A day in the Zohar and Matmor Formations of the Negev

March 15th, 2016

1 Zohar outcrop 031516MITZPE RAMON, ISRAEL — It was another very windy day in southern Israel, but still just fine for fieldwork. Yael Edelman-Furstenburg, Yael Leshno and I returned to Makhtesh Gadol to work on Yael Leshno’s data collection procedures for her PhD project in the Middle Jurassic sequence here. Our first task was figuring out the detailed stratigraphy, which is not especially easy considering all the faulting and somewhat dated lithological descriptions for orientation. The above image is of the Zohar Formation just below its contact with the Kidod Formation (depending on what stratigraphic scheme you follow!).

2 Zohar disconformityThe top few meters of the Zohar Formation are a series of argillaceous limestones with numerous trace fossils (Planolites and Thalassinoides, mainly) and this gorgeous erosion surface (disconformity). The white limestone beneath was lithified when it was exposed and downcut by sand-bearing currents. On the left you can see pieces of the limestone incorporated into the overlying calcareous sandstone. Classic.

3 Goldberg trench 031516We then moved up section into the Kidod Formation (or upper Zohar!) to the site of the first stratigraphic column constructed through these rocks. Right of center you can see a trench dug into the marls by Moshe Goldberg in 1962. This was part of his project to describe the entire Jurassic section in Makhtesh Gadol. We still use his iconic work today as “Goldberg, 1963”.

4 Quadrat start 031516Here are the Yaels starting the very first quadrat measurements within the Matmor Formation. Within a half-meter square they are counting and identifying all the fossils — every little bit over a few millimeters. Student Yael has many of these quadrats in her future!

5 Makhtesh view 031516Here is a view of the Makhtesh with the Yaels at work. You can see our white field vehicle from the Geological Survey in the middle distance.

6 Matmor bedding plane 031516We ended the day at this bedding plane in the upper Matmor Formation I remembered finding many years ago. It has spectacular clam and gastropod fossils across its surface, many in apparent life positions. I’d show you images of the critters, but I’m saving them for a Fossil of the Week post!


Return to Makhtesh Gadol … and introducing the Yaels

March 14th, 2016

1 Yaels Makhtesh view 031416MITZPE RAMON, ISRAEL–Today I went to one of my favorite geological places: Makhtesh Gadol in the northern Negev highlands of Israel. It was a special day as well because I worked there with two excellent geologists: Yael Edelman-Furstenberg of the Geological Survey of Israel, and Yael Leshno, a graduate student at Hebrew University beginning a project comparing the Middle Jurassic communities in the south of Israel with their temporal equivalents in the north. Yael E-F is one of Student Yael’s advisors; I am on her dissertation committee. The two Yaels are shown above in the Matmor Hills of Makhtesh Gadol sorting out the complicated stratigraphy.

2 Yaels at 055 031416Yael Edelman-Furstenberg is on the left and Yael Leshno is on the right (along with my intruding shadow). We are standing at GPS location 055, where fossils from Subunit 51 of the Matmor Formation are abundant. Student Yael is presently surveying the Middle Jurassic sections in Makhtesh Gadol to find suitable places to do stratigraphic fossil collecting and quadrat measurements.

3 Oolite unit bedding planeWe spent some time studying “the oolite unit” (Subunit 63) at the top of the original Goldberg (1963) stratigraphic section. It is, as Goldberg wrote on his column, a “characteristic guide horizon”. It’s curious because there are no other oolitic units in the Matmor Formation, and because it loses its oolitic nature a few hundred meters south and north of the section. I will make a thin-section of this rock and see what’s up with these ooids.

4 Oolite unit weatheringText

5 Jeffs PerchThe top of the triangular cliff has an exposure of a fossiliferous marl of the Matmor Formation. In 2005, Jeff Bowen (’06) perched up there for hours and collected tiny specimens.

