The story behind this... There's this nutball who digs things up in
his back yard and sends the stuff he finds to the Smithsonian
Institute, labeling them with scientific names, insisting that they
are actual archeological finds. The really weird thing about these
letters is that this guy really exists and does this in his spare
time!
Anyway... here's a letter from the Smithsonian Institute from when he
sent them a Barbie doll head.

Paleoanthropology Division
Smithsonian Institute
207 Pennsylvania Avenue
Washington, DC 20078

Dear Sir:

Thank you for your latest submission to the Institute, labeled
"211-D, layer seven, next to the clothesline post. Hominid skull."
We have given this specimen a careful and detailed examination, and
regret to inform you that we disagree with your theory that it
represents "conclusive proof of the presence of Early Man in
Charleston County two million years ago." Rather, it appears that
what you have found is the head of a Barbie doll, of the variety one
of our staff, who has small children, believes to be the "Malibu
Barbie". It is evident that you have given a great deal of thought to
the analysis of this specimen, and you may be quite certain that those
of us who are familiar with your prior work in the field were loathe
to come to contradiction with your findings.  However, we do feel that
there are a number of physical attributes of the specimen which might
have tipped you off to it's modern origin:
1. The material is molded plastic. Ancient hominid remains are
   typically fossilized bone.
2. The cranial capacity of the specimen is approximately 9 cubic
   centimeters, well below the threshold of even the earliest  identified
   proto-hominids.
3. The dentition pattern evident on the "skull" is more consistent
   with the common domesticated dog than it is with the "ravenous
   man-eating Pliocene clams" you speculate roamed the wetlands during
   that time. This latter finding is certainly one of the most intriguing
   hypotheses you have submitted in your history with this institution,
   but the evidence seems to weigh rather heavily against it. Without
   going into too much detail, let us say that:
A. The specimen looks like the head of a Barbie doll that a dog has
   chewed on.
B. Clams don't have teeth.
It is with feelings tinged with melancholy that we must deny your
request to have the specimen carbon dated. This is partially due to
the heavy load our lab must bear in it's normal operation, and
partly due to carbon dating's notorious inaccuracy in fossils of
recent geologic record. To the best of our knowledge, no Barbie dolls
were produced prior to 1956 AD, and carbon dating is likely to produce
wildly inaccurate results.
Sadly, we must also deny your request that we approach the National
Science Foundation's Phylogeny Department with the concept of
assigning your specimen the scientific name "Australopithecus
spiff-arino." Speaking personally, I, for one, fought tenaciously for
the acceptance of your proposed taxonomy, but was ultimately voted
down because the species name you selected was hyphenated, and didn't
really sound like it might be Latin. However, we gladly accept your
generous donation of this fascinating specimen to the museum. While
it is undoubtedly not a hominid fossil, it is, nonetheless, yet
another riveting example of the great body of work you seem to
accumulate here so effortlessly. You should know that our  Director
has reserved a special shelf in his own office for the display of the
specimens you have previously submitted to the Institution, and the
entire staff speculates daily on what you will happen upon next in
your digs at the site you have discovered in your back yard. We
eagerly anticipate your trip to our nation's capital that you proposed
in your last letter, and several of us are pressing the Director to
pay for it. We are particularly interested in hearing  you expand on
your theories surrounding the "trans- positating fillifitation of
ferrous ions in a structural matrix" that makes the excellent juvenile
Tyrannosaurus rex femur you recently discovered take on the deceptive
appearance of a rusty 9-mm Sears Craftsman automotive crescent wrench.
Yours in Science,
Harvey Rowe
Curator, Antiquities