Other posts in this series:
Paleontological Research Tips II: field notes, continued
Paleontological Research Tips III: a complete idiot's guide to taking decent specimen photographs
Paleontological Research Tips IV: the art and science of maintaining a research notebook
Paleontological Research Tips V: manuscript writing, research productivity, peer review, and more
I'm starting off a new series of posts that will cover
various aspects of paleontological research. When I started doing paleo
research I was a bit lost when it came to organizing my thoughts. After all,
there's a lot of work involved in taking fossils and squeezing information out
of them and arriving at a published article. Following the underpants gnomes
meme from South Park:
Step 1: fossils
Step 2: ??
Step 3: paper (profit)
This new series will cover everything in step 2. It's
"easy" to go out and find a fossil, but much more difficult to distil
that into a publication. I'll be giving plenty of examples of dos and don'ts,
personal anecdotes, ideas, and personal preferences. There are some very basic
rules, but most of these are going to be recommendations - it's all about
finding the perfect balance. With a few exceptions, there are no absolutes or
strict rules; it really does boil down to preferences. Also, if any colleagues
or readers have bright ideas, comment away!
Field notes! Everybody hates them but you need to do them.
For starters, this post is directed just as much at my amateur colleagues as it
is for professionals and students alike. Good - or at least satisfactory -
field notes are an absolute must. This is one of the few examples of things
that absolutely must be done if you want to do field paleontology well;
almost everything else will be up to personal taste, but there must absolutely
be a chain of evidence for fossils and paleontological data. Here's a series of
real world examples:
Scenario 1: Joe Blow is a shark tooth
collector in Florida,
and typically finds over a hundred shark teeth a day when he goes out digging.
Occasionally rarer finds are made; on one particular day he comes across a
Pleistocene horse skull sticking out of the gravel at the top of the quarry. He
knows its important, digs it out, sets it in a box in the back of his pickup,
and drives home. Joe doesn't have a particularly sharp long term memory, and five years
later can't remember what quarry or what unit the fossil was collected. When
Joe offers to donate the fossil to a museum, an interested paleontologist
questions him on its provenance but is disappointed at the lack of detail.
Scenario 2: John Doe is an avid master's
student prospecting for trilobites for his thesis on trilobite paleoecology.
It's been a long, hard day in the horrendously hot Marble Mountains of Southern
California; he's got a bad headache, sunburned, and is thinking longingly of
sweet, cold beer back at camp - there's only one day left on his Marble
Mountain trip. He's spent all week collecting hundreds of samples, bagging
them, labelling them, and cross-referencing these field numbers in his
notebook. At the end of the day he finds fragments of a very large invertebrate
- perhaps it's something like Anomalocaris! He quickly chisels out a slab, but
is quickly getting tired and the prospect of beer is more and more attractive.
It's not a locality he's collected from before that he could quickly write
"refer to locality X on page X"; he doesn't have time to turn on his
GPS, so he marks a cairn and will write everything down the next day. The
following day, a flash flood washes out a bridge on the way there, and John
returns to school to begin his horrendous advanced stratigraphy class. Months
later he takes everything out, but finds that no information is associated with
the anomalocarid and he's not even certain what formation it came from.
Scenario 3: Jane Doe (no relation) is a
diligent student collecting stratigraphic data along the coast, and has been
collecting fossils as she goes, though it's not necessarily for her thesis
research. She takes the fossils and shoves them into a plastic bag with the
date written on it in permanent ink. She takes fossils from several different
layers and puts them in the same bag; her notes are perhaps just as well
curated as the rest of John's notes.
Scenario 4: Dave Mould is collecting (with
permission) from the Hell Creek Formation for a well known museum within a few
hundred meters of a property line; they do NOT have permission to dig up
anything from the other side of the fence. He spies a bed of sandstone riddled
with dinosaur bones, and the fossiliferous bed continues past the fenceline. He
doesn't cross it, but within a stone's throw finds an adorable little
ceratopsian skeleton - perhaps it's a Leptoceratops. He spends his time with
his volunteers diligently excavating the delicate bones, and as the thought of
beer, dinner, and a campfire comes he hastily writes down some notes, but cuts
corners and gives a somewhat lacklustre description. Years later he's
affiliated with a different institution, but finds out the rancher from the
other side of the fence is accusing his museum of theft as he remembers seeing
a similar looking skeleton on his property. Now, he's in deep shit because his
notes are wholly inadequate towards proving that they collected the fossil
legally.
