discovermagazine.com/loom/2006/02/08/irish-elk-of-the-jurassic/#comment-2476 > This thin wedge of bone wouldn't have helped the > dinosaur in a fight, which leads the > paleontologists to propose that it was a sexual > display. I flew hang gliders starting in 1978 -- when the wing was entirely in a plane. They had stability issues. The first change was a 'keel pocket' to add a vertical panel, one that could shift from side to side. It helped. I wonder what aerodynamics engineers the paleontologists consulted and what steps they took to rule out the possibility that the crest aided flight control, before deciding they were sexual displays? > This thin wedge of bone wouldn’t have helped the
> dinosaur in a fight, which leads the
> paleontologists to propose that it was a sexual
> display.

I flew hang gliders starting in 1978 — when the wing was entirely in a plane. They had stability issues. The first change was a ‘keel pocket’ to add a vertical panel, one that could shift from side to side. It helped.

I wonder what aerodynamics engineers the paleontologists consulted and what steps they took to rule out the possibility that the crest aided flight control, before deciding they were sexual displays?

]]> By: Carl Zimmer http://blogs.discovermagazine.com/loom/2006/02/08/irish-elk-of-the-jurassic/comment-page-1/#comment-2475 Carl Zimmer Fri, 10 Feb 2006 13:06:41 +0000 http://blogs.discovermagazine.com/loom/2006/02/08/irish-elk-of-the-jurassic/#comment-2475 Jim, thanks on catching the mistake on the date. Now fixed. Jim, thanks on catching the mistake on the date. Now fixed.

]]> By: Dave Hone http://blogs.discovermagazine.com/loom/2006/02/08/irish-elk-of-the-jurassic/comment-page-1/#comment-2474 Dave Hone Fri, 10 Feb 2006 11:47:47 +0000 http://blogs.discovermagazine.com/loom/2006/02/08/irish-elk-of-the-jurassic/#comment-2474 To Michael: T.rex *may* have had feathers, early tyrannosaurus like Dilong seem to have had feather filaments so it is certainly a posiibility. However, an adult T. rex would be looking at losing heat, not insulating as it was so big (Surface area to volume ratios) so probably did not. However, it is possible, even probable that baby rexes had downy coats to keep them warm. As for crests in general Tarpejara is goos, but check out Nyctosaurus! It had a crest approachin 1.8m even though its wingspan was only about 4m. Yes. Really. Most reconstructions give it a 'sail' of skin, but this probably did not exist as it would make it too unsatble to fy well. As for theropods, see also Dilophosaurus, Oviraptor and Cryolophosaurus for some cool headgear. To Michael:

T.rex *may* have had feathers, early tyrannosaurus like Dilong seem to have had feather filaments so it is certainly a posiibility. However, an adult T. rex would be looking at losing heat, not insulating as it was so big (Surface area to volume ratios) so probably did not. However, it is possible, even probable that baby rexes had downy coats to keep them warm.

As for crests in general Tarpejara is goos, but check out Nyctosaurus! It had a crest approachin 1.8m even though its wingspan was only about 4m. Yes. Really. Most reconstructions give it a ‘sail’ of skin, but this probably did not exist as it would make it too unsatble to fy well.

As for theropods, see also Dilophosaurus, Oviraptor and Cryolophosaurus for some cool headgear.

]]> By: Jim A. http://blogs.discovermagazine.com/loom/2006/02/08/irish-elk-of-the-jurassic/comment-page-1/#comment-2473 Jim A. Fri, 10 Feb 2006 06:09:54 +0000 http://blogs.discovermagazine.com/loom/2006/02/08/irish-elk-of-the-jurassic/#comment-2473 Carl, did you mean to write a different date in your third paragraph? At National Geographic's website they estimated the fossils to be 160 rather than 120 million years old. Carl, did you mean to write a different date in your third paragraph? At National Geographic’s website they estimated the fossils to be 160 rather than 120 million years old.

]]> By: Michael http://blogs.discovermagazine.com/loom/2006/02/08/irish-elk-of-the-jurassic/comment-page-1/#comment-2472 Michael Fri, 10 Feb 2006 02:51:26 +0000 http://blogs.discovermagazine.com/loom/2006/02/08/irish-elk-of-the-jurassic/#comment-2472 Does this mean that T-Rex had feathers? Does this mean that T-Rex had feathers?

