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Lab 7: Observations

How This Lab Will Work 1. Open a Word doc or similar on your computer 2. At various points I will ask you to answer a question based on the activities in this lab. 3. I will indicate these points by this symbol:

Please answer these questions in your Word doc.

4. After you have assembled the answers into your Word doc, go to the course Canvas page. 5. On the module for this week there is a link to TurnItIn. 6. Please upload your document using the TurnInIt. 7. That completes the lab assignment. :)

Reminder on Observation Project Please remember that as we go through these, you should be using these fossils to construct your lab observation project, which was detailed last time. Easy to put off, hard to catch up. ;)

Topics Today 1. Trace fossils 2. Archaeaocyathids 3. Graptolites 4. Brachiopods 5. 6. 7. Anomalocaris

Trace Fossils Before we find body fossils in the , there is a long period (nearly 10 million years) where what we primarily see are are the traces left behind by soft-bodied organisms. Trace fossils are also called ichnofossils. These can fall into a variety of shapes and classifications, as shown in this diagram:

Geology 121 Lab 7: Early Paleozoic, page 1 of 9

1. What kind of organisms might have had the right body shape to make these traces? ______

2. Skolithos https://sketchfab.com/3d-models/ichnofacies-skolithos-81daf7ea1f49436c89222bd4e0fd8619

Given the orientation in the 3d model and in the diagram above, what direction do you think is up? ______

What modern marine organisms make burrows in a similar way? ______

3. Cruziana. Trilobites leave very distinctive marks representing their “scuttling” along the bottom. https://sketchfab.com/3d-models/trilobite-cruziana-8362f7f7c07a4fd1abeadf9f11e6cc1e

How can we determine which direction the was going? ______

Please answer these questions in your Word doc.

Geology 121 Lab 7: Early Paleozoic, page 2 of 9 Archaeocyathids Before there were proper porifera sponges, there were archaeocyathids, an extinct line of filter feeders that occupied the same niche as modern sponges.

Examine this diagram:

Try to identify these body parts in the archaeocyathid 3d model https://sketchfab.com/3d-models/porifera-archaeocyathid-08ef7e500f1648528221801f1a2e2b5a

4. How do modern sponges make their living? ______

5. Are they plants or or what? ______

6. If archaeocyathids could make a living in the same way as modern sponges, what does that tell you about the amount of living things at this time? ______

Please answer these questions in your Word doc.

Geology 121 Lab 7: Early Paleozoic, page 3 of 9 Graptolites https://sketchfab.com/3d-models/graptolite1-fd34dc93314a45839fc6588aceda3dfd https://sketchfab.com/3d-models/graptolite2-0918f7a9dc52474dbfd9951cbfbe488b

Graptolites are fascinating, poorly-understood creatures from the middle Cambrian to the . For a long time geologists did not comprehend the elongated, ridged shapes of these fossils. We now think these are part of a filter feeding apparatus.

At first these animals were colonial and fixed to the ocean floor; later graptolites were almost exclusively free-floating. Here’s what they might have looked like in life:

7. Does this look to you like a plant? an ? something else? ______

8. What about their shape suggests a filter-feeding lifestyle? ______

Please answer these questions in your Word doc.

Geology 121 Lab 7: Early Paleozoic, page 4 of 9 Brachiopods Brachs have a long, rich fossil history, and in fact are still among us today. I think of burrowing brachiopods as clam- like in their lifestyle; today they are more common in areas of the oceans not frequented by clams.

The kinds of brachiopods we see here are called inarticulata. Inarticulata do not have a toothed-hinge holding together the shell, but rather do this just with muscle. They tend to make shells from chitin and calcium phosphate.

Another type of brachiopod is the articulata, which do have a toothed-hinge; however, they’ll come in later in the story.

living example: https://sketchfab.com/3d-models/brachiopod-lingula-anatina-pri-76882- bd7e501c2c0d4a6b8b32adc6cf90fe19 example from Chengjiang: https://sketchfab.com/3d-models/lingulella- chengjiangensis-68b160d1bb74432ea4549300bf4ac620 fossil: https://sketchfab.com/3d-models/lingula-fossil-97ba3f63bdc14339876c0c9c071dfcf7

9. What modern animal do these most resemble? ______

Please answer these questions in your Word doc.

Geology 121 Lab 7: Early Paleozoic, page 5 of 9 Trilobites Trilobites are ubiquitous from the Cambrian (the first appearing about 530 Ma) to the mass (251 Ma). You have to give props and respect to critters who thrived for a quarter of a billion years. Anatomically modern humans, by contrast, have only been around for about 200,000 years.

First, the “tri” thing. Trilobites are called “three lobes” not because of their head (cephalon), thorax (middle part), and pygidium (tail), which is pronounced “pie-jid-ee-um”. They are called “three lobes” because of the three-part division going from left to right, which includes the left pleural lobe, the axial (middle) lobe, and the right pleural lobe.

