Wooster’s Fossil of the Week: An encrusted cobble from the Upper Ordovician of Kentucky

December 1st, 2013

Ordovician Kope Encrusted Concretion 111813In 1984 I pulled the above specimen from a muddy ditch during a pouring rain near the confluence of Gunpowder Creek and the Ohio River in Boone County, northern Kentucky. It changed my life.
crinoid bryozoan concretion 111813This limestone cobble eroded out of the Kope Formation, a shale-rich Upper Ordovician unit widely exposed in the tri-state area of Kentucky, Indiana and Ohio. It probably is a burrow-filling, given its somewhat sinuous shape. As you can see in the closer view above, it is encrusted with crinoids (the circular holdfasts) and bryozoans of several types, including the sheet-like form in the upper left and the mass of little calcareous chains spread across the center of the view. There are also simple cylindrical borings called Trypanites scattered about.
OrdovicianEdrio113013There were other cobbles at this site as well, including the one imaged above. It shows an encrusting edrioasteroid (Cystaster stellatus, the disk with the star shape in the middle) and a closer view of those chain-like bryozoans (known as Corynotrypa).
Concretion reverse 111813Significantly, the underside of the cobble pictured at the top of the page is smooth and mostly unencrusted, showing just a few of the Trypanites borings. A closer look, though, would reveal highly-eroded remnants of bryozoans. This means that the cobble sat on the seafloor with its upper surface exposed long enough to collect mature encrusters and borers. It appears, though, that the cobbles were occasionally flipped over, killing the specimens now on the underside and exposing fresh substrate for new encrusters.

How did this cobble change my life? My wife Gloria and I were scouting field trip sites for my Invertebrate Paleontology course. I was a very new professor and needed localities for our upcoming travels. I thought I had seen enough during that wet and chilly day, but Gloria wanted to explore one more outcrop. Fine, I thought, we’ll stop here at this muddy ditch and she’ll be quickly convinced it was time to quit. As I stepped out of the car I saw this cobble immediately. Then we both saw that the ditch was full of them. They showed spectacular encrusting and boring fossils with exquisite preservation, but more importantly they demonstrated a process of ecological succession rarely if ever seen in the paleontological record. It led to two papers the following year that came out just before my first research leave in England. There my new interests in hard substrate organisms led me to my life-long friends and colleagues Paul Taylor and Tim Palmer. Since then we’ve published together dozens of papers on encrusters and borers, now known as sclerobionts, and used them to explore many questions of paleoecology and evolution.

Thank you, Gloria, for one more outcrop!

References:

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

Wilson, M.A. 1985a. Disturbance and ecologic succession in an Upper Ordovician cobble-dwelling hardground fauna. Science 228: 575-577.

Wilson, M.A. 1985b. A taxonomic diversity measure for encrusting organisms. Lethaia 18: 166.

Wilson, M.A. and Palmer, T.J. 1992. Hardgrounds and Hardground Faunas. University of Wales, Aberystwyth, Institute of Earth Studies Publications 9: 1-131.

Wooster’s Fossil of the Week: A long scleractinian coral from the Middle Jurassic of Israel

November 17th, 2013

Enallhelia_370_Callovian_Israel_585Just one image for this week’s fossil, but we make up for the numbers in image length! The above fossil with the alternating “saw teeth” is the scleractinian coral Enallhelia d’Orbigny, 1849. It is a rare component of the diverse coral fauna found in the Matmor Formation (Callovian-Oxfordian) in southern Israel. I collected this particular specimen (from locality C/W-370 in Hamakhtesh Hagadol, for the record) during this past summer’s expedition to the Negev. It is preserved remarkably well considering that its original aragonite skeleton has been completely calcitized.

