One gait fits all: Titanosaur dinosaurs match their pace as they grow.

Researchers at the Institut Català de Paleontologia Miquel Crusafont (ICP, Spain), the universities of Zaragoza and Autonomous of Barcelona (Spain) in collaboration with the University of Manchester (UK) and University of Liverpool (UK) have just published in the journal PLOS ONE. Their study of trackways confirms that the titanosaur sauropod dinosaurs that lived in Fumanya (Catalonia, Spain) during the Late Cretaceous walked in the same way, independently of their body size.

Walking just like its giant parent, a sauropod plays 'catch-up' moving just like an adult!

In this study, palaeontologists have compared a small trackway of a titanosaur sauropod from the Late Cretaceous with those corresponding to larger animals in the same tracksite. The comparison of these trackways has helped to establish a cause-effect relationship between the gait (relative placement of feet as a function of limb movement), footprint size and body proportions of these dinosaurs.
Titanosaurs were a group of sauropod dinosaurs that had a characteristic arrangement of the femur and pelvic girdle that is reflected in the trackways that have been preserved in the fossil track record. Their gait was wide and the footprints left yield a characteristic ‘wide-gauge’ trackway. 

Reconstruction of a dinosaur from the Catalan, pre‐Pyrenees, about 70 million years ago. Credit: Oscar Sanisidro. Institut Català de Paleontologia Miquel Crusafont.

In the study published in PLOS ONE, researchers have compared trackways of specimens of different sizes and have demonstrated that they belonged to animals with many geometric similarities in their body plans. The juvenile dinosaur was basically a ‘replica’ of the adult in terms of limb proportions and shape, despite the large differences in body size. This led to the conclusion that the large and small titanosaurs moved in a dynamically similar way, probably using an ambling gait. 

Juvenile Titanosaur trackway from Fumanya, picture by Bernat Vila

Sauropod dinosaurs form the group of the largest terrestrial vertebrates that ever lived on land. They were herbivorous animals with a long tail and neck that allowed them to reach higher vegetation. The titanosaurs that lived in Fumanya in Berguedà (Catalonia, Spain), could reach up to 15 meters in length and weigh up to 15 tons, but the track of the new juvenile sauropod was roughly the same body trunk size of a large Labrador dog…a mere ~1.5 metres from hip to shoulders…some 10 times smaller than an adult of the same species.

Fumanya, a unique dinosaur site
The Fumanya sites of Fígols and Vallcebre, were declared a Site of National Cultural Interest in 2005. The paleontological site includes the ancient open-cast coal mines in Fumanya Sud, Mina Esquirol, Fumanya Nord and Tumí. On the site, which covers an area of more than 38,000 square meters, more than 3000 dinosaur footprints have been have been found and fossil remains of eggs and bones have been identified, together with tree trunks and leaves from different types of palms. It is considered to be one of the most important sites in Europe for fossil remains of dinosaurs from the Late Cretaceous.

From left to right, Manning, Vila, Egerton and Galobart collect LiDAR data on juvenile
trackway using a Z+F LiDAR unit.

Sauropod dinosaurs form the group of the largest terrestrial vertebrates that ever lived on land. They were herbivorous animals with a long tail and neck that allowed them to reach higher vegetation. The titanosaurs that lived in Fumanya in Berguedà (Catalonia, Spain), could reach up to 15 meters in length and weigh up to 15 tons, but the track of the new juvenile sauropod was roughly the same body trunk size of a large Labrador dog…a mere ~1.5 metres from hip to shoulders…some 10 times smaller than an adult of the same species.
Fumanya, a unique dinosaur site

Titanosaur trackways from Fumanya: LiDAR helps lift the detail.... see paper in PLoS One!

Fumanya, a unique dinosaur site
The Fumanya sites of Fígols and Vallcebre, is for me one of the best examples of Titanosaur trakway surface in the whole of Europe, if not the world. The paleontological site includes the ancient open-cast coal mines in Fumanya Sud, Mina Esquirol, Fumanya Nord and Tumí which were the reason behind in the discovery of the track-bearing horizons by a local school teacher. When you have over 38,000 square meters of exposure and more than 3000 dinosaur tracks...LiDAR is the only way to record, measure and analyse such a vast site. The Manchester team has been working with the ICP team on this site for nearly seven years now and we all know there are many more tracks and trails to be teased from this ancient surface using the light fantastic of LiDAR!

