[Paleontology • 2020] Ubirajara jubatus • A Maned Theropod Dinosaur (Theropoda: Compsognathidae) from Gondwana with Elaborate Integumentary Structures

Ubirajara jubatus 

 Smyth, Martill, Frey, Rivera-Sylva & Lenz, 2020 

DOI: 10.1016/j.cretres.2020.104686  

Illustration: Bob Nicholls twitter.com/PaleoCreations 

 Abstract

Discoveries of dinosaurs with integumentary structures over the last few decades have revolutionised our understanding of the phylogenetic relationships between birds and dinosaurs as well as the origin and evolution of feathers. A remarkable number of dinosaurs have been discovered with a diverse range of preserved integumentary structures. Several of these dinosaurs are adorned with elaborate integumentary structures that have been linked to behaviours including thermoregulation, egg incubation, and sexual display. Among Theropoda, such elaborate structures have only been previously recorded within Maniraptoriformes. However, elaborate monofilamentous structures are also present in some small ornithischians. 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. Herein, we describe a new genus and species of compsognathid theropod from the Lower Cretaceous (Aptian) Crato Formation of Northeast Brazil, representing 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. These include slender monofilaments associated with the base of the neck, increasing in length along the dorsal thoracic region where they form an impressive mane, as well as a pair of elongate, ribbon-like structures likely emerging from the shoulder. Such elaborate integumentary structures are hitherto unknown in any other dinosaur, although superficially similar elongate display feathers emerge from the carpal region of the male standardwing bird-of-paradise (Semioptera wallacii).

Keywords: Crato Formation, Lower Cretaceous, Dinosauria, Compsognathidae, Ubirajara jubatus, Integumentary structures

Ubirajara jubatus (SMNK PAL 29241):
A, Interpretative line drawing showing combined slab and mirrored counter slab.
B, Reconstruction showing preserved skeletal elements in white and integumentary structures in brown, with missing elements in grey. Elaborate display structures reconstructed as emanating from the scapular region in yellow.

DINOSAURIA Owen 1842 

THEROPODA Marsh 1881 

COELUROSAURIA von Huene 1914 

COMPSOGNATHIDAE Cope 1871 

UBIRAJARA gen. nov.

Ubirajara jubatus gen. et sp. nov. 

Etymology. Genus, Ubirajara, is a traditional Tupi name meaning lord of the spear, in reference to the stiffened, elongate integumentary structures associated with the specimen. The specific epithet jubatus is from the Latin, meaning maned or crested.  

Ubirajara jubatus: elaborate integumentary structures.
A, Mane of slender monofilamentous integumentary structures.
B, Paired hypertrophied broad monofilamentous integumentary structures.

Abbreviations: BMFIs, broad monofilamentous integuments; ce, cervical vertebra; cer, cervical rib; d, dorsal vertebra; ga, gastralia; rco, right coracoid; rsc, right scapula; s, sacral vertebra; SMFIs, slender monofilamentous integuments. Scale bars ¼ 20 mm

 

 Robert S.H. Smyth, David M. Martill, Eberhard Frey, Héctor E. Rivera-Sylva and Norbert Lenz. 2020. A Maned Theropod Dinosaur from Gondwana with Elaborate Integumentary Structures. Cretaceous Research.  In Press. DOI: 10.1016/j.cretres.2020.104686

 twitter.com/PaleoCreations/status/1338264588861779969

      

[Paleontology • 2019] A Polar Dinosaur Feather Assemblage from Australia

Australian feathered polar dinosaur.

in Kundrát, Rich, Lindgren, et al., 2019. 

 DOI: 10.1016/j.gr.2019.10.004 

 Illustration: Peter Trusler 

Highlights: 

• Fossil feathers from the Koonwarra Fossil Bed in southeastern Australia record the first demonstrable dinosaur (including birds) integumentary structures described from the Mesozoic polar regions.

• This diverse range of non-avian theropod (paravian) and bird feathers more than doubles the number of Mesozoic fossil feather specimens and morphologies recovered from the Gondwanan landmasses to date.

• Possible traces of eumelanosomes imply original dark colouration and patterning. Some of the geologically oldest barbicel-like structures also evince advanced avian-grade flight feather morphologies in the Early Cretaceous.

ABSTRACT

Exceptionally preserved Mesozoic feathered dinosaur fossils (including birds) are famous, but recognized from only very few localities worldwide, and are especially rare in the Southern Hemisphere. Here we report an assemblage of non-avian and avian dinosaur feathers from an Early Cretaceous polar (around 70°S) environment in what is now southeastern Australia. The recovered remains incorporate small (10–30 mm long) basal paravian-like tufted body feathers, open-vaned contour feathers, and asymmetrical bird-like wing feathers that possess high-angled barbs with possible remnants of barbicels — amongst the geologically oldest observed to date. Such morphological diversity augments scant skeletal evidence for a range of insulated non-avian theropods and birds inhabiting extreme southern high-latitude settings during the Mesozoic. Although some of these fossil feathers exhibit what may be residual patterning, most are uniformly toned and preserve rod-shaped microbodies, as well as densely-packed microbody imprints on the barbules that are structurally consistent with eumelanosomes. Geochemical analysis detected no identifiable residual biomolecules, which we suspect were lost via hydrolysis and oxidization during diagenesis and weathering. Nevertheless, an originally dark pigmentation can be reasonably inferred from these melanic traces, which like the coloured feathers of modern birds, might have facilitated crypsis, visual communication and/or thermoregulation in a cold polar habitat.