Scenario 5: John Doe returns to the Marble
Mountains the
following summer, and miraculously his cairn is still up! He remembers, and
after getting chewed out by his adviser, seizes the opportunity at redemption
and records everything he can. He proceeds to collect quite a few more
specimens and other samples. Upon returning to campus the week later, he
realizes that on one of his days he wrote all the notes down, but forgot to
write his sample/field numbers on the plastic bags, and now he's got a pile of
trilobites he cannot precisely match with his notes. Poor John.
Scenario 6: Curator emeritus Raymond Scott
is a well-respected leader in the study of Cretaceous mammals, and is getting
rather messy and forgetful; his younger coworkers are too timid to remind him
that he needs to clean his office, and attempts to nag him to find and send
back 20+ year loans have gone unheeded. Dr. Scott falls ill, and for the sake
of argument, dies. Younger coworkers find specimens without notes, but probably
collected locally; also specimens with an unfamiliar institution acronym but no
loan documentation.
Every single one of these scenarios share two things in
common: 1) in every case, somebody did something wrong, and 2) all of these
have happened, and happen more often than you would think. Laziness, or
ignorance, will get the better of you. I don't mean to sound preachy - but
maintaining good field notes is important, and it's good to be proactive about
it. Now what happened in each? Joe didn't know any better, and that's fine.
Non-scientists are often perplexed with how anal-retentive academics are, and
that's OK. But in order for specimens to be of real use, we need to know some
basics (more on that later). What about John? In #2 he was lazy - and I've
painted him in a sympathetic light, because this temptation happens to
everyone. In #5 he was both lucky and forgetful. What about Jane? Jane, despite
her attention to stratigraphic detail, didn't really think about where the
fossils were coming from - after all, her thesis is about geochemistry and she
collected the fossils for fun, but decided to give them to her institution.
Nobody realized they come from different layers, despite being separated by
perhaps millions of years, and are now in a museum collection and mistakenly
labeled as being from the same layer & locality. David is thinking he may
need to hire an attorney, as the rancher is threatening to sue the museum, and
the museum is denying responsibility. Dr. Scott has never had somebody
challenge him on the way he conducts his office, and his death means that if
lucky it might take his successors years to figure out the provenance of
various specimens hidden in nooks and crannies.
The common theme here is that yes, notes are important - and
it's not only important to have some notes, but it's also very, very
important to have the right notes. The right notes are the ones that
allow you to clearly say when, where, and how a particular fossil (or bit of
data) was collected. So what are the right notes? And first off, why bother?
What importance could it possibly have?
The chain of evidence - geographic, geologic, and stratigraphic - linking fossil morphology to a position and place in time, eloquently illustrated by Parham et al. (2012).
Why bother?
I'll try and succinctly answer the question of why.
Basically, paleontologists are modern extensions of 19th century style
naturalists - at our core we go out into nature, record observations, and take
little pieces of nature home to study. Yes, many paleontologists make use of
expensive laboratory equipment like scanning electron microscopes and X-ray
diffractors, the bulk of paleontological data is collected by somebody armed
with a rock hammer and a notebook. Our notes are the initial framework for which
fossils or other specimens can be understood in the context of that nebulous
idea called "information". We can't ask Joe's horse fossil how old it
is, or where it came from. Details about the geographic locality are necessary
to not only show where you found it in order to 1) give a researcher an idea of
where it is on a geologic map and 2) how to find the locality again, but also
3) demonstrate that the fossil was collected legally. On a day to day
basis, points 1 and 2 are far, far more common. Geologic data is crucial
towards establishing geologic context: what lithology, layer, formation, etc.
The goal is to write this stuff down, and tie it in with the fossils based on
something other than your memory. Remember, useful data and specimens will be
utilized by paleontologists long after you're dead. To paraphrase this in a way
that should be universally understandable amongst science: recording notes in
sufficient detail ensures that your research is repeatable.
