Archive for December, 2015

Wooster’s Fossil of the Week: Tiny atrypid brachiopods from the Upper Ordovician of southern Ohio

December 25th, 2015

Zygospira modesta Waynesville 585These exquisite little brachiopods are among the most abundant fossils in the Upper Ordovician of the Cincinnati area. My Invertebrate Paleontology students collected dozens of them from the Waynesville Formation on our field trip to Caesar Creek Lake last semester. Their ubiquity, though, doesn’t make them any less precious.
Zygospira modesta dorsalThis is Zygospira modesta (Say in Hall, 1847). Above is a dorsal valve view of a single specimen. At the apex you can see a tiny round hole from which a fleshy pedicle extended to attach the brachiopod to a hard substrate.
Zygospira modesta ventralHere is the ventral valve view. Zygospira is an atrypid brachiopod, meaning that its internal support (brachidium) for the filter-feeding lophophore is looped in a characteristic way, shown below.
Hall diagram ZygospiraThe diagrams above are from Hall (1867) who named the genus Zygospira and wished to further distinguish it from other atrypid brachiopods.

The taxonomy of Zygospira modesta is a bit messy, as many early 19th Century species descriptions tended to be. It was apparently first named Producta modesta by Thomas Say (see below) but not actually published as such. James Hall described it as Atrypa modesta in 1847. Later in 1862 he named Zygospira as a new genus, making Z. modesta its type species but not indicating a type locality.
Thomas_Say_1818We met Thomas Say (1787-1834) earlier in this blog, recognizing him as the scientist who named Exogyra costata in 1820. He is shown above in an 1818 portrait. Say was a brilliant American natural historian. Among his many accomplishments in his short career, he helped found the Academy of Natural Sciences of Philadelphia in 1812, the oldest natural science research institution and museum in the New World. He is best known for his descriptive entomology in the new United States, becoming one of the country’s best known taxonomists. He was the zoologist on two famous expeditions led by Major Stephen Harriman Long. The first, in 1819-1820, was to the Great Plains and Rocky Mountains; the other (in 1823) was to the headwaters of the Mississippi. Along with his passion for insects, Say also studied mollusk shells, both recent and fossil. He was a bit of an ascetic, moving to the utopian socialist New Harmony Settlement in Indiana for the last eight years of his life. It is said his simple habits and refusal to earn money caused problems for his family. Say succumbed to what appeared to by typhoid fever when he was just 47.

References:

Copper, P. 1977. Zygospira and some related Ordovician and Silurian atrypoid brachiopods. Palaeontology 20: 295-335.

Hall, J. 1862. Observations upon a new genus of Brachiopoda. Report New York State Museum, Natural History 15: 154-155.

Hall, J. 1867. Note upon the genus Zygospira and its relations to Atrypa. Report New York State Museum, Natural History 20: 267-268.

Sandy, M.R. 1996. Oldest record of peduncular attachment of brachiopods to crinoid stems, Upper Ordovician, Ohio, USA (Brachiopoda; Atrypida: Echinodermata; Crinoidea). Journal of Paleontology 70: 532-534.

Wooster’s Fossil of the Week: A tabulate coral from the Upper Ordovician of southern Ohio

December 18th, 2015

Calapoecia huronensis Billings, 1865 top 585We have here another fossil collected by a Wooster student on the August 2015 College of Wooster Invertebrate Paleontology field trip to Caesar Creek Lake, Ohio. Eduardo Luna picked up this specimen of the tabulate coral Calapoecia huronensis (Billings, 1865) from the Waynesville Formation (Upper Ordovician). For some reason in all my years of working in the Upper Ordovician, I’ve not come across this coral species before. Eduardo had sharp eyes as you can see it is rather small. The circular tubes are corallites, each of which held a coral polyp in life. This particular coral is distinctive for its septal spines along the inside rim of each corallite, giving them a beaded appearance.

Calapoecia huronensis Billings, 1865 bottom 585This is the underside of Eduardo’s coral. The corallites on the left side are eroded, showing the elongated septal spines that run lengthwise down their inside walls.

CNSPhoto-GEOLOGISTWe met the author of C. huronensis, Elkanah Billings (1820-1876), earlier this year, but why not show the handsome Canadian again? He originally described this coral species in 1865. He was Canada’s first government paleontologist, and he very much looked the part. Billings was born on a farm near Ottawa. He went to law school and became a lawyer in 1845, but he gave up stodgy law books for the bracing life of a field paleontologist. In 1856, Billings joined the Geological Survey of Canada, eventually naming over a thousand new species in his career. The Billings Medal is given annually by the Geological Association of Canada to the most outstanding of its paleontologists.

