Wooster’s Fossil of the Week: A scolecodont from the Upper Ordovician of the Cincinnati region

May 4th, 2014

Cincinnatian scolecodontThis tiny but fearsome jaw is known as a scolecodont, and they are fairly common in the Cincinnatian rocks (Upper Ordovician) in the tri-state area of Ohio, Kentucky and Indiana. The label on this particular specimen does not indicate the exact locality or stratigraphic unit, but it does give a taxonomic name: “Nereidavus varians Grinnell 1877″. More on that below.

Scolecodonts are the jaws of extinct polychaete annelid worms. They are known from the Cambrian right through the Recent, so we’re pretty sure what their functions were: grabbing prey and pulling it into the gullet of the worm. They are made of a very tough chitin (an organic material much like our fingernails) and survive well the vicissitudes of fossilization. I ran across them often when I studied conodonts, which they superficially resemble.

Polychaete mouthThe Telegraph, of all places, has some amazing SEM images of the scary end of living jawed polychaetes, one of which is shown above. (I think they colored it to look like it has blood on its teeth.) Our Ordovician jaw easily fits into this functional model.

For much more on scolecodonts, Olle Hints has a superb website devoted just to these critters, and Rich Fuchs has a very useful page on the Cincinnatian varieties.

Now as for the name of our specimen, it appears that the taxonomy of Ordovician scolecodonts is in a bit of disarray. Nereidavus Grinnell, 1877, is, according to Bergman (1991) and Eriksson (1999), a nomen dubium (dubious name) because the holotype (single primary type specimen) of the type species is lost. That specimen was from Cincinnatian strata, then referred to as “Lower Silurian”. The paratype (sort of a spare type specimen) is N. varians, the same name on the label of our specimen. Eriksson considered that species to be in the genus Ramphoprion Kielan-Jaworowska, 1962. A true diagnosis of our specimen would involve extracting it from the matrix and looking at it its dorsal (oral) surface, but that’s not going to happen. I’m plenty happy just leaving this fossil as Ramphoprion sp.

Kielan-JaworowskaThe paleontologist who named the scolecodont genus Ramphoprion is the famous and incredibly accomplished Zofia Kielan-Jaworowska (above). She is best known for her pioneering work on dinosaur-bearing deposits in Mongolia in the 1960s, but she has worked on many fossil groups from trilobites to mammals. Kielan-Jaworowska (born in 1925) received her Masters Degree in zoology and a doctorate in paleontology (aren’t many of those now) at Warsaw University. She became a professor there and was later the first woman to serve on the executive committee of the International Union of Geological Sciences. I read her 1974 book Hunting for Dinosaurs in college as an adventure tale with a strong narrative framework of science. It was inspirational, and it convinced me that paleontology was the coolest science.

References:

Bergman, C F. 1991. Revision of some Silurian paulinitid scolecodonts from western New York. Journal of Paleontology 65: 248–254.

Eriksson, M. 1999. Taxonomic discussion of the scolecodont genera Nereidavus Grinnell, 1877, and Protarabellites Stauffer, 1933 (Annelida: Polychaeta). Journal of Paleontology 73: 403-406.

Eriksson, M. and Bergman, C.F. 2003. Late Ordovician jawed polychaete faunas of the type Cincinnatian Region, U.S.A. Journal of Paleontology 77: 509-523.

Grinnell, G.B. 1877. Notice of a new genus of annelids from the Lower Silurian. American Journal of Science and Arts 14: 229–230.

Hints, O. and Eriksson, M.E. 2007. Diversification and biogeography of scolecodont-bearing polychaetes in the Ordovician. Palaeogeography, Palaeoclimatology, Palaeoecology 245: 95-114.

Kielan-Jaworowska, Z. 1962. New Ordovician genera of polychaete jaw apparatuses. Acta Palaeontologica Polonica 7: 291-325.

