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.

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’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 .

Wooster’s Fossil of the Week: A gastropod/coral/hermit crab combination from the Pliocene of Florida

October 6th, 2013

Septastrea marylandica_585These two shells show a lovely symbiosis between shallow marine hermit crabs and encrusting scleractinian corals. I was first introduced to the concept of “pagurized” shells by my friends Paul Taylor and Sally Walker. They showed me the many ways by which shells that were carried around by hermit crabs display particular evidence of this specific use, from characteristic wear patterns to patterns of encrustation and boring. Further, there are some situations, such as that shown above, where encrusters and hermit crabs have developed a mutually beneficial relationship that may have even been depended upon by the crabs.

What we have here are gastropod (snail) shells that have been completely encrusted by the scleractinian coral Septastrea marylandica (Conrad, 1841). These are found in great abundance in the Pliocene Pinecrest Sand (foraminiferal zone N20) near Fruitville, Sarasota County, Florida. What is most cool is that the corals have completely encrusted these spiraling snail shells and more. If you look carefully at the aperture of the specimen on the left you see the lower surface of the coral with no snail shell. The coral had encrusted the whole shell and continued to grow from the original aperture outward, elongating the twisting tube farther than the snail ever grew. Why (and how) did it do this?

The answer is that the shells were occupied by hermit crabs. The corals extended the aperture of the shell with the crab shuffling about in the opening. The crabs gained the advantage of a shell that essentially grew along with them, meaning they did not have to make the dangerous switch to a larger shell as often. The corals gained by being carried about into diverse microenvironments, extending their feeding possibilities. Nice arrangement, and elegant fossils to show it.
Septastrea closeSeptastrea marylandica (Conrad, 1841) is a scleractinian coral. We’ve seen this order before on this blog, but usually as a recrystallized version of the original aragonitic shell. In these specimens the aragonite is still preserved in excellent detail. Each of the individual “cups” (corallites) above contained a single coral polyp in life. The radiating vertical walls are called septa and are related to the original soft parts of the polyps. The polyps extended tentacles from these corallites into the surrounding seawater. The tentacles were lined (as they are today) with stinging cells called nematocysts for subduing very small items of prey, such as larvae or tiny arthropods. Corals thus represent an ecological group of sessile benthic epifaunal predators. Sessile means stationary, benthic means on the seafloor, and epifaunal means on the surface of the seafloor (that is, not in the substrate itself). Curiously, then, these corals that encrusted shells with hermit crabs in them became in a sense vagrant rather than benthic because they were moved about on the seafloor. You don’t hear about vagrant benthic corals very often!

References:

Allmon, W.D. 1993. Age, environment and mode of deposition of the densely fossiliferous Pinecrest Sand (Pliocene of Florida): Implications for the role of biological productivity in shell bed formation. Palaios 8: 183-201.

Darrell, J.G. and Taylor, P.D. 1989. Scleractinian symbionts of hermit crabs in the Pliocene of Florida. Memoir of the Association of Australasian Palaeontologists 8:115–123.

Laidre, M.E. 2012. Niche construction drives social dependence in hermit crabs. Current Biology 22: R861–R862.

Petuch, E J. 1986. The Pliocene reefs of Miami: Their geomorphological significance in the evolution of the Atlantic coastal ridge, southeastern Florida, USA. Journal of Coastal Research 2: 391-408.

Taylor, P.D. and Schindler, K.S. 2004. A new Eocene species of the hermit-crab symbiont Hippoporidra (Bryozoa) from the Ocala Limestone of Florida. Journal of Paleontology 78: 790-794.

Vermeij , G.J. 2012. Evolution: Remodelling hermit shellters. Current Biology 22: R882-R884. [Really. The title is spelled exactly this way.]

Walker, S.E. 1992. Criteria for recognizing marine hermit crabs in the fossil record using gastropod shells. Journal of Paleontology 66: 535-558.

Wooster’s Fossil of the Week: A terebratulid brachiopod from the Miocene of Spain

September 29th, 2013

Terebratula maugerii Boni, 1933_585These large brachiopods are of the species Terebratula maugerii Boni, 1933. They were found in Upper Miocene (Tortonian-Messinian) beds near Cordoba, Spain. Wooster acquired them through a generous exchange of brachiopods with Mr. Clive Champion in England.

