RW Moriarty Science Seminars

R.W. Moriarty Science Seminar Presents: The mysterious megaraptorids: giant-clawed meat-eating dinosaurs from the southern continents

Speakers: Matt Lamanna, Carnegie Museum of Natural History

 

Abstract: Over the past quarter-century, paleontological field explorations in landmasses that once comprised the Southern Hemisphere supercontinent of Gondwana have yielded fossil finds representing a host of new and unusual dinosaurs. Among the most extraordinary of these are Megaraptoridae, an enigmatic group of large-bodied, Cretaceous-aged (~125–66 million-year-old) theropods (generally predatory dinosaurs) characterized by low and elongate skulls, proportionally small but sharp teeth, extensively air-filled bones, and, most strikingly, powerfully built forelimbs tipped with enormous claws on the innermost two digits. In this R.W. Moriarty Science Seminar, Dr. Lamanna will present several of he and his Argentine collaborators’ recent megaraptorid discoveries and their implications for scientific understanding of the anatomy, phylogenetic relationships, and paleoecology of these mysterious Cretaceous carnivores. Among these finds are two exceptionally preserved skeletons that cast significant new light on megaraptorid morphology and evolutionary history, strengthening the hypothesis that these animals are Gondwanan cousins of tyrannosaurids, the theropod group that includes the notorious Tyrannosaurus rex.

Bio: Matt Lamanna is the Mary R. Dawson Associate Curator of Vertebrate Paleontology and the principal dinosaur researcher at Carnegie Museum of Natural History. Born and raised in the Finger Lakes region of Upstate New York, he received his B.Sc. from Hobart College in 1997 and his M.Sc. and Ph.D. from the University of Pennsylvania in 1999 and 2004, respectively. Within the past 25 years, he has directed or co-directed field expeditions to Antarctica, Argentina, Australia, China, Croatia, Egypt, and Greenland that have resulted in the discovery of numerous new species of dinosaurs and other fossil animals from the Cretaceous Period, the third and final time period of the Age of Dinosaurs; indeed, he is one of only a handful of paleontologists to have found dinosaur fossils on all seven continents. Lamanna served as chief scientific advisor to Carnegie Museum of Natural History’s $36M Dinosaurs in Their Time exhibition and has appeared on television programs for PBS (NOVA), the Discovery Channel, the History Channel, A&E, the Science Channel, and more.

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R.W. Moriarty Science Seminar Presents: Rethinking Plant Heat Tolerances and Photosynthetic Strategies of Tropical Plants

Speakers: Timothy Perez

Stomata and leaf size thermoregulatory traits, a thermograph of leaves, and a tropical forest.

Abstract: As climate changes so too do the compositions of terrestrial plant communities that sequester carbon and mitigate climate change. However, the physiological mechanisms underpinning these changes are unclear. To understand these mechanisms, Perez and collaborators studied the photosynthetic heat tolerances (PHTs) and carbon assimilation strategies of tropical plants. In this talk he discusses their findings, which suggest that scientists need to rethink how PHTs are measured and assumed to influence plant performance. He also presents research that highlights how plant PHTs are unlikely to improve carbon assimilation at high temperatures, but may characterize thermal generalists with slow resource acquisition strategies. Finally, he presents a case-study using the genus Scalesia, endemic to the Galapagos, that indicates how climate selects for different photosynthetic strategies.

Bio: Timothy grew up in Upstate New York and in 2010 obtained a BSc in plant biology from the University of Vermont. After four years of working for NGO’s, the Bureau of Land Management, and as a research assistant, Timothy started a PhD in the Feeley Lab at the University of Miami. After obtaining his PhD in 2019, Timothy began a postdoctoral position in the Michaletz Lab at the University of British Columbia in Vancouver, Canada, where he is currently a Killam Postdoctoral Scholar. Timothy’s research focuses on how plant ecophysiology can be used to understand plant responses to climate change, and he is motivated by a desire to develop tools that aid plant conservation.

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R.W. Moriarty Science Seminar Presents: Understanding the Mid-Atlantic Flora…One Specimen at a Time

Speakers: Cindy Skema, Morris Arboretum of the University of Pennsylvania

Plant collections and their archiving in herbaria form a cornerstone in the foundation of plant science studies. We will discuss the why, how, and where of this work, as well as the process of digitization, i.e., how we bring these invaluable specimens into the digital realm. The Mid-Atlantic Megalopolis (MAM) Project, a National Science Foundation funded collaboration between 13 institutions including Carnegie Museum of Natural History, has enabled the digitization of >1.2 million specimens since 2016 and the creation of a virtual consortium of herbaria throughout the Mid-Atlantic. I will introduce the project, its participants, and outcomes. We will end with a consideration of Ripariosida hermaphrodita (Virginia mallow), a case study that uses MAM data to better understand the biology of a plant that is threatened in the Mid-Atlantic region.

Photo description:
Close-up of a high resolution image of an herbarium specimen of Cornus florida (flowering dogwood), taken as part of the MAM Project’s herbarium digitization efforts. Copyright Morris Arboretum of the University of Pennsylvania.

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R.W. Moriarty Science Seminar Presents: Resilience and adaptation to climate change and environmental shifts in ancient Egypt and Nubia- the 4.2 ka BP and 3.2 ka BP events reconsidered

Speakers: Nadine Moeller and Emilie Sarrazin

In the history of ancient Egypt, two periods of important societal change have often been linked to major climatic events: the transition from the Old Kingdom to the First Intermediate Period, connected with the so-called “4.2 ka BP event,” and the end of the New Kingdom, roughly associated with the “3.2 ka BP event.” In both instances, seemingly unprecedented periods of aridification are thought to have had a direct impact on the (dis)organization of ancient societies in Egypt, Nubia, and the broader Near East. While the appeal of such a theory is undeniable, the proxy data on which this narrative is based are rarely critically assessed, and the link between the environmental and historical data is rarely conclusively made.

This lecture proposes to re-examine the evidence for both climatic and sociocultural changes at the end of the Old and the New Kingdoms in Egypt and Nubia, with a particular focus on settlement data. The growth, contraction, shifting, and abandonment of sites often reflect important changes happening beyond their bounds. In this regard, the benefits and limitations of using proxy data to explain changes in those settlement patterns will be reviewed, particularly when these changes coincided with periods traditionally associated with societal “collapse” in the scholarly literature.

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Event photograph copyright Gregory Marouard