Wooster’s Fossils of the Week: Bivalve borings, bioclaustrations and symbiosis in corals from the Upper Cretaceous (Cenomanian) of southern Israel

October 17th, 2014

Fig. 2 Aspidiscus1bw_scale 585The stark black-and-white of these images are a clue that the fossil this week has been described in a paper. Above is the scleractinian coral Aspidiscus cristatus (Lamarck, 1801) from the En Yorqe’am Formation (Cenomanian, Upper Cretaceous) of southern Israel. The holes are developed by and around tiny bivalves and given the trace fossil name Gastrochaenolites ampullatus Kelly and Bromley, 1984. This specimen was collected during my April trip to Israel, a day recorded in this blog. I crowd-sourced the identification of these corals, and they were highlighted as earlier Fossils of the Week. Now I’d like to describe them again with new information, and celebrate the publication of a paper about them.

En Yorqe'am040914aThis is the exposure of the En Yorqe’am Formation where Yoav Avni and I collected the coral specimens approximately 20 meters from its base in Nahal Neqarot, southern Israel (30.65788°, E 35.08764°). It is an amazingly fossiliferous unit here with brachiopods, stromatoporoid sponges, zillions of oysters, gastropods, ammonites and the corals.

The abstract of the Wilson et al. (2014) paper tells the story: “Specimens of the small compound coral Aspidiscus cristatus (Lamarck, 1801) containing evidence of symbiosis with bivalves have been found in the En Yorqe’am Formation (Upper Cretaceous, early Cenomanian) of southern Israel. The corals have paired holes on their upper surfaces leading to a common chamber below, forming the trace fossil Gastrochaenolites ampullatus Kelly and Bromley, 1984. Apparently gastrochaenid bivalve larvae settled on living coral surfaces and began to bore into the underlying aragonitic skeletons. The corals added new skeleton around the paired siphonal tubes of the invading bivalves, eventually producing crypts that were borings at their bases and bioclaustrations at their openings. When a boring bivalve died its crypt was closed by the growing coral, entombing the bivalve shell in place. This is early evidence of a symbiotic relationship between scleractinian corals and boring bivalves (parasitism in this case), and the earliest record of bivalve infestation of a member of the Suborder Microsolenina. It is also the earliest occurrence of G. ampullatus.”

Fig. 3 BoringPair2bw_scale 585 Paired apertures of Gastrochaenolites ampullatus in the coral Aspidiscus cristatus.

Fig. 4 EmbeddedBivalve1bw_scale_rev 585Polished cross-section through a specimen of Gastrochaenolites ampullatus in an Aspidiscus cristatus coral. In the lower left of the chamber are layered carbonates (A) representing boring linings produced by the bivalve. An articulated bivalve shell (B) is preserved in the chamber. The chamber has been roofed over by coral growth (C).

Thank you very much to Tim Palmer and Olev Vinn for their critical roles in this paper, and, of course, thanks to Yoav Avni, the best field geologist I know.


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.

Kleemann, K., 1994. Associations of corals and boring bivalves since the Late Cretaceous. Facies 31, 131-140.

Morton, B. 1990. Corals and their bivalve borers: the evolution of a symbiosis. In: Morton, B. (Ed.), The Bivalvia: Proceedings of a Memorial Symposium in Honour of Sir Charles Maurice Yonge (1899-1986) at the 9th International Malacological Congress, 1986, Edinburgh, Scotland, UK. Hong Kong University Press, Hong Kong, pp. 11-46

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.

Wilson, M.A., Vinn, O. and Palmer, T.J. 2014. Bivalve borings, bioclaustrations and symbiosis in corals from the Upper Cretaceous (Cenomanian) of southern Israel. Palaeogeography, Palaeoclimatology, Palaeoecology 414: 243-245.


Wooster’s Fossil of the Week: A barnacle and sponge symbiosis from the Middle Jurassic of Israel

July 4th, 2014

Barnacle boring bioclaustration 1

[Programing note: Wooster's Fossil of the Week is now being released on Fridays to correspond with the popular Fossil Friday on Twitter and other platforms.]

