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Re: "Heel to Toe"

Hi Natasha:

Many people on this have already said a great deal to help you, so I'm just adding a few more notes.

As many people have already stated, all dinosaurs walked on their toes. If you watch a bird walk, that gives you an idea of how the meat-eating varieties' foot would have looked. The way a bird or a meat-eating dinosaur walks would be equivalent to you standing upright on your toes, your heel off the ground. Dinosaurs do have a "heel," but for the most part it is held clear of the ground. If you look at a bird leg, above the toes you will notice that there is a hinge joint that faces backwards. This is the "heel" of a bird.

Except in rare circumstances, the heel never touched the ground. In bigger, heavier dinosaurs, the foot was angled and supported by a flesh pad, but the heel itself was foreshortened and lay next to the ankle. Even sauropods, the big, long-necked herbivores, essentially walked on their toes.

We know this is so because of footprints and from articulating and assembling the foot skeletons of dinosaurs together.

The name of the "heel" bone in a human is called the calcaneus. In dinosaurs and birds it is called the calcaneum. In humans, the calcaneus lies below the ankle (a bone called the talus in humans, astragalus in everything else) and points backwards. This is the case in mammals. In birds, reptiles, and dinosaurs, there is a different situation. The calcaneum lies next to the astragalus, and both form a cylinder-like joint that the foot bones articulate with (metatarsals). The toes (phalanges) lie below the metatarsals, and are usually what touched the ground, occasionally with the metatarsals.

So, humans walk heel-to-toe because our heel lies below our ankle. This was not possible in dinosaurs, because their heel lies next to their ankle and both together form the ankle joint.

Hope this helps on top of what has already been said,

Matt Bonnan
Dept Biological Sciences
Northern Illinois University
DeKalb, IL 60115 USA

From: Natasha Ramsey <dinobabe@earthlink.net>
Reply-To: dinobabe@earthlink.net
To: "dinosaur@usc.edu" <dinosaur@usc.edu>
Subject: "Heel to Toe"
Date: Mon, 31 Jan 2000 19:20:41 -0600

A question came up in my Invertebrate Paleo class today that we did not
know the answer to.  I was wondering if anyone out there knew.  The
question is "Did dinosaurs walk from heel to toe like humans do?"
Thank you in advance.

Natasha Ramsey

Student of Geological Sciences
University of Memphis

Event Coordinator
West Tennessee F-Body Association

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