Wednesday, September 4, 2019

Correlating Fossils for Dummies

index fossils
Representative index fossils
Accompanying the basic lack of knowledge shown by many of the contributions to the former eHow.com¹, our staffers often find that the site's style demands also placed information and accuracy in jeopardy. Why? Because instead of providing a simple answer to a question, eHowians were forced to expand that answer out to several hundred words to meet the site's minimum word count. Many an author got the gist of then answer but cloaked it in such rubbish that it became wortheless... authors like Emma Woodhouse in her Sciencing.com post, "What Is Fossil Correlation?"

Before we go any farther, we'll answer the question: Fossil correlation is the use of the fossils found within and adjacent to a rock unit of unknown age to assign it a relative age. That's the basic, Historical Geology 100 meaning of "fossil correlation." That's twenty-five words, and you can find something to that effect buried within the 350-plus words Woodhouse published in her post. Where she went all bonkers is in the padding, padding that included such bogosity as
  1. "Usually only part of an organism becomes a fossil after the organism dies. This tends to consist of bones and teeth, rather than soft tissue."
  2. "Fossil correlation relies on geologists knowing the ages of certain planets [sic] and animals."
  3. "Index fossils must be found in a large number of areas, but only in a limited thickness of strata."
  4. "Ammonites are the best-known index fossils."
Our crack geological staff had some corrections for Woodhouse:
  1. It's not "bones and teeth," Emma, it's "hard parts." The vast majority of known fossils preserve the shells of animals, not their bones. That's because they didn't have bones.
  2. We suspect you meant "plants." And we would also like to point out that paleontologists know the ages of many, many, many plants and animals; not just "certain" ones.
  3. Instead of "limited thickness of strata," the definition of an index fossil includes a (relatively) brief lifespan. We know this is hard to understand, Emma; but "thickness of strata" is not the same as length of time, because rates of deposition vary widely.
  4. No, ammonites are a good example of an index fossil, but only in the Mesozoic (see image above). Other floating animals are useful in Paleozoic rocks, before the "explosion" of ammonites; and Cenozoic rocks, when they are extinct. Oh, and ammonites didn't have either bones or teeth...
Such is the danger of letting freelancers "expand" on information to meet an arbitrary word count. By demanding filler content, DMS² exponentially increased the likelihood that the contributor was going to say something that would win a Dumbass of the Day award like the one Emma just received.

¹ eHow.com isn't gone, it's just jumped on the "niche-site" bandwagon, parceling out much of its content into sites that are (supposedly) about a relatively narrow topic. Unfortunately, they didn't correct most of it...
² DMS = Demand Media Studios, parent company of eHow, now called Leaf Group. We always like to say that you can't spell "dumbass" without "DMS."
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SI - PALEONTOLOGY

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