This week’s fossil is again from the Matmor Formation (Middle Jurassic, Callovian) of southern Israel. (What can I say? We have a lot of them!) We are looking above at a crinoid pluricolumnal (a section of the stem made of several columnals) almost completely encrusted by a calcareous sponge (the sheet-like form with tiny pores). A round oyster is attached to the sponge in the lower center. In the left half you see the items of our interest this week: ovoid holes produced by barnacles. This specimen was studied by Lizzie Reinthal (’14) as part of her Senior Independent Study on the taphonomy of the Matmor crinoids.
Barnacle boring bioclaustration 2These barnacle holes are interesting because we can see in this closer view that the sponge grew around them. There is thickened sponge wall at the margins of the holes, and the feature in the middle is a thick mound built around one of these holes. The barnacles in the holes and the sponge were living together. If they weren’t either the sponge would have overgrown the empty holes or the barnacle would have cut through the dead sponge skeleton. This is an example of symbiosis. It would be a facultative relationship because the sponge and barnacle did not need each other to survive; each does just fine without the other. It could be considered parasitic if the barnacles acquired nutrients the sponge would have ordinarily received, or vice versa.
Barnacle boring bioclaustration 3This third view is of the edge of the sponge skeleton as it partially overlaps the barnacle holes. Now we see the nature of the intergrowth. The barnacle holes are actually borings into the crinoid pluricolumnal below. They are the trace fossil called Rogerella, which we have seen before in this blog. The sponge grew along the crinoid substrate covering all sorts of small holes, cracks and crevices, but when it reached these borings living barnacles were still in them filter-feeding away with their filamentous legs. The sponge thus laid its skeleton right up to the hole edges, eventually surrounding them with their spongy matrix.

The holes are borings, a kind of trace fossil. The structure created when the sponge surrounds a living boring barnacle like this is more difficult to name. It is not technically a bioimmuration (see Taylor, 1990) because the barnacles were not passively subsumed within the sponge skeleton. It may be a bioclaustration (Palmer and Wilson, 1988) because the sponge adapted its skeleton to isolate and surround the barnacle. I think we can at least say these are trace fossils in the ethological (behavioral) group called Impedichnia (Tapanila, 2005) because the barnacles acted as impediments, or limiting factors, to the growth of the sponge.

I love these examples of symbiosis in the fossil record, and the interesting debates about their interpretations.


Cónsole‐Gonella, C. and Marquillas, R.A. 2014. Bioclaustration trace fossils in epeiric shallow marine stromatolites: the Cretaceous‐Palaeogene Yacoraite Formation, northwestern Argentina. Lethaia 47: 107-119.

Palmer, T.J. and Wilson, M.A. 1988. Parasitism of Ordovician bryozoans and the origin of pseudoborings. Palaeontology 31: 939–949.

Tapanila, L. 2005. Palaeoecology and diversity of endosymbionts in Palaeozoic marine invertebrates: Trace fossil evidence. Lethaia 38: 89–99.

Taylor, P.D. 1990. Preservation of soft-bodied and other organisms by bioimmuration: A review. Palaeontology 33: 1–17.

Vinn, O. and Mõtus, M.A. 2014. Symbiotic worms in biostromal stromatoporoids from the Ludfordian (Late Silurian) of Saaremaa, Estonia. GFF (in press).

Wilson, M.A., Palmer, T.J. and Taylor, P.D. 1994. Earliest preservation of soft-bodied fossils by epibiont bioimmuration: Upper Ordovician of Kentucky. Lethaia 27: 269–270.

Research begins in southern Poland

June 16th, 2014

Gillette 061614SOSNOWIEC, POLAND — On this beautiful day I began research at the University of Silesia with Michał Zatoń and Tomasz Borszcz in this impressive building. (It is reportedly the tallest Earth Science building in the world, although the Chinese are on the case.) Our first project, and the one I will devote most of my remaining Polish time to, is an analysis of fish-bitten echinoid (sea urchin) spines from the Middle Jurassic Matmor Formation of southern Israel (see below).

Spine 173_bittenWe have dozens of these crunched rhabdocidarid spines, which are critical evidence of early predation on regular echinoids. We hope our work will help illuminate the evolution of predator adaptations in the echinoids, and the actions of the hungry fish. More on this later.

