Spiegel Wired National Geographic I am joint lead author with my friend and colleague Steve Brusatte on a new review paper on the dinosaur extinction, published yesterday in the journal Biological Reviews. The paper is currently free to download. To write this paper we brought together an international team of 11 dinosaur and Cretaceous-Palaeogene boundary researchers, to attempt to reach a consensus on the causes and dynamics of the dinosaur extinction. Our primary conclusion is that the asteroid impact was indeed the main killing mechanism, but that dinosaur ecosystems may have been particularly vulnerable to the effects of this impact due to losses in biodiversity among some large herbivorous groups. These biodiversity declines may have been the result of other environmental changes occurring during the Late Cretaceous, such as sea level falls and massive Deccan volcanism. As you might expect, we received a fair degree of media coverage. I did a live TV interview with BBC World/BBC4, radio interviews with the Today programme (BBC Radio 4), BBC Wales, and Radio Forth, and spoke to journalists from the UK, USA, Canada, Spain and Chile. Steve did lots of media, including CBS Evening News, and other members of the research team including Paul Barrett and Phil Mannion also did live TV and radio interviews. I've posted a selection of links to news stories below:
Back in 2009, Octavio Mateus, Steve Brusatte and I took a short trip down to the Algarve in southern Portugal to search for Triassic vertebrate fossils. We were attempting to relocate a bonebed that had been discovered by a German geology student in the early 1980s, and from which he had collected some rather scrappy remains of large amphibians (temnospondyls). We managed to find the site, which actually turned out to be an extremely rich horizon, with multiple complete skulls of a new species of the temnospondyl genus Metoposaurus. With support from several funding agencies, including the German Research Foundation (DFG) and the Jurassic Foundation, we excavated parts of the bonebed in 2010 and 2011, together with a large team including Sébastien Steyer and Jessica Whiteside. In addition to the amphibian material, an exciting discovery from a slightly higher stratigraphic level at the same site was a lower jaw of a phytosaur. Phytosaurs are a group of Late Triassic reptiles that were very crocodile-like in morphology (and probably ecology), and which are well known from central Europe (Germany, Poland, Italy) and from other continents (particularly North America). However, this group had never previously been discovered on the Iberian Peninsula. The association of a phytosaur and the temnospondyl genus Metoposaurus is very similar to early Late Triassic sites in Poland and Germany, and suggests strong faunal similarities across Europe at that time.
Above: Right lower jaw of the Portuguese phytosaur in lateral view. The anterior end of the mandible is missing.
Our new paper on this phytosaur jaw is the first fully published result of our fieldwork. Another paper on the temnospondyl fossils is currently in press, also at Journal of Vertebrate Paleontology. Fieldwork itself is currently on hold, but we hope to get this project up and running again in the near future.
Mateus, O., BUTLER, R. J., Brusatte, S. L., Steyer, J. S. & Whiteside, J. H. 2014. The first phytosaur (Diapsida, Archosauriformes) from the Late Triassic of the Iberian Peninsula. Journal of Vertebrate Paleontology 34:970-975.
It has been a busy few months in terms of papers. As always, a full list of papers is available here. I don't have time to mention everything that we have published, but a few highlights include: In January, Martin published a new paper in PLOS ONE on the possible proterosuchid reptile Tasmaniosaurus from the Lower Triassic of Australia. This paper resulted from Martin's visit to Hobart in Australia in 2012, and includes a comprehensive reassessment of the anatomy of this enigmatic taxon.
Left: Skull reconstruction of the Early Triassic archosauromorph Tasmaniosaurus, modified from Ezcurra (2014).
In February, Martin and I published in PLOS ONE together with Torsten Scheyer of the University of Zurich a comprehensive reassessment of the Permian fossil record of Sauria, one of the most important groups of vertebrates (which includes within it lizards, snakes, birds, crocodiles, and dinosaurs). This included a major new phylogenetic analysis of the evolutionary interrelationships of saurians and their fossil relatives, and has implications for understanding the early evolutionary history of saurians, the impact of the Permo-Triassic mass extinction, and the timing of the bird-lizard split. We named a new genus and species of Permian archosauromorph, Aenigmastropheus parringtoni, based on material collected from Tanzania. This paper results from two year’s worth of intensive research by Martin involving data collection in museums on six continents, including in Russia, China, Argentina, South Africa, Australia and the USA, and forms a key part of his PhD thesis.
Right: Dorsal vertebra of the new archosauromorph Aenigmastropheus, from the late Permian of Tanzania.
