Archive for July 4th, 2014

An evening dinner in Guiyang, China

July 4th, 2014

Guiyang Dinner 070414GUIYANG, CHINA — After the long flights from Shenyang via Nanjing, Team China (let’s just call it that!) arrived in Guiyang, the capital of Guizhou Province. We had an excellent view of the surrounding karstic mountains. I hope to have images of these tomorrow because they are simply enchanting. Above is our evening dinner, hosted by two men from the city. On the far left is Guan Changqing, an associate professor of geology at Northeastern University, then Wang Lin Song, chief engineer of a steel company in Guiyang, Professor Gong En-Pu from the Geology Department of Northeastern University (and our leader), Guo Shu Wei, a senior engineer at the local steel company, and me. Zhang Yongli took the photo with my iPhone. A classic Guizhou dinner is before us. It was very good. Among the many toasts, Yongli and I managed to get one in to the Fourth of July.

Sea cucumber dish 070414One of the dishes contained these green slices of holothurian (sea cucumber). Turns out this delicacy is specially provided for honored guests, so I have now eaten my first echinoderm. I can cross them off the list of invertebrate phyla to taste. I’m sure I’ll have many more culinary surprises.

Speaking of surprises, just before bedtime a team of policemen visited my room asking many questions and studying my passport and visa closely. I’m assured this is standard practice when a foreigner comes to town.

Tomorrow we drive for about three hours to Ziyun County for the start of our fieldwork.

 

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.

References:

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.