Enallhelia is in the Family Stylinidae, also named by French naturalist Alcide Charles Victor Marie Dessalines d’Orbigny. (Love that name; he was briefly profiled in a previous entry.) There are many species in the genus (at least two dozen), but I can’t figure out which this one is. I’ll need a coral expert because half of the available species look pretty much the same to me. Enallhelia is a dendroid coral, meaning its corallum has tree-like branches, only one of which we see here. Each branch has alternating corallites on each side, which in life would have held the individual tentacular polyps. Each corallite has radial symmetry, not the usual hexameral symmetry as seen in most scleractinians. The genus ranges from the Jurassic into the Cretaceous and is cosmopolitan. Enallhelia is especially well known from Europe, but that may be just a collector effect.

What I like about Enallhelia is that it can be an excellent paleoenvironmental marker. Leinfelder and Nose (1997) show that it is most often found in “marly coral meadows” near storm wavebase on carbonate platforms. This means it is in shallow but quiet waters well within the photic zone most of the time, but may be occasionally disturbed by storm wave currents. This is an accurate description of most of the depositional environment of the Matmor Formation.

References:

Hudson, R.G.S. 1958. The upper Jurassic faunas of southern Israel. Geological Magazine 95: 415-425.

Leinfelder, R.R. and Nose, M. 1997. Upper Jurassic coral communities within siliciclastic settings (Lusitanian Basin, Portugal): Implications for symbiotic and nutrient strategies. Proceedings of the 8th International Coral Reef Symposium 2: 1755-1760.

Olivier, N., Martin-Garin, B., Colombié, C., Cornée, J.-J., Giraud, F., Schnyder, J., Kabbachi, B. and Ezaidi, K. 2012. Ecological succession evidence in an Upper Jurassic coral reef system (Izwarn section, High Atlas, Morocco). Geobios 45: 555-572.

Wooster’s Fossil of the Week: A colonial scleractinian coral from the Pliocene of Cyprus

November 10th, 2013

Cladocora_585This week’s fossil is another from the collection made in 1996 on a Keck Geology Consortium expedition to Cyprus with Steve Dornbos as a Wooster student. Steve and I found a spectacular undescribed coral reef in the Nicosia Formation (Pliocene) near the village of Meniko (N 35° 5.767′, E 33° 8.925′). Finding a reef was a surprise because the unit is mostly quartz silt, which is not a sediment you usually associate with coral reefs. It was an advantage, though, because the silt was poorly lithified and could be easily removed from the fossils. The significance of this reef was that it represents the early recovery of marine faunas following the Messinian Salinity Crisis and the later refilling of the Mediterranean basin (the Zanclean Flood). Steve and I published our observations and analyses of this reef community in 1999.

The coral is a species of the genus Cladocora Ehrenberg, 1834. This genus, a member of the Family Caryophylliidae, ranges from the Late Cretaceous to today, so it is a hardy group. This may be because it is unusually diverse in its habits, ranging from the shallow subtidal down to at least 480 meters, and including both zooxanthellate (containing symbiotic photosynthesizing organisms called zooxanthellae) and azooxanthellate (with no such symbionts) species. Since our fossils lived in shallow water, they were almost certainly zooxanthellate.

(Courtesy of Wikimedia Commons user Esculapio)

(Courtesy of Wikimedia Commons user Esculapio)

Cladocora is still found today in the Mediterranean (see the above Cladocora caespitosa). Like all zooxanthellate scleractinian corals, these shallow species of Cladocora obtain their nutrition from the byproducts of their photosynthetic symbionts and a diet of small animals (mostly arthropods and larvae) they collect with their tentacles. These tentacles are lined with “stinging cells” called nematocysts.
CladocoraSpondylus_585Our Pliocene Cladocora formed the framework of a reef at least six meters high and 50 meters wide. It had many shelled organisms living entwined in the branches of the coral, like the bivalve Spondylus pictured above. You can see the corallites (individual tubes) embedded in the shell.
EhrenbergChristianGottfried_585Christian Gottfried Ehrenberg (1795-1876) named the genus Cladocora from specimens in the Red Sea. He was a German naturalist and explorer who is often credited with founding the field of micropaleontology (the study of microfossils such as foraminiferans, ostracodes and diatoms). He earned an M.D. at the University of Berlin and remained on the university staff for his entire career. He was no homebody, though, traveling as a scientist throughout the Mediterranean and Middle East, Central Asia and Siberia. (His first expedition to the Middle East was an adventure, as you can read at the link.) He was the first to prove that fungi reproduce via spores, to describe the anatomy of corals, and to identify plankton as the source for marine phosphorescence. Ehrenberg was also the first to discover microfossils in rocks, noting that some rocks (like chalk) are made almost entirely of them. His best known books include Reisen in Aegypten, Libyen, Nubien und Dongola (1828; “Travels in Egypt, Libya, Nubia and Dongola”) and Die Infusionsthierchen als volkommene Organismen (1838; “The Infusoria as Complete Organisms”). That last concept (“volkommene Organismen” or “complete organisms”) was his idea that even the smallest organisms had all the working organs of the largest. That one didn’t go so well!