How, part I: connecting notes to specimens
There's several ways to do it. First, you could scribble
everything down in permanent ink on the outside of your ziplock bag. That's
fine for short term, but after 1-2 years it can rub off. Some folks use a
pre-printed standardized specimen card: all of the information is written on
that. Others will write directly onto a tag with a string that you physically
tie around the specimen. These work for a lot of people, but I like to have all
the data written down in a central location, like a ledger. Problem is, it's
separate from the fossil and its field packaging. So, in the field, I write an
entry in my notebook with my initials RWB followed by the field number. My very
first entry was RWB-1; I wrote on the ziplock bag the same number in a sharpie
and voila, that problem is fixed. Numbers are entered in chronologically, as
you find new fossils. Now there's a sample number on the fossil, and if you
look it up in the notebook, you can see all the necessary data. This system is
generally called the Grinnell System. As the fossils are prepared, I paint a
little white swatch of acrylic paint and write the field number on with an
archival pen. Many marine mammal fossils at UCMP still bear the field numbers
of the people who collected them - including LGB (Larry Barnes), DPD (Daryl
Domning), CAR (Charles Repenning), FAP (Frank Perry), RHT (Richard Tedford),
and of course the highly prolific JHH (J. Howard Hutchison). If you really want
to include more information with the actual specimen, go ahead - try both. You
can try any of these methods - but the take home message is to tie the
information physically to the specimen (somehow!) to maintain a hopefully unbreakable
chain of data.
Here's an example: above is a photograph of UCMP
219261 from UCMP locality V99869. You can
see my RWB field number - RWB-82 - clearly on the specimen. If you look it up
in my field notes, you'll see this entry on p. 35:
RWB-82. 1/4/2009.
Capitola, Concretionary Bed. ~400' west of Saxon Ave.
Carcharodon tooth, ?odontocete scapula, bone frags, big fish vert.
In this case, the notes indicate 1) what was found, 2) when
it was found, 3) what layer it was found in (the Concretionary Bed is a
specific, ~15-40 cm thick horizon), and 4) roughly where it was found. For
coastal exposures like this where I know the stratigraphy well, I'm more
particular about where stratigraphically a specimen was collected and give a
general estimate of the locality relative to nearby landmarks. Saxon
Avenue is a street that dead-ends at the top of
the cliffs near here, and though it's not very visible from the beach, I'm
familiar enough with the locality (from 2005 to 2011 I visited this spot at
least 10 days a year) to know where each street is based upon the houses atop
the cliffs. Further to the point, UCMP
locality V99869 is a locality I established to contain only material from the
"Concretionary bed".
How, part II: geographic data
Recording geographic data can use some creativity. There are
many ways to skin a cat - it's probably best not to write down "about 100
paces past the old oak tree, and a bit left." For starters, the oak tree
is probably not permanent, paces are a measureless unit, and god knows what way
is left. Fortunately for you, we now live in the days of cheap, accurate
handheld GPS units; so, go ahead and just write down the coordinates once the
accuracy is reasonable. Give a brief description of the location. I typically
work in linear cliff outcrops, which makes life very easy because all I need to
do is estimate how far from the end of the cliff I am (e.g., 200 meters south
of Herpetocetus creek). And use official names given to places on USGS
maps; some local nickname for a location might die out, or heaven forbid it's
your own nickname you haven't bothered telling anyone about, in which case your
description is useless. An example is Pleasure Point in Santa
Cruz: the actual name is Soquel Point, but locals call
it the former. Another tip: If I collect at a locality I'm absolutely certain I
remember collecting from before, a detailed description is a waste of time -
I'll write in my notebook "same locality as RWB-64, see page #".
Better yet, use photos - or Google earth! Every time I make
a new locality in my notebook I add a pin with my locality notes to Google
earth. You can also print off a map, airphoto, or other imagery with you (maybe
it's just a panorama you took on an earlier visit), put a pinhole at the spot
where your fossil site is, and on the back draw a circle and mark the field
number there. This can be done in the field, and is the preferred method of
record strikes and dips by geologic mappers. If you go into geology, you'll do
a lot of this for field camp (and yes, it's fun as hell). Most of my fieldwork
consists of day trips, so I usually have time that night (or the following morning
if I'm really exhausted) to add in all the new localities.
Make a sketch! Locality sketches, regardless of your
artistic abilities, are of immense utility. A picture is literally worth a
thousand words. Speaking of...
Take pictures! A camera is your best friend in the field.
You don't want a fancy camera in the field - they're expensive and easy to
damage. Take a little digital point and shoot. My undergraduate adviser Dave
Varricchio used a polaroid camera until 2009 when Kodak stopped making the film
- he'd take the picture in the field, let it develop, tape it directly into his
field notebook and annotate the photo more or less immediately. I watched him
use his very last polaroid picture (he may have found more, though, as another
company, or maybe Kodak, announced that they were going to re-release polaroid
film). If you have access to a computer shortly after fieldwork, upload all
your pictures and make a word file in that notebook stating what's being
depicted in each and where each was taken. Nowadays many cameras have a built
in GPS that takes coordinates when you take a picture. Another fascinating
strategy is used by MSU/MOR Ph.D. student Denver Fowler, who records short
videos where he narrates what fossil was found, pans around, and gives a short
description of the location - in addition to field notes. Denver
may love the sound of his own voice (only kidding a little bit) but it's an
effective strategy to supplement your notes with a redundancy. I tend to
organize photos on my computer by the date and general location of the field
trip so that I can refer back to them easily if necessary.