Spines arrayed 061614Here we have a simple sorting of the spines in relation to their likely position on the echinoid test (body skeleton). Pretty simple, but it was an easy way for us to discuss spine morphology and function.

Michal office 061614To give you a glimpse of my new surroundings, here is a view of Michał’s office. As with every working paleontologist, there are plenty of specimens, books and papers!

Office view 061614The view from Michał’s office of Sosnowiec.

Silesia dorms 061614This is looking from Michał’s department building towards a series of dormitories for students at the University of Silesia.

Lunch 061614You know at some point I need to show some Polish food. This is today’s lunch. Note the crunchy latke and the pierogis. You pay for this food by its weight on the plate. This scrumptiousness plus a Sprite cost me $4.

Hotel Cumulus 061614This is my hotel in neighboring Będzin.

Hotel area Będzin Castle 061614Będzin Castle, which is a short walk from my hotel. You can expect a history post coming up soon!


Wooster’s Fossil of the Week: A geopetal structure in a boring from the Middle Jurassic of Israel

June 15th, 2014

Geopetal Structure 585We have a very simple trace and body fossil combination this week that provides a stratigraphic and structural geologic tool. Above is a bit of scleractinian coral from the Matmor Formation (Middle Jurassic, Callovian) of Makhtesh Gadol in southern Israel. The coral skeleton was originally made of aragonite. It has been since recrystallized into a coarse sparry calcite, so we can no longer see the internal skeletal details of the coral. In the middle of this polished cross-section is an elliptical hole. This is a boring made by a bivalve (the trace fossil Gastrochaenolites). Inside the boring you see a separate elliptical object: a cross-section of a bivalve shell. This could be the bivalve that made the boring or, more likely, a bivalve that later occupied the boring for a living refuge. This, then, is the trace fossil (Gastrochaenolites) and body fossil (the bivalve shell) juxtaposition.

That stratigraphic and structural interest is that the boring and the bivalve shell are partially filled with a yellow sediment. This sediment has gravitationally settled to the bottom of these cavities (at slightly different levels). These holes have thus acted as natural builders’ levels showing is which way was down and which was up at the time of deposition. We can tell without any clues from the recrystallized coral the “way up” before any later structural deformation (or in this case rolling around on the outcrop) changed the orientation of the coral. Pretty cool and simple, eh? The name for this feature is a geopetal structure. There are some faulted and folded sedimentary rock exposures in the world where we search diligently for these little clues to original orientation (see, for example, Klompmaker et al., 2013). Not all geopetal structures have fossil origins (i.e., Mozhen et al., 2010), but most do. A little gift from paleontology to its sister disciplines.


Klompmaker, A.A., Ortiz, J.D. and Wells, N.A. 2013. How to explain a decapod crustacean diversity hotspot in a mid-Cretaceous coral reef. Palaeogeography, Palaeoclimatology, Palaeoecology 374: 256-273.
Mozhen, G., Chuanjiang, W., Guohui, Y., Xueqiang, S., Guohua, Z. and Xin, W. 2010. Features, origin and geological significance of geopetal structures in Carboniferous volcanic rocks in Niudong Block, Santanghu Basin. Marine Origin Petroleum Geology 3: 15.
Wieczorek, J. 1979. Geopetal structures as indicators of top and bottom. Annales de la Societé géologique de Pologne 49: 215-221.

Wooster Geologist on the Baltic Coast

June 11th, 2014

HotelBalconyView061114SOPOT, POLAND — Yes, that’s a view from my hotel window. I’ve suddenly found myself in an old resort town on the Baltic coast of Poland near the cities of Gdansk and Gydnia. Another one of those astonishing geographic transformations we can so easily make.

I’m here for the Larwood Meeting, an annual gathering of bryozoologists held in various places around the world. Besides learning more about these complex little colonies (both fossil and recent), I’ll be presenting a summary of the work Steph Bosch (’14), Paul Taylor and I did on the new bryozoans from the Middle Jurassic of southern Israel. After the meeting I travel south by train with Tomasz Borszcz to visit Michal Zaton at the University of Silesia for some joint projects. From there it is on to London for a few days with ace paleontologist Paul Taylor at the Natural History Museum. I’m at the end of a research leave this summer so I have more travel than usual.

