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Wooster’s Fossil of the Week: A Middle Jurassic trace fossil from southwestern Utah

November 10th, 2017

1 Gyrochorte 2 CarmelTime for a trace fossil! This is one of my favorite ichnogenera (the trace fossil equivalent of a biological genus). It is Gyrochorte Heer, 1865, from the Middle Jurassic (Bathonian) Carmel Formation of southwestern Utah (near Gunlock; locality C/W-142). It was collected on an Independent Study field trip a long, long time ago with Steve Smail. We are looking at a convex epirelief, meaning the trace is convex to our view (positive) on the top bedding plane. This is how Gyrochorte is usually recognized.
2 Gyroxhorte hyporelief 585A quick confirmation that we are looking at Gyrochorte is provided by turning the specimen over and looking at the bottom of the bed, the hyporelief. We see above a simple double track in concave (negative) hyporelief. Gyrochorte typically penetrates deep in the sediment, generating a trace that penetrates through several layers.
3 Gyrochorte Carmel 040515Gyrochorte is bilobed (two rows of impressions). When the burrowing animal took a hard turn, as above, the impressions separate and show feathery distal ends.
4 Gyrochorte 585Gyrochorte traces can become complex intertwined, and their detailed features can change along the same trace.
5 Gibert Benner fig 1This is a model of Gyrochorte presented by Gibert and Benner (2002, fig. 1). A is a three-dimensional view of the trace, with the top of the bed at the top; B is the morphology of an individual layer; C is the typical preservation of Gyrochorte.

Our Gyrochorte is common in the oobiosparites and grainstones of the Carmel Formation (mostly in Member D). The paleoenvironment here appears to have been shallow ramp shoal and lagoonal. Other trace fossils in these units include Nereites, Asteriacites, Chondrites, Palaeophycus, Monocraterion and Teichichnus. (I also ran into Gyrochorte in the beautiful Triassic of southern Israel.)

So what kind of animal produced Gyrochorte? There is no simple answer. The animal burrowed obliquely in a series of small steps. Most researchers attribute this to a deposit-feeder searching through sediments rather poor in organic material. It may have been some kind of annelid worm (always the easiest answer!) or an amphipod-like arthropod. There is no trace like it being produced today.

We have renewed interest in Gyrochorte because a team of Wooster Geologists is going to southern Utah this summer to work in these wonderful Jurassic sections.
6 Heer from ScienceOswald Heer (1809-1883) named Gyrochorte in 1865. He was a Swiss naturalist with very diverse interests, from insects to plants to the developing science of trace fossils. Heer was a very productive professor of botany at the University of Zürich. In paleobotany alone he described over 1600 new species. One of his contributions was the observation that the Arctic was not always as cold as it is now and was likely an evolutionary center for the radiation of many European organisms.

References:

Gibert, J.M. de and Benner, J.S. 2002. The trace fossil Gyrochorte: ethology and paleoecology. Revista Espanola de paleontologia 17: 1-12.

Heer, O. 1864-1865. Die Urwelt der Schweiz. 1st edition, Zurich. 622 pp.

Heinberg, C. 1973. The internal structure of the trace fossils Gyrochorte and Curvolithus. Lethaia 6: 227-238.

Karaszewski, W. 1974. Rhizocorallium, Gyrochorte and other trace fossils from the Middle Jurassic of the Inowlódz Region, Middle Poland. Bulletin of the Polish Academy of Sciences 21: 199-204.

Sprinkel, D.A., Doelling, H.H., Kowallis, B.J., Waanders, G., and Kuehne, P.A., 2011, Early results of a study of Middle Jurassic strata in the Sevier fold and thrust belt, Utah, in Sprinkel, D.A., Yonkee, W.A., and Chidsey, T.C., Jr. eds., Sevier thrust belt: Northern and central Utah and adjacent areas, Utah Geological Association 40: 151–172.

Tang, C.M., and Bottjer, D.J., 1996, Long-term faunal stasis without evolutionary coordination: Jurassic benthic marine paleocommunities, Western Interior, United States: Geology 24: 815–818.