More tips on photos from the comments below, courtesy Andy Farke and KRH: Photos of the locality and the fossil you collect have multiple applications. Oftentimes coordinates alone might not be useful enough for re-discovering an old locality (or, more importantly, interpreting the stratigraphy). Photographs showing the exact locality and clearly showing where the fossil is in relation to a datum bed (see below) or an easily recognizable landmark (uniquely shaped hill or promontory, tree, seawall, drainage pipe, etc.) are of immediate utility for helping someone zero in on the exact spot. Photos taken of the fossil as discovered or during excavation can also be quite informative for whoever prepares the fossil. I tend to prepare all of my own fossils - not because I am a control freak (well, I can be) but because I don't have funding to pay a preparator and most of my volunteers have helped out until they get bored. If you're so lucky, giving the preparator more than just a pile of rocks or a jacket without anything other than a field number will make them happy rather than resent you.
More tips on photos from the comments below, courtesy Andy Farke and KRH: Photos of the locality and the fossil you collect have multiple applications. Oftentimes coordinates alone might not be useful enough for re-discovering an old locality (or, more importantly, interpreting the stratigraphy). Photographs showing the exact locality and clearly showing where the fossil is in relation to a datum bed (see below) or an easily recognizable landmark (uniquely shaped hill or promontory, tree, seawall, drainage pipe, etc.) are of immediate utility for helping someone zero in on the exact spot. Photos taken of the fossil as discovered or during excavation can also be quite informative for whoever prepares the fossil. I tend to prepare all of my own fossils - not because I am a control freak (well, I can be) but because I don't have funding to pay a preparator and most of my volunteers have helped out until they get bored. If you're so lucky, giving the preparator more than just a pile of rocks or a jacket without anything other than a field number will make them happy rather than resent you.
Lastly, maps are great. If you can manage, bring one with
you into the field in some sort of waterproof map case. If you can get
photocopies made, stick a pinhole through the paper at the spot your locality
is, draw a circle around it on the backside and write your field number.
How, part III: geologic data
This part is a bit trickier because it relies upon the
collector having a basic knowledge of geology in the field - so I'll reiterate
a few of the basic premises:
Fossils are of course buried in rock. Mappable units of
sedimentary rock of a given type are named formations. Geologic maps use
formations (and occasionally smaller units within a formation called members)
to color in the outcrop pattern onto a topographic map. Most (for all intents
and purposes) sedimentary rocks are deposited in nearly flatlying layers. How
do you find out what formation your fossil is in? In most cases, you've
followed somebody else's directions to the locality and already know what to
look for, but otherwise that is what the geologic map is for - whatever color
is present at the place you're standing can be matched with the map's key. Ok,
great, we know the formation at a new locality, so we're done, right? Not even
close.
We need to record the position of the fossil within the
formation - usually to the nearest meter is fine. Not all formations are
created equally: some are nicely separated into clear sections with distinctive
key horizons within - but many are internally boring and thick, with few
distinctive horizons. Other formations are so poorly exposed that perhaps
detailed internal stratigraphy has not yet been worked out within the
formation. So, in some cases, short of recording your own stratigraphic column,
it may not be possible to record what level within a formation a particular
fossil came from. Stratigraphic position is key because often available dates
will 1) not be from the same position as your fossil and 2) will not be from
the very top or the very bottom of the formation. Here's a brief scenario:
Scenario 7: Jane Doe (no relation) is
reading some horrendous notes provided by a former student who collected a
fossil dolphin from some cliffs on the shoreline. The former student prepared
away all the matrix and fossil shells associated with the skull, but did not
keep them. The cliffs are a few miles long, and about halfway down the cliffs
an early Pliocene index fossil clam was found indicating an age of 3-4 Ma; the
rocks are dipping, and may be as old as 6 Ma at one end and 1 Ma at the other.
The student's notes state that the dolphin was collected "about a mile
down the cliffs", but in no further detail.