References:

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.

Citizen scientist to the rescue (in more ways than one)

November 9th, 2013

StephLizzie110913NEW LONDON, OHIO–The Wooster paleontologists spent a pleasant afternoon with our favorite amateur fossil collector Brian Bade. Brian has been mentioned in this blog previously for the many important fossils he has found and donated. He is a spectacular citizen scientist with a deep love (some would say obsession) with fossils of all kinds. He has a tremendous collection of fossils from the region and elsewhere carefully cataloged as to formations and localities. He knows what specimens may have scientific importance, and he has always been most generous with his time and fossils.

Today Steph Bosch (’14), Lizzie Reinthal (’14) and I visited Brian to examine specimens he recently collected from the Waldron Shale (Silurian) exposed in the St. Paul Stone Quarry in St. Paul, Indiana. My colleagues and I need to examine Silurian microconchids from North America and, sure enough, Brian came to the rescue with his collections and eagle eyes. Not only did he have his cleaned and sorted Waldron material laid out for us, he also had segregated specimens that had encrusting microconchids on them. The fossils were fantastic. Check out this webpage to get an idea of the paleontological diversity at this site.

Brian also brought out other trays and boxes of fossils from the Silurian and Early Devonian that had encrusters. Lizzie and Steph proved adept at picking out the tiny microconchids with their bare, young eyes as I struggled with my usual handlens. (This was the typical situation during our fieldwork in Israel this summer as well.) We accumulated several excellent specimens for later study under a Scanning Electron Microscope. Brian once again came through with critical fossils collected with all the right information for scientific analysis.

And the other rescue by Brian? You can see the situation in the image below. After all the driving I did in exotic places this summer, I managed to burrow into deep mud in Brian’s front yard. My little car was completely mired. (Note the smirking students in the background getting ready to tweet photos.) Brian has a tractor, fortunately enough, and a long chain. I left behind two deep trenches in his grass, and a little bit of my pride.
CarStuck110913

Wooster’s Fossils of the Week: Very common orthocerid nautiloids from the Siluro-Devonian of Morocco

November 3rd, 2013

Nautiloids585_092313If you’ve been to a rock shop, or even googled “fossil”, you’ve seen these beautiful and ubiquitous objects. They are polished sections through a nautiloid known as “Orthoceras“. We put quotes around the genus name because with these views it is nearly impossible to identify the actual genus, so “Orthoceras” becomes the go-to term for unknown orthoconic (straight) nautiloids. We also do not know exactly where in Morocco these fossils come from, but chances are they were dug out of the Orthoceras Limestone (Siluro-Devonian) exposed near Erfoud in the Ziz Valley near the edge of the Sahara Desert. They are easily excavated, take a nice polish, and look good from almost any angle of cut. People bring these to me often to ask about their origin, so let’s do a Fossil of the Week about the critters.

