Ubirajara jubatus – One Very Flashy Dinosaur

A new genus of feathered dinosaur Ubirajara jubatus has been described.

News about the discovery of a species of feathered dinosaur has now become relatively commonplace.  Yet, it is worth remembering that it was just twenty-four years ago, back in 1996, that the first, non-avian dinosaur species with evidence of fuzzy feathers was described.  Named Sinosauropteryx this lithe meat-eater literally “rocked” scientists as the long-awaited proof of feathered dinosaurs was revealed to the world.  Sinosauropteryx was a compsognathid, a team of researchers, including scientists from the University of Portsmouth have described another feathered dinosaur, this new feathered theropod is a compsognathid too, but with a more elaborate and spectacular integumentary covering.

Ubirajara jubatus

The newly described Ubirajara jubatus is the first Gondwanan non-avian theropod with preserved filamentous integumentary structures.  It is also the first non-maniraptoran possessing elaborate integumentary structures that were most likely used for display.

A Life Reconstruction of the Newly Described Brazilian Compsognathid Ubirajara jubatus

Picture credit: Bob Nicholls/Paleocreations

Dressed to Impress

Described as the most elaborately dressed-to-impress dinosaur described to date, the research team co-led by Professor David Martill and researcher Robert Smyth (University of Portsmouth), propose that U. jubatus will shed new light on how birds evolved elaborate display structures.

This chicken-sized dinosaur possessed a mane of long bristles running down its back and stiff ribbons projecting out and back from its shoulders, a combination of features never seen before in the fossil record.

The scientific paper has been published in the journal of Cretaceous research and involved a collaboration between the University of Portsmouth and the appropriately named Professor Dino Frey at the State Museum of Natural History, Karlsruhe, Germany, who discovered the new species while examining fossils in Karlsruhe´s collection and Héctor E. Rivera-Sylva of the Departamento de Paleontología, Museo del Desierto in Saltillo, Mexico.  The fossil was authorised by the Brazilian authorities for export some time ago, but was only recently studied.

Bizarre Integumentary Structures

The bizarre integumentary structures must have had a purpose, whilst the body covering may have originally evolved to provide insulation, the stiff ribbons on either side of the shoulders were probably used for display, perhaps to attract a mate, deter a rival or to frighten a potential predator.

Professor Martill commented:

“We cannot prove that the specimen is a male, but given the disparity between male and female birds, it appears likely the specimen was a male, and young, too, which is surprising given most complex display abilities are reserved for mature adult males.  Given its flamboyance, we can imagine that the dinosaur may have indulged in elaborate dancing to show off its display structures.”

Not Scales or Fur

The ribbons are not fur or scales, they are not feathers in the modern sense, as seen on an extant bird.  They appear to be structures unique to this animal.

Mr Smyth added:

“These are such extravagant features for such a small animal and not at all what we would predict if we only had the skeleton preserved.  Why adorn yourself in a way that makes you more obvious to both your prey and to potential predators?  The truth is that for many animals, evolutionary success is about more than just surviving, you also have to look good if you want to pass your genes on to the next generation.”

The Holotype of Ubirajara jubatus Preserved as a Slab and Counter Slab

Picture credit: Smyth et al /Cretaceous Research

From the Lower Cretaceous (Aptian) Crato Formation of North-eastern Brazil

Fossil discoveries starting with the ground-breaking Sinosauropteryx specimen that was described in 1996 have fundamentally changed our understanding of the phylogenetic relationships between birds and dinosaurs as well as the origin and evolution of feathers.  A variety of elaborate integumentary coverings and structures are now known from the Theropoda and from ornithischian dinosaurs too.  They have been linked to behaviours including egg incubation, mating displays and thermoregulation.

The Colourful PNSO Model of the Chinese Compsognathid Sinosauropteryx

The picture (above) shows a PNSO Sinosauropteryx dinosaur model.

To view the range of PNSO models and figures: PNSO Age of Dinosaurs Models.

Within the Theropoda, such features have only been previously recorded within the Maniraptoriformes, a theropod clade which includes birds and is defined as “the most recent common ancestor of the ostrich mimic Ornithomimus and Aves (birds) and all descendants of that common ancestor.”