Wooster’s Fossil of the Week: A helpful echinoid from the Upper Cretaceous of Israel

April 27th, 2014

Echinoids a 042214These beaten-up fossils have served me well in the field this month. They are the regular echinoid Heterodiadema lybicum (Agassiz & Desor, 1846). They are common in the Cenomanian throughout northern Africa and the Middle East. These particular specimens, the other sides of which are shown below, are from the En Yorqe’am Formation we’ve been studying here on the rim of Makhtesh Ramon, southern Israel. When I find them in abundance I know I’m in the top half of that formation. They’ve previously been featured indirectly as a Fossil of the Week for the bites they made into the shells of oysters, producing the trace fossil Gnathichnus.
Echinoids b 042214The species Heterodiadema lybicum was named by Pierre Jean Édouard Desor (1811-1882) in 1846. We’ll meet him in a later entry. The genus Heterodiadema was erected in 1862 by Gustave Honoré Cotteau (1818-1894), who is pictured below. There is not much at all about Cotteau in the English literature, but with Google Translate I was able to sort out a bit of his story from the French. He was one of those glorious amateurs who make such important contributions to the science of paleontology. (I like the new term “citizen scientists” for this group, although I emphasize I’m a citizen too!) Cotteau was a judge in Auxerre, Burgundy, France. In his spare time he had a passion for living and fossil echinoids, eventually amassing a collection of over 500 species. He was also, as you might guess, a volunteer curator of the city museum in Auxerre. In 1889 he was President of the Société zoologique de France, a highly prestigious position. He was an important force in the early understanding of echinoderms.
Cotteau GustaveAgain, these specimen photos were taken under “field conditions” in Israel with a cleaner’s cloth for a background. As you read this, though, I am with luck back in my cozy home in Wooster.

References:

Agassiz, L. and Desor, P.J.E. 1846. Catalogue raisonné des familles, des genres, et des espèces de la classe des échinodermes. Annales des Sciences Naturelles, Troisième Série, Zoologie 6: 305-374.

Geys, J.F. 1980. Heterodiadema libycum (Agassiz & Desor, 1846), a hemicidaroid echinoid from the Campanian of Belgium.  Anales de la Societe geologique du Nord 99: 449-451.

Smith, A.B., Simmons, M.D. and Racey, A. 1990. Cenomanian echinoids, larger foraminifera and calcareous algae from the Natih Formation, central Oman Mountains. Cretaceous Research 11: 29-69.

Among citizen scientists in southern Israel

April 24th, 2014

Zichor M2 M3 042414MITZPE RAMON, ISRAEL–Today Yoav Avni and I drove south to meet an enthusiastic group of naturalists in Arava of the Jordan Rift Valley. The group is led by Dr. Hanan Ginat and consisted of a micropaleontologist and three amateur collectors who have all added considerably to scientific knowledge. We did fieldwork together in the magnificent Menuha Formation (Upper Cretaceous). The outcrop above is the boundary between a middle unit of the Menuha (“M-2″) and the upper chalks (“M-3″) in Wadi Zichor.

Gidon and fossils 042414Here is Gidon and a fraction of his collection, which is mostly from the local Cretaceous. There were fossil types here I’ve never seen before. Like all good citizen scientists, he knows how to collect and observe with location and stratigraphic control, and he has learned an immense amount about fossils and the organisms they represent.

Winny home 042414We had tea in Winny’s desert house. The interior (and exterior) is dominated by delightful fossils (and many other objects). It is a classic desert-dweller’s home. The micropaleontologist Sarit is in the foreground. (I have only phonetic first names. I’ll collect last names later!)

Stratodus Winny 042414Winny collected this four-meter long Cretaceous fish named Stratodus. She must now be the world’s expert on its complex anatomy. It is just a taste of her other fossils, including a bryozoan-encrusted ammonite from the Ora Formation (Turonian) she freely and eagerly gave me for research.

Field party 042414The field party is here assembled to study a site where they helped find and excavate an Elasmosaurus plesiosaur — the first in Israel.

Menuha view 042414A view of the Menuha Formation in the Arava. This is an extraordinary outcrop, and you can tell by the minimal vegetation that this is the driest part of the Negev.

I very much enjoyed my time with this fun and dedicated crew. They reminded me so much of the naturalists I grew up with in my own desert home of Barstow, California. I made many connections here that will benefit future research programs and Independent Study projects for Wooster students. It was inspiring to see what joy these people have in pursuing their scientific passions, like all other citizen scientists I work with.