Wilson. M.A. 1997. Trace fossils, hardgrounds and ostreoliths in the Carmel Formation (Middle Jurassic) of southwestern Utah. In: Link, P.K. and Kowallis, B.J. (eds.), Mesozoic to Recent Geology of Utah. Brigham Young University Geology Studies 42, part II, p. 6-9.

[An earlier version of this article was posted on April 17, 2015.]

West Antarctic mantle plumes: A lesson in ice flow and science communication

November 9th, 2017

Newsweek published a scary-looking headline yesterday: “NASA DISCOVERS MANTLE PLUME ALMOST AS HOT AS YELLOWSTONE SUPERVOLCANO THAT’S MELTING ANTARCTICA FROM BELOW.” It’s a scary idea, right? That heat that drives Yellowstone’s steam vents, boiling hot springs, and explosive geysers is sitting under Antarctica, and scientists didn’t even know about it?? It has certainly generated some discussion in our department. But don’t panic yet – scientists have been aware for decades of volcanic activity under West Antarctica, and it’s not nearly as hot as the article would like you to think.

The Newsweek article goes on to explain some of the details of a study that was published last month in the Journal of Geophysical Research: Solid Earth (Seroussi et al., 2017). The study used an ice flow model to try to capture the ice dynamics of West Antarctica as accurately as possible, and then used that model to glean some details about how much heat is being released through the ground (that’s called the “geothermal heat flux”) under the West Antarctic Ice Sheet.

What they found is both unsurprising and important. West Antarctica has a much higher heat flux than surrounding areas, because there is hot mantle rock near the surface driving volcanic activity. That’s hardly a secret in glaciology – for example, it was an important consideration in this study by J. Weertman from 1982. Ice flow models of the area have always had to take into account this warming of the base of the ice to accurately model how easily the ice slides and deforms. What this new paper brings us is some more accuracy to use in our models. It gives us more reliable numbers for just how much heating there is and where it is concentrated, so we can make our ice flow models more accurate. Specifically, the authors calculate that the mantle plume is bringing up to 150 milliwatts of heat per square meter to the base of the West Antarctic Ice Sheet, with isolated areas perhaps getting to 180 milliwatts of heat per square meter.

What this article really gives us is a lesson in science communication and how a story can be easily hyped into something much scarier than it is. The Newsweek article uses two images – the first is of part of West Antarctica (Mari Byrd Land, by NASA/Michael Studinger), and the second of the Grand Prismatic Hot Spring in Yellowstone (by Mark Ralston/AFP/Getty Images):

                  

Putting these two images next to each other evokes some strong reactions. If you put ice on top of that hot spring, it’s going to melt – FAST!! The problem is, the heat flux numbers in Seroussi et al. (2017) don’t come anywhere near the heat flux you’d get at Grand Prismatic Spring. According to the USGS, some of Yellowstone’s thermal areas have heat fluxes of over 100 watts per square meter. Seroussi et al. (2017) measured heat flux under West Antarctica in milliwatts – 1000x smaller than a watt. So that picture of Grand Prismatic Spring probably represents a heat flux of something like 100,000 milliwatts per square meter, while the ice in the other picture is sitting on top of 150 milliwatts per square meter.

Now, you could argue averages with me – even if 150 milliwatts per square meter is the average, there could be some areas that are much hotter, just like in Yellowstone. The evidence really isn’t there for that, however. If a region under the ice did have a heat flux of 100,000 milliwatts per square meter, it would be hard to miss. I haven’t built the models, but we would expect obvious aberrations in ice flow and water discharge in the area, which isn’t consistent with our observations. It’s more likely that it’s a bit warmer in some areas and a bit cooler in others, but we aren’t going to find Grand Prismatic Spring under Antarctica.

