Soriatitan golmayensis of the Lower Cretaceous of Spain

Say hello to Europe’s newest member of the Brachiosauridae family – Soriatitan golmayensis, a sauropod estimated to have been longer than a badminton court!  This new species of herbivorous dinosaur has been described in a scientific paper published in the journal “Cretaceous Research”.  The fossil material, consisting of a single tooth, elements from the hips, limb bones including a partial femur and fragmentary tail bones were excavated over several years from the turn of the century.  The study of the fossil material finally culminating in the establishment of a new species of brachiosaurid.

Soriatitan golmayensis

The genus name means “Soria Titan”, a reference to Soria Province in central Spain where the fossils come from.  The species name honours the Lower Cretaceous Golmayo Formation (upper Hauterivian-lower Barremian), from which the fossil material was extracted.

An Illustration of the Newly Described Early Cretaceous Sauropod Soriatitan golmayensis

An illustration of the brachiosaurid Soriatitan golmayensis.

Picture credit: Fundación Conjunto Paleontológico de Teruel-Dinópolis

Approximately Fourteen Metres Long

With less than 15% of the skeleton to work with, the researchers, which included lead author of the paper, Rafael Royo-Torres (Fundación Conjunto Paleontológico de Teruel-Dinópolis/Museo Aragonés de Paleontología, Spain), were able to identify this dinosaur as a brachiosaur by comparing the bones to better-known species.  To estimate the size, the scientists scaled up the dinosaur based on the dimensions of the 1.25-metre-long humerus (upper arm bone).  When this bone was compared to the humeri of other brachiosaurids the team concluded that their specimen represented a fourteen-metre-long individual.

The Size of Soriatitan Was Calculated Using the Humerus

The humerus from Soriatitan which was used to estimate the animal’s size.

Picture credit: Fundación Conjunto Paleontológico de Teruel-Dinópolis

The Brachiosauridae Family

Brachiosaurs probably originated in the late Middle Jurassic and survived the break-up of Pangaea before finally becoming extinct in the Early Cretaceous.  Fossils of these long-necked, heavy-limbed plant-eaters are known from North America, Africa, Europe and southern England.  The Brachiosauridae is one of the three groups that make up the larger clade the Titanosauriformes.

The research team estimate that Soriatitan roamed the Iberian Peninsula some 132 million years ago.  Although, other fragmentary fossils notably those of Pelorosaurus conybeari from the Grinstead Clay Formation (West Sussex, England), have been tentatively assigned to the Brachiosauridae, the discovery of Soriatitan is extremely significant.  Dinosaurs such as the similar sized P. conybeari have been found in slightly older strata (Valangian faunal stage of the Early Cretaceous), Soriatitan provides evidence that brachiosaurids persisted in the Early Cretaceous of Europe for longer than previously thought.

Palaeontologist Rafael Royo-Torres explained:

“Until now it was believed that brachiosaurids had become extinct in Europe around 130 million years ago, the discovery of Soriatitan changes our perception of the European Early Cretaceous biota.”

The Break-up of Pangaea

The single, spoon-shaped tooth is typical of a brachiosaurid.  This tooth and the shape of a number of bones such as the presence of middle caudal neural spines helped the researchers to assign this dinosaur to the Brachiosauridae family.  In addition, the team deduced that Soriatitan may have been closely related to Abydosaurus, Cedarosaurus and Venenosaurus, which are all known from Lower Cretaceous-aged strata from Utah (United States).

The presence of Early Cretaceous brachiosaurids in both North America and Europe, give support to the hypothesis of a connection between the tectonic plates of these continents at some point during the Early Cretaceous.  A land connection between Europe and North America must have been present to enable closely related dinosaurs to be found in both Spain and the western United States.

Views of the Single Tooth of Soriatitan golmayensis

Views of the single tooth of Soriatitan from the Lower Cretaceous of Spain.

Picture credit: Fundación Conjunto Paleontológico de Teruel-Dinópolis

The Evolution of the Titanosauriformes in Europe

The discovery of Soriatitan, may help palaeontologists to better understand the evolution of the Titanosauriformes in Europe.  Rafael Royo-Torres was part of the research team that described the non-brachiosaurid titanosauriform Tastavinsaurus sanzi recovered from a dig site in Peñarroya de Tastavins (Teruel) at the base of the marine Xert Formation in 2008.  It is one of the most complete and best-preserved sauropod dinosaur skeletons from the European Early Cretaceous.  Tastavinsaurus roamed Spain some 125 million years ago.  The discovery of Soriatitan may help fill the evolutionary gap between Late Jurassic brachiosaurs and the European titanosaurs of the Early Cretaceous.

Rafael Royo-Torres Photographed Next to the Partial Femur (Thigh Bone)

Palaeontologist Rafael Royo , lead author of the scientific paper examines a Soriatitan golmayensis femur.

Picture credit: Fundación Conjunto Paleontológico de Teruel-Dinópolis

Communal Roosting in the Dinosauria

Attendees at the annual meeting of the Society of Vertebrate Palaeontology (SVP) in Calgary (Alberta, Canada), were treated to a presentation outlining the discovery of a trio of young oviraptorid dinosaurs that may have been preserved sleeping as a group.  This might provide the first evidence of communal roosting, a practice seen in many extant animals today, where members of the same species sleep together for mutual protection and to help keep themselves warm.  Communal roosting is seen in many species of birds, notable examples being starlings and rooks.  Communal roosting is also known amongst primates, bats and butterflies.