For now I’m enjoying an extraordinary day on the Baltic shore before the first meeting event this evening. My next images will be much more prosaic! My posts will be a bit shorter than usual because I have to stand in the shower to get enough wireless signal to connect. (There’s an accident waiting to happen …)

Wooster’s Fossil of the Week: A fragment of an asteroid (the sea star kind) from the Upper Cretaceous of Israel

June 8th, 2014

zichor asteroid aboral 585This is not an important fossil — there is not enough preserved to put a name on it beyond Family Goniasteridae Forbes, 1841 (thanks, Dan Blake) — but it was a fun one to find. It also photographs well. This is a ray fragment of an asteroid (from the group commonly known as the sea stars or starfish) I picked up from the top meter of the Zichor Formation (Coniacian, Upper Cretaceous) in southern Israel (Locality C/W-051) on my field trip there in April 2014. We are looking at the aboral (or top) surface; below is the oral view.
zichor asteroid oral surface 585In this oral perspective you can see a group of tiny, jumbled plates running down the center. This is the ambulacrum, which in life had a row of tube feet extending out for locomotion and grasping prey.
asteroid 2004Above is a sea star held by my son Ted on Long Island, The Bahamas, back in 2004. You can see a bit of resemblance between this modern species and the Cretaceous fossil, mainly the  large knobby ossicles running down the periphery of the rays.

The asteroids have a poor fossil record, at least when compared to other echinoderms like crinoids and echinoids. It appears that all post-Paleozoic asteroids derive from a single ancestral group that squeaked through the Permian extinctions (Gale, 2013). There is a significant debate about the evolution of the asteroids (see Blake and Mah, 2014, for the latest). Unfortunately our little critter is not going to help much in its resolution.

Recently it has been discovered that some living asteroids have microlenses in their ossicles to provide a kind of all-surface photoreception ability. Gorzelak et al. (2014) have found evidence that some Cretaceous asteroids had similar photoreceptors. Maybe our fossil goniasterid fragment could yield this kind of secret property with closer examination.


Blake, D.B. and Mah, C.L. 2014. Comments on “The phylogeny of post-Palaeozoic Asteroidea (Neoasteroidea, Echinodermata)” by AS Gale and perspectives on the systematics of the Asteroidea. Zootaxa 3779: 177-194.

Gale, A.S. 2011. The phylogeny of post-Paleozoic Asteroidea (Neoasteroidea, Echinodermata). Special Papers in Palaeontology 38, 112 pp.

Gale, A.S. 2013. Phylogeny of the Asteroidea, p. 3-14. In: Lawrence, J.M. (ed.), Starfish: Biology and Ecology of the Asteroidea. The Johns Hopkins University Press, Baltimore.

Gorzelak, P., Salamon, M.A., Lach, R., Loba, M. and Ferré, B. 2014. Microlens arrays in the complex visual system of Cretaceous echinoderms. Nature Communications 5, Article 3576, doi:10.1038/ncomms4576.

Loriol, P. de. 1908. Note sur quelques stellérides du Santonien d’Abou-Roach. Bulletin de l’Institut égyptien 2: 169-184.

Mah, C.L. and Blake, D.B. 2012. Global diversity and phylogeny of the Asteroidea (Echinodermata). PLOS ONE 7(4), e35644.

Wooster’s Fossil of the Week: My favorite part of a crinoid (Middle Jurassic of Israel)

June 1st, 2014

Apiocrinites negevensis proximale 585In April of this year I completed my 11th trip to southern Israel for fieldwork in the Mesozoic. My heart warmed every time I saw these robust plates of the crinoid Apiocrinities negevensis, which was reviewed in a previous blog post. They are thick disks of calcite with a heft and symmetry like exotic coins. They are easy to spot in the field because of their size and incised perfect star. They have been a critical part of our paleoecological and systematic studies of the Matmor Formation (Callovian, Middle Jurassic) in the Negev. Lizzie Reinthal (14) and Steph Bosch (14) know them particularly well!
negevensis proximales 1This part of the crinoid is called the proximale. It has a round base that articulates with the columnal below it in the stem, and its top has five facets that hold the basal plates of the calyx. It is thus the topmost columnal, specialized to serve as the integration between the articulated stem below and the complicated head above. The pentastellate (five-armed star, but you probably figured that out) impression is called the areola. In the very center is the open hole of the lumen, which goes from the head all the way down through the stem to the holdfast as an internal fluid-filled cavity.
Composite Miller Apiocrinites arrowedAbove are Miller’s (1821) original illustrations of Apiocrinites rotundus with the proximale shown by the red arrow. Note how thin this piece is compared to the equivalent from Apiocrinites negevensis. The significant thickness of the proximale is one of the distinguishing features of the Negev species.