The majority of theropods preserving integumental structures come from the Upper Jurassic and Lower Cretaceous of China or the Upper Jurassic of southern Germany and all are of Laurasian origin.  Ubirajara jubatus from the Lower Cretaceous (Aptian) Crato Formation of north-eastern Brazil, is the first non-maniraptoran possessing elaborate integumentary structures that were most likely used for display.

Ubirajara jubatus the First Non-avian Theropod with Preserved Filamentous Structures

It is also the first non-avian theropod with preserved filamentous integumentary structures to have been described from the southern hemisphere landmass of Gondwana.

The researchers compare Ubirajara to living birds stating that many modern Aves are famed for their exotic and colourful plumage along with their complex displays that are used to win mates.  Male peacocks with their stunning tails and male birds of paradise are examples of this.

Ubirajara jubatus (pronounce You-bi-rah-jar-rah jew-bay-tus), lived approximately 110 million years ago (Aptian faunal stage of the Early Cretaceous).  The genus name is derived from the local Tupi dialect and translates as “lord of the spear”, whilst the trivial or specific name is from the Latin for “mane” a reference to the integumentary covering on its back.

Able to Raise its Hackles Like a Dog?

The mane running down its back is thought to have been controlled by muscles allowing it to be raised, in a similar way a dog raises its hackles or a porcupine raises its spines when facing a threat. Once the danger had passed, Ubirajara could lower its mane close to the skin allowing this little dinosaur to move quickly through the undergrowth without getting tangled up.

Professor Martill explained:

“Any creature with movable hair or feathers as a body coverage has a great advantage in streamlining the body contour for faster hunts or escapes but also to capture or release heat.”

The unique body plan of Ubirajara with its long, flat, stiff shoulder ribbons of keratin, each with a small sharp ridge running along the middle, described by the authors as “enigmatic” might have looked cumbersome, but in reality they were located on the body in such a way as not to impede movement allowing Ubirajara to preen, hunt, move around and display unencumbered.

The scientific paper: The scientific paper: “A maned theropod dinosaur from Gondwana with elaborate integumentary structures” by Robert S. H. Smyth, David M. Martill, Eberhard Frey, Héctor E. Rivera-Sylva and Norbert Lenz published in Cretaceous Research.  This paper was withdrawn in July 2022.

Visit the Everything Dinosaur website: Everything Dinosaur.com

Two New South American Titanosaurians

The last type of sauropod to have lived were the Titanosauria, a clade consisting of a variety of taxa that were geographically widespread.  Fossils of titanosaurs have been found on every continent.  These long-necked herbivores seem to have been particularly successful in South America, with some of the largest tetrapods of all time – Argentinosaurus, Patagotitan and Dreadnoughtus known from this continent.

A team of scientists based in Argentina recently published a paper describing two new South American titanosaurs from the province of La Rioja located in the north-west of that country.  The dinosaurs named Punatitan coughlini and Bravasaurus arrierosorum, help to fill a gap between the types of titanosaurs associated with Patagonia and south-western Brazil, the two main locations associated with Titanosauria fossil discoveries from South America.

Skeletal Drawings Punatitan coughlini (c) and (d) Bravasaurus arrierosorum

Picture credit: Hechenleitner et al (Communications Biology)

Dinosaurs from the Andes – Titanosaurs Demonstrate Philopatry

The fossil material representing three individuals was found in the Upper Cretaceous red beds of the Quebrada de Santo Domingo locality in the Andes of La Rioja province.  In addition, a large number of titanosaurian egg clutches and eggshells were recovered.  Such was the abundance of eggshell found that this location is regarded as one the largest dinosaur nesting sites known in the world.  These fossils help to support the theory that these types of dinosaurs returned to the same, favoured nesting area year after year, the titanosaurs demonstrated philopatry (the tendency of an organism to habitually return to the same location, usually to breed or to nest).

Cervical and dorsal vertebrae of Punatitan coughlini

Picture credit: Hechenleitner et al (Communications Biology)

Limb Bones Associated with Bravasaurus arrierosorum

Picture credit: Hechenleitner et al (Communications Biology)

Titanosauria Phylogenetic Analysis

A phylogenetic analysis undertaken by the research team suggests that both Bravasaurus and the much larger Punatitan have affinities with both Patagonian and Brazilian titanosaurs.  The discovery of these two genera, both classified within the sub-clade of the Rinconsauria, supports the hypothesis of a close relationship between titanosaurian faunas in South America during the Late Cretaceous.