Furthermore, while this is a new study that uses an impressive set of models to show that a mantle plume is likely causing the heat flux, it is hardly a new discovery that the ground is relatively warm under West Antarctica. Heat flux is already included in the models, and scientists are always working to refine their estimates and increase model accuracy. But regardless of the discovery, it’s always important to read scientific news articles critically, to understand if their main points are scientifically reasonable, or if there’s a spin to get you to click on the article. In this case, it’s the latter.

 

 

#GSA2017 Wrap Up

November 4th, 2017

It’s hard to believe that we were at the 2017 GSA Annual Meeting in Seattle, Washington just last week. Once again, the Wooster Geologists had a strong showing.

Macy Conrad (’18) kicked off our student presentations on Sunday with a poster on the paleoecology of encrusting sclerobionts in the Type Campanian of southwestern France. You can read more about Macy’s work in this Fossil of the Week blog post.

Brandon Bell (’18) followed Macy on Monday with his poster on the American scientific and cultural interaction with Japan and Europe after the 1906 earthquake. Brandon learned how historical methods can be used to study geologic phenomena like earthquakes and landslides.

You may remember Keck Geology Team Utah from their summer research exploits. They are Addison Thompson (’20, Pitzer), Madison Rosen (’19, Mt. Holyoke), Emily Randall (’20, Wooster), and Sam Patzkowsky (’20, Franklin and Marshall). At GSA, they presented the results of their research on dating young lava flows in the Black Rock Desert in Utah.

The intrepid Keck Geology Team Alaska, who also blogged about their summer research experiences, presented their dendrochronology research on declining yellow cedar and correlations with climate. They are Chris Messerich (’20, Washington and Lee), Malisse Lummus (’20, Trinity), Alora Cruz (’20, Macalester), and Josh Charlton (’19, Wooster).

Even our own Dr. Wilson had a poster presentation. His research on the bioerosion of oysters in the Type Campanian of southwestern France was the counterpart to Macy’s presentation.

As always, we had a fantastic alumni gathering where we caught up with recent graduates and former Wooster Geologists who have done wonderful things in their careers. Our students had an opportunity to interact with current graduate students, new geology department chairs, and emeritus faculty who specialize in paleontology, sedimentology, geochemistry, oceanography, and a vast range of Earth sciences. Once a Wooster Geologist, always a Wooster Geologist.

 

Wooster’s Fossils of the Week: The tiniest of brachiopods (Middle Jurassic of Utah)

November 3rd, 2017

While preparing for this summer’s expedition to the Middle Jurassic of southwestern Utah, I found this specimen in our collection from the 1990s. You may be able to just make out the wedge-shaped outline of a mytilid-like bivalve with several cup-like oysters (Liostrea strigilecula of oyster reef and oyster ball fame) encrusting the shell exterior. This specimen, labeled EM-1, is from our Eagle Mountain exposure of Member D, Carmel Formation, near Gunlock, Utah.

If you look very closely near the middle of the clam, you will see some super-small encrusting shells the size of sand grains. Two are shown above, photographed with all the extension tubes on my camera. Believe it or not, these are shells of thecideide brachiopods, among the smallest known. They are, as far as I can tell, the only brachiopods thus far recorded from the Carmel Formation. They are abundant in this unit, encrusting carbonate hardgrounds as well as shells.

We know who these minuscule critters are from the careful analysis of their interiors by my colleague Peter Baker at the University of Derby. They are, in fact, the first thecideide brachiopods to be described from the Jurassic of North America. We published a description of them in 1999, naming them as the new genus and species Stentorina sagittata. The etymology of the genus name: “From the Greek Stentor (herald, of the Trojan War) in recognition of the first discovery of thecideoid brachiopods in the Jurassic of North America.” How’s that for classical drama about an itty-bitty brachiopod? We said of the new species name: “From the way the edges of the hemispondylium converge on the median ridge to form a characteristic arrowhead-shaped structure on the floor of the ventral valve.” Sagittate means arrowhead-shaped.

I’m looking forward to more paleontological treasures from the Carmel Formation of southern Utah.