These fossil nautiloids consisted in life of a long, straight conical shell with internal chambers pierced by a long tube. The shells were originally made of aragonite, but almost all have been replaced and recrystallized with calcite. A squid-like animal produced the shell. Most of its body was in the large body chamber at the open end of the cone. They were effective nektic (swimming) predators during the Paleozoic Era around the world. In some places (like Morocco) nautiloids were so common that their dead shells carpeted shallow seafloors. Nautilus is a living descendant.
SingleNautiloid092313 annotatedIn this closer cross-sectional view of a Moroccan “Orthoceras“, we can identify the critical parts. A = a chamber (or camera); B = the siphuncle (tube running through the center of the shell); C = a septum that divides one chamber from another; D = an orthochoanitic (straight) septal neck of shell that runs briefly along the siphuncle. The white to gray material is crystalline (“sparry”) calcite that filled the empty shell after death and burial.

By the way, you can buy “Orthoceras healing stones“. A quote from that site: “Fossils are believed to increase life span, reduce toxins, anxiety, stress, balance the emotions, make one more confident. Containing supernatural and physical healing powers. They promote a sense of pride and success in business. Healers use fossils to enhance telepathy and stimulate the mind. Traditionally, fossils have been used to aid in  reducing tiredness, fatigue, digestive disorders, and rheumatism.” No wonder paleontologists are always the very image of health and wealth!
BRUGIEREThe genus Orthoceras was named in 1789 by the French zoologist (and physician) Jean Guillaume Bruguière (1749–1798). The only image I could find of him is the small one above. Bruguière earned a medical degree from the University of Montpellier in 1770, but like many aspiring naturalists, he never practiced. He traveled very widely for an 18th Century scientist, usually to pursue living and fossil mollusks on various expeditions. That he was a Republican in revolutionary France probably saved his head, but he lost his income in the turmoil. Most of his descriptions of fossil taxa appeared in print decades after he died on a voyage back from Persia. Of all his taxonomic contributions, the genus Orthoceras is the most widely known.

References:

Histon, K. 2012. Paleoenvironmental and temporal significance of variably colored Paleozoic orthoconic nautiloid cephalopod accumulations. Palaeogeography, Palaeoclimatology, Palaeoecology 367–368: 193–208.

Kröger B. 2008. Nautiloids before and during the origin of ammonoids in a Siluro-Devonian section in the Tafilalt, Anti-Atlas, Morocco. Special Papers in Palaeontology 79, 110 pp.

Lubeseder, S. 2008. Palaeozoic low-oxygen, high-latitude carbonates: Silurian and Lower Devonian nautiloid and scyphocrinoid limestones of the Anti-Atlas (Morocco). Palaeogeography, Palaeoclimatology, Palaeoecology 264: 195-209.

Wooster Geologists at GSA 2013: Last one standing

October 30th, 2013

And that would be me. This morning I gave a talk about a project Paul Taylor and I have been working on for about two years. In fact, it was about a year ago that I was in the Smithsonian National Museum of Natural History tracking down specimens for this study. (Thanks again, Kathy Hollis!) Our paper’s title:

Title103013Here is the link to our GSA abstract. It was a fun topic to talk about, and goodness knows I obsessed over the slides for a long time. I’m always pleased to showcase the Scanning Electron Microscopy skills of Paul Taylor:

Slide103013Now I have just a couple brief meetings, then a red-eye flight back to Ohio and home. I’ve now finished my 35th GSA meeting. I think I’m getting the system down.

Wooster paleontologists present at the Geological Society of America meeting in Denver

October 28th, 2013

Lizzie102813DENVER, COLORADO–Yesterday Oscar Mmari (’14) gave the first presentation from Wooster’s Team Israel 2013 at the annual meeting of the Geological Society of America in Denver. Today our two paleontologists on the team discussed their posters.

Above is Lizzie Reinthal (’14) cheerfully giving her poster entitled: “Taphonomic feedback and facilitated succession in a Middle Jurassic shallow marine crinoid community (Matmor Formation, southern Israel)“. Her work is co-authored with our friend Howie Feldman. Below Steph Bosch (’14) is ready to discuss her work: “First bryozoan fauna described from the Jurassic tropics: Specimens from the Matmor Formation (Middle Jurassic, Upper Callovian) in southern Israel“. Steph’s poster has the famous palaeontologist Paul Taylor as a co-author.