6 Jeffs viewThis would have been Jeff’s view of the makhtesh as the sun began to set. I hope he appreciated it!

7 Sponge embedment MatmorFinally, here is a bathroom counter (the best light in my hotel room) image of a calcareous sponge I found in Subunit 60 (just below Jeff’s location above) with embedment structures (bioclaustrations). Some worm-like organisms lived within the sponge body, and the sponge grew skeleton around them. I’ve not seen these before in sponges.

Wooster Geologist Returns to Israel: A visit to the Cretaceous Ora Formation

March 13th, 2016

1 Ora at GerofitMITZPE RAMON, ISRAEL — This is my 14th visit to Israel. I’ll be spending ten days here doing fieldwork in places I’ve come to love: Makhtesh Ramon, Makhtesh Gadol, and the Aravah Valley. I’ve returned to complete some Jurassic studies, explore a bit of the Cretaceous, and collect specimens for future Independent Study projects by Wooster geology majors. I’ve also come to work with an excellent Israeli graduate student, Yael Leshno. I’ll introduce her and her project later in this blog.

The top image is of my first field site of the trip: an exposure of the Ora Formation (Upper Cretaceous, Turonian) at Gerofit Junction at the edge of the Aravah Valley in southern Israel. It is a fun location because you can eat lunch while gazing at mountains and valleys in nearby Jordan. Of course, since it is the junction of routes 40 and 90, it’s a noisy place. The Ora Formation is well exposed north of the road junction.

2 Ora Gerofit faultThis outcrop is significantly faulted, so you must pay close attention to the stratigraphy to work your way through it. This is a low-angle normal fault. Note that it does not cut the topmost units. All sorts of tectonic situations are possible here next to the Dead Sea Transform system. Dr. Judge would love these structures! Me, not so much.

3 Ora limestone 031316Parts of the Ora Formation are very fossiliferous. This is a platy limestone rich in small oysters. Other beds have zillions of tiny gastropods, still others with plant and terrestrial arthropod remains. I came here ot find bryozoans, but found only a single specimen encrusting an oyster.

4 Mishhash view 031316On the way back to Mitzpe Ramon, I stopped at another exposure of the Ora Formation just south of Makhtesh Ramon. It is a place very familiar to several Wooster students, especially Andrew Retzler and Micah Risacher who did much of their I.S. field research on those steep slopes ahead. We often stopped to look at the Ora exposed in the wadis. The view is a bit hazy because of the typical Saharan dust that moves into the Negev in the spring.

5 Ora hardground MRThere is a fantastic bivalve-bored carbonate hardground in the Ora Formation at this second locality. It is especially well exposed now, probably because of winter floods washing away the soft sediment covering it.

6 Ora oysters 031316One amazing bed, about a half-meter thick, is packed with thin-shelled oysters. Every time I visit I look for encrusting bryozoans here, but none have appeared. They’ve got to be there!

It was a good start for these few days of fieldwork. I’m now acclimated, my geological eyes are tuned, and I’m ready for tomorrow’s fieldwork in the Matmor Formation of Makhtesh Gadol — the main event!

Wooster’s Fossil of the Week: A mystery from the Middle Devonian of Ontario, Canada

March 11th, 2016

Hungry Hollow 1This week’s fossil is a strange one. Mr. Darrell Ellis collected the above tiny specimen from the Hungry Hollow Member (Middle Devonian) at the famous Hungry Hollow location near Arkona, Ontario. (He also took this excellent photograph.) In the classic way exploratory paleontology works, he contacted an expert, my friend Olev Vinn at the University of Tartu in Estonia. Olev was puzzled, having never seen anything like it, so he sent the image to me. I was baffled. Darrell next sent me the actual specimen, which I examined an photographed. I could see that it is a calcitic spiral, flattened tube extending from a discoidal holdfast at its proximal end. I then passed images on to another buddy and expert, Paul Taylor at the Natural History Museum in London. The form is new to Paul as well, and he suggested it might be an odd microconchid, a twisty tube-dweller now extinct. That made sense, even if no microconchid like this has ever been described. We know that some microconchids did grow tubes extended upwards (such as Helicoconchus from the Permian of Texas, described earlier in this blog). Since we need to see the microstructure of the calcitic tube to support the hypothesis that this is a microconchid, I then sent the specimen to yet another friend, Michał Zatoń at the University of Silesia in Poland. He will examine the specimen with a scanning electron microscope (SEM). This is citizen science at work. Thank you, Darrell, for donating this specimen to science. It is also a reflection of how small scientific networks exchange ideas, information and specimens — Olev, Paul and Michał have been featured in this blog many times; we are old friends and colleagues with similar interests and diverse skill sets (and equipment!).