References:

Baker, P G. and Wilson, M A. 1999. The first thecideide brachiopod from the Jurassic of North America. Palaeontology 42: 887-895.

Carlson, S.J. 2016. The evolution of Brachiopoda. Annual Review of Earth and Planetary Sciences 44: 409-438.

Wooster’s Fossils of the Week: Bryozoan encrusting a bryozoan (Campanian of southwestern France)

October 27th, 2017

Today’s post is in honor of Macy Conrad’s (Wooster ’18) poster at the annual meeting of the Geological Society of America, which was held earlier this week. It is also to recognize again the Scanning Electron Microscopy (SEM) genius of our friend Paul Taylor (Natural History Museum, London). The scene is the curving bryozoan ?Oncousoecia sp. encrusting the bifoliate erect bryozoan known as Onychocella aglaia (d’Orbigny, 1851). The specimen is from the Biron Formation (Upper Campanian,Upper Cretaceous), at Cailleau on the north side beneath fishing carrelets near Talmont-sur-Gironde, Charente Maritime, France. We collected from this location this past summer on our wonderful French paleontological expedition. This image comes from a fantastic library of Type Campanian encrusting bryozoan SEM photographs Paul gave us for our identifications in the Wooster lab. I especially like encrusters on encrusters.

This encrusting ?Oncousoecia is, as you can tell from the question mark, not placed for certain in this cyclostome genus, but it is similar to other known examples. This is a closer view of its ancestrula, the first zooid. You can also see pseudopores in the skeleton. The underlying Onychocella aglaia (d’Orbigny, 1851) is a cheilostome bryozoan. This is another reason I find this view interesting: Our larger project examines the dynamics of cyclostome and cheilostome distribution in the Campanian.

This image of Macy’s GSA poster is only symbolic because it is way too small to read. It at least conveys Macy’s neat organization and colorful images. You can read her published abstract on the GSA site. Nice work, Macy, and a major milestone on your way to completing your Independent Study thesis.

References:

Agostini, V., Ritter, M., Macedo, A., Muxagata, E., and Erthal, F., 2017, What determines sclerobiont colonization on marine mollusk shells? PLOS ONE, v. 12, doi.org/10.1371/journal.pone.0184745.

Neumann, M., Platel, J.-P., Andreiff, P., Bellier, J.-P., Damotte, R., Lambert, B., Masure, E., and Monciardini, C., 1983, Le Campanien stratotypique: étude lithologique et micropaléontologique: Géologie Méditerranéenne, v. 10, p. 41-57.

Platel, J.-P., Célerier, G., Duchadeau-Kervazo, C., Chevillot, C., and Charnet, F., 1999, Notice explicative, Carte géologie France (1/50 000), feuille Ribérac, Orléans, BRGM, 103 p.

Taylor, P.D. and Wilson, M.A. 2003, Palaeoecology and evolution of marine hard substrate communities: Earth-Science Reviews, v. 62, p. 1-103.

Taylor, P.D. and Zatoń, M. 2008. Taxonomy of the bryozoan genera Oncousoecia, Microeciella and Eurystrotos (Cyclostomata: Oncousoeciidae). Journal of Natural History, v. 42, p. 2557-2574.

Wooster’s Fossils of the Week: Foraminifera clustered around a sponge boring (Campanian of southwestern France)

October 20th, 2017

If all goes to plan, today I leave for the Annual Meeting of the Geological Society of America, held this year in Seattle, Washington. To mark the occasion, this week’s fossil is from a poster Macy Conrad (’18), Paul Taylor (Natural History Museum, London) and I are presenting on Tuesday at the meeting. It comes from our delightful work in southwestern France this summer. There we explored the Type Campanian (Upper Cretaceous) and collected bucketfuls of the oyster Pycnodonte vesicularis. We’ve been studying the sclerobionts on these oysters ever since.

Above are two bore holes formed by a clionaid sponge, making the trace fossil Entobia. A group of foraminiferans has encrusted around one of the holes, making a kind of chimney. Bromley and Nordmann (1971) described a nearly identical occurrence from the Maastrichtian (Upper Cretaceous) of Denmark. It is likely the forams grew around the hole to take advantage of the sponge’s feeding currents, thus making this another example of symbiosis in the fossil record.