Although, it is easy to misinterpret fossils of this nature, oviraptorids, members of the Maniraptora clade of dinosaurs which are closely related to Aves (birds), are believed to have been social animals and a spokesperson for Everything Dinosaur stated that behaviour of this nature is within the “realms of expectation for these dinosaurs”.

The Fossilised Remains of Three Oviraptorid Dinosaurs – Is this Evidence of Communal Roosting?

The three oviraptorid fossil skeletons within the single block.

Picture credit: Gregory F. Funston

The picture above shows the plaster-jacketed block containing the three individuals and a line drawing showing the location of each skeleton and the layout of the bones.  Greg Funston (University of Alberta), who led the fossil study explained that the three sleeping dinosaurs were probably relatives, perhaps from the same brood.  The fossil material first came to the attention of academics when Mongolian customs officials seized the specimen at an airport in 2006.  The stone block was being illegally smuggled out of the country, sadly, there is a thriving black market in illicit fossils from Mongolia and China, despite the very best attempts of the authorities to stop this trade.

Identifying the source of such illegally acquired fossils is always tricky, but a geochemical analysis of the surrounding matrix by scientists from the University of Bologna (Italy), led by Federico Fanti, suggested that the fossil came from the Bugiin Tsav area of the Gobi Desert (Upper Cretaceous sediments associated with the Nemegt Formation – Maastrichtian faunal stage).  Dr Fanti has also presented his findings at the SVP.

Sleeping Oviraptorids

Oviraptorids were extremely bird-like, feathered dinosaurs, with short skulls, beaks and deep lower jaws which were largely edentulous (lacking teeth).  Several genera have been named and these dinosaurs lived in the northern hemisphere during the Late Cretaceous.  Most of these dinosaurs were relatively small, around two-three metres in length (Gigantoraptor being an exception) and they were particularly abundant in Asia.  Fossils of their nests have been found, along with adults incubating eggs.  Most palaeontologists believe that these dinosaurs were social animals with similar behaviours to those seen in extant birds.  The diet of oviraptorids is uncertain, these bipeds could have been mainly herbivorous, but omnivory and durophagy (eating hard-shelled items like nuts, seeds and molluscs) is not ruled out.

An Oviraptor Exhibit at a Museum (Frankfurt Natural History Museum)

An Oviraptor and its nest. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

The three individuals are from the same species, which is new to science, these oviraptorids have yet to be formally named.  Like several other oviraptorids, a prominent, domed skull crest has been identified.  These types of dinosaurs seem to have been highly successful, the vertebrate biota of some Upper Cretaceous deposits of China are dominated by oviraptorids, for a case in point: Not Another Ganzhou Oviraptorid.

Juveniles Huddling Together

Two of the dinosaurs have been preserved crouched down on their stomachs, these two specimens, which are more complete than the third, have their necks curled back towards their bodies, whilst their arms cradle their heads, this is very reminiscent of a sleeping posture adopted by many types of living bird.

The fossilised remains of allegedly sleeping dinosaurs have been found before, perhaps most notably Mei long from the Liaoning Formation of north-eastern China.  M. long was named in 2004 after a spectacular fossil showing a head tucked under an arm and a tail curled round the body was discovered.  This little troodontid was either resting or sleeping when it was smothered by a layer of volcanic ash.

An Illustration of the “Sleeping Dragon” Mei long

A Mei long dinosaur figure.

Dinosaurs Roosting Together

This is the first fossil evidence to support the idea that some kinds of dinosaurs roosted together (communal roosting).  Bone histology indicates that these animals were juveniles and roughly the same age when they died, it has been speculated that this fossil represents a “teenage gang” of sub-adult dinosaurs that died in their sleep.

If the layout of the fossils reflects their true posture and the bone position has not been affected by the fossilisation process, then the position of the three dinosaurs implies they were touching each other.  The researchers think the youngsters were probably huddling for warmth.  That suggests that the animals had tried to maintain a constant body temperature, or perhaps they were frightened and huddling together for protection and comfort.  David Varricchio (Associate Professor at Montana State University), has commented that he wondered whether these dinosaurs were resting or taking shelter from harsh weather rather than sleeping.

Communal Roosting in Oviraptorids

Funston argues that modern animals that roost together don’t usually make direct contact except for warmth.  Animals that died in events such as floods are preserved in very different positions from that of the oviraptorid trio, making it unlikely that the young dinosaurs were awake when they met their demise.

An Illustration of Roosting Oviraptorids

Roosting oviraptorids.

Picture credit: Mike Skrepnick

Fossils that are Difficult to Interpret

The three dinosaurs do seem to have perished together, their body positions indicate that the carcasses were unlikely to have been transported far before accumulating and forming this assemblage, but interpreting the fossil is difficult.  Other researchers have expressed reservations about the communal resting hypothesis.  For example, biologist John Grady (Bryn Mawr College, Pennsylvania), has stated that the dinosaurs may have huddled together to hide or merely because the location was “a great place to sleep.” 

However, this fossil material is interpreted, it adds to the growing body of evidence that many types of dinosaurs, including Maniraptorans were highly social creatures and capable of exhibiting quite complex behaviours.

For a 2013 article that looks at evidence for oviraptorid courtship displays: Dinosaurs Shaking Tail Feathers and Strutting.

Canadian dinosaur helps to prove dinosaurs were show-offs: Fossil Discovery Reinforces Idea of Dinosaurs Displaying.

Visit the Everything Dinosaur website: Everything Dinosaur.