This was my last day of fieldwork on this expedition. Tomorrow the long trip home begins!

A 10K run into the Eocene of the Negev

April 20th, 2014

Horsha view 042014MITZPE RAMON, ISRAEL–Yoav and I had a long hike today into the Eocene succession of rock units in the northern Negev. We wanted to look especially at the Horsha Formation (Eocene, Lutetian) because it has some cool trace fossils and massively large oysters. Along the way there are also interesting features like submarine debris flows, thick chalk deposits, unconformities and faulting.

rainstorm 042014Despite the sunshine in the top image, we started the day with a thunderstorm at our back. It was the first time I’d heard thunder in Israel, and for awhile we contemplated in which rocky crevice we should take cover. (It’s not like we carry raingear with us here.) We did get rained upon, but not seriously.

Yoav and layer 042014Yoav is here looking at a thin limestone unit near the base of the Horsha Formation (at GPS 072; N 30.32537°, E 35.00653°). Note the sharp base and yellowish mineralization of the chalk.

Horsha traces 042014There are fantastic trace fossils in convex hyporelief on the base of this limestone layer.

Trace nummulitids 042014The small disks near this trace are nummulitid foraminifera. They are a major component of this limestone.

Horsha algae 042014There are also many broken bits of calcareous algae.

Giant oysters 042014These giant oysters are common in this unit. Some are bored, which you might be able to see in the specimen on the far left. We will return to this area tomorrow for continued exploration.

Negev Berry shrub large 042014On the long way back to the car we encountered this shrub. I wish I knew the name. Yoav said it was called “Bread of the Monks”, but that has led me nowhere. It may be Ochradenus baccatus, also known as sweet mignonette.

Negev Berry shrub close 042014I’m not one to eat wild plants I don’t know, but Yoav assured me the berries on this shrub were tasty. Indeed. Sweet like blueberries. Worth the risk!

Wooster’s Fossils of the Week: A scleractinian coral and its tube-dwelling symbionts (Middle Jurassic of Israel)

April 20th, 2014

MatmorCoral010114aI have a weakness for the beautiful scleractinian corals of the Matmor Formation (Middle Jurassic, Callovian-Oxfordian) of southern Israel. This particular specimen is Microsolena aff. M. sadeki from locality C/W-367 in Hamakhtesh Hagadol, southern Israel. (The “aff.” in the name means “affinities with”. It is a way of saying this looks like a particular species, but we’re not quite sure.) This is a place we’ve now had ten Wooster Team Israel expeditions, the latest of which was last summer. The corals are a prominent part of the very diverse fossil fauna there. Note in the above side view of the specimen the star-shaped corallites (which held individual polyps) each with radiating septa. In the middle of the view you can see a narrow tube covered by coral skeleton. (More on this below.)
MatmorCoral010114bThis is a top view of the coral. It has a generally flat base and an upper surface with extended knobs. Usually this particular species is flat across the top as well as the base, giving it a platter shape as in this previous Fossil of the Week.
MatmorCoral010114cFlip the coral over and we see how it is preserved. The skeleton was originally made of the mineral aragonite, which dissolved after the death and burial of the colony. The resulting void was filled with stable calcite, preserving even fine details of the septa (see below). This delicate preservation, though, is only of the exterior of the skeleton. The interior is coarsely crystalline calcite with no trace of internal coral structures. This preservation, then, is properly called a cast, not true replacement.
MatmorCoral010114tubeThese scleractinian corals had many symbionts (organisms that lived with them). Among them were tube-dwelling worms, probably polychaetes, that spread across the surface. We know this happened while the coral was alive because, as seen above, the septa sometimes grew over the tubes. The tubes themselves are here preserved in three dimensions because they are originally calcitic and did not dissolve after death and burial.

We have much to learn about these gorgeous Jurassic fossil corals of Israel. They are virtually unstudied and offer a great opportunity for comparing them to the global Jurassic coral world.

References:

Martin-Garin, B., Lathuilière, B. and Geister, J. 2012. The shifting biogeography of reef corals during the Oxfordian (Late Jurassic). A climatic control?. Palaeogeography, Palaeoclimatology, Palaeoecology 366: 136-153.

