Looking beyond: how CT scanning opens up new horizons in understanding South American cynodonts and mammalian origins.

I would like to start by thanking the IAS Benjamin Meaker Visiting Professor Fellowship, Prof. Emily Rayfield and Dr. Pam Gill that made my visit to Bristol possible. This was my second time in Bristol which was an important visit to consolidate collaborative projects started in 2014 and to discuss further ventures for the future. I felt the University of Bristol and especially the Earth Sciences Department as my home during my visit. Cordiality and professionalism were two important aspects that I noted, together with the polite work we developed with students and professors.

Our collaborative project deals with mainly Brazilian fossils, from Triassic rocks (about 225 million years old), of small sized non-mammalian cynodonts. That is, animals closely related to the earliest mammals which have a mixture of primitive and derived features on the skeleton, illustrating the previous steps to the mammalian condition. We performed several computed tomography (CT) scans of skulls and jaws in order to observe in detail internal structures, such as nasal and brain cavities, replacing teeth, vascular innervations, etc. The high-resolution images we obtained in Bristol University under the advice, extraordinary dedication and professionalism of Dr Tom Davies are unique and reveal many previously unknown features of the skull. Without this technology, our conclusions would always have been partial. We scanned more than 30 specimens and collected more than 40 scans that are, and will be, the base of several projects.

During this visit, I spent a great deal of time discussing tooth replacement mechanisms with Pam Gill and Emily Rayfield (and also with Bristol alumni Dr Ian Corfe, with whom we started this project in 2014 in Helsinki), devising new hypotheses to explain the process and evolutionary patterns of tooth replacement in these precursors of mammals. I also had the opportunity to share discussions and ideas with two students from Bristol University: Erasmus visiting student Sofia Holpin and MSc Palaeobiology student Charles Salcido, both of whom are working on research projects using CT data collected from the Brazilian cynodonts. Sofia is working on the nasal cavity of a rodent-like cynodont called Riograndia and Charles on the biomechanics of the jaw of brasilodontids, the sister group of mammaliaforms. In our discussions, I was amazed how far the students had advanced in only a few months of hard work. Seeing important results being taken by these young students is always a good sign for the advance of the science. Being able to offer two seminars for students and professors at Bristol University was an exciting opportunity and, at the same time, important to divulge the South American fossil record and the research were are developing in our institutions.

We have delineated new future projects that will be important to maintain the collaborative research between the University of Bristol with the Universidade Federal of Rio Grande do Sul (Brazil) and the Museo Argentino de Ciencias Naturales “Bernardino Rivadavia” (Argentina). I would like to say that it is only the beginning of this project, which started in 2014, that will bring more novelties to vertebrate palaeontology in the near future.

Emily Rayfield, Pam Gill, Colin Palmer, Sofia Holpin, Charles Salcido from Bristol, Ian Corfe from Helsinki, Marina Bento Soares, Pablo Rodrigues and Cesar Schultz from Brazil and the IAS Benjamin Meaker Visiting Fellowship have made possible my visit to United Kingdom and to have access to novel data from the amazing Brazilian fossil specimens.

Finally, and no less important, the IAS Fellowship gave me the opportunity to stay and discover the city of Bristol. A city I believe is fantastic to which I will definitely return.

Dr. Agustín G. Martinelli

Sección Paleontologia de Vertebrados, Museo Argentino Ciencias Naturales “Bernardino Rivadavia”, Buenos Aires, Argentina.