In March, I was a coauthor on a paper published in Nature Communications and led by Roger Benson of the University of Oxford that examined body size evolution in the Mesozoic flying reptiles, the pterosaurs. In this paper we examined pterosaur body size evolution over 150 million years of the Mesozoic. We demonstrated that early pterosaur body size evolution was relatively constrained, but that from the Late Jurassic onwards pterosaurs underwent strong evolutionary pressures towards the evolution of larger body sizes. This evolutionary trend culminated in giant pterosaurs with wing spans of 10 metres or more. We proposed that our results provide support for controversial hypotheses that pterosaurs were competitively replaced by the adaptive radiation of Mesozoic birds.
Left. Pterosaur wingspan plotted against time, and across pterosaur phylogeny.
Finally, just this month we published a paper in BMC Evolutionary Biology, together with Liu Jun and Corwin Sullivan of the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, on the phylogeny of early archosaurs. This paper grew out of our visit to Beijing in 2013, when we examined two species of enigmatic early archosaur from the Middle Triassic of China: Turfanosuchus dabanensis and Yonghesuchus sangbiensis. In this paper we propose that these two species form a previously unrecognised clade of early archosaurs, Gracilisuchidae, together with Gracilisuchus stipanicicorum from the Middle Triassic of Argentina, and we examine the biogeographical and evolutionary implications.
Left: holotype skull of the Middle Triassic archosaur Turfanosuchus dabanensis from China in left lateral and dorsal views.
Back in January, I was awarded a Marie Curie Career Integration Grant for the project “ARCHOSAUR RISE – The early Mesozoic rise of archosaurs: New insights into an exemplar evolutionary radiation”. The grant is worth €100,000, will run from 2014-2018, and is focused on understanding faunal changes during the Triassic period that led to the rise of dinosaur-dominated ecosystems. The grant is already underway, and has already been used to purchase a dedicated workstation for CT analysis with Avizo software, and to support fieldwork in South Africa during May. More updates as the grant progresses!
In late May, we completed two weeks fieldwork in South Africa, working together with a team of local researchers led by Dr Jonah Choiniere of the University of the Witwatersrand. We were working on remote farmland in Eastern Cape Province, eight hours drive south of Johannesburg. The aim of our fieldwork, which was partially funded by a Marie Curie Career Integration Grant from the European Union, was to hunt for vertebrate fossil localities in the Middle Triassic Burgersdorp Formation. In particular, we were interested in the uppermost part of the Burgersdorp Formation (Cynognathus Assemmblage Zone, Subzone C), which is around 240 million years old, and has previously yielded fossils of cynodonts, dicynodonts and temnospondyls.
Above: Field team for the South African expedition. L-R: Roland Sookias, Jonah Choiniere, Blair McPhee, Kathleen Dollman, Martin Ezcurra, Richard Butler (photograph by Mike Day).
The expedition was very successful, identifying new localities and good new fossil material for all of these groups, as well as the first potential archosauromorph remains from this horizon. The best discoveries were made on a game farm, where we were treated to regular sightings of springbok, wildebeest, ostrich, and rather noisy baboons. Detailed study of these fossils is now planned for early 2015, and will be combined with further fieldwork.
Above: Roland Sookias with a large piece of temnospondyl jaw found as float.
Following the fieldwork, Martin and Roland travelled on to Cape Town to study fossils at the Iziko South African Museum, as part of the final phase of data collection for their PhDs.
Once again, I've allowed way too much time to pass since updating our news page. I'm going to attempt to remedy this with some updates on some of the most important things that we've been up to over the last six months or so. I'm very pleased that we are currently hosting Dr Felipe Montefeltro, from UNESP (São Paulo State University) in São Paulo, Brazil. Felipe has joined us as a University of Birmingham Brazilian Visiting Fellow, and is in Birmingham from May to July. Felipe is currently carrying out postdoctoral research looking at the evolution of the ear among crocodilians and their extinct relatives (crocodylomorphs), and particularly at the ear morphology in crocodylomorphs with extreme morphologies or which occupied unusual ecological niches.
While in Birmingham, Felipe has been working on two fossil crocodylomorph species from the Mesozoic of the UK: the basal eusuchian Hylaeochampsa vectiana and the marine crocodylomorph Pelagosaurus typus. We've micro-CT scanned specimens of both of these taxa at the Natural History Museum in London, and Felipe is currently working on segmenting these datasets using our new dedicated workstation for CT analysis.
Above: Felipe with the CT scanner in the basement of the NHM in London during CT scanning of the Pelagosaurus skull.
While in Europe, Felipe is also taking the opportunity to visit fossil collections in Germany, Belgium, London, Warwick and Shropshire, and is working together with our team on the description of a new rhynchosaur taxon from South Africa. We'll provide updates on the results of his research as the project progresses.
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.