Martín has just published an open access paper in the journal Scientific Reports about a rather unusual topic: the oldest evidence for communal latrines in the fossil record. Here, he explains a bit more about the paper... and check out this article in National Geographic by Karl Gruber as well.
Above: reconstruction of dicynodonts going about their daily business.
"In autumn 2011 we found eight discrete areas with exceptionally abundant coprolites (up to 90 per m2) during field work inthe Middle-Late Triassic Chañares Formation (ca. 240 million year old deposits) of northwestern Argentina. Three lines of evidence, namely the abundance of coprolites, the areal size of the accumulations and the autochthony of the deposits, allowed us to interpret these coprolite fields as communal latrines (areas in which animals defecate repeatedly). These communal latrines are 220 million years older than the previous oldest record of this behaviour in the fossil record. This defecation behaviour is present in several large living herbivores, such as rhinos and elephants, and is related with intra- and interspecific communication, and prevention of parasite re-infestation. Thin-sections and CT-scans allowed the study of the internal content of the coprolites, which was mostly composed of micro-plant remains. The latter and the large size (up to 35 cm) and abundance of coprolites allowed us to infer that the communal latrines were produced by large herds of a group of distant mammal relatives called dicynodonts. The dicynodonts of the Chañares Formation (Dinodontosaurus turpior) were rhino-like synapsids with a body mass that exceeded 3,000 kg and skulls that are characterized by a pair of large tusks. As a result, the communal latrines found in the Chañares Formation are the first evidence of communal latrines among non-mammal megaherbivores. This research was published in Scientific Reports of the Nature Publishing Group, and leads into several questions and lines of future research. For example, fossil communal latrines can shed light on feeding variation during different seasons and age stages, and may allow estimations of population sizes in dicynodonts, and plant diversity. This information would be useful to study the events that drove the evolution of the flora and fauna in South America 240 million years ago."
Above: the coprolites as found in the field.
Fiorelli, L. E., EZCURRA, M. D., Hechenleitner, E. M.,
Arganaraz, E., Taborda, J. R. A., Trotteyn, M. J., von Baczko, M. B. & Desojo, J. B.
2013. The oldest known communal latrines provide evidence of gregarism in
Triassic megaherbivores. Scientific Reports 3: 3348 (DOI: 10.1038/srep03348)
We have just returned from the 2013 Annual Meeting of the Society of Vertebrate Paleontology, which took place this year in downtown Los Angeles, California. This was an excellent opportunity for us to present our research on early archosauromorphs to a large audience, meet-up with and discuss joint projects and future collaborations with many of our friends and colleagues from around the world, and participate in the running of the Society (I am now a member of the Program Committee and the Editorial Board of the Journal of Vertebrate Paleontology). In total we were involved in six presentations:Martín gave a talk on the Permian archosauromorph record and a new taxon from Tanzania, together with Torsten Scheyer and me. This work is currently in review at PLOS ONE, and forms one of the chapters of Martín's thesis. Martín was also involved in a poster presentation led by David Rubilar-Rogers on a new silesaurid dinosauromorph from the Atacama Desert in Chile. Roland gave a poster presentation together with Andrey Sennikov, Dave Gower and me on a revision of the Russian basal archosauriform Dorosuchus, a taxon identified in the past as a possible euparkeriid. This research came out of our visit to Moscow in early 2013, and is one of the chapters of Roland's thesis. Roland is currently putting the final touches to the manuscript which should hopefully be submitted before the end of the year. I gave a talk on a new early erythrosuchid, a new species of Garjainia, from the Early Triassic of South Africa, together with John Hancox, Andrey Sennikov, Jennifer Botha-Brink and Dave Gower. This work came out of our research visit to South Africa in 2012, and the manuscript (led by Dave Gower) will be submitted to PLOS ONE before the end of 2013. I was also involved in the presentations of Martín and Roland, as well as a talk on pterosaur biogeography by Paul Upchurch and a talk on Triassic macrostratigraphy of the western USA and its relationship to vertebrate diversity by Dave Lovelace. Both of these talks will produce publications within the near future. A personal highlight for me was seeing the life reconstructions of the tiny North American ornithischian dinosaur Fruitadens on display in the new dinosaur gallery at the LA Natural History Museum, having led the work describing Fruitadens in 2010 and 2012.
Me at the LA Natural History Museum, with models of the tiny Fruitadens in the background. Photograph by Mark Wildman.
Our participation in SVP was supported by an Emmy Noether Programme award from the DFG.
Martín has recently completed a fieldtrip in Argentina,
and has this update:
Martín (right) and Maximiliano Iberlucea collecting fossils in the Chañares Formation. Photograph by Agustin Martinelli.
