And finally, because the embryos had poorly developed teeth, they lacked the most characteristic Troodon feature - teeth with unusually large and distinctive serrations .
The points of the serrations concentrate force while the little concave sections between these points offer more cutting surface.
The teeth are closely spaced and positioned so that the serrations are obliquely oriented relative to the long axis of the tooth row.
And, in the original description, a special point is made that Protarchaeopteryx teeth are characterized by the lack of serrations .
He turned the knife over so that the serrations were along the outer edge.
The tip of his lance got caught by the serrations of her sword, and he wrenched it out of her grasp, thinking he had won.
The important variables in the analysis were edge shape, width-to-thickness ratio, and serrations .
Most mill files are made for right-handed people, and the serrations are angled so they will grip the steel only when pushed in a left-to-right, forward motion.
Buffing the back, or flat side of the serrations ever so lightly will refresh the edge.
In addition, the number of marginal serrations was scored only in seventh leaves.