As you examine these, please pay special attention to the shapes of their cephalons and pygidiums, as well as how the legs (if present) are visible beyond the shell itself. These diagrams may be useful to you:

10. Elrathia kingi. https://sketchfab.com/3d-models/elrathia-kingi-dd13f6475e4c41f1947bbf43897641c1

11. Peronopsis interstricus. https://sketchfab.com/3d-models/question-3c-peronopsis- interstricus-5c768fb4445d4c27b2eac126ecd17ee2

Geology 121 Lab 7: Early Paleozoic, page 6 of 9 12. Bathyuriscus formosus. https://sketchfab.com/3d-models/question-3a-bathyuriscus- formosus-0308f81c0a2842f7a3234870bd043f08

Later on we will see many more trilobites as they evolve into a variety of shapes.

Anomalocaris The Cambrian was a time of killing. The Ediacaran period had organisms that did not seem to have eyes or claws or teeth—or even mouths. Maybe everyone was cool and just chilled, filter-feeding or photosynthesizing, leaving everyone else in peace.

But all this changed with the Cambrian. Life started ravenously eating other life. The Ediacarans disappear in a flash. The entire Cambrian explosion, some hypothesize, might have been driven forward so rapidly by a kind of life-death arms race between predators and prey. The Cambrian is a time period of death and murder. And this is one of the killers.

What you’re seeing here is one the major killers, Anomalocaris, a manta-like organism that, when found intact, seems to have an awful lot of trilobite skeletons in its guts. Like, as if they really liked eating trilobites. https://sketchfab.com/3d-models/anomalogaris-02-0542a380cc72485c89ae08b8966391b8 The coloration here is speculative; however, given the water depth and the way the water column scatters blue-range light, an organism with orange-pink hues would have been less visible, so this coloration is plausible. https://sketchfab.com/3d-models/anomalocaris-a11f71d33a024078acd4188238644a95

The first example, a reconstruction as in life, was made difficult by the fact that Anomalocaris apparently easily disarticulated into its constituents, including the grasping claws. For years it was not understood that the grasping claws, mouth parts, and body were part of the same organism.

Mouth parts: https://burgess-shale.rom.on.ca/en/fossil-gallery/view-.php?id=1&m=11&

Geology 121 Lab 7: Early Paleozoic, page 7 of 9 The Burgess Shale

The Burgess Shale is perhaps the most famous fossil site in the world. It is what is known as a lagerstätte, which is a German word indicating exceptional preservation conditions, especially in regards to soft tissues which do not normally preserve. In lecture we’ll get into hypotheses about why Burgess preservation was so extraordinary.

One thing to look for in these pictures is the presence of dark, glossy material near the edges of the fossils. These extraordinary dark patches are actual carbon from the original organism.

13. Check out these videos of a “dive” to the Burgess from the Royal Ontario Museum: https://burgess-shale.rom.on.ca/video/sea-odyssey/seq_1.mp4 https://burgess-shale.rom.on.ca/video/sea-odyssey/seq_3.mp4 https://burgess-shale.rom.on.ca/video/sea-odyssey/seq_7.mp4 https://burgess-shale.rom.on.ca/video/sea-odyssey/seq_5.mp4 https://burgess-shale.rom.on.ca/video/sea-odyssey/seq_4.mp4 https://burgess-shale.rom.on.ca/video/sea-odyssey/seq_6.mp4 https://burgess-shale.rom.on.ca/video/sea-odyssey/seq_8.mp4

14. I’d like to turn you loose on the Royal Ontario Museum’s website, https://burgess-shale.rom.on.ca/en/index.php

This has a wealth of information and you could spend pleasurable hours here.

There’s a great fossil gallery (https://burgess-shale.rom.on.ca/en/fossil-gallery/list-species.php ).

Geology 121 Lab 7: Early Paleozoic, page 8 of 9 Make sure to see examples of: Wiwaxia Hallucigenia Marella Aysheaia Canadia Olenoides Opabinia Pikaia Sidneyia Waptia Yohoia

There’s lot of info about the site history and geology (https://burgess-shale.rom.on.ca/en/science/ burgess-shale/02-geological-background.php ).

There are even splendid videos on the collection, preparing, and categorization of specimens (https://burgess-shale.rom.on.ca/en/science/fieldwork-collections/labwork-collections/ index.php ).

So… spend some time looking at what interests you. :)

(Note that this old site still uses Flash for videos and 3d models, and Flash is no longer supported by modern browsers. However, each video should have an MP4 alternative to view.)

15. What did you find most interesting? ______

Please answer these questions in your Word doc.

Geology 121 Lab 7: Early Paleozoic, page 9 of 9