Hungry Hollow 2This is a closer view of the top of the spiral. We hope that Michał will be able to see the microstructure of the calcite on these broken surfaces.

Hungry Hollow 3This is the simple holdfast of this specimen. The tube began to grow  upwards very early in its ontogeny.

If you have ever seen a specimen like this before, whole or partial, please let me know in the comments or by email. We have only this one specimen that is clearly “new to science”. Other collectors and paleontologists may have bits of this they did not recognize before.

Again, thank you to Darrell Ellis for his sharp eyes, eagerness to contact experts, and generosity!


Wilson, M.A., Vinn, O. & Yancey, T.E. 2011. A new microconchid tubeworm from the Artinskian (Lower Permian) of central Texas, USA. Acta Palaeontologica Polonica 56: 785-791.

Zatoń, M. & Vinn, O. 2011. Microconchids and the rise of modern encrusting communities. Lethaia 44:5-7.

Zatoń, M., Wilson, M.A. and Vinn, O. 2012. Redescription and neotype designation of the Middle Devonian microconchid (Tentaculita) species ‘Spirorbis’ angulatus Hall, 1861. Journal of Paleontology 86:417-424.


Wooster’s Fossil of the Week: A low-spired, battle-worn trochid gastropod from the Pliocene of Cyprus

February 26th, 2016

1 Gibbula Risso, 1826 apexThis shell looks like a cinnamon roll. It is another product of the 1996 Wooster-Keck expedition to Cyprus with Steve Dornbos (’97) and me. Like the rest of the Cypriot specimens on this blog, it is from the Nicosia Formation (Pliocene) exposed on the Mesaoria Plain in the center of the island. This specimen comes from the Coral Reef locality described in Dornbos and Wilson (1999). We are looking at a well-preserved specimen of the herbivorous gastropod Gibbula Risso, 1826. (I can’t fit it into any known species within the genus.)
2 Gibbula Risso, 1826 sideIn this side view the growth lines are evident (they are parallel to the aperture; the thin ribs following the whorls are ornamentation), as are a couple of shallow, circular pits drilled by some unsuccessful predator. That predator could have been another gastropod or even an octopus. The pits are known by the trace fossil name Oichnus.

Those growth lines are interesting in  this genus. Schöne et al. (2007) studied a species of modern Gibbula and determined that they formed “microgrowth lines” in association with tidal cycles, forming “distinct fortnight bundles of microgrowth increments and lines”. We would need to section this shell and examine it microscopically to see such patterns.

3 Gibbula Risso, 1826 baseHere is the basal view of our Gibbula specimen.

4 RissoThe genus Gibbula was named and described by Giuseppe Antonio Risso (1777-1845), called Antoine Risso, was a productive Italian (more or less; he later can be considered French) naturalist. He was born in the city of Nice, then in the Duchy of Savoy. In 1792, soon after the French Army occupied Nice, Risso became a pharmacist’s apprentice, which encouraged his interest in medicinal botany. Risso was also a pioneering mountaineer in the Alps and other European ranges. He published several books on invertebrates, fish and plants. The work most relevant to us is his 1826 tome entitled: Histoire naturelle des principales productions de l’Europe Méridionale et particulièrement de celles des environs de Nice et des Alpes Maritimes. Risso’s Dolphin is named after him.


Donnarumma, L., Bruno, R., Terlizzi, A. and Russo, G.F. 2015. Population ecology of Gibbula umbilicaris and Gibbula ardens (Gastropoda: Trochidae) in a Posidonia oceanica seagrass bed. Italian Journal of Zoology, DOI: 10.1080/11250003.2015.1073377

Dornbos, S.Q. and Wilson, M.A. 1999. Paleoecology of a Pliocene coral reef in Cyprus: Recovery of a marine community from the Messinian Salinity Crisis. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 213: 103-118.

