Published: July 22, 2012

Brazil 2012 Fieldwork Diary Entry 4: Paleontology in Brazil: Meet the Team

Ken Angielczyk, MacArthur Curator of Paleomammalogy and Section Head, Negaunee Integrative Research Center

One of the things that I enjoy about being a paleontologist is that I get to collaborate on research projects with a lot of very interesting people from all over the world. 

One of the things that I enjoy about being a paleontologist is that I get to collaborate on research projects with a lot of very interesting people from all over the world. I'm privileged to be part of a great team of people working on the Parnaíba Basin project, and I'm sure you'll be hearing more about them as our fieldwork proceeds. Before that happens, though, I would like to introduce you to them. That way you will know who they are when they're mentioned in later posts, but it will also give you a bit of insight into some of the rationale and planning that goes into arranging paleontological fieldwork. Although all of the team members have interests in Permian paleontology, we each bring particular research interests and experiences to the project, and that combined expertise is important for being able to interpret the fossils we find and the data we collect. To give you an example of this, I once almost threw away what seemed to be an undiagnostic fossil bone fragment that I found while doing fieldwork in Tanzania. Luckily, one of my collaborators on the trip asked me what I found before I tossed it, and he recognized it as part of a femur (thigh bone) of a dinosaur relative. It was one of the first of many specimens we found of that animal at the locality that day, which we later described and named Asilisaurus kongwe. Asilisaurus is one of the most important things we found on that trip because it indicates that the origin of dinosaurs occurred about ten million years earlier than previously thought.

I'll start by introducing myself. I'm Ken Angielczyk, and I work in the Department of Geology at The Field Museum in Chicago. My research focuses on a group of therapsids called dicynodonts. Dicynodonts were the most diverse and abundant herbivores in terrestrial communities for much of the Permian and Triassic periods of Earth history, so they're important for understanding how those communities functioned ecologically and how they were affected by the end-Permian mass extinction (the largest mass extinction in Earth history).

Juan Carlos Cisneros works at the Universidade Federal do Piauí, which is located in the city of Teresina in Brazil. Conveniently, Teresina lies within the Parnaíba Basin and some of the areas we want to explore this year are quite close to the city. Juan's research focuses on a group of extinct reptiles called procolophonoids, although he's also worked on therapsids and even mammals. You should check out Tiarajudens, a therapsid that Juan recently discovered in the Permian of Brazil.

Jörg Fröbisch works at the Leibniz-Institut für Evolutions- und Biodiversitätsforschung an der Humboldt-Universität zu Berlin (in Berlin). Jörg is one of the few other people in the world who has  intensively studied dicynodonts, and he recently spent two years working with me at the Field Museum. His current research involves studying how the major groups of therapsids are related to one another, a topic that has received surprisingly little attention from paleontologists.

Members of the 2012 Parnaíba Basin fieldwork team. Upper row, left to right: Martha Richter, Ken Angielczyk, Roberto Ianuzzi (a paleobotanist who won't be on this year's trip), Claudia Marsicano, Juan Cisneros, Domingas de Conceiçáo (an undergraduate at the  Universidade Federal do Piauí). Bottom row, left to right: Christian Kammerer, Roger Smith, Jörg Fröbisch, Jeff Johnson. Photos by Ken Angielczyk, Christian Kammerer, Jörg Fröbisch, Jeff Johnson. Not Shown: Mayana de Castro Silva (an undergraduate at the  Universidade Federal do Piauí).

Christian Kammerer also is based in Berlin; he's a postdoctoral researcher working with Jörg. Christian was a graduate student at the University of Chicago during the time Jörg was at the Field Museum, and the three of us recently completed a large work on the dicynodont Dicynodon that we began at that time. Christian has experience studying broad evolutionary patterns in synapsids, and has done detailed work on several synapsid subgroups.

Claudia Marsicano is based at the Universidad de Buenos Aires. Her research focuses on the large, often crocodile-like archaic amphibians that were common members of Permian and Triassic communities. This expertise is especially important for our fieldwork because the only terrestrial vertebrate currently known from the Pedra de Fogo Formation is an archaic amphibian called Prionosuchus plummeri. Fossil footprints are another of Claudia's interests.

Martha Richter works at the Natural History Museum in London, and she specializes on fossil sharks and bony fish from the Permian Period. She's a key member of the team because most of the vertebrate fossils found in the Pedra de Fogo Formation are bony fish and shark remains, and she also has previous experience doing fieldwork in the Parnaíba Basin. If I get any of the names of fossil fish we find right in future posts, it will be because Martha is reading over my shoulder.

Roger Smith works at the Iziko South African Museum in Cape Town, and much of his research focuses on sedimentology (i.e., using the structure and composition of sedimentary rocks to understand the environments in which they formed) and taphonomy (i.e., the study of the processes by which animal remains are preserved as fossils). He's also done a ton of fieldwork in the Permian all over the world, and is one of the most skilled fossil finders I know. Most of the paleontology exhibit at the Iziko South African Museum is a testament to Roger's ability to find amazing specimens, and if we do discover any synapsids on this trip, it wouldn't surprise me if Roger is the first to find them.

Finally, Jeff Johnson is a videographer who is accompanying us in the field. Jeff will be taking photos and videos of us as we do our work, which we use for making short educational videos. 