Jane should be either a bit pissed off or disappointed
(perhaps both), because this level of detail is insufficient to tell whether or
not the dolphin was collected from the same horizon, above, or below the clam;
more precise data would have helped. How do we determine the stratigraphic
position of a fossil? We use distinctive layers and define them as a
"datum plane" - individual fossils can be collected and their
position recorded however many meters above/below the datum. The datum might be
an ash bed, a sandstone bed with pebbles, or a layer of resistant limestone
amongst calcareous shale - anything that easily stands out.
This is all rather simple if we're just talking about a few
specimens. But what about this scenario:
Scenario 8: Jane Doe has been gently
encouraged by her adviser to be more judicious in her collecting to record the
exact geographic and stratigraphic position instead of tossing fossils from
multiple sites and levels into the same ziplock bag. She finds a bonebed along
the cliffs with bones along a 200 meter section of beach, where bones are
spaced about 20-30 cm apart, and she takes about 1 in 5 promising looking bones
and teeth. She finds a tiny ray tooth, and compelled to look more carefully,
finds another bonebed two meters below. She knows assigning a single field
number to everything is going to get her a lecture from her adviser. She is
torn between assigning unique numbers for every single specimen, or assigning a
single number for all the material in each bonebed, or some sort of a
compromise.
This one comes down to personal preferences. My perspective
is that if a single horizon is continually fossiliferous along a stretch of
cliff or other outcrop - especially if it's a nice linear outcrop - it's
preferable to reduce the number of localities entered into a museum collection
database and define the locality as being between two GPS coordinates. There's
simply no need to enter in 30 different localities if all are reasonably close
and within the same layer. More specific information from your notes can be
written down on a sheet of paper and given to the museum along with your
fossil. Usually museums hire people capable enough to not throw that piece of
paper away once it comes into the museum (but hey, it happens occasionally).
Real life example: fossils that Frank Perry (Santa Cruz Museum Nat. Hist.)
collected in the 1970s and donated to UC Berkeley from UCMP
locality V6875 all within a single bonebed exposed along nearly 2 miles of
cliffs all have very detailed notes written on index cards indicating exactly,
to within ~10 meters, where every single specimen was collected. These
notecards are still stored with the fossils, and I utilized all of that data
for my master's thesis research - and followed Frank's example with my own
collecting (more on that below). So if it were up to me, Jane would use two
localities, defined more on stratigraphic position than geographic location.
Put it this way: in some parts of the world, 2 meters of sediment between two
fossiliferous horizons can mark more than 10 million years. Simply marking the
geographic location alone (i.e. without taking notes about stratigraphic
position) is just not enough at some localities.
The next basic aspect of geology a field worker must be
familiar with is lithology - rock type:
Scenario 9: Our dear friend Joe Blow has made another
discovery - this time, it's a short faced bear or something similar, only he
thinks it's from Pliocene marine limestones, and tells the same museum curator
about the find. The curator is ecstatic, because that would mean the age of
short faced bear in Florida
would be extended back quite a ways. He gets in his car and meets Joe, but is
again disappointed when he sees that the bear jaw is in fact covered in white
sand, not limestone; he doesn't know a tactful way of breaking it to Joe that
the fossil is not quite as spectacular as initially thought.
This also applies to being able to read the rock record: if
you're not familiar with identifying rocks, it will be difficult to tell A)
which formation a fossil is from and B) how far it is down from the bed of
glauconitic sand in the quarry wall. Fortunately, identifying rocks is easy
with enough practice. If you can identify all sorts of weird fossils,
identifying rocks in the field based upon carbonate content, clastic grain
size, texture, and sedimentary structures is relatively straightforward. Moral
of the story: invest some time in identifying sedimentary rocks in the field
and it will really pay off.
How, part IV: taphonomic data
Occasionally, you might be interested in recording some
basic taphonomic data in the field. I won't get into it too much, because
taphonomic data recording in the field quickly becomes very nuanced if not
outright complicated - and involves all sorts of activities that generally will
be beyond the scope of fieldwork being undertaken by a student or an amateur
collector, such as carefully excavating a skeleton and making a bonebed map.
Most taphonomic data regarding the surface preservation of a fossil won't be
knowable until the fossil is completely prepared - for example, if it's got
tooth marks, borings, or attached epifauna. Occasionally, you might see some of
this evidence on the bone exposed in the field - in which case, photograph it!
Then make sure you are careful during excavation, and if fragile then use a bit
of extra padding or consolidant. Most taphonomic data being recorded in the
field will instead be related to fossil orientation, association, and distribution.
