Thanks to the seemingly ceaseless work by Edward Hitchcock in the nineteenth century, Amherst College houses one of the premier fossil footprint and track collections. Once stored in the basement of the Pratt Museum, an old gym, the 1,700 slabs of rock now rest in the college’s newer Beneski Museum. As I have mentioned elsewhere, I had the privilege of seeing those footprints in toto a number of times before they were moved from the Pratt basement. The image of someone in a very old gym basement looking at slabs of rocks with footprint impressions, might conjure the stereotype of a lonely nerd isolated from society by choice, particularly if that person returns to the subject of the footprints in a blog. But those footprints teach a lesson about the complex layers of our lives.
Morgan L Turner, Peter L. Falkingham, and Stephen M. Gatesy, authors of an article in Biology Letters, have examined Hitchcock’s collection in conjunction with experiments involving guineafowl walking through a muddy environment.* What they discovered is that tracks can be, well, misleading. The birds—and by extension, ancient animals—made two kinds of tracks, those made by a downward force and those made by an upward one: Toes going into and out of the mud. Such rocks lend themselves to cleavage, so Hitchcock separated the footprint-bearing rock into layers that reveal stratigraphic “horizons.” Long before the development of computer-generated images of 3D phenomena, Hitchcock laid out an actual 3D example of the process in “pages” of shales and siltstones he put in “three-ring binders (see video link below).**
In short, both guineafowl and dinosaurs stepped into and out of mud in a “looping” fashion. What appears on the surface as a modern or fossil track is just part of the story. There is an underlying tale to be told. A single species can make multiple kinds of tracks, some represented by the foot going in and others by the foot going out. The air-surface layer isn’t the only place where animals make tracks in soft sediments though that layer is the one often interpreted. Erosion of the original surface and subsequent preservation of a lower layer might reveal a “different looking” track from that made on the surface layer.
What’s this have to do with you—or with anyone else? In our lives we make impressions by our actions. For the most part, only the “surface” track is apparent to others. But for any past action, the going into was accompanied by the going out of; stepping in was always accompanied by the loop of stepping out or withdrawing. When you look back on your own life, what “horizon” or layer of the step do you see? What layer do you see in the tracks of others’ lives? Remember that every step is a complex one, a looping one. The movement outward also makes a track though very few of us pay attention to that “footprint.”
*Morgan L Turner, Peter L. Falkingham, and Stephen M. Gatesy 2020It's in the loop: shared sub-surface foot kinematics in birds and other dinosaurs shed light on a new dimension of fossil track diversity Biol. Lett.1620200309 http://doi.org/10.1098/rsbl.2020.0309
https://www.sciencedaily.com/releases/2020/07/200701125504.htm
**There is a video on the subject of “Hitchcock’s Track Book” by Alfred J. Venne, the museum’s curator. In Impressions from a Lost World: Edward Hitchcock’s Track Book, Venne explains the process that Turner et al. studied in guineafowl. https://dinotracksdiscovery.org/static/special/video/media/venne-track-book.mp4
Morgan L Turner, Peter L. Falkingham, and Stephen M. Gatesy, authors of an article in Biology Letters, have examined Hitchcock’s collection in conjunction with experiments involving guineafowl walking through a muddy environment.* What they discovered is that tracks can be, well, misleading. The birds—and by extension, ancient animals—made two kinds of tracks, those made by a downward force and those made by an upward one: Toes going into and out of the mud. Such rocks lend themselves to cleavage, so Hitchcock separated the footprint-bearing rock into layers that reveal stratigraphic “horizons.” Long before the development of computer-generated images of 3D phenomena, Hitchcock laid out an actual 3D example of the process in “pages” of shales and siltstones he put in “three-ring binders (see video link below).**
In short, both guineafowl and dinosaurs stepped into and out of mud in a “looping” fashion. What appears on the surface as a modern or fossil track is just part of the story. There is an underlying tale to be told. A single species can make multiple kinds of tracks, some represented by the foot going in and others by the foot going out. The air-surface layer isn’t the only place where animals make tracks in soft sediments though that layer is the one often interpreted. Erosion of the original surface and subsequent preservation of a lower layer might reveal a “different looking” track from that made on the surface layer.
What’s this have to do with you—or with anyone else? In our lives we make impressions by our actions. For the most part, only the “surface” track is apparent to others. But for any past action, the going into was accompanied by the going out of; stepping in was always accompanied by the loop of stepping out or withdrawing. When you look back on your own life, what “horizon” or layer of the step do you see? What layer do you see in the tracks of others’ lives? Remember that every step is a complex one, a looping one. The movement outward also makes a track though very few of us pay attention to that “footprint.”
*Morgan L Turner, Peter L. Falkingham, and Stephen M. Gatesy 2020It's in the loop: shared sub-surface foot kinematics in birds and other dinosaurs shed light on a new dimension of fossil track diversity Biol. Lett.1620200309 http://doi.org/10.1098/rsbl.2020.0309
https://www.sciencedaily.com/releases/2020/07/200701125504.htm
**There is a video on the subject of “Hitchcock’s Track Book” by Alfred J. Venne, the museum’s curator. In Impressions from a Lost World: Edward Hitchcock’s Track Book, Venne explains the process that Turner et al. studied in guineafowl. https://dinotracksdiscovery.org/static/special/video/media/venne-track-book.mp4
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