Pandey, D.K., Ahmad, F. and Fürsich, F.T. 2000. Middle Jurassic scleractinian corals from northwestern Jordan. Beringeria 27: 3-29.

Reolid, M., Molina, J.M., Löser, H., Navarro, V. and Ruiz-Ortiz, P.A. 2009. Coral biostromes of the Middle Jurassic from the Subbetic (Betic Cordillera, southern Spain): Facies, coral taxonomy, taphonomy, and palaeoecology. Facies 55: 575-593.

Wilson, M.A., Feldman, H.R., Bowen, J.C., and Avni, Y. 2008. A new equatorial, very shallow marine sclerozoan fauna from the Middle Jurassic (late Callovian) of southern Israel. Palaeogeography, Palaeoclimatology, Palaeoecology 263: 24-29.

Wilson, M.A., Feldman, H.R. and Krivicich, E.B. 2010. Bioerosion in an equatorial Middle Jurassic coral-sponge reef community (Callovian, Matmor Formation, southern Israel). Palaeogeography, Palaeoclimatology, Palaeoecology 289: 93-101.

Our camel friends in the Negev

April 18th, 2014

camel head 041814MITZPE RAMON, ISRAEL–It is a problematic relationship between camels and me. My first experience with a camel out here was watching one eat my lunch, bag and all, when I foolishly left it in the shade of the vehicle while I measured a section. My students and I have been dissuaded more than once from visiting a particular outcrop by aggressive, bellowing camels standing their ground and looked very, very big and toothy. I was thus a bit hesitant when Yoav just walked up to this beauty on our way to the center of Makhtesh Gadol. I followed and did just fine within touching distance. This is a female (hence the lack of attitude) and a pregnant one at that. She is part of a small herd owned by a Bedouin family that may or may not have an arrangement to graze animals in this nature reserve. She eased my camel anxieties.

camel bed fossils 041814After our encounter I realized that camels actually play a role in our work. This is one of our most productive fossils sites (“GPS 055″). It is an exposure of a marl in subunit 51 in the Matmor Formation. This is also a camel resting spot. They love the soft sediment, probably as a break from the rocky soil elsewhere. We thus find such dry camel wallows often in our explorations of the Matmor. By stirring up the marl, the camels unearth fossils that would otherwise lay hidden.

Random Echinoderm bits 041814Here is a random assortment of crinoid and echinoid bits found in this camel haven. If we ignore the poop and flies, and avoid the angry males, these camels have done us a scientific favor!

Wooster’s Fossil of the Week: An unusual scleractinian coral from the Upper Cretaceous of Israel

April 13th, 2014

Aspidiscus 041114aOriginally this was going to be a mystery fossil for a crowd-sourced identification while I’m here in Israel doing fieldwork, but through the wonders of the internet I finally found a match for the strange fossil above: it is the scleractinian coral Aspidiscus König, 1825 (Family Latomeandridae) Yoav Avni and I found several specimens in the lower third of the En Yorqe’am Formation (Upper Cretaceous, Cenomanian) in the Negev of southern Israel. I had never seen anything like it before.

The view above is of the upper surface of this discoidal fossil. There are several short and seemingly random ridges, which I learned later are called monticules in this genus. Each monticule has a series of septa, or thin vertical partitions. This was a compound coral, meaning it had multiple polyps on its surface, presumably each sitting on a monticule.
Aspidiscus 041114bThis is a reverse view of the En Yorqe’am variety of Aspidiscus. The pits appear to be molds of a gastropod on which the young coral must have recruited. It then grew centripetally, making a fine series of growth lines across a soft sediment.
Aspidiscus cristatus diagramThis diagram from Pandey et al. (2011) is a diagram of Aspidiscus cristatus found in the Cenomanian of Sinai, not too far from here. (This species is also found in Algeria, Tunisia, Spain, Greece, and Afghanistan — all in the Cenomanian.) Note that the center of A. cristatus has two large crossing monticules and the Israeli specimen does not. This is why I’m keeping it in open nomenclature — it doesn’t appear to be the same species. A. cristatus is found in the middle to early late Cenomanian; the En Yorqe’am specimen seems so far to be only in the early Cenomanian. This may mean the Israeli version is an older species. Both clearly liked living in marly shallow marine sediments.
Aspidiscus symbiontsHere’s the bonus: look at the round holes in the upper surfaces of these two specimens. These are caused by symbionts of some kind that lived within the growing coral. You can see best in the specimen on the right how the coral grew around the symbionts, producing a kind of tube. Nice.

