The Man on the Hill: A Geologic Mystery Solved over Breakfast

A historic photo from my hometown opens up a mystery of geologic proportions.

This is an old post that was found on my previous website. I am archiving it here, it was originally published in December 2015.

This morning, while enjoying my breakfast, drinking coffee, and reading my hometown newspaper, The Nephi Times-News, I was intrigued by an old photo of an unidentified man, wearing dusty overalls and standing on an outcrop of rock in the foothills of a mountain. Behind him, a large “N” emblazoned on the hill. The photo was ran by the newspaper as part of their “Blast from the Past” feature, essentially a #ThrowbackThursday featuring vintage images of people and the area brought in by members of the community. (As a sidenote that really has nothing to do with this post other than the fact that I’m still reading my hometown paper, the Times-News has been run by my family for ~5 generations, my father and sister are currently the Publisher and Editor, respectively.)

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The photo caught my eye. It is a captivating image in itself. I’ll never know who the man is. But the geologist in me is wondering where he is and what he is doing. So, I poured myself another cup of coffee and decided to chase this little mystery.

I grew up in Nephi, Utah (a small community of around 5,000 people), in the shadow of Mount Nebo. Mt. Nebo is the southernmost and also the tallest mountain of the Wasatch Range (at a modest elevation of 11,928 ft/3,636 m above sea level). I’d recognize Nebo anywhere, having spent a lot of time hiking its lower slopes, playing in its canyons, and admiring its geology and wilderness. Nebo is like an old friend that never changes (well, incrementally changes over geologic time, anyways).

The mountain in the far background of the image is Nebo’s southern slope, and is what is most visible to the residents of Nephi (the actual peak is farther north, closer to Mona, Utah).

Now, non-westerners might be wondering, what’s up with the “N” on the hill? Something that was so common to me growing up in Utah is like some wacky mystery to others not from a mountainous region (this is based upon my experience in the midwest). So, to give a quick and dirty explanation: in most cases in Utah, the letters represent the nearest highest-level school. For example, if you find yourself in Provo, Utah, the highest-level school is Brigham Young University, symbolized by a giant “Y” on the hill. In Nephi, the highest-level school is the local high school. It’s just some way of establishing territory/dominance/school pride by the local community.

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The current “J” on the hill for Juab High School, Nephi, Utah

According to The Times-News, the “N” stands for Nephi High School, which was the name of the school until 1932, when it was changed to Juab High School (for Juab County), my alma mater. (Go Wasps!) So that gives this image a minimum age of 1932. Mystery 1 solved, sort of. I’m sure someone could analyze his clothing or hairstyle, or the type of film used to figure out a more precise age of the photo, but out of my realm.

Mystery 2: the placement of the “N.” What was most obvious to me is that the “N” is in the wrong place. Now, of course the “N” isn’t there anymore; when it changed to JHS obviously the letter on the hill was changed to a “J” where still today the seniors of the high school give it a fresh coat of paint each year during homecoming week. But the “J” is on a much lower hill, closer to the freeway. This “N” seems higher, and doesn’t feel right to me. Where is it exactly? Enter Google Earth. Using the shape of Nebo and the foothills, and exposed geologic outcrops, I figured it out. Although the image is in black and white, there is a obviously change in the texture and color along the lower left of the hill and it’s lower slopes. The “N” is obviously on the that flattened/smooth part of the hill spur, far away from where the current “J” is! Mystery 2: solved definitely!

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Mystery 3: Where is the man and why is he so dusty? My first inclination is that he’s mining gypsum. At the mouth of Salt Creek Canyon (which runs east of Nephi, through the mountains south of Nebo and into Sanpete Valley), there is a gypsum mine that has been operational since its discovery in 1889. However, this man is not at the large gypsum mine, but at some small outcrop north of the mine in the canyon. I pinpointed my guess of his location below.

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Thankfully, the Utah Geological Survey provides interactive topographical geologic maps, so one I had used Google Earth to approximate his location, it was very easy to see that he was standing in a smaller, northern exposure of the same gypsum deposits, which are in the Arapien Shale. The Arapien Shale is middle Jurassic in age, and comprises mudstones, shales and some limestones rich with evaporites, such as salt and gypsum. Pioneers that first settled the area noted the salty creek (hence Salt Creek Canyon), and traced the origin of the salt back to some of these salt deposits in the Arapien, where they are also mined in addition to the gypsum.

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The interesting thing about the Arapien Shale is that it was severely deformed and twisted during the Sevier Orogeny (mountain-building) event that created the Wasatch mountains during the Cretaceous and Tertiary. Some of the thrusting and folding (yes, I am aware of all of the geologic innuendo!) caused the Arapien Shale to break and be thrust upon itself, causing some repeated sequences that were then uplifted and exposed, thus creating the lucrative mining operations for the Nephi community and mining companies.