I saw many more of these beautiful fossils in the field this year. We don’t need any more for our research, but they always indicate that other good fossils are nearby.


Ausich, W.I. and Wilson, M.A. 2012. New Tethyan Apiocrinitidae (Crinoidea; Articulata) from the Jurassic of Israel. Journal of Paleontology 86: 1051-1055.

Miller, J.S. 1821. A natural history of the Crinoidea or lily-shaped animals, with observation on the genera Asterias, Euryale, Comatula, and Marsupites. Bryan & Co, Bristol, 150 pp.

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.

Wooster’s Fossil of the Week: One sick crinoid from the Middle Jurassic of Israel

May 11th, 2014

IsocrinidAMy first thought on seeing this distorted fossil was how much it evoked one of those Palaeolithic “Venus figurines“. It is certainly difficult to deduce that this is actually a crinoid column (or stem). It was found during my last expedition to the Middle Jurassic Matmor Formation in Makhtesh Gadol, southern Israel (location C/W-506). This particular crinoid was infected by parasites that caused the grotesque swellings of the skeletal calcite in the individual columnals (button-like sections of the column). The infection of a species of Apiocrinites in the Matmor is the subject of a paper now in press by me, Lizzie Reinthal (’14) and the pride of Ohio State University, Dr. Bill Ausich. That story will be a later Fossil of the Week entry. The specimen above, though, is different. To my surprise, it is a parasitic infection in an entirely different crinoid order.

IsocrinidBHere’s another view of the crinoid column. The top third shows some of the original star-shaped columnals in side view. This tells us that the crinoid was an isocrinid, possibly the cosmopolitan Isocrinus nicoleti. This group contains the famous and somewhat creepy crawling crinoids. We have just a handful of isocrinid stem fragments in the Matmor despite a decade of searching for a distinctive calyx (the head of the little beast). Note that the gall-like swellings have holes in them. This will be important in a later analysis of the parasitic system here.

IsocrinidCAnd now the other side of the fossil. Again, in the top part you can make out star-shaped columnals, but that distinctive outline is lost in the swollen column below. The stem must have been seriously hindered from flexing and bending with such a debilitating infection.


Salamon, M.A. 2008. The Callovian (Middle Jurassic) crinoids from northern Lithuania. Paläontologische Zeitschrift 82: 269-278.

Tang, C.M., Bottjer, D.J. and Simms, M.J. 2000. Stalked crinoids from a Jurassic tidal deposit in western North America. Lethaia 33: 46-54.

Wilson, M.A., Reinthal, E.A. and Ausich, W.I. 2014. Parasitism of a new apiocrinitid crinoid species from the Middle Jurassic (Callovian) of southern Israel. Journal of Paleontology (in press).

Last work of Team Israel, Matmor Division

May 5th, 2014

Team Israel 050514WOOSTER, OHIO–Steph Bosch (’14) and Lizzie Reinthal (’14) volunteered to examine the Matmor Formation fossils I collected last month in Israel. Each fossil, most of which are crinoid ossicles, must be scanned under a microscope for tiny encrusters (especially bryozoans), borings, and bite marks. In the image above you can see the collection bags on the left and our three ‘scopes arranged so that we can exchange interesting bits that we find. I had planned to do this work all by my lonesome, and it would have taken a full day. With Steph and Lizzie, though, we were done in an hour and a half. No wonder — they’ve spent the last year doing this kind of analysis!

Israel specimens 050514And here are the results. Each paper tray has a particular category of fossil from a specific location. We found many little (and I mean little) treasures that my future students and I can now study. I’m grateful for the expert help.

Team Israel 2013 will be graduated a week from today. Congratulations to them!

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.


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.

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