I know you can’t actually read this poster, one of a pair Macy and I are presenting, but at least you can see its colorful arrangement! Here’s a link to the abstract. In a later blog post you’ll see the second poster on which Macy is the senior author. My second presenting senior, Brandon Bell, will also get his moment of blog fame soon.

The Geology Department faculty hopes to have numerous posts from the GSA meeting, so more to come!

References:

Breton, G. 2017. Les sclérobiontes des huîtres du Cénomanien supérieur du Mans (Sarthe, France). Annales de Paléontologie 103: 173-183.

Bromley, R.G. and Nordmann, E. 1971. Maastrichtian adherent foraminifera encircling clionid pores. Bulletin of the Geological Society of Denmark 20: 362-368.

Coquand, H. 1858. Description physique, géologique, paléontologique et minéralogique du département de la Charente: Besançon, Dodivers, 420 p.

Platel, J.-P. 1996. Stratigraphie, seédimentologie et évolution géodynamique de la plate-forme carbonatée du Crétacé supérieur du nord du basin d’Aquitaine. Géologie de la France 4: 33-58.

Taylor, P. and Wilson, M. 2003. Palaeoecology and evolution of marine hard substrate communities. Earth-Science Reviews 62: 1-103.

Wooster’s Fossils of the Week: “Ghosts” in the Upper Ordovician of Kentucky

October 13th, 2017

This year Caroline Buttler (Department of Natural Sciences, Amgueddfa Cymru – National Museum Wales) and I had a great project describing a cave-dwelling fauna in the Upper Ordovician of northern Kentucky. We hope that work will appear soon in the Journal of Paleontology. During our lab studies of thin-sections and acetate peels of massive trepostome bryozoans, we found several examples of clear calcite bodies in the middle of sediment-filled borings. These structures were described from the Ordovician of Estonia as “ghosts” of soft-bodied organisms by Wyse Jackson and Key (2007). They appear to be mineralized casts of organisms that were buried when sediment filled the borings that they occupied.

Meanwhile, Luke Kosowatz (’17) has a senior Independent Study project assessing bioerosion in the Upper Ordovician of the Cincinnati area. He and I have also found numerous examples of these ghosts in borings, so many that they have become a phenomenon in themselves for study. Above is an acetate peel made tangentially to the bryozoan surface showing the numerous tubular zooecia punctured by a few larger borings. Most of these borings are filled with sediment, but the two indicated by the arrows have these calcitic ghosts. This specimen is from the Corryville Formation near Washington, Mason County, Kentucky (38.609352°N latitude, 83.810973°W longitude; College of Wooster location C/W-10).

Above is one of our many heavily-bored trepostome bryozoans. This one comes from the Bellevue Formation (Katian) exposed on Bullitsville Road near the infamous Creation Museum (C/W-152). The irregular holes are the cylindrical boring Trypanites. The ghosts are not visible without sectioning.

Here is a close view of one of the ghostly calcitic casts in an acetate peel. The boundaries are sharp between the ghosts and the surrounding sediment.

The arrows above show ghosts in longitudinal cross-sections. Note their extended oval shapes. These are clearly organic shapes under these circumstances. (This is a thin-section.)

So what do the ghosts represent? They could be remains of the boring organisms themselves. If they are, they can be used to address a problem we have with bioerosion: What is the temporal relationship between the borings? How many were active in a given substrate at a given time? The percentage of borings with ghosts may give us a minimum amount of contemporary bioerosion. If, again, these are remnants of the borers themselves.

Maybe the ghosts are of later organisms that occupied the borings after the borers died? This happens often, with the secondary inhabitants called nestlers.

I know of no way to sort possible borers from nestlers with this kind of evidence.