During late September–early October I co-led a
two week fieldtrip with Julia Desojo, Jimena Trotteyn, and Lucas Fiorelli to explore the extremely productive fossil outcrops of the Middle–Late
Triassic Chañares Formation of north-western Argentina. The field crew also included
Sterling Nesbitt, Agustin Martinelli, Jeremias Taborda, Belén von Bazcko,
Martin Hechenleitner and the geologist Mikki. The first week was extremely
cold, contrasting with temperatures that were close to 40ºC during previous
field seasons conducted at the same time of the year. In the two weeks we
discovered dozens of fossil amniote specimens, including multiple cynodonts,
dicynodonts and archosauromorphs. The herbivorous cynodont Massetognathus and the large dicynodont Dinodontosaurus were the most abundant taxa. However,
proterochampsid archosauriforms were also well represented among our
discoveries. During our time in the field, a publication by our team appeared
in the German journal Paläontologische Zeitschrift that
described the first rhynchosaur remains from the Chañares Formation and the
oldest record of the group in Argentina. These remains were found during our
fieldwork in 2011 and this record was mainly based on a fragment of dentary. At
the same time that this paper appeared,
we discovered a more complete rhynchosaur specimen in another locality of the
formation! The new specimen is represented by a fragment of dentary, possible
maxilla, sacrum, first caudal vertebra and a partial pelvis. This new specimen
will shed light on the anatomy and phylogenetic relationships of rhynchosaurs
in the Middle–Late Triassic of southern Gondwana. Discoveries were not
restricted to fossil bones; we also found thousands of coprolites (fossil faeces)
that probably belong to dicynodonts. Coprolites appear in extremely high
abundances in restricted areas of the Chañares outcrop, and we have a very
interesting story about them that will be published soon in the journal Scientific Reports of the Nature
Publishing Group. We had a very good time in the field, among good friends and
tons of fossils, and our excellent results will lead to several publications,
improving our knowledge of the Triassic evolution of archosauromorphs.
Fieldwork was funded by the Jurassic Foundation, Agencia Nacional de
Investigaciones Científicas y Técnicas and Conicet.
The Chañares Formation. Photograph by Agustin Martinelli.
- Richard Please send either Martín or I an email if you need the PDF of his paper. Both of these publications have been supported by an Emmy Noether Programme award from the DFG. Together with lead author Sterling Nesbitt and David Gower, I have just published a new paper in PLOS ONE on a new fossil archosauriform from the Middle Triassic of Tanzania. The new species hails from the well-known Manda beds, which have also yielded the oldest silesaurid dinosauriform, potentially the oldest dinosaur, an erpetosuchid and a ctenosauriscid. It is based on a partial skull that was discovered by a British expedition in 1963, and which lay unstudied in the bowels of the Natural History Museum in London until Sterling recognised it as something interesting a few years back. We named the new species Asperoris mnyama, which approximately means "rough-faced beast" (mnyama is Swahili for animal or beast). The "rough-faced" part of the name is based upon the prominent rugosities that cover much of the surfaces of the cranial bones. Whereas the Manda beds have previously yielded several crown archosaur taxa, our phylogenetic analysis placed Asperoris outside of the crown as a stem-archosaur, or non-archosaurian archosauriform (bit of a mouthful). Asperoris is the latest contribution by our team to the understanding of Manda archosauromorphs, but there is much more to come, given that "Mandasuchus", "Teleocrater" and "Pallisteria" all remain undescribed...
Above: Reconstructed skull of the holotype of Asperoris mnyama (NHMUK PV R36615) in right lateral view.
Meanwhile, Martín Ezcurra and a team of co-authors have published a paper in Paläontologische Zeitschrift describing rhynchosaur fossils from the Chanares Formation of Argentina that are the geologically oldest yet known from that country. The fossils were collected by a fieldcrew including Martín in 2011, and although very fragmentary they mark an important new record for the Chanares Formation. Despite decades of work in the Chanares having yielded numerous vertebrate taxa, no trace of rhynchosaur material had previously been recognised.
Again, we’ve allowed far too much time to go by without updating our news page, and some pretty major and exciting stuff has happened. The most important news is that during August and September 2013 we have moved institutions, leaving Munich and Germany and transferring to the University of Birmingham in the UK. This is the result of Richard obtaining an exciting, research-intensive position as a Birmingham Fellow (approximately equivalent to a UK Lecturer or a US Assistant Professor) in the School of Geography, Earth and Environmental Sciences (GEES), where we will be joining the Geosystems Research Group. A Birmingham Fellowship is a permanent appointment that provides protected time to develop high-profile research activities. This is a fantastic time to be joining the University, with major recent investment in research and teaching resulting in it greatly strengthening its national and international reputations. Richard will also be taking over as Academic Keeper of the Lapworth Museum of Geology, and will be involved in a planned major redevelopment and renovation of the museum that is currently underway.