Risso, A. 1826. Histoire naturelle des principales productions de l’Europe Méridionale et particulièrement de celles des environs de Nice et des Alpes Maritimes. Paris: F.G. Levrault. Vol. 4: IV, 1-439, 12 pls.

Schöne, B.R., Rodland, D.L., Wehrmann, A., Heidel, B., Oschmann, W., Zhang, Z., Fiebig, J. and Beck, L. 2007. Combined sclerochronologic and oxygen isotope analysis of gastropod shells (Gibbula cineraria, North Sea): life-history traits and utility as a high-resolution environmental archive for kelp forests. Marine Biology 150: 1237-1252.

Williams, E.E. 1964. The growth and distribution of Gibbula umbilicalis (da Costa) on a rocky shore in Wales. The Journal of Animal Ecology 33: 433-442.

Wooster’s Fossil of the Week: A conid gastropod from the Pliocene of Cyprus

February 19th, 2016

Conus pelagicus Epsilos 585Cyprus again for this week’s fossil. This is a nearly complete shell of the predatory snail Conus pelagicus Brocchi 1814 found at the Epsilos exposure of the Nicosia Formation (Pliocene) on the Mesaoria Plain of central Cyprus by Steve Dornbos (’97) and me in 1996. In life this species no doubt had an intricate shell color pattern, as their cousins do today.

The taxonomic intricacies of the genus Conus are far beyond the scope of a mere blog entry, so I’ll simply link to a list of associated genera, subgenera and synonymies. Conus as an organism is fantastic. These are venomous predators famous for shooting radular teeth loaded with very effective toxins. Some species can kill a human in less than five minutes. No worries, though — the venom contains analgesic compounds so there is little pain. The best way to demonstrate the extraordinary killing process used by Conus is to look at a video. You’ll never look at snails the same way again.
BrocchiImageConus pelagicus was originally described by Giovanni Battista Brocchi in 1814. We met him in a previous blog entry, so much of this information is repeated. Brocchi (1772-1826) was an Italian natural historian who made significant contributions to botany, paleontology, mineralogy and general geology. He was born in Bassano del Grappa, Italy, and studied law at the University of Padova. He liked mineralogy and plants much better than lawyering, though, and became a professor in Brescia. His work resulted in an appointment as Inspector of Mines in the new kingdom of Italy. He famously said, “The science of fossil shells is the first step towards the study of the earth.”

Brocchi wrote the first thorough geological assessment of the Apennine Mountains, and he included in it a remarkable systematic study of Neogene fossils. He compared these fossils to modern animals in the Mediterranean — a very progressive thing to do at the time.
Brocchi plate 122915Above are drawings made by Brocchi of the conid (and a couple cypraeid) fossils he found in the Apennines during his extensive study published in 1814. Note that in the Continental fashion still followed today, the shells are figured aperture-up. Americans and the rest of the English-speaking world orient them in the proper way. Figures 11a, b and c, though, are oriented in the opposite direction, maybe to fill the space efficiently.

Brocchi was an adventurous traveler, but it eventually did him in. He died in Khartoum in 1826, a “victim of the climate” and a martyr for field science.


Brocchi, G.B. 1814. Conchiologia fossile subapennina con osservazioni geologiche sugli Apennini e sul suolo adiacente. Milano Vol. I: pp. LXXX + 56 + 240; Vol. II, p. 241-712, pl. 1-16.

Cowper Reed, F.R. 1935. Notes on the Neogene faunas of Cyprus, III: the Pliocene faunas. Annual Magazine of Natural History 10 (95): 489-524.

Cowper Reed, F.R. 1940. Some additional Pliocene fossils from Cyprus. Annual Magazine of Natural History 11 (6): 293-297.

Dornbos, S.Q. and Wilson, M.A. 1999. Paleoecology of a Pliocene coral reef in Cyprus: Recovery of a marine community from the Messinian Salinity Crisis. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 213: 103-118.

