Friday 22 August 2014

Publishing on private specimens

Martin Munt and I recently published a short letter in the august journal Nature, commenting on their publication of the beautiful, but privately-owned, eleventh Archaeopteryx specimen (Barrett & Munt, 2014). While we're grateful that Nature took our concerns seriously enough to publish on this issue (especially as our letter was intended as a direct criticism of their editorial policy in allowing a private specimen to be published) they heavily edited our original letter, so that the published version omits some of the more nuanced and general points that we wanted to make. Although Martin and I agreed readily to publication of the edited version - so that we could open the debate on this question more widely - I'd like to make the content of the original available here. As an aside, in the name of openness and full disclosure, Martin and I sent this original text to the authors of the Archaeopteryx paper: we have since had a constructive discussion with them and they paid us the same courtesy by sending the draft of a reply. Text of the original letter ran as follows:

"Collaborations between private fossil collectors and professional palaeontologists generate significant mutual benefits, facilitating access to productive localities and important specimens and remedying the overlooked scientific contributions of amateur collectors. Such collaborations should be encouraged where they bring new material and data into the public domain. However, publication of fossil specimens held in private collections is problematic due to issues surrounding future accessibility and the independent verification of published observations. Journals have a duty to ensure the repeatability of the observations forming the basis of new scientific interpretations prior to publication: for this reason, many journals refuse publication of specimens held in private collections. Foth et al. (Nature 511, 79–82; 2014) described the spectacular eleventh specimen of the earliest bird Archaeopteryx and documented features of the plumage that were previously unknown for this pivotal taxon. While we congratulate the authors and owner for making this information available, there is, however, no guarantee of access to this specimen for other researchers. This Archaeopteryx has been registered under the ‘Act to Prevent the Exodus of German Cultural Property’ (see http://www.gesetze-im-internet.de/englisch_kultgschg/englisch_kultgschg.html), a positive move that requires its whereabouts to be recorded and that prevents the loss of German palaeontological patrimony. Nevertheless, this act has no provision guaranteeing access to future generations of researchers, with access remaining at the owner’s discretion. Without access, these published observations cannot be independently verified, reducing the utility of the specimen to the scientific community. We urge Nature, and other journals interested in such material, to consider these concerns more seriously and to ensure that all authors submitting to the journal can provide meaningful assurances regarding future access to the material on which they publish."

Barrett, P. M. & Munt, M. 2014. Private collections hold back science. Nature 512, 28. (doi:10.1038/512028a)

Wednesday 6 August 2014

An unexpected ornithischian





We know surprisingly little about the early evolutionary history of the ornithischian dinosaurs (Irmis et al. 2007). Indeed, the global record of Late Triassic ornithischians consists of only three partial specimens and all of these suffer from incompleteness and have suffered controversy over their exact geological ages and phylogenetic positions. The situation improves in the Early Jurassic with rich faunas from southern Africa and other material from Europe and North America. Nonetheless, few of these sites are well dated, meaning that they cannot place precise constraints on the timing of key events in Ornithischia.


Today, my colleagues and I were excited to announce the discovery of a new early ornithischian that sheds some much needed light on the early stages of their evolutionary history – Laquintasaura venezuelae. Laquintasaura was a small biped, around 1 m in total length, and is known on the basis of at least four individuals that were found together in a rich bonebed (Barrett et al. 2014). The name is based on the La Quinta Formation, from which the material comes, and the country of Venezuela, honouring the fact that Laquintasaura is the first Venezuelan dinosaur and, more broadly, the first to be named from the whole of northern South America. The first specimens were found in the early 1990s and continuing fieldwork by Marcelo Sánchez-Villagra and collaborators has led to the accumulation of a large collection of material, numbering many hundreds of individual bones. Marcelo and I first started working on this material together when he joined the staff of the Natural History Museum in the mid-2000s, but the pressures of other work and the need to find additional diagnostic material led to a long incubation period for the paper.

Laquintasaura provides us with several insights. Critically, we were able to use high-precision radiometric dating techniques to provide a maximum age for the bonebed of 200.9 Ma. This places the deposition of the bonebed within 1 million years of the end-Triassic extinction event, which has a number of implications. It could mean that ornithischians went through the extinction relatively unscathed and/or bounced back very quickly after the extinction. It might also indicate that ornithischians, which were previously rare, benefitted from some kind of ecological release in the wake of the extinction that allowed them to diversify and increase in abundance in a way that wasn’t possible prior to the extinction. Maybe key competitors or predators were wiped out or reduced in number, although such ideas are difficult to test.

The occurrence of at least four individuals in the bonebed – and probably many more (some material remains unprepared and there is still potential for further discoveries at the site) – is intriguing. It hints at the possibility that these little dinosaurs were living in a social group at the time they died. Histological work indicates that the smallest individual we found was around three years old, while the largest was 10–12 years in age. Could this have been a small multigenerational herd? If so, it would be a very early example of ornithischian sociality. More work is needed on the taphonomy of the site to establish exactly how it was formed to confirm or reject this proposal.

The provenance of the new dinosaur is also interesting. Very few dinosaur localities are known from so close to the palaeoequator – indeed it has been suggested that arid climatic belts either side of the equator might have prevented large animals from colonising this region. At a stroke, Laquintasaura shows that dinosaurs were capable of living in this area, whose climate is thought to have experienced seasonal semi-arid and moist intervals.

A quick word on the lovely reconstruction of Laquintasaura produced by Mark Witton. As some of you may know, I have a pet idea that many basal dinosaurs were omnivores, and I wanted this new image to show something other than the usual docile herbivore munching on a fern. The teeth of Laquintasaura are perhaps its most unusual feature as they possess many ‘carnivore-like’ features (they are long, slender and slightly recurved) – these features suggest to me that they were used not only for plants, but also for small animal prey (at least some of the time).

This paper was a big team effort and I’d like to thank all of the other team members: Richard Butler and Randy Irmis for their ornithischian expertise; Roland Mundil for conducting the radiometric analyses; Torsten Scheyer for working out just how old each individual was; and especially Marcelo for his invitation to work on this exciting material, sorting out all of the logistics, and for his constant reminders that I had to get on and finish the work. In addition, we also relied on the efforts of many preparators at several institutions (Scott Moore-Fay, J. Carillo and U. Oberli) and Mark Witton and Scott Hartman's artistic talents. Now on to the longer-term project that will be the full description …

Barrett, P. M. et al. 2014. A palaeoequatorial ornithischian and new constraints on early dinosaur diversification. Proceedings of the Royal Society B 281, 20141147. (doi:10.1098/rspb.2014.1147)

Irmis, R. B. et al. 2007. Early ornithischian dinosaurs: the Triassic record. Historical Biology 19, 3–22. (doi:10.1080/08912960600719988)