The specimen on the left is oriented with the dorsal valve upwards. The ventral valve is below and visible at the top of the image. The ventral valve of terebratulids has a rounded opening through which the attaching device, called the pedicle, extended. The specimen on the right is shown with its ventral valve upwards. Since this is the largest valve, you can’t see the dorsal valve below.

I like these specimens because they have that beautiful fold in the center of the shell. This is much more pronounced than in the usual terebratulid brachiopod (it is said to be “strongly plicated“), so students get to see some variety in this large but generally uniform group.

By the Cenozoic, brachiopods are rather rare in fossiliferous deposits. Shelly beds from the Paleocene on are dominated by mollusks, especially bivalves. This large brachiopod, though, is an exception found in the Upper Miocene shellbeds of southern Spain. It is found in meter-thick accumulations, making it for a very short time a significant carbonate component in marine sediments. Terebratula maugerii was most common in the deep subtidal in high-energy deposits. (See Reolid et al., 2012, for details.)
RomanLampFinally, brachiopods are commonly called “lamp shells“, which makes no sense to most modern students. They were given this nickname way back in the 18th century because of their resemblance to Roman oil lamps, such as those figured above in the same orientation as our shells. These were filled with oil through the central hole and a wick was placed in what we now see as the “pedicle opening”. It is an archaic comparison, but it works!

References:

Boni, A. 1933. Fossili miocenici del Monte Vallassa. Bolletino della Società Geologica Italiana 52: 73-156.

García Ramos, D.A. 2006. Nota sobre Terebratulinae del Terciario de Europa y su relación con los representantes neógenos del sureste español. Boletín de la Asociación Cultural Paleontológica Murciana 5: 23-83.

Llompart, C. and Calzada, S. 1982. Braquio ́podos messinienses de la isla de Menorca. Bol R Soc Espanola Hist Nat 80: 185–206.

Reolid, M., García-García, F., Tomasovych, A. and Soria, J.M. 2012. Thick brachiopod shell concentrations from prodelta and siliciclastic ramp in a Tortonian Atlantic–Mediterranean strait (Miocene, Guadix Basin, southern Spain). Facies 58: 549-571.

Toscano-Grande, A., García-Ramos, D., Ruiz-Muñoz, F., González-Regalado, M.L., Abad, M., Civis-Llovera, J., González-Delgado, J.A., Rico-García, A., Martínez-Chacón, M.L., García, E.X. and Pendón-Martín, J.G. 2010. Braquiópodos neógenos del suroeste de la depresión del Guadalquivir (sur de España). Revista Mexicana de Ciencias Geológicas 27: 254-263.

Wooster’s Fossil of the Week: A delicate brachiopod from the Pliocene of Cyprus

September 22nd, 2013

Terebratulid Pliocene CyprusThese thin-shelled brachiopods were collected in the summer of 1996 on a Keck Geology Consortium project in Cyprus. Strangely enough, they were the first brachiopods I had ever seen in the Cenozoic. These are ventral valves of the terebratulid Maltaia pajaudi García–Ramos, 2006. On the left is the external view, and on the right is the internal. In the internal view at the top (posterior) portion of the shell you can see the rounded pedicle opening and two teeth of the hinge mechanism that articulated the valves.

The fieldwork that summer was with three students: Steve Dornbos (’97) of Wooster, Ellen Avery of Bryn Mawr, and Lorraine Givens of SUNY-Buffalo State. We found hundreds of gorgeous fossils, many of which have been described in these webpages. All are from the Nicosia Formation (Pliocene) exposed on the Mesaoria Plain in the center of Cyprus near the village of Meniko. The brachiopods above were found at a site we termed “Pelican-Brachiopod” that had 37 different fossil species. It was an unusual paleocommunity with large numbers of predatory gastropods, many of which left their marks as boreholes in shells. We figured from the microfossils present, as well as the fine silty sediment, that this fauna lived in relatively deep waters, probably several hundred meters. We had other Nicosia Formation sites in very shallow waters (including a coral reef), so we were able to show considerable paleoenvironmental diversity in this thick unit.
G. Arthur Cooper and the "Emerald Queen"The Mediterranean brachiopod genus Maltaia was named in 1983 by the famous American paleontologist G. Arthur Cooper (1902-2000). I actually met the man in 1977 when I was an undergraduate attending the North American Paleontological Convention in Lawrence, Kansas. I was awestruck because he was legendary for his prodigious systematic work with brachiopods, especially those of the Permian in western Texas. The classic photo above shows him in the field with his Smithsonian Institution vehicle he named the “Emerald Queen”.