Wooster’s Fossil of the Week: A muricid gastropod from the Pliocene of Cyprus

February 12th, 2016

1 Bolinus brandaris coral reef 585We return to Cyprus for this week’s fossil. This is a broken shell of the predatory muricid Bolinus brandaris (Linnaeus, 1758) found at the Coral Reef exposure of the Nicosia Formation (Pliocene) on the Mesaoria Plain of central Cyprus by Steve Dornbos (’97) and myself in 1996. It has had some significant battering, probably by a crab peeling away the shell to get to the goodies. The ribs are prominent on the whorls, representing previous strengthened apertures. The base was a long, narrow siphonal canal now broken off. You can see the complete shell shape in modern examples.
2 Bolinus brandaris opened coral reef 585On the other side of the same specimen we see that the last whorl has been opened, showing the spiral columella at the axis of coiling. The arrow points to a puncture hole in an upper whorl. This appears to be the result of a “ballistic” impact on the shell by some predatory organism. Pether (1995) gave the name Belichnus to this trace fossil, attributing it to stomatopod crustaceans and their wicked-fast and powerful claws. Cadée and de Wolf (2013) expanded the possible tracemakers of Belichnus to seagulls.

Bolinus brandaris is well known today throughout the Mediterranean as the Purple Dye Murex. It has been used since ancient times as the source of a deep, permanent fabric dye called Tyrian Purple. It was highly prized by royalty and the wealthy elite for millennia.

Linnaeus originally placed this species in the genus Murex, but in 1837 Georg Gottlieb Pusch described a new but similar genus Bolinus, to which the species now belongs. Pusch, who also had the Polish name Jerzy Bogumił Koreński, was a very interesting fellow in the early days of paleontology and geology. He was born in Kohren, Saxony, in 1790 (or 1791, depending on which calendar you use). He was very early interested in what would become geology, so in 1806 he enrolled in the Mining Academy in Freiberg. In his first year he was recognized as an outstanding student by the famous Abraham Gottlob Werner. In 1811 he also studied law in Leipzig. After graduating he explored the geology of Saxony, and in 1813 participated in battles against Napoleon. Then in 1816, Pusch moved to Poland, which at that time was partitioned by foreign powers. He became professor of Chemistry and Metallurgy at the Kielce Academy and later head of the Mining and Mineralogy Department in Warsaw. His most important geological work was to explore and describe the geology of the Carpathians. He died in 1846.
3 Gottlieb Pusch on 1944 Nazi stampTo his misfortune, a portrait of Georg Gottlieb Pusch was used on the above 1944 German Occupation of Poland postage stamp, probably for the simple reason that he was a German who had done well in the Polish territories. I like to think Pusch would have been appalled to have been used in this way. He was a hero of geology.


Cadée, G. C. and de Wolf, P. 2013. Belichnus traces produced on shells of the bivalve Lutraria lutraria by gulls. Ichnos 20: 15-18.

Cowper Reed, F.R. 1935. Notes on the Neogene faunas of Cyprus, III: the Pliocene faunas. Annual Magazine of Natural History 10 (95): 489-524.

Cowper Reed, F.R. 1940. Some additional Pliocene fossils from Cyprus. Annual Magazine of Natural History 11 (6): 293-297.

Dornbos, S.Q. and Wilson, M.A. 1999. Paleoecology of a Pliocene coral reef in Cyprus: Recovery of a marine community from the Messinian Salinity Crisis. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 213: 103-118.

Pether, J. 1995. Belichnus new ichnogenus, a ballistic trace on mollusc shells from the Holocene of the Benguela region, South Africa. Journal of Paleontology 69: 171-181.

Radwin, G.E. and D’Attilio, A. 1986. Murex shells of the world. An illustrated guide to the Muricidae. Stanford University Press, Stanford, 284 pages.