Sorry for the lower quality of images this week. I’m photographing the fossils as best I can with a bedside lamp, a tiny tripod, and a shirt for background.

References:

Avnimelech, M. 1947. A new species of Aspidiscus from the Middle Cretaceous of Sinai and remarks on this genus in general. Eclogae geologicae Helvetiae 40: 294-298.

Gill, G.A. and Lafuste, J.G. 1987. Structure, repartition et signification paleogeographique d’Aspidiscus, hexacoralliaire cenomanien de la Tethys. Bulletin de la Societe Geologique de France 3: 921-934.

Pandey, D.K., Fürsich, F.T., Gameil, M. and Ayoub-Hannaa, W.S. 2011. Aspidiscus cristatus (Lamarck) from the Cenomanian sediments of Wadi Quseib, east Sinai, Egypt. Journal of the Paleontological Society of India 56: 29-37.

Field trip to the lesser known makhteshim at Har ‘Arif

April 10th, 2014

Har 'Arif 041014MITZPE RAMON, ISRAEL–We’ve talked a lot about makhteshim in this blog, with so much of our geological work located in Hamakhtesh Hagadol and Makhtesh Ramon. A makhtesh is essentially a breached anticline, usually with a single drainage running from it. There are two small makhteshim at Har ‘Arif that are rarely seen because it takes some effort to get to them (major dirt road challenges and a significant hike) and they are in a military area that has very limited access. The Geological Survey of Israel got permission to run a field trip up to the top of Har ‘Arif today, and I was privileged to go along. The image above is of Har ‘Arif (the peak in the middle) looking up through the axis of the larger of the two makhteshim here. Its elevation is 956 meters, and it is the ninth highest peak in Israel. It is noted for its craggy, angular top, which is unlike most other Negev mountains with their rounded or flattened outlines.

Geologist camp 041014We began the day with an early departure from Mitzpe Ramon to meet most of the team camped out near Har ‘Arif. Note as the sun rises the crew has jackets on. It was an unseasonably cool start.

Hike begins 041014The hike begins. The goal is the very tippy-top of the mountain, so lots of work ahead in this beautiful setting.

Group outcrop 041014As with any geology field trip, we stopped occasionally for lectures on the outcrops. These lectures were in Hebrew so I was a spectator. It’s funny that after awhile I could pick out what the major arguments were from the tone of voice and various hand gestures. Several participants (especially Yoav) kindly interpreted for me afterwards. We are here examining an outcrop of the Middle Triassic Raaf Formation. This is a unit low in the Triassic that is not seen elsewhere in Israel.

Ripples Gyrochorte 041014These are ripplemarks in a fine sandstone of the Gevanim Formation (Middle Triassic, Anisian). Note the trace fossils that are convex epirelief, meaning they are positive relief on the surface of the bed. They are of the ichnogenus Gyrochorte, an old friend of mine from the Jurassic of Utah.

View west Har 'Arif 041014We reached the top of the mountain after an arduous climb. The coordinates are N 30.42591°, E 34.734°. (Really, google map these numbers. I worked hard for them!) This is the view to the east looking over the Negev all the way to the mountains of Jordan. One limb of the smaller makhtesh is below.

Har 'Arif Makhtesh 041014Here is the larger of the two makhteshim, looking west from the top of Har ‘Arif. It is gorgeous. All the rocks making the floor and walls are Triassic. The ridge line in the far distance is the border with Egypt.

I’ll have more later on the abundant flowers of the Har ‘Arif area. Right now it is a much-anticipated bedtime for me!