Titanosaur Palaeogeographical Distribution and Phylogeny

Picture credit: Hechenleitner et al (Communications Biology)

The Site of the Fossil Discoveries and Plotting the Location of Titanosaurs in South America

Picture credit: Hechenleitner et al (Communications Biology)

The scientific paper: “Two Late Cretaceous sauropods reveal titanosaurian dispersal across South America” by E. Martín Hechenleitner, Léa Leuzinger, Agustín G. Martinelli, Sebastián Rocher, Lucas E. Fiorelli, Jeremías R. A. Taborda, and Leonardo Salgado published in Communications Biology.

Visit the Everything Dinosaur website: Everything Dinosaur.

Small Skull of Fossil Bird Has Big Implications (Falcatakely forsterae)

A team of international researchers including scientists from Ohio University, Stony Brook University (New York) and University College London have published a scientific paper describing a new type of enantiornithine bird (Falcatakely forsterae) from the Late Cretaceous of Madagascar.

Named Falcatakely, this crow-sized early avian offers a new perspective on the evolution of face and beak shape in the ancestral group leading to modern-day birds.

A Life Reconstruction of Falcatakely forsterae in the Late Cretaceous of Madagascar Surrounded by Other Archosaurs

Picture credit: Mark Witton

A Mesozoic Toucan?

Although palaeontologists are aware of a wide range of Mesozoic birds such as enantiornithines and hesperornithiforms which vary in size, flight adaptations and lifestyles, they all exhibit relatively conservative patterns of beak shape and development.  Modern birds (neornithines), such as the finches studied by the famous naturalist Charles Darwin, show a huge range of beak morphologies, all associated with different feeding and behavioural ecologies.  Falcatakely forsterae bucks this trend for birds from the Late Cretaceous, it has a beak morphology unlike other Mesozoic birds, one that is superficially similar to that of extant toucans.

Falcatakely forsterae, a combination of Latin and Malagasy words inspired by the small size and the scythe-like shape of the beak, which represents a completely novel face shape in Mesozoic birds.

Co-author of the scientific paper Dr Ryan Felice (University College London), explained how the study of birds have helped many scientists understand the subtleties of convergent evolution:

“Ever since Charles Darwin’s observations of Galapagos finches with differently-shaped beaks, birds have shaped our understanding of evolution through natural selection.  This new discovery tells us even more about how the predecessors of modern birds evolved, by showing how different forces in different places can contribute to similar traits in distantly related animals.”

Falcatakely forsterae

Described from a single skull specimen which had remained uncatalogued for several years since its discovery in 2010, lead author Patrick O’Connor (Ohio University) and his colleagues used high resolution CT scans to build up a picture of the skull and beak.

The Skull of Falcatakely forsterae with CT Scans and Interpretative Line Drawing

Picture credit: O’Connor et al

Bird fossils are rare.  Their light fragile bones tend not to fossilise well.  Bird skulls are especially rare, but although crushed, the powerful CT scans have been able to reveal many unique features of the bones and the beak.  For example, the researchers were able to identify a single preserved tooth in the premaxilla, probably one of several teeth lining the beak of this resident of north-western Madagascar some 68 million years ago.

Everything Dinosaur acknowledges the assistance of a media release from the University of Ohio and University College London in the compilation of this article.

The scientific paper: “Late Cretaceous bird from Madagascar reveals unique development of beaks” by Patrick M. O’Connor, Alan H. Turner, Joseph R. Groenke, Ryan N. Felice, Raymond R. Rogers, David W. Krause and Lydia J. Rahantarisoa published in Nature.

Visit the Everything Dinosaur website: Everything Dinosaur.

First Dinosaur Remains from Ireland

Scientists from the University of Portsmouth, National Museums of Ireland and Queen’s University Belfast have confirmed that fossils found by the late Roger Byrne on the east coast of County Antrim (Northern Ireland), are dinosaur bones.  These are the only dinosaur bones known from the island of Ireland.  Roger Byrne donated a number of specimens to Ulster Museum but they had not been closely studied, a scientific paper published in the Proceedings of the Geologists’ Association remedies that and confirms that two of the pieces are dinosaurian and although they were found at the same location, they represent bones from two different dinosaurs.