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Likely this guy was a miner for one of these salt or gypsum operations in the early 1900s. Maybe he was exploring some of these northern deposits, in hopes of staking a mining claim of his own? As far as I know, the gypsum is really more lucrative on the south side of the canyon, and I’m unaware of any mines to the north of the canyon in the southermost foothills of Nebo, though I do know that there are some other mines on the western slopes of Nebo (because I went sledding there as a kid).

So that’s that. A seemingly simple photo of a man, but teeming with geological conundrums, Utah pioneer history, and an answer that seems obvious to any Nephite that might be reading this post. But it was fun to solve anyways.

Back to my coffee.

New Paper: Evolution of multicuspid teeth in a Triassic fish from Utah

An enigmatic holostean from the Triassic of Utah possesses an unusual tooth morphology. What was the purpose of these teeth?

This is an old post I am archiving here on my website. It was originally posted on the KU Biodiversity Institute blog in February 2015.

Just yesterday, my newest paper was published online in the journal The Science of Nature: Naturwissenschaften about a rather unusual fish from the Upper Triassic Chinle Formation of southeastern Utah. The fish, Hemicalypterus weiri, was a deep-bodied, disc-shaped fish, with enameled ganoid scales covering the anterior portion of its flank, and a scaleless posterior half, which presumably aided in flexibility while swimming. Although Hemicalypterus was first described in the 1960s (Schaeffer, 1967), recent collecting trips recovered many new specimens of Hemicalypterus, and I decided to reinvestigate this enigmatic fish as part of my dissertation research.

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Holotype of Hemicalypterus

While cleaning specimens of Hemicalypterus at the University of Kansas Vertebrate Paleontology prep lab, I noticed rather unusual teeth on the lower jaw that I had exposed from the rock matrix. These teeth look like a mouthful of little forks, and there were at least six individual teeth on the lower jaw. As I prepared other specimens, I found that these teeth were also on the premaxillae. Each tooth has a long cylindrical base and a flattened, spatulate edge with four delicate, individual cusps. I hadn’t seen anything like this before in other fossil fishes, and so I started searching the literature and talking to other ichthyologists.

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Multicuspid teeth of Hemicalypterus

Well, as it turns out, this tooth morphology has evolved multiple times in several independent lineages of teleost fishes, and quite often fishes with similar dentition scrape algae off of a hard substrate. These teeth indeed act like little forks (or “sporks” might be more appropriate) for these herbivorous/omnivorous fishes. Examples of extant fishes with similar teeth include freshwater forms such as the algae-scraping cichlids and characiforms, as well as many marine forms that are key in controlling algae growth in coral reef environments, such as acanthurids (surgeonfishes, tangs) and siganids (rabbitfishes). Of course, these modern-day fishes also feed on other things (e.g., phytoplankton), but algae is often the primary staple, and these fishes use this specialized dentition for a specific feeding behavior.

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Multicuspid teeth of Labeotropheus, an algae-scraping cichlid.

So while it is impossible to prove definitively what a species of fish that lived over 200 million years ago fed upon (without gut contents being preserved….or a time machine), it is still safe to infer that Hemicalypterus occupied an ecological niche space similar to algae-scraping cichlids or other modern-day herbivorous fishes and may have scraped algae off of a hard substrate, based on this unusual tooth morphology and its similarity to modern forms.

This discovery also extends evidence of herbivory in fishes clear back to the Early Mesozoic, whereas prior to this discovery it was assumed that herbivory evolved in the Middle Cenozoic in marine teleost fishes. Frankly, there was no evidence to say otherwise, as most Mesozoic fishes have general caniniform or styliform (peg-like) teeth, or they have heavy crushing or pavement-like teeth consistent with crushing hard-shelled organisms. The teeth of Hemicalypterus are very delicate, and wouldn’t really do well with durophagy. This is the first potential evidence of herbivory in the Mesozoic, and in a non-teleost, ray-finned fish.

Original Source: Gibson, S.Z. 2015. Evidence of a specialized feeding niche in a Late Triassic ray-finned fish: evolution of multidenticulate teeth and benthic scraping in †Hemicalypterus. The Science of Nature — Naturwissenschaften 102:10.

Also cited: Schaeffer, B. 1967. Late Triassic fishes from the western United States. Bulletin of the American Museum of Natural History 135: 289–342.

Behind the Research: Identifying a New Species of Fossil Fish

How does a paleontologist identify a new species?

This is an old post I am archiving here on my website. It was originally posted on the KU Biodiversity Institute blog in October 2014.

A fundamental part of being a scientist is publishing your research. Scientists ask questions, formulate hypotheses, rigorously test these hypotheses, and publish their research and their results. Other people can then read these results and build off of these studies, either to question or refute the findings, or to use the findings to ask other questions. It is how science grows and evolves.