A mission in the Cretaceous of southern Israel

April 9th, 2014

Wadi Mishar viewMITZPE RAMON, ISRAEL–Today Yoav and I set out to solve a mapping dilemma concerning the boundaries of the Upper Cretaceous (Cenomanian) En Yorqe’am Formation in the Negev and, eventually, the Judean Desert to the north. It involved a bumpy ride deep into some of the most beautiful areas of the country, and it produced all sorts of delicious paleontological and sedimentological mysteries. I’ll talk more about this trip in later entires. Since it was 12 hours and I get up at 4:00 a.m. tomorrow, this is a truncated entry!

The setting is the stratigraphy of the En Yorqe’am and its bounding units: the Hevyon Formation below and the Zafit Formation above. Our job was to examine the contacts between these units and help come up with consistent definitions that can be used throughout the region. Right now there is considerable fuzziness as to where each formation begins and ends. Above is a labeled image showing the magnificent outcrop in Wadi Mishar (taken from our studied section at N 30.54899°, E 34.98843°).

Oysters En Yorqeam 040914In the process of sharpening the definition of the En Yorqe’am, we found some magnificent fossils. There are many paleontological and sedimentological projects possible in this unit. Oysters dominate the En Yorqe’am in most places we visited. Above is a close view of one outcrop (at N 30.65788°, E 35.08764°; Nahal Neqarot) showing that the sediment is almost entirely oyster. The shells are often beautifully bored, but strangely there are virtually no encrusters.

Stromatoporoid En Yorqeam 040914To our surprise, we found these large roundish objects that look very much like stromatoporoids (at N 30.65788°, E 35.08764°). The lack visible mamelons (or corallites, for that matter), but internally they appear to show the typical laminations and pillars of these calcareous sponges. I’ve never seen them in the Cretaceous before, which is at the end of their range. I could be wrong and these fossils are odd altered corals. Only cutting and polishing will tell.

Terebratulids En Yorqeam 040914Also unexpected was the prevalence of brachiopods in parts of the En Yorqe’am (at N 30.65788°, E 35.08764°). These are articulated terebratulid brachiopods. They look very Jurassic in their appearance, but here they are in the Upper Cretaceous.

I’m looking forward to working with Wooster students on these outcrops next year! More on the En Yorqe’am later this week.

Cretaceous echinoderms are today’s stars

April 8th, 2014

Zichor 040814MITZPE RAMON, ISRAEL–There’s a joke in the title, in case you didn’t notice! I was on my own for my second day of fieldwork in southern Israel. I revisited yesterday’s outcrops of the Upper Cretaceous (Coniacian) Zichor Formation, taking more time to plot out future section-measuring and fossil-collecting sites for students. I was also able to spend a lot of classic nose-on-the-ground time sorting out the fossils.

The outcrop above is about the top half of the Zichor Formation in this area (N 30.30587°, E 34.96543°). Note the cemented limestones near the top and the soft marls in the foreground. Both have plenty of fossils, but you can imagine which is easier to collect from.

Filograna? 040814One mystery of this unit is at the very top of the section in one of the last bedding planes. There are extensive amounts of a twisty worm-tube called Filograna (or at least something close to it). You can see it in the above image. I was told earlier it was a “mat”, but it appears to be instead broken fragments of tube accumulations scattered about. Strange critter, this worm.Echinoid tests 040814The marls of the Zichor have an impressive echinoderm content. Since they have calcitic tests, they are very well preserved. Above are five heart urchins showing their classic pentameral symmetry.

Echinoid test plates 040814Here are fragments of a cidaroid echinoid test. In the middle of each plate is a circle with a boss extending outwards. Spines were attached to these, one of which is included in the image. I hope on our later expedition we can find whole specimens. Students are always up for these discovery challenges.

Asteroid ray oral 040814This was a first find for me: an asteroid (sea star) ray fragment. I don’t think I’ve ever found a sea star fossil before. We are looking above at the oral side where tube feet would have extended.

Asteroid ray aboral 040814This is the other side of the fragment — the aboral side. Beyond being cool, I’m afraid there is not a lot of significance for this fossil unless I can identify it further. Sea stars are famous for living in all sorts of marine environments, from the intertidal to deep trenches.

Some future Wooster students are going to have a good time with this unit sorting out the paleontological, sedimentological and stratigraphic contexts and then comparing this tropical fauna to the better known assemblages in the temperate north.

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