The above image shows it’s possible that some of the ghosts are of organisms that had shells. The arrow is pointing to a dark line that may represent the remains of some type of shell. I’ve seen little tiny lingulid brachiopods in some borings before.

A fun mystery!

For technical interest, here is our photomicroscope we use to produce images like those in this post.

References:

Cuffey, R.J. 1998. The Maysville bryozoan reef mounds in the Grant Lake Limestone (Upper Ordovician) of north-central Kentucky, in Davis, A., and Cuffey, R. J., eds., Sampling the layer cake that isn’t: the stratigraphy and paleontology of the type-Cincinnatian. Ohio Department of Natural Resources Guidebook 13: 38-44.

Wyse Jackson, P.N. and Key, M.M. Jr. 2007. Borings in trepostome bryozoans from the Ordovician of Estonia: two ichnogenera produced by a single maker, a case of host morphology control. Lethaia 40: 237-252.

 

A “Dry Summer” in Wooster?

October 12th, 2017

I moved to Wooster at the very end of July.  Since that time, I’ve heard a frequent refrain that “it’s been a dry summer”.  Being a climate scientist, and knowing that everyone (including me) likes to complain about the weather, I thought I’d fact-check my neighbors.  In meteorology, “summer” usually means June, July, and August (JJA).  Based on data from the Wooster Experimental Station, 11.12 inches of rain fell during JJA 2017.  Is that dry?

It turns out, that’s nearly average.  The Wooster weather station goes back to the 1800s, and for the period 1900-2016*, the average JJA precipitation was 11.52 inches.  The minimum is 4.34 inches (1910), and the maximum is a 23.72 inches (1935).  However, my neighbors may be on to something, because digging deeper, most of that rain fell in June and July.  Early summer was really wet actually — the 9.83 inches Wooster received in June and July was greater than 75% of all years since 1900.  In August, though, we only received 1.29 inches — well below average.

September was even drier at 1.13 inches.  The main storm track that brings rain to Wooster has been farther north than normal since July, and most storms have missed us.  We also often receive rain from the remnants of hurricanes in September.  Although September had plenty of Atlantic hurricanes, Harvey is the only one that affected Wooster, dropping 0.76 inches of rain.  That’s a pittance for a tropical system, but it was also over half the rain we saw all month.

If you combine August and September, we had 2.42 inches of rain.  That’s good for 4th lowest since since 1900 (Figure 1).  Also, it’s the lowest August-September precipitation since 1922 — almost 100 years ago.  So yeah, this is rare.

Figure 1. In 2017, Wooster received 2.42 inches of precipitation in August and September. That’s 4th lowest since 1900. Data from National Centers for Environmental Prediction.

In fact, it’s so rare that Wooster is currently in a moderate drought (Figure 2). Cincinnati, Louisville, and other cities farther south are fine — they received ample rain from the tropics this year.  Much of the midwest is dry, though.  With that said, these midwest droughts are nowhere near as bad as the recent one in California (which still lingers in southern California, by the way). They are not as bad as what Montana and the Dakotas are currently facing, either.  Besides the moderate severity, they’re also currently short-term droughts — meaning it’s only been around for a few months.  Such droughts may have adverse impacts on agriculture, but there’s typically no long-term impact.  Just hope for plenty of snow this winter!

Figure 2. Droughts in the USA as of 3 October 2017. Wooster, OH is in a short-term moderate drought. Data from drought.gov.

 

*There are some data gaps before 1900 in the NCEI data, so I skipped those years.

Wooster’s Fossil of the Week: A terebratulid brachiopod from the Upper Cretaceous of southwestern France

October 6th, 2017

Yes, we’ve had a run of French Cretaceous fossils here. This is because we’re in the midst of a major project stemming from summer fieldwork in the Type Campanian of southwestern France. The fossils are delicious, and they are before us every day in the lab.

The above terebratulid brachiopod was found by Macy Conrad (’18) at our Caillaud South locality in the Biron Formation. It is so beautifully symmetrical that it just had to be a Fossil of the Week. I’ve apparently felt this way before about terebratulid brachiopods since I’ve previously written about Triassic, Jurassic and Miocene examples before in this blog. A Cretaceous example at least completes the Mesozoic set.

