The skeleton of 150 million years old Lizard fossil was found
by Michael K.Han  in Yosemite Area.

This could be the oldest fossil found in human history 
meld & hide in a hug rock and could well beyond
150 millions years ago and yet to be confirmed by American
paleontologists.

On May 24Th of 2007, two days before memorial holiday
started, my sewage line was
blocked and needed to replace the old pipe line.
I called my friend named Bill Tucker
to dug out the old sewage pipe line and replace 4 inches
new PVC pipe. Apparently the heavy rock smashed
the old Pipe and caused the blockage.
Bill removed the huge rock with his backhoe and replaced
the old with the new. Bill asked me where I wanted to place
the rock. It came to me that it would be
not a bad idea to place it in front of our loop lawn
as an attraction. At time of removing, it was just a dirty
and dirt rock covered with all contaminated stuff.
I washed it with water and rinsed many times.

It came out still ugly. I decided that I used the bleach 50%
and 50% water sucked in a foam rubber cleaner. After 
it had been heavily rubbed many times , it came in its original shape and
color. It looked like a brown piece of huge  brown jade.
When I took a careful look on the back of the rock,
Bingo, the back of the rock is hiding an apparent fossil
of a huge lizard with head neck 4 limb and body in shape
about 28.5inches length  and 14 inches limbs extended widely.
I took a picture of it and decide to have it publicized
to share with others.

Remarks:

the following is a search result from Google.
"A pair of Argentine paleontologists have discovered numerous
90-million-year-old fossils of a new type of
sphenodontian—an ancient lizard-like reptile thought to have gone
extinct about 120 million years ago except for a few relicts that
live today in New Zealand, the tuatara."