References:

Billings, E. 1865. Notice of some new genera and species of Palaeozoic fossils. Canadian Naturalist and Geologist, New Series 2: 432–452.

Browne, R.G. 1965. Some Upper Cincinnatian (Ordovician) colonial corals of north-central Kentucky. Journal of Paleontology 39: 1177-1191.

Cox, I. 1936. Revision of the genus Calapoecia Billings. Bulletin of the National Museum of Canada 80: 1–48.

Jull, R.K. 1976. Review of some species of Favistina, Nyctopora, and Calapoecia (Ordovician corals from North America). Geological Magazine 113: 457-467.

Wooster’s Fossil of the Week: A common trilobite from the Upper Ordovician of Ohio

December 11th, 2015

Flexicalymene meeki cephalon view 585This beautiful specimen was collected by Wooster student Eve Caudill on this year’s College of Wooster Invertebrate Paleontology field trip to Caesar Creek Lake, Ohio. It is the iconic trilobite Flexicalymene meeki (Foerste, 1910) from a soft, “buttery” shale in the Waynesville Formation (Upper Ordovician). This is one of the most common trilobite species in the world, and it has been photographed thousands of times, so I posed it at an unconventional, rakish angle. We are looking here at the cephalon (head) of the animal. I like the way the remnants of the enclosing sedimentary matrix cling to the low places, highlighting the bumps and ridges. The center of the cephalon shows the distinctive glabella with its side lobes. The stomach of the trilobite was housed underneath it. The two eyes are visible on either side of the glabella, the one on the right split by the slightly-open facial suture used for dividing its exoskeleton during molting (ecdysis).

Flexicalymene meeki pygidium view 585This is a view of the pygidium (tail end) of the same Flexicalymene meeki specimen. It is tucked under the leading edge of the cephalon in the classic enrollment position. Trilobites likely enrolled for several reasons, but the primary one was almost certainly to affect a pill-bug-like defense against predators.

Flexicalymene meeki side view 585This is a side view of the enrolled trilobite. The articulated segments between the cephalon and pygidium constitute the thorax.foerste-1936We met the author of Flexicalymene meeki four years ago in this blog, so let’s visit him again. August F. Foerste (1862-1936) was one of the pioneers of Cincinnatian paleontology and stratigraphy. He grew up and worked in the Dayton, Ohio, area. Foerste went to Denison University where he was a very successful undergraduate, publishing several geological papers. He returned to Dayton after graduation with a PhD from Harvard, teaching high school for 38 years. When he retired he was offered a teaching position at the University of Chicago, but instead went to work at the Smithsonian Institution until the end of his life.

A final note from the Invertebrate Paleontology class this year: We were greatly assisted by two fantastic paleontological websites, one by Alycia Stigall at Ohio University called The Digital Atlas of Ordovician Life, and the other by Steve Holland at the University of Georgia titled The Stratigraphy and Fossils of the Upper Ordovician near Cincinnati, Ohio. Thank you to my most excellent and productive colleagues.

References:

Brandt, D.S. 1993. Ecdysis in Flexicalymene meeki (Trilobita). Journal of Paleontology 67: 999-1005.

Brett, C.E., Thomka, J.R., Schwalbach, C.E., Aucoin, C.D. and Malgieri, T.J. 2015. Faunal epiboles in the Upper Ordovician of north-central Kentucky: Implications for high-resolution sequence and event stratigraphy and recognition of a major unconformity. Palaeoworld 24: 149-159.

Esteve, J., Hughes, N.C. and Zamora, S. 2011. Purujosa trilobite assemblage and the evolution of trilobite enrollment. Geology 39: 575-578.

Evitt, W.R. and Whittington, H.B. 1953. The exoskeleton of Flexicalymene (Trilobita). Journal of Paleontology 27: 49-55.

Foerste, A.F. 1910. Preliminary notes on Cincinnatian and Lexington fossils of Ohio, Indiana, Kentucky, and Tennessee. Denison University Science Laboratories Bulletin 16: 17-87.

Frey, R.C. 1987. The paleoecology of a Late Ordovician shale unit from southwest Ohio and southeastern Indiana. Journal of Paleontology 61: 242-267.