What almost all scientific publications lack, however, is the flair, the backstory, and general behind-the-scenes action that is part of everyday research. Scientific publications are whittled down to the most concentrated version, filled with the jargon of the discipline, and stripped of any extraneous behind-the-scenes anecdotes. So while any given scientific paper can be exciting to a scientist who wants to learn more about the organism or the methods addressed, they can be a bit unfriendly to a general reader.

So for fun, I have decided to tell some behind-the-scenes stories of the research I do, in the context of my published papers. Hopefully I give you a sense of what it is really like to be a paleontologist, and the work that is involved.

I’ll begin with my two solo-authored papers that I published in 2013. The papers can be found here and here, and if you cannot access those journals, please contact me and I will send you a PDF.

These two papers establish a new genus and two new species of fishes within a group called semionotiforms. Semionotiforms are an extinct group of fishes, but are closely related to living gar, and like gar, their bodies were covered with thick enamel scales (ganoid scales). Semionotiforms are found in geologic deposits worldwide, and range in age from Middle Triassic (~237 million years ago) to Early Cretaceous (~145 million years ago). A lot of variety occurs in semionotiforms in the shape of the body, the characteristics of the skull, the teeth, etc., and part of my research is to figure out what makes these particular fishes different from other species that have been described in the literature by other scientists. So you could say that my hypothesis for these studies is that these fishes represent new species, and I am testing that hypothesis by comparing the anatomy and morphology of these fishes to other semionotiform fishes to see if my hypothesis is correct or incorrect.

Some of the fossil specimens I work on are from museum collections, such as the American Museum of Natural History (AMNH) and the Smithsonian and were collected in the 1950s and 1960s, yet remained in these collections unstudied and undescribed for decades. I began working on these fishes in 2006, when I worked at the St. George Dinosaur Discovery Site (SGDS) as an undergraduate student intern and later as the prep lab and collections manager. The crew of staff and volunteers from SGDS had just gone out to a site in southeastern Utah and collected hundreds of fossils (outlined in Milner et al., 2006), but most of these fishes were not identified. So as I started cleaning the fossils (fossil prep—to be discussed in a later blog!), I started looking for characteristics that defined them as either new or belonging to a described species of semionotiform fish. While I worked on the new specimens, I looked at older literature, in particular a (1967) paper by an AMNH paleontologist Bobb Schaeffer, who mentioned collecting many semionotiforms from the same area but didn’t describe them or give them names. So, in 2008, I went to the collections of the AMNH to look at those old specimens collected decades before and reexamined them, seeing which of them could be the same species as the new specimens the SGDS crew had just collected. I identified at least two different species, though there are likely more than that.

Now, identifying a new species is more than just a “Eureka!” moment. A scientist cannot know what is new unless he/she knows what already exists, and so scientists have to be very familiar with other scientists’ work in the field. An inordinate amount of any scientist’s time is spent reading books and papers, and I spent months pouring over scientific literature, some as old as 1820, to find the characteristics of other semionotiforms. As I looked at each bone on the fossil fishes from the AMNH and those newly collected from SGDS, I compared it to the same bones in other semionotiform fishes, and I had to look for similarities and differences. Eventually, I found a suite of anatomical and morphological characters that distinguished these fishes from all other semionotiform fishes, and I had enough to publish two papers on two distinct species. In these papers, I had to give an exhaustively detailed description of every single bone, and I mean EVERY bone (these fishes have hundreds of bones, dozens in their skull alone!) that I could see on the specimens, because other scientists, when trying to identify new species of their own, may turn to my work for comparison, and so my papers have to be provide as much anatomical detail as possible!

Next time….naming a new species!!

References

Gibson, S.Z. 2013a. A new hump-backed ginglymodian fish (Neopterygii, Semionotiformes) from the Upper Triassic Chinle Formation of southeastern Utah. Journal of Vertebrate Paleontology 33: 1037–1050. 

Gibson, S.Z. 2013b. Biodiversity and evolutionary history of †Lophionotus (Neopterygii: †Semionotiformes) from the western United States. Copeia 2013: 582–603.

Milner, A.R.C., Mickelson, D.L., Kirkland, J.I., and Harris, J.D. 2006. Reinvestigation of Late Triassic fish sites in the Chinle Group, San Juan County, Utah: new discoveries. In: A Century of Research at Petrified Forest National Park: Geology and Paleontology (Eds. Parker, W.G., Ash, S.R., and Irmis, R.B.). Museum of Northern Arizona Bulletin 62: 163–165.

Schaeffer, B. 1967. Late Triassic fishes from the western United States. Bulletin of the American Museum of Natural History 135: 289–342.