footprint fallacies (was "Large theropod speed record")

["Emma C. Rainforth" <emmar@ldeo.columbia.edu>]

Title: footprint fallacies (was "Large theropod speed record

> Reading the
> recent news on the new dinosaur tracks in the UK got me wondering. 
> What is the current trackway evidence for large
> theropods?

er....there IS trackway evidence of large theropods :-)

which means they probably walked around, at least some of the time. (At least, trackways indicate that large theropods didn't all fly, or swing from treetop to treetop...)

>  I am
> aware of only two trackways of running large theropods, this recent
> British study quotes 30 km/hour and Kuban, 1989, quotes 36 km/hr for a
> trackway in Glen Rose, Texas.

Right. And as we all know,

speed = distance/time.

And of course, we know exactly how long it took for the dinosaur in question to cover the ground and make that trackway....

oh wait, no we don't. Darn, can someone invent time travel please?

Please please please - while dino tracks are really cool, and give us lots of interesting info, we can NOT - and never will be able to - tell the ACTUAL speed at which they were moving when they left a particular trackway. The figures given in various articles should be taken with a liberal sprinkling of salt. At best, we can estimate the "relative" speed - and say something along the lines of 'dino A was moving twice as fast as dino B'. But even then, you can only compare two critters of the same size and taxon.

emma