 

A True Liberal Arts Experience

December 9th, 2015

Guest Blogger: Mary Reinthal

If you were to poll the campus about their fall break, not many would say that they spent 20 hours over 2 days in an FTIR lab analyzing glass chips for volatile content. But if you were to ask geology senior Mary Reinthal and her advisor Dr. Meagen Pollock, that’s exactly what they would say. Fly in on a Monday; analyze samples at University of Massachusetts Amherst Tuesday and Wednesday; fly out Thursday. It was a lot of work, but somebody had to do it (for their Independent Study). The time was spent looking at the volatile spectra from individual, doubly polished glass chips collected from British Columbia, Canada.

Not a lot of windows in the FTIR lab, so Mary had to look at glass chips.

Not a lot of windows in the FTIR lab, so Mary had to look at glass chips.

After all that time in the lab, a lot of data were collected (yay!). These numbers will hopefully help us understand the evolution of glaciovolcanic tindars in British Columbia. Until then, however, these data will to be sifted through and looked at more closely as the semester continues.

Mary measuring thickness of glass wafers. To understand the bigger picture of volatile effects on eruptions you have to look small. Like micron-scale small.

Mary measuring thickness of glass wafers. To understand the bigger picture of volatile effects on eruptions you have to look small. Like micron-scale small.

Of course, the visit to U-Mass. Amherst wasn’t all science and glass chips. After finishing a 9-hour stint in the lab on Wednesday, Dr. Pollock and Mary ventured to Concord, Massachusetts to visit Walden Pond. In short, a truly liberal arts education was had by all.

Mary and Thoreau pondering life and science.

Mary and Thoreau pondering life and science.

 

Wooster’s Fossils of the Week: Zig-zag oysters from the Middle Jurassic of southern Israel

December 4th, 2015

Actinostreon Matmor Jurassic 171 173 585These pretty little oysters are from the Matmor Formation (Middle Jurassic, Callovian) of Makhtesh Gadol in southern Israel. Because I regrettably missed going to Israel for fieldwork this summer, I thought I’d choose these exquisite fossils to be celebrated this week. The genus is Actinostreon Bayle, 1878. There may be more than one species here, so we’ll just leave the identification at the genus level.
Actinostreon single 585Actinostreon is very common in some units of the Matmor Formation. Hundreds can be found scattered through a single unit. They were epifaunal filter-feeders as all oysters, and like most attached to hard substrates. The Actinostreon in the Matmor Formation commonly settled on small shell fragments in marl, giving them the appearance of dwelling in mud. Their zig-zag commissures (their shells are formally called plicate) strengthened their shells with ribs and helped them maintain high water inflow for filter-feeding with a relatively small opening (gape).
bayle 300The French paleontologist and mineralogist Claude Émile Bayle (1819-1895) named the genus Actinostreon in 1878. Bayle was raised in the beautiful French coastal city of La Rochelle. His family was related to Alcide Dessalines d’Orbigny (1802-1857), one of the greatest French naturalists, so collecting and analyzing fossils and modern shells was encouraged. Bayle studied at the Ecole Polytechnique and then the Ecole des Mines. After his schooling he was employed as the Chief Engineer of the Corps des Mines. He assembled a large collection of fossils (about 185,000 of which were cataloged). In 1848 he began teaching paleontology and mineralogy at the Ecole des Mines, retiring in 1881. His paleontological specialties were mollusks (especially Jurassic and Cretaceous bivalves) and Cenozoic mammals. He had a fairly modest publication record until he produced his magnum opus, an 1878 fossil atlas to accompany a new geological map of France. It is here that he described Actinostreon, and many other new taxa.

References:

Alberti, M., Fürsich, F.T. and Pandey, D.K. 2013. Seasonality in low latitudes during the Oxfordian (Late Jurassic) reconstructed via high-resolution stable isotope analysis of the oyster Actinostreon marshi (J. Sowerby, 1814) from the Kachchh Basin, western India. International Journal of Earth Sciences 102: 1321-1336.

Bayle, E. 1878. Fossiles principaux des terrains: Explication carte geologique France. France Service Carte Geologique, vol. 4, pt. 1, pl. 132.

Hirsch, F. 1980. Jurassic bivalves and gastropods from northern Sinai and southern Israel. Israel Journal of Earth Sciences 28: 128-163.

Machalski, M. 1998. Oyster life positions and shell beds from the Upper Jurassic of Poland. Acta Palaeontologica Polonica 43: 609-634.