Association/articulation is the easy one: is the bone/tooth isolated? If not,
are the other elements simply next to it (disarticulated) or are they still
"put together" in life position (articulated)? You may not be able to
tell until it's partially excavated, and occasionally not even until you've
opened up a plaster jacket in the lab. Draw a sketch if you think it's
necessary.
Basic terms for fossil orientation, from Kidwell et al. (1986).
Orientation data is next, and this is primarily going to
fall into two categories: fossils with an actual long axis, and fossils that
sort of don't but are "kind of" flat. In the first category, you can
use a brunton compass to take a trend/plunge measurement: the compass direction
the bone or elongate shell or tree trunk points (trend), and then a measurement
of the angle that it deviates from horizontal (plunge). This is very similar to
taking strike and dip if you're familiar with that, but less abstract of a
concept. Back at home your data can be entered into a program and generate a
"rose diagram" to tell if there is a preferred orientation (e.g. most
of the bones point northeast/southwest - perhaps they're aligned with water
currents). For fossils without a clear long axis, but are not exactly
spherical, you can give a quick visual estimate of orientation in two
perspectives: cross section (e.g. a cliff) and map view (e.g. an exposed
bedding plane). In cross section, you can simply denote whether fossils (e.g.
clams, sand dollars) are parallel with bedding (concordant), at a high angle
with bedding, say anywhere from 20-70 degrees (discordant), or perpendicular
(edgewise) - each of these will tell you something about taphonomy.
Fossil assemblage geometry - from Kidwell et al. (1986).
Lastly, there's distribution, and this generally refers to
the proportion of 1) fossils to sediment and 2) how close the fossils are to
one another. There's a lot more than just this, and rather than give you way
more to read, I'll include a couple of self-explanatory figures from Kidwell et
al. (1986) to give you an idea of what sort of data you can reasonably collect.
How, part V: stratigraphic (and biostratigraphic) data
In addition to preservational data, many paleontologists will
be interested in the stratigraphy of the rocks a particular fossil is entombed
within. There are many reasons for this, but could include important
information like 1) stratigraphic position relative to other fossil
occurrences, 2) position relative to a dated horizon, or 3) the depositional
environment of the host sediment. Measuring thickness involves using a jacob's
staff and a Brunton compass, and is fairly straightforward. "Measuring a
section" is a bit different, and is shorthand for measuring and describing
sedimentary rocks. There's a ton of information needed for this, but at it's
most basic, for each layer, information including 1) lithology (e.g. grain
size, sorting, rounding, composition, color, grading, rock name), 2)
sedimentary structures (e.g. cross bedding, varves), thickness (in centimeters
or meters), 3) geometry (tabular, wedge, lens, etc.), 4) nature of upper/lower
contact (sharp or gradational), 5) lateral extent of bed (can be estimate), 6)
body fossils (which is covered in part IV - generally this will consist of
taphonomic data, and listing which species are present based on field IDs), and
7) trace fossil content (similar to above - listing which ichnotaxa and any
vertical/lateral changes in traces/bioturbation). You can assign numbers to
each column the way you assign field numbers to fossils. Want to collect rock
samples? Same thing!
Example of a stratigraphic log sheet you can fill in (left; from http://www.southampton.ac.uk/~imw/osring.htm) and a stratigraphic column with lateral thickness based upon weathering profile (right, from http://dawnssedstrat.blogspot.com/2012/03/interpreting-stratigraphic-columns.html).
This is best done graphically, rather than relying
completely upon written notes. There are two ways to do this: use a
stratigraphic log, which you can design yourself (a bit advanced) or use
somebody else's (see above). This is fine but often doesn't allow you to scale
the width of our stratigraphic column/section to either grain size (my
preference) or weathering profile (more relevant in interior continental
settings). My personal preference is to draw the column yourself and have a
checklist for which types of data to collect - this permits a bit more freedom,
and also allows you to write everything down on waterproof paper like a Rite in
the Rain notebook, the golden standard for geological field studies. Waterproof
notebooks are also necessary for doing fieldwork on the California
coastline - for obvious reasons.
A page out of my master's thesis field notebook showing my hand-drawn column and some of the written notes.
Amateurs and professionals alike are already quite capable
of collecting biostratigraphic data associated with the "more
important" fossil in question - it involves taking similar notes as above
for fossils, or just collecting a bunch of other fossils from the same stratum
in the vicinity of your locality. Let's say you're digging out a fossil dolphin
from Pliocene sediments of the Yorktown Formation in a clay pit in North
Carolina: simply bag & number any fossil
invertebrates or other fossil vertebrates. If you really want to be useful,
keep a small sample of matrix (sediment) that can be sampled for microfossils.