Cooper earned his B.S. degree at Colgate University with a chemistry major in 1924. He did his PhD work at Yale University with the epic paleontologists Carl O. Dunbar and Charles Schuchert, earning his degree in 1929. He loved brachiopods and was encouraged to pursue them by Schuchert. Cooper joined the paleontological staff at the United States National Museum in 1930, flourishing there through his retirement in 1974 into active emeritus status. He named hundreds of new fossil brachiopods during his career. I would not be surprised to hear he has the record of new fossil taxonomic descriptions. He was much honored in his time, including receipt of the second Paleontological Society medal in 1964.

References:

Bitner, M.A. and Martinell, J. 2001. Pliocene brachiopods from the Estepona Area (Málaga, South Spain). Revista Española de Paleontología 16: 177-185.

Bitner, M.A. and Moissette, P. 2003. Pliocene brachiopods from north-western Africa. Geodiversitas 25: 463-479.

Cooper, G.A. 1983. The Terebratulacea (Brachiopoda), Triassic to Recent: A study of the brachidia (loops). Smithsonian Contributions to Paleobiology 50: 1–445.

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.

Toscano-Grande, A., et al. 2010. Neogene brachiopods from the southwestern Guadalquivir basin (south Spain). Revista Mexicana de Ciencias Geologicas 27: 254-263.

Wooster’s Fossils of the Week: An ancient predator/prey system from the Lower Pleistocene of Sicily

September 15th, 2013

Bored and Borer for FOTWThe above fossils were collected from a Lower Pleistocene silty marl exposed near the Megara archaeological site east of Augusta, Sicily, Italy. I was on that epic International Bryozoology Association field trip this summer I’ve been blogging about. The shells in this locality are very abundant with hundreds of species represented, from foraminiferans to shark teeth. I thought this little vignette of a predator and its typical prey was worth noting.

On the far right is a naticid gastropod (moon snail). These mollusks are predators who kill and consume their prey by drilling holes into their shells with a specialized radula (a kind of tooth-bearing “tongue”). Their holes are distinctively beveled, with a wider portion on the outside narrowing to a smaller inner opening. The three organisms on the left all show boreholes indicating that they were likely killed and eaten by a naticid.

Or at least that’s the traditional story. A paper came out this year (Gorzelak et al., 2013) comparing predatory drill holes in shells with holes produced by physical abrasion by experimental tumbling. The sizes, shapes and locations of these abrasion-produced holes are shockingly similar to those made by drilling predators. It looks like we must be careful which holes we assign to predation and which were produced by other means.

As I look at the three victims above, two of them (the high-spired turritellid gastropod on the far left and the bivalve second from the right) have nicely beveled holes with almost perfectly circular shapes. The gastropod shell that is second from the left, though, presents problems. First, it has two holes that completely penetrate the shell. Predators occasionally bore a shell twice, but not very often. Second the holes are more irregular in shape and don’t have a noticeable beveling. This could be a feature of the thinner shell of this gastropod not recording the usual naticid boring evidence, or it could be the result of physical abrasion and not predation. It is a difficult call but an important one to those plotting the evolution of this predator/prey system through time.

References:

Gorzelak, P., Salamon, M.A., Trzęsiok, D. and Niedźwiedzki, R. 2013. Drill holes and predation traces versus abrasion-induced artifacts revealed by tumbling experiments. PLoS ONE 8(3): e58528. doi:10.1371/journal.pone.0058528

Kelley, P.H. and Hansen, T.A. 2006. Comparisons of class- and lower taxon-level patterns in naticid gastropod predation, Cretaceous to Pleistocene of the US Coastal Plain. Palaeogeography, Palaeoclimatology, Palaeoecology 236: 302–320.

Kowalewski, M., Dulai, A. and Fürsich, F.T. 1998. A fossil record full of holes: The Phanerozoic history of drilling predation. Geology 26: 1091–1094.

Tyler, C.L. and Schiffbauer, J.D. 2012. The fidelity of microstructural drilling predation traces to gastropod radula morphology: paleoecological applications. Palaios 27: 658–666.

« Prev - Next »