GEOLOGY & GEOPHYSICS NEWS Yale University I Department of Geology and Geophysics Spring 2018 Chair’s Letter tributions of students and postdoctoral scholars, Jay Ague ([email protected]) as well as his public outreach activities with the Yale Peabody Museum of Natural History. Welcome to the Spring 2018 We continue to build our faculty and have sev- edition of the Geology and eral searches ongoing or planned. Currently, we Geophysics newsletter! It’s have positions open in geochemistry and climate been a while since our last sciences. We have interviewed a broad spectrum newsletter, and much has of candidates for these positions and plan on happened in the interim. bringing new faculty on board in the next year or I am pleased to intro- so. And a new search in stratigraphic paleontology duce Assistant Professor is being planned as well. Alan Rooney, who joined Herein you can also catch up on the activi- the faculty in 2017. Alan ties and interests of faculty, students, and alums is an isotope geochem- from around the globe. This includes a compelling ist interested in a wide spectrum of problems account by G&G alum Neil Williams G ’76 of an ranging from the history of Earth’s core to the 1840 field trip undertaken by J.D. Dana and W.B. development of complex life on our planet to Clarke in New South Wales, Australia. the dynamics of ancient In sad news, Geochemistry Professor Mark and recent ice sheets. He Pagani, and Emeritus Geophysics Professor Syd uses high-precision isotope Clark passed away. You can read moving tributes measurements of platinum to their remarkable lives, careers, and legacies in group metals, particu- the pages of this newsletter. Each has left an indel- larly the Re-Os system, to ible mark on G&G and the geosciences generally, make breakthroughs in and their contributions will live on and shape our understanding the timing, field long into the future. duration, and geochemical In closing, this will be my last newsletter as signatures of geologic pro- Chair. It has been a tremendous privilege to serve the G&G community over the past six years, and a Alan Rooney, Assistant cesses and events, including Professor groundbreaking new evi- great pleasure to get to know so many departmen- dence for the severe icehouse “Snowball” Earth tal friends and alumni. Please keep us posted about in the Neoproterozoic, and the recent behavior of your activities so we can feature them in future the Greenland ice sheet. newsletters. Best wishes for the rest of 2018! In these pages you will also read about the many exciting facets of Assistant Professor Anjan Inside this Issue Bhullar’s research in vertebrate paleontology Faculty Research. .2 which integrates evidence from genes, growth, In Memoriam—Sydney P. Clarke. 6 and development using laboratory experiments Memories of Mark Pagani. 7 and fossils to study the evolution of major verte- Alumni in Memoriam—A. Lee McAlester. 13 brate groups. For example, he has traced the ori- Recent Awards and Honors: Faculty. .14 gin of the bird skull through retention of the juve- Recent Awards and Honors: Students. 16 nile morphology of dinosaurs, and illuminated the Student News. .18 evolutionary origin of the bird beak. His work on Commencement .................................... 23 ancient life also captures the public’s imagination, Visitors. 24 and is commonly featured in media outlets includ- Field Trips .......................................... 26 ing the New York Times. This newsletter provides Dana and Clarke’s Exploration of the Illawarra District. 28 a fascinating glimpse into the inner workings of Alumni News. 33 Anjan’s laboratory operation highlighting the con- Center for Earth Observation ..........................41 GEOLOGY & GEOPHYSICS NEWS Spring 2018 FACULTY RESEARCH Tracing the Deep History of Vertebrates through Earth History and Experimentally Resurrecting the Past Bharat-Anjan Bhullar ([email protected]) The story of vertebrate life on Earth is immediately and perpetually interest- ing because it is, funda- mentally, our story, and the story of our closest relatives—echoes and varia- tions of ourselves among Alligator embryo tail stained for muscle nerve and cell nuclei. all the vast diversity in the biosphere. Because the sity and change stands in contrast to that of other vertebrate skeleton has laboratories with molecular developmental capa- such high preservational potential, and because bilities, while our emphasis on experimental ma- it is locked within the body and intimately associ- nipulation stands in contrast to that of other labo- ated with unpreserved soft tissues, the vertebrate ratories concerned with evolutionary processes on fossil record records many of the transitions and the scale of hundreds of millions of years. Major transformations in body form that generated the projects and initiatives include the following, many breathtaking variety of backboned animals now of which are in collaboration with other labs in on the planet. Our lab focuses on these major G&G and other departments and units at Yale. Our transformations within and outside