Wooster’s Fossil of the Week: A bitten brachiopod (Upper Ordovician of southeastern Indiana)

February 5th, 2016

1 Best bitten Glyptorthis insculpta (Hall, 1847)This brachiopod, identified as Glyptorthis insculpta (Hall, 1847), was shared with me by its collector, Diane from New York State. She found it in a muddy horizon of the Bull Fork Formation (Upper Ordovician) in southeastern Indiana. She immediately noted the distorted plicae (radiating ribs) on the left side of this dorsal valve, along with the invagination along the corresponding margin. (Thanks for showing this to me, Diane, and allowing me to include it in this blog.)
2 Best closer Glyptorthis insculpta (Hall, 1847)Above  is a closer view of the unusual plicae. Note that they radiate from the top center of the brachiopod, extending as the shell grew outward along its margins. Something happened, though, when the brachiopod was growing. The shell was seriously damaged by a puncturing object. The brachiopod repaired the hole by closing it up with additional shell material coming from either side. The inwardly-curved plicae show the pattern of shell regrowth.
3 Reverse of best Glyptorthis insculpta (Hall, 1847)This is a view of the same brachiopod from the other side, showing that the ventral valve was damaged in the same event, but with slightly less destruction.

So how did such damage occur on that Ordovician seafloor? Some predator likely took a bite out of the brachiopod as it lay in its living position with the valves extended upwards into the seawater. Most brachiopods do not survive such events, but this one did.

Who was the probable predator? For that we turn to the work of the late Richard Alexander (1946-2006). He did the definitive study of pre mortem damage to brachiopods in the Cincinnatian Group in 1986, concluding that the most likely predators on these brachiopods were nautiloid cephalopods. Some of this figures show nearly identical healed scars on similar orthid brachiopods.
4. Richard AlexanderRichard Alexander was an accomplished paleontologist who lost his life in a swimming accident off the coast of St. Lucia just over nine years ago. He was born in Covington, Kentucky, right across the river from Cincinnati. As is so common with children in that part of the world, he developed a passion for fossils. He attended the University of Cincinnati, majoring in geology, He then went to Indiana University, completing a PhD dissertation titled: “Autecological Studies of the Brachiopod Rafinesquina (Upper Ordovician), the Bivalve Anadara (Pliocene), and the Echinoid Dendraster (Pliocene).” (We don’t see such diverse projects very much these days.) He taught at Utah State University from 1972 to 1980, and then at Rider University in New Jersey from 1981 until his death. He served as an administrator at several levels at Rider, and was known as an excellent teacher. His research interests changed when he moved to the East Coast, becoming increasingly focused on modern mollusks. No doubt he would still be contributing to paleontology but for the randomness of a freak wave in the Caribbean.


Alexander, R.R. 1981. Predation scars preserved in Chesterian brachiopods: probable culprits and evolutionary consequences for the articulates. Journal of Paleontology 55: 192-203.

Alexander, R.R. 1986. Resistance to and repair of shell breakage induced by durophages in Late Ordovician brachiopods. Journal of Paleontology 60: 273-285.

Dodd, J.R. 2008. Memorial to Richard Alexander (1946-2006). Geological Society of America Memorials 37: 5-7.

Wooster’s Fossil of the Week: A brachiopod with a heavy burden (Upper Ordovician of southeastern Indiana)

January 29th, 2016

1 Trepostome on Hebertella richmondensisYes, the above image doesn’t look much like a brachiopod, but just wait. We see a trepostome bryozoan with extended knobs and a few borings. Flip it over, though …
2 Hebertella richmondensis ventral view 585… and we see that the bryozoan almost entirely covers a brachiopod. So far, so common among Ordovician fossils. However, look closely at the margin of the brachiopod valve and how clearly it is delineated from the bryozoan. It is apparent that the bryozoan had encrusted a living brachiopod, and the brachiopod stayed alive, keeping the essential commissure (the gap between the valves) open for feeding. We are looking at the valve that was in contact with the substrate (the underside of the living brachiopod). The bryozoan occupied the upper exposed surface, growing across that valve (which is invisible to us now), past its edge, but not closing the gap with the other valve. The same bryozoan species is found on the above visible valve, but only as two thin films unconnected to the colony on the upper side.
3 Hebertella richmondensis bryo close annotatedA closer view of the brachiopod hinge shows additional evidence that the bryozoan and brachiopod were living together. The red arrow on the left points to where the fleshy pedicle (attaching stalk) of the brachiopod extended from the shell to meet the substrate. The bryozoan here curves around the now-vanished pedicle. The yellow arrow on the right shows how the bryozoan growth surface folded to accommodate the opening valves at the hinge. Pretty cool.