Bernat Vila, Oriol Oms, Àngel Galobart, Karl T. Bates, Victoria M. Egerton and Phillip L. Manning. "Dynamic similarity in Titanosaur sauropods: evidence from the Fumanya ichnological tracksite dinosaur (Southern Pyrenees)." PLOS ONE http://dx.plos.org/10.1371/journal.pone.0057408 

Bridges, bones and stressful behavior

Sometimes bones do strange things…or should I say, they are capable of remarkable feats. This living biological composite is the literal backbone of all vertebrates on Earth. It is somewhat surprising that we know so little about its behavior, mechanical properties and the impact of bone shape between species. Charlotte Brassey (a PhD student at the University of Manchester) has been exploring the wonderful world of bone behavior, but with particular focus on the size, shape and relative position of a limb in relation to its mechanical properties. One particular property Charlotte and her colleagues was interested in is ‘safety factor’. In engineering terms, the “factor of safety” of a structure is the ratio of its failure strength to the maximum stress it is likely to encounter, in the same way the safety factor of a bridge will be the largest load (and some) that it might encounter during service.

It is remarkable that the limb bones of an elephant are considered to experience similar peak stresses during locomotion as a shrew. The “Safety factor” seems to be maintained across the entire range of body masses through a combination of robusticity of long bones, postural variation, and modification of how an animal walks, trots and runs (in other words, its gait). The relative contributions of these variables remain uncertain, so Charlotte and the team tested the role of shape change in bones. She undertook X-ray tomographic scans of the leg bones of 60 species of mammals and birds, and extracted key properties on the shape and form of each bone scanned. The maximum resistible forces the bones could withstand before breaking under compression, bending, and torsion were calculated using standard equations more familiar to engineers. The studies main aim was to consider the impact of bone robusticity, curvature, and angle on safety factors, in relation to locomotion and peak dynamic forces (such as when running).

The new paper has just been published in The Anatomical Record, and explores the theory of postural adjustment to maintain safety factors. However, it seems that the animals studied had the last laugh (quack and squawk) given their idiosyncratic behavior and locomotor styles frequently overlaid the key relationships between force, bone angle, and body mass, particularly in birds. So, while it seems important that you are made of the right stuff…but it is also significant what you do with it!

Brassey, C., Kitchener, A. C., Withers, P., Manning, P. L., and Sellers, W.I. 2013. The Role of Cross-Sectional Geometry, Curvature, and Limb Posture in Maintaining Equal Safety Factors: A Computed Tomography Study. The Anatomical Record, DOI 10.1002/ar.22658

Bright Lights and Dinosaurs

This year I embark on a rather fun adventure. The splendid folks at the Science and Technology Facilities Council (STFC) have made me one of their Science in Society Fellows. My fellowship proposal was entitled 'Bright Lights and Dinosaurs' and will high-light the work that my team and I undertake at some of the brightest light sources on the planet, such at the STFC's Diamond Synchrotron (near Oxford).

I find myself tonight at the very same STFC facility writing these words...as we are currently exploring some new techniques to extract chemical information from the fossil remains. These wonderful beasties that saw fit to survive the slings and arrows of deep-time...by becoming immortalised in stone (aka, fossils).

Over the next two years I will be developing several outreach projects to help demonstrate to those who are choosing their GCSE's or wading through A-levels, that the wonderful world of science, technology, engineering and mathematics has a vital role to play in all walks of life...even extinct life! Through the scanning of dinosaur bones to the unpicking of belemnite biology and even the teasing of virtual muscle groups in high-performance computers, I hope to show how advances in science are breathing new life into ancient bones and beasties...but at the same time, show that science is splendidly exciting. So, if you know of a school that wants or needs an injection of prehistoric fun into physics or even a morphometric meddling with mososaurs, why not contact me at the University of Manchester, and I will do my best to visit your school and help you explore the wonderful world of Bright Lights and Dinosaurs.