The Triassic limestones at Góra Świętej Anny, Poland

June 18th, 2014

Gora sw. Anny signSOSNOWIEC, POLAND — My friends Michał Zatoń and Tomasz Borszcz took me on a very pleasant day trip to Góra Świętej Anny in southwestern Poland about an hour’s drive northwest from Sosnowiec. This is a place of considerable geological and historical interest. It is an eroded volcanic caldera and the easternmost occurrence of the fine-grained igneous rock basalt in Europe. You would think I’d be able to show you at least a bit of basalt, but we saw only the surrounding Middle Triassic limestone country rock. (Sorry, Dr. Pollock.) We’ll talk about the history later. Now we’ll look at the geology.

Muschelkalk long 061814Here is a great exposure of the Muschelkalk, a Middle Triassic sequence of limestones and dolomites that extends across central and western Europe. This is its best exposure in Poland. The rock appears very massive in this old quarried wall, but it actually has many distinct layers. Michał is standing at the top of stairs that lead down into a massive Nazi amphitheater called a Thingstätte, but more on this later.

Muschelkalk brachs 061814Part of the Muschelkalk unit is dominated by terebratulid brachiopods, many of which are seen on this slab.

Triassic encrinite 061814The topmost Muschelkalk here contains thick beds made primarily of crinoid skeletal debris, a kind of deposit known as an encrinite. We’ve seen encrinites before in this blog.

trace fossil sign 061814You don’t often see informative signs dedicated to the description of a trace fossil type. Rhizocorallium commune is the most common ichnofossil in this part of the Muschelkalk. It is a ropy, loopy tube produced in this case by crustaceans, probably including the decapod shrimp Pemphix.

Rhizocorallium 061814The slabs used to pave the walks and plazas in this area are filled with Rhizocorallium commune traces.

View 061814Finally, this is a view west from Góra Świętej Anny towards the Oder River. It is the highest place around, dominating this fertile valley rich with farms, mines and factories. This will be the reason it is so culturally and historically significant in Silesia.

A new Polish colleague (and cool dinosaur model)

June 17th, 2014

T rex 061714SOSNOWIEC, POLAND — The above full-scale model of Tyrannosaurus rex is one of my favorite dinosaur reconstructions. It sits in front of the Earth Sciences Building at the University of Silesia. Since it is outside the lighting is always dramatic, and the artists paid close attention to even tiny details like the reported coat of downy feathers on its back (see below).

T rex feathers 061714The roughening you see in the upper half of the image represents the feathery covering. We can only imagine what colors were present in the original.

Alina MW 061714Here is a new Polish colleague I met this morning. Alina Chrząstek is a paleontologist at the University of Wroclaw. She is a specialist in invertebrates and trace fossils. A few months ago she sent me photos of rock and fossil specimens she had questions about, and I told her we could meet when I was in Poland. She came today with boxes and bags of specimens, a few of which are shown below.

Erratics collection 061714These are glacial erratics from a moraine in southwestern Poland. They are rocks of a variety of types and ages scraped up by glaciers in the north and deposited in the south. Alina is sorting through what fossils are in them. It is a fun collection because it contains rocks from the Cambrian to the Cenozoic, with all manner of trace and body fossils. They can be quite a challenge to identify because the stratigraphic context is gone.

Half my day was spent writing, so I have nothing else to report. Tomorrow, though, is going to contain a field trip to the Góra Świętej Anny Mountain. (I hope everyone is noticing how hard I work at getting the Polish letters correct!)

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.

References:

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.

The last presentations of the 2014 Larwood Meeting, including a sober reminder for paleontologists

June 13th, 2014

pdt lecturing 061314SOPOT, POLAND — This morning we had the final set of talks at Larwood 2014. Out of all the presentations, the one that struck me the most was by Paul Taylor and Andrea Waeschenbach entitled “Molecular phylogeny and the adequacy of skeletal characters in cyclostome taxonomy: The alarming case of Diaperorcia purpurascens.” Paul is shown delivering it above. This project represents the best of what these bryozoan conferences are about: the combination of biology and paleontology to further our understanding of the evolution and ecology of this large phylum. It also warned paleontologists to never be complacent about the value of morphology (shape and form) for sorting out systematic and evolutionary relationships.

Diaperoecia purpurascens is a “fixed-walled, tubuliporine” cyclostome bryozoan species common in New Zealand waters today. Molecular sequence data, though, shows it is without a doubt within the “free-walled cerioporine” cyclostome genus Heteropora. You don’t need to know why those terms actually mean to understand that the molecular work has shown that two dissimilar groups share a surprisingly close common ancestor — so close that the systematics are now fully disrupted. When we knew only the morphology of these bryozoans the differences between them were apparent at a high taxonomic level. Now that we have molecular data it is brutally clear that our reliance on shape and form to separate the groups was an illusion. Molecules trump skeletal evidence — and all paleontologists have to work with are the skeletons.
pdt image 2 061314Paul and Andrea did find, though, that in the early colony growth (astogeny) of these bryozoan groups they share a common pattern of tiny pores (pseudopores) on the earliest portion of the colonial skeleton (the protoecium; see above and below). It is this morphological feature, as subtle as it is, that shows the groups share a close common ancestor.
pdt slide 1 061314The lesson is that paleontological systematics are always provisional. We do our best with morphology alone because that’s what we have, but we should be forever haunted by the knowledge that we lack full biological evidence.

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.

References:

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.

