# Re: T rex walking speed WAS: Re: Addendum to Trex vision as support for scavenging...

```Hmmm. So, taking a hopefully still conservative 6km/h, Trex could reasonably be
expected walk to its far point in one hour? And by walking in a straight line
for 8 hr, could efficiently monitor an area 2 far points by 8 far points (546
sq km), assuming the presence of visual tell-tales. Or, by walking the
perimeter of a circle with a radius of 1 far point, monitor an area of 452 sq
km (111,644 acres) in 6.3 hr, and end up where it started. That's a lot of
theoretical ground. Again, assuming theoretical visual tell-tales.

So, back to the question that started the thread. What actors are available to
play the theoretical role of vulture analog, helping to evolve wonderfully keen
Trex vision? So far, no suggestions (other than Quetz) have been made. I would
think something as big or somewhat bigger than a turkey buzzard, lots of
razor-sharp teeth, and no crest to hamper entry into large carcasses...

Don

----- Original Message ----
From: Martin Baeker <martin.baeker@tu-bs.de>
To: don ohmes <d_ohmes@yahoo.com>
Cc: dinosaur mailing list <dinosaur@usc.edu>
Sent: Tuesday, July 4, 2006 7:14:11 AM
Subject: T rex walking speed WAS: Re: Addendum to Trex vision as support for
scavenging...

> If my figures are correct--
>

> Taking a Trex stride as 1.76m, assuming a stride frequency of 2
>seconds (I believe 2 sec is conservative), and using Stevens' far
>point of 6 km, Trex could walk to his limiting far point in ~1.9
>hrs. This means that, assuming visual cues in the form of volant
>scavengers were available, Trex could monitor, from a stationary
>position, ~113 sq km (11340 hectares) with a two hour arrival
>time. Traversing a regular circuit, or moving with a herd of prey
>animals, could obviously enlarge this area several fold.

I believe this to be a *very* conservative estimate of a T rex walking
speed - after all, it amounts to a bit more than 3km/h.

>From scaling (Froude number as used by Alexander, Fr = v^2/ gL), I
would expect a T rex, with more or less four times the leg length of
humans, to walk at two times the speed, i.e. at about 10-12km/h.
Alexander used footprints to estimate walking speeds of large

Cheers,

Martin.

Priv.-Doz. Dr. Martin BÃker
Institut fÃr Werkstoffe
Langer Kamp 8
38106 Braunschweig
Germany
Tel.: 00-49-531-391-3073
Fax   00-49-531-391-3058
e-mail <martin.baeker@tu-bs.de>

```