The PETM and Conservation Paleoecology (November 19 &21)

This is our last week of regular classes and labs. Next week on Tuesday 8-9 am we’ll have an optional PowerPoint workshop for those who want advice on their presentations. There will be no lab, and of course the rest of the week is Thanksgiving Break.

Our topics this week will start with the Paleocene-Eocene Thermal Maximum, a significant interval of climate change much like we’re experiencing today. It followed the end-Cretaceous extinctions by about ten million years and is correlated with the magnificent adaptive radiation of the Early Cenozoic mammals. We will then use this event to introduce the concept of Conservation Paleoecology.

Geology in the News —

Dramatic decreases in insect diversity and abundance are upon us. After last week’s discussion of pollination vectors, you know how dangerous this will be.

During the Cretaceous there were feathered dinosaurs near the South Pole.

Here’s a cool new fossil bird from the Early Cretaceous of Japan. It is considered basal to the bird lineage and thus has new details regarding the evolution of the clade. It is also preserved in three dimensions rather than a flattened two.

Terrestrial ecosystems: Mesozoic plant and animal communities (November 12 & 14)

We are now returning to the Mesozoic, this time on land. Our topics will include the terrestrial recovery biota from the massive Permian extinctions (note that plants did not apparently suffer that much in the Permian extinctions), Mesozoic vertebrate paleoecology on land (including an introduction to the archosaurs and a diversification in part due to the break-up of Pangaea), and the complex relationships between the new angiosperm plants and their animal pollen vectors. (In an article that came out just this week, paleontologists announced the discovery of the earliest known pollinating animal, an insect in amber 99 million years old.) Dinosaur paleoecology will happen.

Here’s an 11-minute review of Mesozoic life.

Geology in the News —

A fossil ape has been found in Germany that may change the way we understand the origin of bipedality in our lineage. Danuvius guggenmosi has, to simplify, arms for swinging in the trees and legs of “walking”, apparently on branches.

Axolotls, famed amphibian examples of neoteny, are endangered in their native Mexico. Somehow they made headlines on the BBC Travel page.

Was Equisetum a superfood in the Mesozoic?

Terrestrial ecosystems: Paleozoic plant and animal communities (November 5 & 7)

Now that we have sorted out the basics of plant biology and systematics, we can dive into the early history of plants on land. We’ll begin with the evolution of soil from microbial mats, then proceed through the first vascular land plants rooted in that new soil. Our first event will be the Devonian Wood Crisis and its effects on the atmosphere and oceans, leading to the Devonian Mass Extinction. Here’s a popular account of the Devonian marine eutrophication hypothesis. It’s a good story at the intersection of many paleoecological themes we have developed.

After the leafy stage is set, the first land animals appeared in all their creeping glory. First will be land invertebrates (the earliest being Pneumodesmus) and then the early tetrapods. As you know, this is not a systematic paleontology course, so we will concentrate on changing ecological relationships over time. One such ecological event was the Carboniferous Rainforest Collapse.

Geology in the News —

Humpback whales have a sophisticated way of catching fish. They swim in circles making a “net” of bubbles to concentrate their prey. Very smart. The technique is called “pectoral herding”.

Our current ecological crisis just gets worse. Now it is not only birds and insects that are declining, but spiders too.

The German space agency has just released an amazing DEM map of Earth. It has a vertical precision of one meter. And it’s free to explore and download!

Terrestrial ecosystems: Vascular land plants (October 29 & 31)

We are now transitioning out of marine paleoecology to explore terrestrial ecosystems. Again, we will use the history of life through the fossil record to sort out paleoecological principles, concepts, and events.

Let’s start by looking at terrestrial ecosystems today, concentrating on how nutrients and energy flow through trophic systems on land. We will then move into the deep history of terrestrial ecosystems, developing additional paleoecological concepts and tracking some dramatic events revealed in the plant fossil record.

Geology in the News —

Strange linear “conga lines” of Ordovician trilobites have paleontologists talking!

Here’s that story about the near-instaneous acidification of the oceans when the asteroid hit at the end of the Cretaceous. The old volcanic hypothesis for the K/Pg extinctions is nearly dead now.

An exciting new paper in Science describes amazing evidence for ecosystem recovery after the End-Cretaceous extinction. [PDF of Science article here if you’re on campus.] Ask Claire Wineman about her connection to this story!

Reef communities (October 22 & 24)

We will start the week with an analysis of the Mesozoic Marine Revolution and then move into our main topic: The paleoecology of reefs. We will concentrate on reefs with a biological framework, studying modern scleractinian coral reefs and then diving into deep time to examine reefs made by other organisms, like archaeocyathids, sponges, bryozoans, brachiopods and rudist clams.

The Brachiopod Lab Report is due on October 22 by 5:00 pm in your Dropbox folder; Research Project Title and References are due on October 22 by 1:00 pm on paper.

Here is the Foram Identification website you need for lab this week.

Geology in the News —

Here’s the original National Geographic article featuring our own Dr. Karen Alley and her upside-down rivers in Antarctica. Very cool work.

Could we detect a past industrial civilization in the rock record? Turns out we may not be making the geological mark we may think we are. Thoughtful article.

Nice evolution GIF!

Phanerozoic marine communities: Mesozoic Marine Revolution, KPg extinction (October 15 & 17)

This week we return to the oceans to explore the paleoecology of the marine Mesozoic and Cenozoic. We will look at the Triassic recovery faunas, the rise of modern ecosystems in the Jurassic (the Mesozoic Marine Revolution), the Cretaceous extinction, and then the Paleocene recovery fauna that begins the Cenozoic. I suspect this may push into next week!