References:

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: A fly in amber

May 25th, 2014

Fly in amber 012614A classic fossil this week. I wish I could say more about it. The specimen lost its label years ago, so I don’t know where it is from or its age (although a good guess is Neogene). I also can’t identify it with my skill set beyond “fly” (Order Diptera). Beautiful, though. The images were not easy to make. I used our photomicroscope and played with a combination of light from below (transmitted) and above (reflected). The polished amber fragment is about the size of a pea and the fly is near the middle of it.
Fly legs in amber 012614A closer view here of the legs. Each segment can be seen, along with their tiny spines. This seems to be a particularly long-legged fly.

Preservation in amber is a well known phenomenon. An insect like ours gets itself trapped in a drop of tree resin. The resin hardens into amber by losing much of its volatile content with heat over time. Polish the piece and you can peer inside and see the occasional treasures of three-dimensionally preserved organisms. Oddly enough, in most cases these fossils are hollow external molds with no internal tissues preserved. What we see is the outside of this cavity with pigments embedded in the amber. (This fly has gorgeous red eyes, for example.) Remember the Jurassic Park premise that dinosaur DNA had been recovered from blood in a mosquito’s belly preserved in Dominican amber? It just doesn’t happen. In fact, a recent study (Penney et al., 2013) showed that insect DNA doesn’t even survive in sub-fossil assemblages.

I know from experience that it is very easy to be fooled by fake amber. As a policy, I’ve learned to not buy it in an Estonian open market (just as an example!). After Jurassic Park appeared, the demand for amber shot up, especially if it had animals in it. Artificial amber, and amber made from shavings and fragments (“pressed amber”) flooded the market. Caveat emptor. I tested our piece and it passed.

For more images of insects in amber, please follow the link or just search “amber”.

References:

Penney, D. 2002. Paleoecology of Dominican amber preservation: spider (Araneae) inclusions demonstrate a bias for active, trunk-dwelling faunas. Paleobiology 28: 389-398.

Penney, D., Wadsworth, C., Fox, G., Kennedy, S.L., Preziosi, R.F. and Brown, T.A. 2013. Absence of ancient DNA in sub-fossil insect inclusions preserved in ‘Anthropocene’ Colombian copal. PloS one 8(9), e73150. DOI: 10.1371/journal.pone.0073150

Poinar Jr, G.O. 1993. Insects in amber. Annual Review of Entomology 38: 145-159.

Wooster’s Fossils of the Week: “Star-rock” crinoids from the Middle Jurassic of Utah

May 18th, 2014

Isocrinus_nicoleti_Encrinite_Mt_Carmel_585This little slab of crinoid stem fragments comes from the Co-op Creek Member of the Carmel Formation (Middle Jurassic) exposed in northwestern Kane County, Utah. I collected it with my friend Carol Tang as we explored a beautiful encrinite (a rock dominated by crinoid skeletal debris) exposed near Mount Carmel Junction. In 2000, Carol and her colleagues published a description and analysis of this unit and its characteristic crinoid, Isocrinus nicoleti (Desor, 1845). This piece sits on a shelf in my office because it is so ethereal with its star-shaped columnals (stem sections). In fact, the local people in the area collect pieces of the encrinite and sell them as “star rocks“. As I recall, some folks were rather territorial about the outcrops!

Isocrinus nicoleti is one of only three crinoid species known in the Jurassic of North America. (The others are I. wyomingensis and Seirocrinus subangularis.) Tang et al. (2000) showed that this species migrated into southwestern North America by moving southward through a very narrow seaway for thousands of kilometers. I. nicoleti had long stems and relatively small crowns, so it left us zillions of the columnals and very few calices. These washed into large subtidal dunes creating the cross-bedded encrinite.
Isocrinus asteriaThe genus Isocrinus is still alive, most notably in the deep waters around Barbados in the Caribbean. Above is a diagram of Isocrinus asteria originally published by Jean-Étienne Guettard in 1761. The long stem is star-shaped in cross-section.
Pierre Jean Edouard DesorThis gentleman is Professor Pierre Jean Édouard Desor (1811-1882), who named Isocrinus nicoleti in 1845. He is shown here 20 years later. Desor was a German-Swiss geologist who studied two very disparate subjects: glaciers and Jurassic echinoderms. He trained as a lawyer in Germany, but got caught up in the democratic German unity movement of 1832-1833 and had to flee to Paris. In 1837 he met Louis Agassiz and began to collaborate with him on a variety of projects paleontological and glaciological. He even had a trip to the United States where he helped survey the coast of Lake Superior. He took a position as professor of geology at the academy of Neuchâtel, Switzerland, in 1852, eventually retiring in genteel affluence. (This is not how these geological biographies usually end!)

References:

Ausich, W.I. 1997. Regional encrinites: a vanished lithofacies. In: Brett, C.E. and Baird, G.C. (eds.): Paleontological Events, p. 509-519. Columbia University Press, New York.

Baumiller, T.K., Llewellyn, G., Messing, C.G. and Ausich, W.I. 1995. Taphonomy of isocrinid stalks: influence of decay and autotomy. Palaios 10: 87-95.

Desor, É. 1845 Résumé de ses études sur les crinoides fossilies de la Suisse. Bulletin de la Societe Neuchateloise des Sciences Naturelles 1: 211-222.

Hall, R.L. 1991. Seirocrinus subangularis (Miller, 1821), a Pliensbachian (Lower Jurassic) crinoid from the Fernie Formation, Alberta, Canada. Journal of Paleontology 65: 300-307.

Peterson, F. 1994. Sand dunes, sabkhas, streams, and shallow seas: Jurassic paleogeography in the southern part of the western interior basin. In: Caputo, M.V., Peterson, J.A. and Franczyk, K.J. (eds.): Mesozoic Systems of the Rocky Mountain Region, USA, p. 233-272. Rocky Mountain Section-SEPM, Denver, Colorado.

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.

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