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Across
2. The approach to assigning species
names to new fossil skeletons
based on the idea that if two
fossils look slightly different,
they should be categorized as
being from two different species.
This approach emphasizes minor
differences. People who maintain
this approach are generally
referred to in the biological
sciences as "splitters".
5. The study of the fossil and
archaeological record of humans
and their primate ancestors.
10. The term for a date that gives the
time of an event only with
reference to another event that is
not worldwide in scale. It only
indicates that one event occurred
earlier or later than another.
For instance, the observation that
strata 2 is younger than strata 1
beneath it in a geological deposit
does not provide information about
how many years ago strata 2 was
laid down. It only indicates its
age relative to strata 1.
11. The remains of a plant or animal
of a species that is known to have
lived only during a specific time
period. The discovery of such a
fossil in an archaeological site
is circumstantial evidence of the
approximate time period that it
was occupied. These fossils can
be used to relatively date the
remains of our ancient ancestors
if they were found in association
with each them.
15. The term for breaks in the
original stratigraphic sequence of
a geological deposit.
16. The study of the conditions under
which plants, animals, and other
organisms become altered after
death, buried, and sometimes
preserved.
18. The name for the relative dating
technique that is based on the
discovery of index fossils.
19. The term for any remains or traces
of ancient organisms. Often they
are mineralized bone, though they
may be animal tracks, frozen or
desiccated bodies, creatures
trapped in amber, etc.
20. The name of a presumably very
ancient human skull and jaw found
in England in 1912 by Charles Dawson. In 1953, this fossil was
found to be an elaborate hoax. |
Down
1. The principle or idea that if
there are layers in a sedimentary
deposit, those laid down first
will be on the bottom and those
laid down last will be on the top.
This principle is the basis for
one of the commonly used relative
dating techniques.
3. The approach to assigning species
names to new fossil skeletons
based on the idea that if two
fossils have major similarities
they should be categorized as
being members of the same species.
From this perspective, minor
anatomical differences within the
same population are expected since
the members of living species have
individual variation. People who
advocate this viewpoint are also
referred to in the biological
sciences as "lumpers."
4. The study of earlier forms of all
life present in the fossil record.
6. A term referring to the position
in a site where an object was
originally deposited. Finding an artifact or fossil undisturbed in
this way allows a researcher to
apply the principle of association
in dating and interpreting it.
This can not be done if the object
is in a secondary context, which
is to say that it was moved to a
new location after the original
deposition.
7. The term for a group of similar
fossils whose range of
morphological variation does not
exceed the range of variation of a
closely related living species.
8. The term for a fossil consisting
of a bone that has lost its
organic components and now
consists only, or primarily, of
minerals. This is characteristic
of surviving dinosaur and other
very ancient bones.
9. The principle or idea that if two
objects are found undisturbed in
the same strata of a site, they
very likely date to the same time
period.
12. A relative dating method based on
the fact that bones buried in the
ground progressively lose nitrogen
and gain fluorine and other trace
elements. If two bones from the
same site have markedly different amounts of nitrogen and fluorine,
it is a strong indication that
they did not come from the same
time period. The bone with the
least amount of nitrogen and the
greatest amount of fluorine is
most likely the oldest.
13. The study of geological strata, or
layers of rock or soil, usually
for relative dating based on the
principle of superposition.
14. The term for a date that places an
event in its chronological
position with reference to a
universal time scale such as a
calendar. Such dates usually are
given in terms of the number of
years before or after a calendar
starting point. For instance,
1950 B.C. was 1950 years before
the beginning date of the
Gregorian calendar, which is
commonly used today.
17. Permanently frozen soil. This is
a common condition above the
arctic circle and in other
similarly cold environments.
18. A kind of chronometric date that
is measured in years before the
present. |