]]> By: Jaime A. Headden http://blogs.discovermagazine.com/loom/2006/02/08/irish-elk-of-the-jurassic/comment-page-1/#comment-2471 Jaime A. Headden Thu, 09 Feb 2006 12:02:00 +0000 http://blogs.discovermagazine.com/loom/2006/02/08/irish-elk-of-the-jurassic/#comment-2471 I think Creationists will use the crest to indicate how DIFFERENT this animal is and thus capsize on the ignorance involved similarities versus differences when dealing with biology and phylogeny. As it is, arguments of lumping by "kind" are done so not based on similarities, but differences, since if it doesn't look like it's "folks", then it's not the same thing. This is in ignorance of the details of anatomy. I think Creationists will use the crest to indicate how DIFFERENT this animal is and thus capsize on the ignorance involved similarities versus differences when dealing with biology and phylogeny. As it is, arguments of lumping by “kind” are done so not based on similarities, but differences, since if it doesn’t look like it’s “folks”, then it’s not the same thing. This is in ignorance of the details of anatomy.

]]> By: steve s http://blogs.discovermagazine.com/loom/2006/02/08/irish-elk-of-the-jurassic/comment-page-1/#comment-2470 steve s Wed, 08 Feb 2006 22:49:57 +0000 http://blogs.discovermagazine.com/loom/2006/02/08/irish-elk-of-the-jurassic/#comment-2470 It must be a pretty sucky time to be a creationist. It must be a pretty sucky time to be a creationist.

]]> By: Pharyngula http://blogs.discovermagazine.com/loom/2006/02/08/irish-elk-of-the-jurassic/comment-page-1/#comment-2479 Pharyngula Wed, 08 Feb 2006 22:42:19 +0000 http://blogs.discovermagazine.com/loom/2006/02/08/irish-elk-of-the-jurassic/#comment-2479 <strong>Guanlong wucaii</strong> a, b, Cranial reconstruction in left lateral (a; shaded area indicates the unpreserved portion) and dorsal (b) views. adc, anterodorsal concavity; al, anterior lamina; an, angular; aof, antorbital fenestra; d, dentary; dg, dentary groove; emf, externa... Guanlong wucaii

a, b, Cranial reconstruction in left lateral (a; shaded area indicates the unpreserved portion) and dorsal (b) views. adc, anterodorsal concavity; al, anterior lamina; an, angular; aof, antorbital fenestra; d, dentary; dg, dentary groove; emf, externa…

]]> By: Dan S. http://blogs.discovermagazine.com/loom/2006/02/08/irish-elk-of-the-jurassic/comment-page-1/#comment-2469 Dan S. Wed, 08 Feb 2006 20:20:49 +0000 http://blogs.discovermagazine.com/loom/2006/02/08/irish-elk-of-the-jurassic/#comment-2469 "Dinosaur paleontologists don't look for fossils simply because dinosaurs are cool" Yeah, but look at the reconstruction. That's <i>cool</i>. re: Sexual displays and sexual selection - is this a widespread thing? I'm trying to think . . . most of them do seem to have that odd take a generic so-and-so and stick-something-on look, but I don't know enough about any of the species involved to judge. And behaviorally, I wonder? Now for people - I know human males are rather well-endowed compared to our relatives* - might this be another example, or are their more plausible/supported explanations . . . * and they don't even get showered in spam about it. Go figure? “Dinosaur paleontologists don’t look for fossils simply because dinosaurs are cool”

Yeah, but look at the reconstruction. That’s cool.

re: Sexual displays and sexual selection – is this a widespread thing? I’m trying to think . . . most of them do seem to have that odd take a generic so-and-so and stick-something-on look, but I don’t know enough about any of the species involved to judge.
And behaviorally, I wonder?

Now for people – I know human males are rather well-endowed compared to our relatives* – might this be another example, or are their more plausible/supported explanations . . .

* and they don’t even get showered in spam about it. Go figure?

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