Steph102813It is great fun to see these students make the transition, both intellectually and physically, from the scorched desert floor of the Negev to such a professional setting. The faculty are very proud.

 

Wooster’s Fossils of the Week: Bits of a bamboo coral from the Lower Pleistocene of Sicily

October 27th, 2013

Keratoisis melitensis (Goldfuss, 1826) 585Earlier this summer I participated on a pre-conference field trip of the International Bryozoology Association throughout Sicily. We had an excellent time and saw many wondrous things. At one stop on the western side of the Milazzo Peninsula in the northwestern part of the island we collected fossils from a fascinating foraminiferal ooze deposit known as the “Yellow Calcareous Marls” (Gelasian, Lower Pleistocene). Among the fossils in this unit were the objects pictured above. They looked like finger bones at first, but are actually the internodes (calcitic skeletal elements) of an octocoral known as “bamboo coral“. This particular species is Keratoisis melitensis (Goldfuss, 1826). I’ve never seen this group before in the fossil record. (Note, by the way, that these specimens are encrusted by foraminiferans and octocoral holdfasts. This means they rolled around on the seafloor for an extended period before burial.)
ModernBambooCoralBamboo coral belongs to the octocoral group and is only a distant relative of reef-forming “hard corals” or scleractinians. They are common today in deep seas because they do not need sunlight for photosynthetic symbionts like most hard corals do. They have multiple polyps for feeding, none of which can retract back into the skeleton. That is why the surface of these internodes is so smooth and without the usual corallite holes. Above is a colony of white bamboo coral (Keratoisis flexibilis); image from Wikimedia Commons.
bamboo_coral_585Here we have a dried specimen of Keratoisis from the Florida Straits. You can see the white calcitic internodes of the skeleton separated from each other by the black nodes made of an organic material called gorgonin. This explains why our fossil specimens consist entirely of the isolated internodes — the chitinous parts did not survive fossilization. (Image from NOAA.)

Bamboo corals are long-lived, and it has been recently discovered that they incorporate trace elements in their skeletons as they grow, making them excellent specimens for studying changes in the chemistry and circulation of deep-sea waters. These fossils may thus someday be useful for sorting out the complex changes in the Mediterranean during the Pleistocene.

References:

Langer M. 1989. The holdfast internodes and sclerites of Keratoisis melitensis Goldfuss 1826 Octocorallia in the Pliocene foraminifera marl Trubi of Milazzo Sicily Italy. Palaeontologische Zeitschrift 63: 15-24.

Sinclair, D.J., Williams, B., Allard, G., Ghaleb, B., Fallon, S., Ross, S.W. and Risk, M. 2011. Reproducibility of trace element profiles in a specimen of the deep-water bamboo coral Keratoisis sp. Geochimica et Cosmochimica Acta 75: 5101-5121.

Wooster’s Fossil of the Week: A carnivorous snail from the Pliocene of Cyprus

October 20th, 2013

Euthria Gray 1850 Pliocene Cyprus_585These drab and worn shells from the Pliocene of Cyprus are the remains of deadly little snails still around today. They are from an unknown species of the genus Euthria Gray, 1850. (Sometimes Euthria is considered a subgenus of Buccinulum.) They are fossil whelks (Family Buccinidae) from the Nicosia Formation coral reef community described in earlier posts and in a paper by Dornbos and Wilson (1999).

Whelks are carnivorous snails of a group formerly known as the neogastropods. They have an incredible underwater sense of smell through an organ known as the osphradium, enabling them to track down prey items such as clams, other snails, and carrion. (Yes, “tracking down” mostly sessile critters does seem to lack a bit in drama.) With their radulae (essentially tooth-bearing ribbons) they can drill through thick shells. Some are known to cause extensive damage in oyster farms. Their characteristic boreholes have been found in shells since the Cretaceous.