That sediment sample can also be useful in case somebody comes along later and
is skeptical about where you collected a fossil; the associated lithology can
help a researcher prove/disprove what locality/stratum a particular fossil is
"supposed" to be from. There's obviously a lot more involved in
recording stratigraphic data, but that's a whole other ballgame and this more
or less covers the basics.
Because there's a crapload of information to write down, and I'm not smart enough to remember it all, I printed off this checklist, laminated it (waterproof) and then taped it into the front page of my notebook.
How, part VI: some additional tips
Some researchers prefer to have entries set up by the day
and start with a short description of what the goals for the day are, where you
are, the weather, and additional details. In the long run, these are not
intended to be useful in terms of data, but more so act as "memory
anchors" - if you forgot to write down field numbers on a fossil, but
remember that it was the afternoon where it rained a lot and you were
particularly cold, wet, and miserable - this information is a good failsafe.
One of the professors at U. Otago, Andrew Gorman, has his students draw a
couple of symbols for the weather and your mood - when grading field notebooks
as a TA in New Zealand I typically saw happy faces coinciding with little sun
drawings denoting sunny weather, and rain clouds associated with unhappy faces;
I also saw a lot of bored faces in notebook entries from the afternoons of
fieldtrips.
How, part VII: A note for amateur paleontologists
Hopefully some of you reading this are amateur or avocational paleontologists. Collecting scientific data is essential if fossils are going to be meaningful other than just a pretty curio or a paperweight. Some amateurs are not interested in donating fossils - others are. For those with the interest, it's imperative that at least some data is collected. At the minimum, either take some notes in the field, or write something down as soon as you get home - and either write the field numbers onto the fossil, or store the information with the fossil. What if you collect hundreds of shark teeth? Is it reasonable to expect somebody to do all of this for every single specimen? It is, up to a point; after a point it's impractical. So, you can always assign a field number and a few sentences of notes to a collection of fossils that all came from one spot. At the very minimum, please write down something about 1) geographic location, 2) which specimen it is, 3) the date, and 4) the formation (and position within the formation, if possible!).
What if you don't want to give up your secret fossil site? Every collector has one, and it is a legitimate concern. If you give up your locality, the unwashed hordes may come in and ransack the site. Despite being a legitimate concern, it is not a legitimate reason for not taking notes or giving those notes associated with the fossil to the museum when it is donated. Why? Because in most cases, paleontologists don't publish exact locality details in the peer reviewed literature - for that exact same reason. We're just as concerned with keeping fossil sites secret. Why invite competition? In fact, many museums (UCMP) and land management organizations (Bureau of Land Management, National Park Service, National Forest Service) expressly prohibit exact locality information to be published in order to prevent fossil poaching. I've also never heard of a museum openly sharing locality data online. Detailed locality data is generally only shared in an academic fashion, when a researcher needs to see all the field/locality notes associated with a particular fossil. So rest assured, your locality information is safe in the museum.
How, part VIII: fossils collected ex situ as float and reworked fossils
What if a fossil is clearly reworked (eroded from an older unit into a younger unit)? Simple: record the final stratum, note that it is likely reworked, and speculate what the original unit was. What about a fossil found on a beach or riverbank? There's essentially little contextual information left. In cases like this, you will be limited to the geographic position and the geologic data will be limited entirely to any matrix still stuck on the fossil itself - it's imperative to keep associated matrix in these cases.
The ideal situation - being able to reconstruct all of this from the notes of a paleontologist no longer with us. The geographic, stratigraphic, geochronologic, and environmental context of UCMP 86060, a periotic of Parapontoporia. From Boessenecker and Poust (2015).
Conclusion - or, the triumph of accurate field notes
As should be obvious by now, fossils are not simply
anatomical data points without context - matter of fact, the entire point of
this post is to ensure that fossils are properly collected with necessary data.
If that data doesn't exist, a fossil becomes exactly that: an context-less
anatomical data point. In other words, all we know of is the anatomy. To
conclude all this with a stellar example of why good field notes are important,
consider the case of UCMP 86060, a periotic
of the "river" dolphin Parapontoporia. We already have tons of
periotics (earbones) of Parapontoporia from elsewhere in California,
so finding another one is not groundbreaking. All fossils are curiously from
marine rocks, despite Parapontoporia being closely related to the recently
extinct Chinese river dolphin (Lipotes vexillifer). This fossil,
however, was recorded as being collected from the Tulare Formation of central California,
which is a nonmarine unit predominantly reflecting lacustrine and fluvial
deposition. I asked my buddy (and eventual coauthor on project) Ashley Poust, a
Ph.D. student at UC Berkeley, to look up the field notes. As it happens, it was
collected by former UCMP director J.T. Gregory, who collected it on October 3, 1963. His notes are very
detailed, and accurate to within a hundred meters or better - which was
critical in trying to figure out if this specimen actually was collected from
nearby marine rocks and misattributed to the Tulare.