Ken Angielczyk
MacArthur Curator of Paleomammalogy and Section Head

I am a paleobiologist interested in three main topics: 1) understanding the broad implications of the paleobiology and paleoecology of extinct terrestrial vertebrates, particularly in relation to large scale problems such as the evolution of herbivory and the nature of the end-Permian mass extinction; 2) using quantitative methods to document and interpret morphological evolution in fossil and extant vertebrates; and 3) tropic network-based approaches to paleoecology. To address these problems, I integrate data from a variety of biological and geological disciplines including biostratigraphy, anatomy, phylogenetic systematics and comparative methods, functional morphology, geometric morphometrics, and paleoecology.

A list of my publications can be found here.

More information on some of my research projects and other topics can be found on the fossil non-mammalian synapsid page.

Most of my research in vertebrate paleobiology focuses on anomodont therapsids, an extinct clade of non-mammalian synapsids ("mammal-like reptiles") that was one of the most diverse and successful groups of Permian and Triassic herbivores. Much of my dissertation research concentrated on reconstructing a detailed morphology-based phylogeny for Permian members of the clade, as well as using this as a framework for studying anomodont biogeography, the evolution of the group's distinctive feeding system, and anomodont-based biostratigraphic schemes. My more recent research on the group includes: species-level taxonomy of taxa such as Dicynodon, Dicynodontoides, Diictodon, Oudenodon, and Tropidostoma; development of a higher-level taxonomy for anomodonts; testing whether anomodonts show morphological changes consistent with the hypothesis that end-Permian terrestrial vertebrate extinctions were caused by a rapid decline in atmospheric oxygen levels; descriptions of new or poorly-known anomodonts from Antarctica, Tanzania, and South Africa; and examination of the implications of high growth rates in anomodonts. Fieldwork is an important part of my paleontological research, and recent field areas include the Parnaíba Basin of Brazil, the Karoo Basin of South Africa, the Ruhuhu Basin of Tanzania, and the Luangwa Basin of Zambia. My collaborators and I have made important discoveries in the course of these field projects, including the first remains of dinocephalian synapsids from Tanzania and a dinosaur relative that implies that the two main lineages of archosaurs (one including crocodiles and their relatives and the other including birds and dinosaurs) were diversifying in the early Middle Triassic, only a few million years after the end-Permian extinction. Finally, the experience I have gained while studying Permian and Triassic terrestrial vertebrates forms the foundation for work I am now involved in using models of food webs to investigate how different kinds of biotic and abiotic perturbations could have caused extinctions in ancient communities.

Geometric morphometrics is the basis of most of my quantitative research on evolutionary morphology, and I have been using this technique to address several biological and paleontological questions. For example, I conducted a simulation-based study of how tectonic deformation influences our ability to extract biologically-relevant shape information from fossil specimens, and the effectiveness of different retrodeformation techniques. I also used the method to address taxonomic questions in biostratigraphically-important anomodont taxa, and I served as a co-advisor for a Ph.D. student at the University of Bristol who used geometric morphometrics and finite element analysis to examine the functional significance of skull shape variation in fossil and extant crocodiles. Focusing on more biological questions, I am currently working on a large geometric morphometric study of plastron shape in extant emydine turtles. To date, I have compiled a data set of over 1600 specimens belonging to nine species, and I am using these data to address causes of variation at both the intra- and interspecific level. Some of the main goals of the work are to examine whether plastron morphology reflects a phylogeographic signal identified using molecular data in Emys marmorata, whether the "miniaturized" turtles Glyptemys muhlenbergiiand Clemmys guttata have ontogenies that differ from those of their larger relatives, and how habitat preference, phylogeny, and shell kinesis affect shell morphology.

A collaborative project that began during my time as a postdoctoral researcher at the California Academy of Sciences involves using using models of trophic networks to examine how disturbances can spread through communities and cause extinctions. Our model is based on ecological principles, and some of the main data that we are using are a series of Permian and Triassic communities from the Karoo Basin of South Africa. Our research has already shown that the latest Permian Karoo community was susceptible to collapse brought on by primary producer disruption, and that the earliest Triassic Karoo community was very unstable. Presently we are investigating the mechanics that underlie this instability, and we're planning to investigate how the perturbation resistance of communities as changed over time. We've also experimented with ways to use the model to estimate the magnitude and type of disruptions needed to cause observed extinction levels during the end-Permian extinction event in the Karoo. Then there's the research project I've been working on almost my whole life.

Morphology and the stratigraphic occurrences of fossil organisms provide distinct, but complementary information about evolutionary history. Therefore, it is important to consider both sources of information when reconstructing the phylogenetic relationships of organisms with a fossil record, and I am interested how these data sources can be used together in this process. In my empirical work on anomodont phylogeny, I have consistently examined the fit of my morphology-based phylogenetic hypotheses to the fossil record because simulation studies suggest that phylogenies which fit the record well are more likely to be correct. More theoretically, I developed a character-based approach to measuring the fit of phylogenies to the fossil record. I also have shown that measurements of the fit of phylogenetic hypotheses to the fossil record can provide insight into when the direct inclusion of stratigraphic data in the tree reconstruction process results in more accurate hypotheses. Most recently, I co-advised two masters students at the University of Bristol who are examined how our ability to accurately reconstruct a clade's phylogeny changes over the course of the clade's history.