Roland and Martin are also in the process of transferring to Birmingham and will complete their PhD research here. We expect to be advertising additional PhD opportunities in due course – keep an eye on this page from November onwards. Opportunities are available to seek funding through EU and UK sources for postdoctoral researchers to work with us – if you are interested in joining our group then send Richard an email with your CV and details of your research interests. Opportunities may be available regardless of your country of origin. Special funding opportunities may be available for Brazilian students, postdoctoral researchers and early career scientists due to the University’s strategic focus on Brazil – again, please send Richard an email to discuss possibilities. The University of Birmingham is set on a very attractive campus in a cosmopolitan city in the heart of England, and has excellent transport connections to the rest of the UK and Europe. Once our research infrastructure is fully up-and-running we will have excellent facilities for the processing of CT data (with access to a micro-CT scanner within the University), to add to existing facilities for histological analysis, microscopy, and fossil preparation.
Undergraduate students at Birmingham will also have opportunities to get involved in our research activities though completion of Master’s research projects – we have just been joined by our first Birmingham MSci student.
Former research group member Olja Toljagic has just published her Master's research in the UK journal Biology Letters. This work focused on patterns of morphological diversity in the crocodilian stem-lineage (Pseudosuchia) across the Triassic–Jurassic mass extinction, which occurred 200 million years ago. Olja aimed to reevaluate previous work suggesting a major crash in pseudosuchian morphological diversity during this extinction. Her results suggested that morphological diversity of pseudosuchians during the Early Jurassic was similar to that of the Late Triassic (when corrected for sampling differences), and thus that the Triassic–Jurassic mass extinction was likely followed by a rapid ecological radiation of one major group of pseudosuchians, the crocodylomorphs.
There is quite a nice news story on this paper here.
Above: Estimated changes in pseudosuchian morphological diversity from the Late Triassic to Early Jurassic.
TOLJAGIC, O. & BUTLER, R. J. 2013. Triassic/Jurassic mass extinction as trigger for the Mesozoic radiation of crocodylomorphs. Biology Letters 9: 20130095.
We are now at the end of a very productive, and very busy
and tiring, first week in the Moscow collections. We’ve spent a lot of time
with material of several key taxa (Garjainia, Sarmatosuchus, Dorosuchus,
Eorasaurus, Archosaurus), collected a lot of data, and set-up some interesting
projects with our collaborators Dave Gower and Andrey Sennikov. Dave has now
returned to the Natural History Museum in London, but we (Martin, Roland and I)
are staying on for another week, and aiming to see as much additional material
as possible. Today we took a well-earned break, and Andrey and his wife took us
on a very enjoyable excursion to the Kremlin, Red Square, and St Basil’s Cathedral. We're enjoying some time off, but also looking forward to getting back into the collections come Monday.
Left: Dave Gower, Roland, Richard, Andrey Sennikov, and Martin outside the Paleontological Institute. Right: Roland, Martin and Richard in front of St Basil's Cathedral on Red Square.
We (Richard, Roland and Martin) are currently visiting the
Paleontological Institute (PIN) in Moscow. We’re visiting together with Dave Gower, and are being hosting by and working together with Andrey Sennikov, whom
it has been a pleasure to meet and discuss archosauromorph anatomy and taxonomy with. We’re here working on the fantastic collections of
Permian–Triassic archosauromorphs, which include numerous key species for
understanding the Triassic archosaur and archosauromorph radiations, such as
Archosaurus, Garjainia, Dorosuchus, Sarmatosuchus, Chalishevia and many others.
The amount of material here, much of it excellently preserved, is a bit overwhelming, but we're working frantically (11 hours in the collection today plus two hours commuting back and to the PIN...) to see as much of it as possible over the next couple of weeks.
Left: Richard (left), Roland (middle) and Martin (right), studying Garjainia and Dorosuchus material. Right: outside the entrance to PIN, with dinosaur-themed gates.
Back in 2011, at the Annual Meeting of the Society of Vertebrate Paleontology in Las Vegas, Phil Mannion, Roger Benson and myself organised a special symposium on patterns of vertebrate diversity (primarily species richness, but also morphological diversity, evenness and other metrics) in deep time, how differential sampling of the fossil record through time affects our ability to reconstruct those patterns, and how best to correct for sampling biases. This is currently a major area of debate in vertebrate palaeontology and palaeontology more broadly, and an exciting area to be working in. We had many excellent talks within the symposium, and now, some 18 months later, we have published a special volume of papers based on work presented in Las Vegas.
The special volume was recently published as a special issue of the journal Palaeo3 (Palaeogeography, Palaeoclimatology, Palaeoecology), and was edited by Phil, Roger and myself with help from David Bottjer. It includes 11 papers focusing on deep time diversity patterns in everything from fossil fish to mammals, with several papers focused on early vertebrate diversity and the Permian–Triassic extinction event. I am involved with two of the papers: a lead authored paper on pterosaur diversity patterns through time and their relationship with sampling, and a co-authored paper led by Roger Benson on tetrapod diversity patterns during the Cretaceous and relationships between regional and global metrics of sampling.
Above: cover of the special volume (left) and contents (right).
It's great to see this volume out finally, and thanks to all involved. I'm happy to send PDFs of any of the papers from the volume to anyone interested: just drop me an email.