Gregory's field notes were accurate and specific enough to exclude this and
other possibilities that the earbone was not from the Tulare Formation - which
led us to conclude the specimen, and its important sedimentary context,
actually reflected a dolphin inhabiting or at least dying in nonmarine rocks.
We were able to publish this fascinating little bone in the journal Palaeontology
earlier this year. Despite being collected over fifty years ago by a
paleontologist we couldn't talk to anymore, the notes associated with this
fossil were more than sufficient to permit publishing a marginally provocative
hypothesis that Parapontoporia - at least on occasion - was not a
strictly marine dolphin.
Lastly, I want to emphasize that these methods outlined
above may not work to everyone's preferences - and so I humbly request readers
to suggest their own tips. Any suggestions good enough will warrant inclusion
as additional text. I'm looking forward to hearing tips!
References
Boessenecker, R.W. and Poust, A.W. 2015. Freshwater occurrence of the extinct dolphin Parapontoporia (Cetacea: Lipotidae) from the upper Pliocene nonmarine Tulare Formation of California. Palaeontology 58:3:489-496.
Kidwell, S.M., Fursich, F.T., and Aigner, T. 1986. Conceptual framework for the analysis and classification of fossil concentrations. Palaios 1:228-238.
Parham, J.F. et al. 2012. Best practices for justifying fossil calibrations. Systematic Biology 61:346-359.
References
Boessenecker, R.W. and Poust, A.W. 2015. Freshwater occurrence of the extinct dolphin Parapontoporia (Cetacea: Lipotidae) from the upper Pliocene nonmarine Tulare Formation of California. Palaeontology 58:3:489-496.
Kidwell, S.M., Fursich, F.T., and Aigner, T. 1986. Conceptual framework for the analysis and classification of fossil concentrations. Palaios 1:228-238.
Parham, J.F. et al. 2012. Best practices for justifying fossil calibrations. Systematic Biology 61:346-359.
Excellent post!
ReplyDeleteA few more tips re: photos. Taking a snapshot (or, preferably, multiple) of every specimen at the time you collect it. This captures the state of the specimen as found, which can be useful if it gets damaged or rearranged later. Plus, these photos can help you relocate the exact place you found the specimen if you revisit the site, or jog your memory if you're trying to write up more detailed notes later on. If possible, get pictures of the specimen in situ, from moderate distance, marked with a hammer or field assistant or whatever is necessary to help you locate it on the outcrop. Bonus points if you can frame the shot so that you can see the specimen's position in relation to a major physical feature in the outcrop (key marker bed, fault, etc). If you're using a smartphone camera, adjust its settings so that GPS coordinates are stored in the photo metadata, for future reference.
For long term storage, I keep my photos in directories with names that contain both date and general locality information, usually with the format: {year}_{month}_{day}_{locality name}_{county}_{state}. For example, 2015_10_09_Rt_421_roadcut_north_of_Madison_Jefferson_Co_IN.
I've also started uploading all my fieldwork photos to Flickr---it's free, with 1TB of storage space, and lets me create organize, tag, and add descriptions. Having the photos online makes it easy to share them with colleagues and access them when I'm away from my main computer.
Thank you ....its been a delight reading your blog and will be reading much more of it in the future.
ReplyDeleteExcellent post - I'll be passing this along to our volunteers and students. Minor addition -- always record the datum used w/GPS coordinates (as well as the coordinate error, if your GPS gives it to you).
ReplyDeleteAnd for photos--include both close-ups of the fossil in-situ as well as a panoramic with something to mark the location of the fossil horizon. Last two comments pertain to the times I've gotten a close-up photo w/a datum-free GPS coordinate...almost (but not quite) as useless as no GPS or photo at all.
ReplyDeleteWould love to have a pdf of your cheat sheet checklist
ReplyDeleteVery useful blog for Palaeontology students.
ReplyDeleteDo you know Role of Palaeontology in Biotechnology
As a 'newbie' to the field I found this very helpful. I will certainly endeavour to follow the information that you have lad out.
ReplyDeleteMany Thanks