Lead Researcher Dr Mike Simms Holding the Two Dinosaur Fossil Bones

Picture credit: The University of Portsmouth

Dinosaur Bones

Lead author of the research Dr Mike Simms stated:

“This is a hugely significant discovery.  The great rarity of such fossils here is because most of Ireland’s rocks are the wrong age for dinosaurs, either too old or too young, making it nearly impossible to confirm dinosaurs existed on these shores.  The two dinosaur fossils that Roger Byrne found were perhaps swept out to sea, alive or dead, sinking to the Jurassic seabed where they were buried and fossilised.”

Lias Group Exposures

The two fossil bones found by the Roger Byrne, a schoolteacher and avid fossil collector, come from Lower Jurassic strata exposed in Islandmagee.  They had been suspected of representing dinosaur bones, although they were found in marine deposits.  A detailed analysis of their histology and shape indicated that two of the pieces that Roger donated were indeed the bones of dinosaurs.  Originally, it had been thought that the bones represented a single type of dinosaur but the research team were surprised to discover that they represent bones from two very different types.

One specimen has been interpreted as the proximal end of the left femur of a basal thyreophoran ornithischian.  It has been tentatively assigned to Scelidosaurus, a primitive armoured dinosaur, fossils of which are known from Dorset (southern England) and date from the Sinemurian to the Pliensbachian faunal stages of the Early Jurassic.  The strata from which the femur fragment was found dates from slightly earlier, both the fossil bones are around 200 million years old.

A Model of the Early Armoured Dinosaur Scelidosaurus

Picture credit: Everything Dinosaur

The picture (above) shows the CollectA Deluxe Scelidosaurus figure.

To view the CollectA Deluxe range of prehistoric animals: CollectA Deluxe Prehistoric Life Models.

Evidence of a Meat-eating Dinosaur

The second fragment of bone has been identified as the proximal part of the left tibia of an indeterminate neotheropod, perhaps a member of the averostran-line similar to Sarcosaurus, or a megalosauroid.  Sarcosaurus fossils are associated with Lower Jurassic strata (Hettangian-Sinemurian faunal stages), of England.  Together, the two fossil dinosaur bones represent the first dinosaur remains reported anywhere in Ireland and some of the west westerly in Europe.

An Illustration of Sarcosaurus

Picture credit: Everything Dinosaur

The researchers used high-resolution, three-dimensional replicas to confirm the identity of the items donated by Roger Byrne.

University of Portsmouth researcher Robert Smyth explained:

“Analysing the shape and internal structure of the bones, we realised that they belonged to two very different animals.  One is very dense and robust, typical of an armoured plant-eater.  The other is slender, with thin bone walls and characteristics found only in fast-moving two-legged predatory dinosaurs called theropods.”

An Illustration of the Fossil Bones from County Antrim

Picture credit: Roger Byrne/National Museums of Ireland

Very Important Fossil Discoveries

Despite their fragmentary and weathered nature, these fossils are extremely important as they date from the Hettangian stage of the Early Jurassic, shortly after the End Triassic extinction event when the Dinosauria start to diversify and become more widespread.  Very few dinosaur fossils are known from this stage of the Early Jurassic, so Roger’s fossils are globally significant.

One of the other items donated by Roger Byrne probably represents an element from the skull or jawbone from a large marine reptile, perhaps an ichthyosaur or a pliosaur, whilst a polygonal-shaped piece was determined not to be a fossil at all, but a piece of Palaeocene basalt, similar to that found at the famous Giant’s Causeway on the northern coast of County Antrim.

Scelidosaurus a Beachcomber?

Commenting on the number of Scelidosaurus fossils associated with marine deposits, Professor Martill (University of Portsmouth), suggested:

“Scelidosaurus keeps on turning up in marine strata, and I am beginning to think that it may have been a coastal animal, perhaps even eating seaweed like marine iguanas do today.”

The fossils were on display at the Ulster Museum during the “Dippy on Tour” exhibition in 2018, but it is hoped that these important fossil bones will be able to go on permanent display once the COVID-19 restrictions are lifted.

Everything Dinosaur acknowledges the assistance of a media release from the University of Portsmouth in the compilation of this article.

The scientific paper: “First dinosaur remains from Ireland” by Michael J. Simms, Robert S.H. Smyth, David M. Martill, Patrick C. Collins and Roger Byrne published in the Proceedings of the Geologists’ Association.

Visit the Everything Dinosaur website: Everything Dinosaur.