Again for lab this week, you’ll appreciate these links to the Ordovician Atlas, a Cincinnatian fossil guide, and a strat-paleo guide to the Cincinnatian.

The Brachiopod Lab Report is due on October 22 by 5:00 pm in your Dropbox folder; Research Project Title and References are due on October 22 by 1:00 pm on paper.

Geology in the News —

The excellent novelist Cormac McCarthy gives tips on how to write a great science paper. This is good advice on paper structure we rarely see.

Meet the giant “lion” larger than a polar bear who was once the apex predator in Africa. Simbakubwa is about 22 million years old. Note the museum drawer effect!

Fake Moon rock! This is an odd story since petrified wood is very far from looking like a basaltic Moon rock. We need more public geologists!

Phanerozoic marine communities: Ordovician – Permian (October 1 & 3)

We will begin this week with the Great Ordovician Biodiversification Event (GOBE), and end it with the ecological catastrophe of the Permian Extinctions. (A nice cheery note to send you off into Fall Break!) Along the way we will discuss the Sepkoski Marine Evolutionary Faunas with diagrams like the one below —

For lab this week, you’ll appreciate these links to the Ordovician Atlas, a Cincinnatian fossil guide, and a strat-paleo guide to the Cincinnatian.

Geology in the News —

A story to warm Andy’s heart: This Bolivian town sits astride at least 3500 dinosaur footprints. Such trackways are rich with paleoecological information. These trace fossils are Cretaceous.

I’m not sure this is really the first evidence that non-avian dinosaurs nested in colonies, but it is a good story. These nests are from the Upper Cretaceous of Mongolia.

Phanerozoic marine communities: Ediacaran and Cambrian (September 26)

We have a truncated schedule this week because I will be in Phoenix at the annual meeting of the Geological Society of America giving this presentation. No class or lab on Tuesday; back to class and lab on Thursday. I will return your graded tests Thursday morning.

Our topic on Thursday will be Early Paleozoic marine communities. We’ll introduce the major players in the ecosystems and explore the Cambrian Explosion. It will be a story weaving together rising oxygen levels, the coelom and the first skeletons. We will use the iconic Burgess Shale fossils as our first example of a Lagerstätte.

Geology in the News —

Here’s an article on that new arthropod from the Burgess Shale (Middle Cambrian) of Canada. You know Mollisonia plenovenatrix well from your first test!

I don’t cite the Daily Mail very often, but they did make this story exciting: New evidence about the end-Cretaceous extinction event recovered from a core recovered from the Chicxulub Crater.

Microbial communities (September 17 & 19)

Our first test is on Thursday. This is the first paleoecology exam for all of us! We’ll spend some time talking about it on Tuesday. Remember it is an open-note test, meaning you can use any of your hand-written notes. It covers from our first day through whatever we complete on Tuesday, including what we covered in lab (except for the specimens).

We will finish trace fossils on Tuesday with some applied examples of trace fossils in paleoecology. Please review the previous links.

Our main topic will be microbial communities in the fossil record and how they are a fundamental factor in evolutionary paleoecology. Please start your web-reading with the Wikipedia page on stromatolites. These are not the only microbial structures we’ll study, but they are the most prominent. Next meet our main prokaryotic players, the cyanobacteria. Oddly enough, a colleague and I actually described cyanobacteriial mats from the Upper Ordovician of the Cincinnati area. These are rare because they are replaced with pyrite and three-dimensional.

Our primary paleoecological case study with microbial mats will be the Cambrian Substrate Revolution. Microbial mats served us well as oxygen-producers and sediment stabilizers, but the tie finally came for animals to break through them to exploit the nutrients in the sediment and do all those other infaunal activities we talked about with trace fossils. A Wooster alumnus, Steve Dornbos, is one of the paleontologists who developed this scenario.

Geology in the News —

Here’s a fascinating set of Neanderthal footprints found in France. Human trace fossils! They may tell us something about Neanderthal family life, information we can’t get from bones alone.

Here’s a cool super-sized pterosaur found in the Cretaceous of western Canada. Note the complicated taxonomic history to finally get this critter a proper name and description.

Trace Fossils (September 10 & 12)

Let’s start with the Wikipedia page for trace fossils. Note that trace fossils are sometimes called ichnofossils, and the study of them is ichnology. Wooster has an excellent collection of hardgrounds, especially from the calcite seas of the Ordovician and Jurassic, on which we will see many borings and other examples of bioerosion. We also have a good soft-sediment trace fossil set, much of it inherited from the late Professor Richard G. Osgood, Jr.

You will see that the large majority of our trace fossils are marine because, naturally, most traces come from marine sedimentary rocks. I wish we had more dinosaur tracks, but they are best enjoyed and studied when they are still in place.

Our summative project for trace fossils will be the descriptions, distribution, and analysis of ichnofacies. Done correctly, an ichnofacies study can reveal much about paleoecosystems.

Dr. Patricia Kelley visits class on Thursday, September 12; she will speak on drilling predation. She also gives a Geology Club talk at 11:00 a.m. in Scovel 205 (required).

Lab report #1 due in Dropbox by noon on Tuesday.

Geology in the News —

A cool trace and body fossil combination found in the Ediacaran of China. This rare kind of trace is called a mortichnium. (You can figure out those roots.) The specimen has started an interesting conversation about evidence for the earliest animal motion. Here is the original article in Nature.

Why did coyotes survive from the Pleistocene but not saber-toothed cats? Apparently coyotes, which are notorious omnivores, adapted better to changing climates and food resources.