Euthria is very widespread today, and contains innumerable species poorly separated from each other by shell morphology. No doubt some later genetic study will show that the genus consists of relatively few species with considerable ecophenotypic variability.
John Edward Gray 1851Euthria was described by the English naturalist John Edward Gray (1800-1875) in 1850. Gray, who eventually became a fellow of the Royal Society, started his zoological career in a classic way: he volunteered to collect insects for the British Museum in London when he was just 15 years old. He joined the Museum officially in 1824 and stayed there for 50 years, publishing hundreds of papers on zoological topics, from reptiles and birds to snails and clams. Oddly enough, for all his scientific fame, he is also recognized as the first postage stamp collector. In 1840 he purchased a group of Penny Black stamps in order to save them as curiosities rather than use them for mailing.

References:

Beets, C. 1987. Notes on Buccinulum (Gastropoda, Buccinidae), a reappraisal. Scripta Geologica 82: 83-100.

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.

Fraussen, K. 2002. A new Euthria (Gastropoda: Buccinidae) from New Caledonia. Gloria Maris. Tijdschrift uitgegeven door de Belgische Vereniging voor Conchyliologie 41: 70-74.

Petit, R.E. 2012. John Edward Gray (1800–1875): his malacological publications and molluscan taxa. Zootaxa 3214: 1-125.

Zunino, M. and Pavia, G. 2009. Lower to Middle Miocene Mollusc assemblages from the Torino Hills (NW Italy): Synthesis of new data and chronostratigraphical arrangement. Rivista Italiana di Paleontologia e Stratigrafia 115: 349-370.

Wooster’s Fossil of the Week: A cheilostome bryozoan and serpulid worm bryolith from the Recent of Massachusetts

October 13th, 2013

Cheilostome Serpulid Muffin TopA bryolith is a mobile, unattached mass of bryozoans. Cheilostome bryozoans are especially good at forming bryoliths because of their hardy skeletons and relatively rapid rates of growth. The above specimen is a bryolith collected by my good friend Al Curran in March 2008 from Duck Creek in Cape Cod Bay near Wellfleet, Massachusetts. It is a modern specimen, so not actually a fossil, but I present it here because these objects have a good fossil record. The bottom view of the bryolith is below.
Cheilostome Serpulid Muffin ReverseThe tubes twisting about in this mass are those of polychaete serpulids. These are filter-feeding “tubeworms” common on marine shells, hardgrounds and rocks since the Triassic. We’ve met them many times in this blog. They are frustrating to identify from the tube alone because the soft anatomy (especially the genitalia, if you can imagine them) are needed to sort out most taxa. They tend to live on the undersides and cryptic spaces of hard substrates, which you can see when comparing the top and bottom of the above specimen.
Cheilostome Serpulid Muffin closerWith this closer look (above) we can see the fabric of the bryozoan skeleton (the zoarium). Individual zooecia (the skeletal tubes of the living zooids) are coming into focus. It appears from the intergrown nature of the serpulid tubes and bryozoan that these two groups were living together at the same time.
Cheilostome Serpulid Muffin closer yetIn this even closer view we see a serpulid tube embedded in a matrix of cheilostome zooecia. The apertures of the zooecia are now visible, and a bit of the frontal walls.
Cheilostome Serpulid Muffin closestThis is the closest I could get with our camera equipment. The frontal walls and apertures of the zooecia are easily seen. In life each aperture would have had a little door (an operculum). The frontal walls are a beautiful lattice-work of calcite.

I hesitate to suggest an identification for this cheilostome bryozoan because one of the world’s experts, my English good friend Paul Taylor, reads this blog. Nevertheless, I think these are of the widespread genus Schizoporella. Paul will correct me quickly if I’m wrong!

References:

Kidwell, S.M. and Gyllenhall, E.D. 1998. Symbiosis, competition, and physical disturbance in the growth histories of Pliocene cheilostome bryoliths. Lethaia 31: 221-239.

Klicpera, A., Taylor, P.D. and Westphal, H. 2013. Bryoliths constructed by bryozoans in symbiotic associations with hermit crabs in a tropical heterozoan carbonate system, Golfe d’Arguin, Mauritania. Marine Biodiversity: http://dx.doi.org/10.1007/s12526-013-0173-4 .

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