The above view of our articulated specimen shows the fragmentary smooth dorsal valve of the terebratulid, with the posterior portion of the ventral valve extending upwards at the top. The ventral valve has the characteristic round pedicle opening.

This is the flip side showing only the exterior of the ventral valve. A bit of chalky matrix adheres in the lower left, and the darker circles at the top are a form of silicification called beekite rings.

Here is the side view of our terebratulid, with the dorsal valve on top and larger ventral valve below. You can see why brachiopods were given the common name “lamp shells” because of the resemble to a Roman oil lamp.

References:

Coquand, H. 1858. Description physique, géologique, paléontologique et minéralogique du département de la Charente. Besançon, Dodivers, 420 p.

Platel, J.-P. 1996. Stratigraphie, sédimentologie et évolution géodynamique de la plate-forme carbonatée du Crétacé supérieur du nord du basin d’Aquitaine. Géologie de la France 4: 33-58.

Wooster’s Fossils of the Week: An oyster reef from the Middle Jurassic of southwestern Utah

September 29th, 2017

It was a pleasure to pull this massive specimen out of the cabinets, where it had been sitting for more than 20 years. It is a small reef of the oyster Liostrea strigilecula (White, 1877) from the Carmel Formation (Middle Jurassic) near Gunlock, southwestern Utah. It is out of storage because I’m returning to this section in Utah with students this summer to begin fieldwork again. The rocks and fossils are fascinating, and it is time someone looked seriously at them again.

A closer look at these little oysters shows how they could construct such a tight, nearly seamless structure. Each oyster grew in a cup-like fashion (first pointed out by Tim Palmer) so that they nestled together rather than overgrowing each other. These same oysters in this same locality also formed the famous oyster balls (ostreoliths). These reefal equivalents grew on carbonate hardgrounds, which are abundant in the Carmel Formation.

Liostrea strigilecula was named by Charles Abiathar White (1826-1910) as Ostrea strigilecula in 1877. White was an American paleontologist and geologist who did considerable work on midwestern and western North America. He was born in Massachusetts and worked in Iowa as the state geologist from 1866 to 1870. He returned east to teach at Bowdoin College for a couple of years, and then he joined the United States Geological Survey from 1874 into 1892. In 1895 he became an associate in paleontology at the United States National Museum. White was one of the first fellows of the American Association for the Advancement of Science, one of the first members of the Geological Society of America, and he was elected a member of the National Academy of Sciences in 1889. Abiathar Peak in Yellowstone National Park was named after him. A more thorough biography can be found at the link.

I’m looking forward to seeing these beautiful oysters in the field again!

References:

Bennett, K. 2017. White, Charles Abiathar. The Biographical Dictionary of Iowa. University of Iowa Press, 2009. Web. 19 September 2017

Nielson, D.R. 1990. Stratigraphy and sedimentology of the Middle Jurassic Carmel Formation in the Gunlock area, Washington County, Utah. Brigham Young University Geology Studies 36: 153-192.

Taylor, P.D. and Wilson, M.A. 1999. Middle Jurassic bryozoans from the Carmel Formation of southwestern Utah. Journal of Paleontology 73: 816–830.

Wilson, M.A. 1998. Succession in a Jurassic marine cavity community and the evolution of cryptic marine faunas. Geology 26: 379–381.

Wilson, M.A. 1997. Trace fossils, hardgrounds and ostreoliths in the Carmel Formation (Middle Jurassic) of southwestern Utah, in Link, P. and Kowallis, B., eds., Mesozoic to recent geology of Utah, Brigham Young University, v. 42, p. 6–9.

Wilson, M.A., Ozanne, C.R. and Palmer, T.J. 1998. Origin and paleoecology of free-rolling oyster accumulations (ostreoliths) in the Middle Jurassic of southwestern Utah, USA. Palaios 13: 70–78.

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