Me and My Fossils
by Liz Brosius

    Arranged along my windowsill, in shades of gray and brown, are assorted rocks, souvenirs of outings into Kansas history. Trapped within (or imprinted on) these limestones are the fossilized remains of creatures that lived millions of years ago in this spot we call Kansas.

    Kansas rocks are full of fossils, and most of these are the smaller creatures without backbones known as invertebrates: clams, crinoids and corals, to name a few common ones.

    For a year, I've had a chance to indulge my fascination with these ancient remains as I've worked on an overview of Kansas invertebrate fossils.

    Fossils are the remains or evidence of once-living plants and animals. Bone, shell, even tracks and burrows are considered fossils.

    Winding up as a fossil isn't easy; most life forms vanish without a trace. Those that make it generally have hard parts (bones in vertebrates, shells or external skeletons in invertebrates). For obvious reasons, hard parts hold up better than soft tissue, muscle, skin. But hard parts alone won't make you a fossil. It's also essential that you be buried quickly so that you won't be eaten by scavengers or attacked by bacteria or worn down by wind or wave.

    Typically, animals in water have a better chance of rapid burial than those on land because the soft ooze on the seafloor makes a good burial ground. Over millions of years, the seafloor sediments solidify into rock, entombing within them the remains of these ancient creatures.

    Which is why Kansas is a good place to find these fossils. In contrast to its current landlocked position, for long intervals in the distant past, Kansas was covered by shallow seas that extended across much of North America. Here at KU, for example, if we could travel back 300 million years ago (the age of most rocks that crop out in eastern Kansas), we'd find ourselves swimming in a warm, tropical sea full of exotic creatures like trilobites and crinoids, as well as more familiar looking clams, oysters and corals.

    To experts, Kansas fossils are a source of information about ancient life forms -- some long extinct -- and their connections to animals living today. Fossils also are clues about the climate and ecology of a particular locality many millions of years ago. They are valuable pieces of scientific evidence.

    But that's probably not why I continue to pile fossils on my windowsill. As an English major transplanted into the world of geology, I'm captivated by them because of the story they tell. Incomplete though the story may be, as fragmentary as a piece of an insect wing miraculously preserved in a 250-million-year-old rock from central Kansas, it's a story that fires the imagination. Fossils connect me to the deep history of the place, remind me of the brevity of human history on the planet and give me another way to know this place I call home.

    For more information on Kansas fossils, see the GeoKansas web site here.

Brosius is an assistant editor at the Kansas Geological Survey.