Dinosaurs Never Held Heads High

richard_za writes "The common notion that long necked dinosaurs held there necks high to graze from treetops has been proven impossible. Roger Seymour, from Adelaide University's Environmental Biology Department and Harvey Lillywhite from the University of Florida. According to a research paper published at the Proceedings of the Royal Society in London, he explained that due to heart size and metablic rates the only way they could have functioned on land was with a horizontal neck. This flies in the face of images popularised in Hollywood movies such as Jurassic Park. However it is doubted that this new evidence will have any effect on the Mozilla Project."

Comments

mozilla will be affected most of all

[VAXGeek]

actually, mozilla will be affected most of all. they do have the slowest metabolism rate out of any open source project i've ever seen.
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a funny comment: 1 karma
an insightful comment: 1 karma
a good old-fashioned flame: priceless

oh really

[Anonymous Coward]

As somone with a biology background, if you studied the skeletal remains of a giraffe you might think the same thing. Due to the fact that I don't think there has ever been enough soft tissue find that could irrefutably say that these animals did not have valves for blood flow in their necks. I mean for goodness sakes they still are divided on if they were poikilothermic or homeothermic, if they were endotherms or exotherms...so given we know very little about their metabolism anything based on metabolism is a best guess at best :) Ok ok I did take 2 semesters of classes on dinosaurs.... Anyway just kinda found this one ridiculous.

Re:oh really

[Anonymous Coward]

Hi, here is another one, who teaches zoology at the undergraduate level.

You are right. This article and its arguments are crap.

The giraffes have a blood corpuscle (like a fine branched network) which helps to relieve the pressure above (i.e. closer to the head) that network. This way the giraffes' heads don't explode from the water column when it leans formard to drink water.

Of course they were homeothermic:

1: The fine canals inside bony tissues are of a kind only found in the warm-blooded mammals and birds, but not in other amniotes like crocodiles, lizards, snakes, or turtles.

2: Birds are dinosaurs, in the same manner as bats are mammals. The are thus strong reasons to believe their most proximate ancestors also were warm-blooded. [Somewhat circular]

3: Erect posture. You just cannot walk upright for long distances, lifting your own body weight, unless you have the metabolism for it.

4: Proportion between predators and prey. In current, homeothermic ecosystems (like the African Savannah) there are about 1-5% predators in terms of body mass. In ecosystems dominated by cold-blooded predators (crocodiles or large varans) there may be up to 30% predators. In Perm, before the dinosaurs, the predators were about 10-30% of all fossils. During Triassic, Jurassic, and the Cretaceous the predators sank to 1-5% of the fossils in terms of (estimated) live body mass; the same is true for mammalian dominated fossils more recent.

Cheers!

Erect and long!