I can’t identify the bryozoan beyond Order Trepostomata without cutting it open. The brachiopod, though, appears to be Hebertella richmondensis Foerste, 1909. This specimen is from the Whitewater Formation (Upper Ordovician, upper Katian) exposed near Richmond, Indiana. It was collected on one of my field trips in 2003.
4 Hebertella richmondensis ventral view 585 annotatedWhat do we learn from this little assemblage? We first see a relatively uncommon example of a clear living relationship between a sclerobiont and its host. We also learn that the brachiopod could continue to open its valves for feeding despite the heavy calcitic bryozoan weighing it down. We even can see that this brachiopod was not living on a soft muddy substrate because only a small triangular-shaped area (see above) in the center was clear of encrusters; the thin bryozoan (and maybe a bit of the stromatoporid sponge Dermatostroma) had enough space between the valve and the substrate to feed and respire. None of this is surprising, but it is nice to see our models of how these organisms lived are congruent with the evidence.


Alexander, R.R. and Scharpf, C.D. 1990. Epizoans on Late Ordovician brachiopods from southeastern Indiana. Historical Biology 4: 179-202.

Foerste, A.F. 1909. Preliminary notes on Cincinnati fossils. Bulletin of the Scientific Laboratory of Denison University 14: 208–232.

Walker, L.G. 1982. The brachiopod genera Hebertella, Dalmanella, and Heterorthina from the Ordovician of Kentucky. USGS Professional Paper 1066-M.

Wright, D.F. and Stigall, A.L. 2013. Phylogenetic revision of the Late Ordovician orthid brachiopod genera Plaesiomys and Hebertella from Laurentia. Journal of Paleontology 87: 1107-1128.

Wooster’s Fossils of the Week: Gastropod opercula from the Pliocene of Cyprus

January 22nd, 2016

Opercula coral reef Pliocene Cyprus 585This week’s brief entry (it is short because we’re in the first few days of a new semester at Wooster) is related to last week’s post. Above are two gastropod opercula from the Nicosia Formation (Pliocene) of Cyprus. They were collected on a Keck Geology Consortium expedition to Cyprus in the summer of 1996 with Steve Dornbos (’97). An operculum for a gastropod is a kind of hard door attached to the muscular foot that closes off the aperture when the snail is fully retracted into its shell. On the left is the inside of an operculum, and on the right is the elegantly spiraled outside. The operculum provides protection for the snail from both drying out during a low tide and from prying (literally!) predators.

We can’t tell for certain, but we think these opercula are from the herbivorous gastropod Astraea rugosa featured in last week’s entry. We found them at our fossil coral reef site in the same deposit as the A. rugosa shells. They also look very much like these modern A. rugosa opercula.
Astraea_Screen Shot 2013-08-22 at 8.37.54 PM copyAbove is a diagram of Astraea rugosa with the operculum (“opérculo calcificado”) in place. (The drawing comes from a Spanish webpage no longer in existence.)


Checa, A.G. and Jiménez-Jiménez, A.P. 1998. Constructional morphology, origin, and evolution of the gastropod operculum. Paleobiology 24: 109-132.

Cowper Reed, F.R. 1935. Notes on the Neogene faunas of Cyprus, III: the Pliocene faunas. Annual Magazine of Natural History 10 (95): 489-524.

Cowper Reed, F.R. 1940. Some additional Pliocene fossils from Cyprus. Annual Magazine of Natural History 11 (6): 293-297.

Dornbos, S.Q. and Wilson, M.A. 1999. Paleoecology of a Pliocene coral reef in Cyprus: Recovery of a marine community from the Messinian Salinity Crisis. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 213: 103-118.

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