of Vertebrata, work is also intimately tied to activities in the Yale and seeks to understand them using the rock Peabody Museum of Natural History. record of their progression in combination with evidence from modern descendants, in particular Developmental and Genetic Bases for Major the molecular and cellular mechanisms of embry- Evolutionary Phenomena onic development, which are the processes that Broad-scale evolution sometimes involves major enact the sculpting of body form anew in each shifts in tempo and mode enacted by fundamental generation. We are particularly interested in 3D changes in developmental processes. Alterations and 4D imaging and modeling. Thus, as in many in overall rate and timing of embryonic events other labs in Geology & Geophysics, we are push- can, for example, enact juvenilization or paedo- ing the boundaries of our field by attempting, morphosis within a lineage. Our previous work experimentally and computationally, to model the has suggested that juvenilization underlies many processes by which Earth system change occurs of the prominent anatomical transitions along the on a geologic timescale—in our case, the morpho- line to modern birds, and we continue to inves- logical, environmental, and genetic processes that tigate ways in which the phenomenon impacted account for long-term biospheric dynamics in the avian evolution. Projects involving postdoc Adam form of biotic evolution. We tend to focus on ways Pritchard, graduate student Michael Hanson, and in which important features of the ancestors of major, instantly recognizable, vertebrate radiations were gradually assembled: the origin of mam- mals, of birds, of reptiles, of jawed vertebrates or vertebrates as a whole. In addition to enormous numbers of fossils, virtual and physical, from prior and current collecting efforts, we have in the lab embryos of taxa as diverse as acorn worms, amphioxus, fish, salamanders, frogs, lizards and snakes, turtles, alligators, several kinds of birds, Matteo Fabbri, Elizabeth Clark, Adam Pritchard and Michael Hanson mice, squirrels, and opossums. Our focus on diver- processing 3D datasets of fossils and embryos. 2 GEOLOGY & GEOPHYSICS NEWS Spring 2018 FACULTY RESEARCH several undergraduates and high school volun- ing the evolution of features in these groups soon teers including Adrien Gau, Indira Khera, Jane after the extinction, as well as exceptionally pre- Lockery, and Amber Polk, use 3D imaging of fos- served primitive mammal material from very early sils and extant taxa to address anatomical aspects in the Cenozoic “age of mammals.” of juvenilization along the avian line. Complemen- tary work, led by Human Frontier Science post- Developmental and Genetic Links between the doctoral fellow João Botelho, includes cellular Brain and Other Tissues of the Head and molecular analyses of skeletal development, At first glance, the evolutionary history of a com- in vivo and in culture, to determine whether the plex structure – and none is more complex than basic growth properties of tissues differ between the vertebrate head – consists of a bewildering birds and nonavian reptiles. Projects led by Ph.D. number of small changes within lineages, some student Daniel Smith deal with major rearrange- concurrent and others spread out through geo- ments of early embryonic body structures at the logic time. We are interested in ways in which origins of anatomically divergent reptile groups multiple seemingly independent events might such as turtles and snakes. actually be nonindependent, linked by a common developmental process. In the head, which is both History, Contingency, and Evolutionary Radiation evolutionarily important and well-represented in In addition to the anatomical and developmental the fossil record owing to a high degree of skeletal mechanisms that produce large-scale evolutionary ossification, we are particularly interested in the changes in form and function, we are interested first structure to gain distinct form in the embryo, in the historical contexts that permitted the di- the brain. There is evidence from biomedical fields versification of each of the disparate major clades that the brain has a primacy in the development of vertebrates and within which morphological of the head and that it is an important molecu- transformations took place. Precipitous events in lar signaling structure. Moreover, it is structurally Earth history such as the end-Cretaceous asteroid important and, for instance, the mere physical ex- impact preceded many, if not most, of the great pansion of the brain in groups like birds and mam- vertebrate radiations, and patterns of extinction mals likely causes a number of alterations in the and survival as well as the fossil record of morpho- form of the head. Our experimental work attempts logical evolution proximal to these events provide to replicate ancestral modes of brain development some insight into the effects of sudden geologic and to determine whether doing so can resurrect change and catastrophe upon vertebrate history. ancestral modes of skull development.