Keywords: Mesozoic birds, Aves, Paravesmelanosomes, Early Cretaceous

 Martin Kundrát, Thomas H. Rich, Johan Lindgren, Peter Sjövall, Patricia Vickers-Rich, Luis M. Chiappe and Benjamin P. Kear. 2019. A Polar Dinosaur Feather Assemblage from Australia. Gondwana Research. In Press. DOI: 10.1016/j.gr.2019.10.004 

Researchgate.net/publication/254219016_A_polar_dinosaur-track_assemblage_from_the_Eumeralla_Formation_Albian_Victoria_Australia

First evidence of feathered polar dinosaurs found in Australia - Uppsala University  mynewsdesk.com/uk/uu/pressreleases/first-evidence-of-feathered-polar-dinosaurs-found-in-australia-2942524 

[Paleontology • 2014] New Specimen of Archaeopteryx provides Insights into The Evolution of Pennaceous Feathers | The Flight for First Bird

Archaeopteryx’s status is changing, but the animal is still key to the dinosaur–bird transition.

Illustration by Emily Willoughby; Graphics: Jasiek Krzysztofiak/Nature;
doi: 10.1038/nature13467 | 10.1038/516018a

The iconic status of Archaeopteryx, the first animal discovered with both bird and dinosaur features, is under attack. More-recently discovered rival species show a similar mix of traits. But Archaeopteryx still hogged the opening symposium at the 2014 Society of Vertebrate Paleontology meeting in Berlin last month, and even festooned the official conference beer glasses.

As the simplistic idea of a ‘first’ bird gives way to a messy evolutionary transition, newly discovered fossils and improved analysis techniques put Archaeopteryx in prime position to unravel the details. “Research on Archaeopteryx is really catching a new breath,” says palaeobiologist Martin Kundrat of Uppsala University in Sweden, who co-organized the symposium at the November meeting.

The first Archaeopteryx fossil specimens turned up in limestone quarries in Bavaria, southern Germany, in the early 1860s. Until recently, they were the only fossil specimens found to mix bird- and dinosaur-like features. On the one hand, they are small — the fossils show juvenile creatures about the size of a magpie, which as adults may have been raven-sized — and have broad feathered wings that look good for gliding; on the other, they have a jaw with sharp teeth, dinosaur-like claws and a bony tail. These features led to the idea of the first bird, and generations of scientists have treated the 145-million-year-old animal as a ‘transitional species’ — the key piece of evidence linking birds and dinosaurs (Archaeopteryx is Greek for ‘ancient feather’, whereas its German name, ‘Urvogel’, means ‘first bird’).

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doi: 10.1038/516018a

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Discoveries of bird-like theropod dinosaurs and basal avialans in recent decades have helped to put the iconic ‘Urvogel’ Archaeopteryx into context and have yielded important new data on the origin and early evolution of feathers. However, the biological context under which pennaceous feathers evolved is still debated. Here we describe a new specimen of Archaeopteryx with extensive feather preservation, not only on the wings and tail, but also on the body and legs. The new specimen shows that the entire body was covered in pennaceous feathers, and that the hindlimbs had long, symmetrical feathers along the tibiotarsus but short feathers on the tarsometatarsus. Furthermore, the wing plumage demonstrates that several recent interpretations are problematic. An analysis of the phylogenetic distribution of pennaceous feathers on the tail, hindlimb and arms of advanced maniraptorans and basal avialans strongly indicates that these structures evolved in a functional context other than flight, most probably in relation to display, as suggested by some previous studies. Pennaceous feathers thus represented an exaptation and were later, in several lineages and following different patterns, recruited for aerodynamic functions. This indicates that the origin of flight in avialans was more complex than previously thought and might have involved several convergent achievements of aerial abilities.

Christian Foth, Helmut Tischlinger and Oliver W. M. Rauhut. 2014. New Specimen of Archaeopteryx provides Insights into The Evolution of Pennaceous Feathers. Nature. 511, 79–82. doi: 10.1038/nature13467

Amy M. Balanoff, Gabe S. Bever, Timothy B. Rowe and Mark A. Norell. 2013. Evolutionary origins of the avian brain. Nature. 501, 93–96 doi: dx.doi.org/10.1038/nature12424

Ryan M. Carney, Jakob Vinther, Matthew D. Shawkey, Liliana D'Alba and Jörg Ackermann. 2012. New evidence on the colour and nature of the isolated Archaeopteryx feather. Nature Communications. 3, Article number: 637 doi: 10.1038/ncomms1642

Ewen Callaway. 2014. Rival Species recast significance of ‘First Bird’. Nature. 516, 18–19 (04 December 2014) doi: 10.1038/516018a

[Paleontology • 2004] Dilong paradoxus 'emperor dragon' • Basal tyrannosauroids from China and evidence for protofeathers in tyrannosauroids

Figure 1: Dilong paradoxus.

Figure 2: IVPP V11579.

a, Skeletal reconstruction showing preserved bones.

Figure 3: Integumentary structures of IVPP V11579.

a, b, Filamentous integumentary structures along the dorsal edge of the distal caudal vertebrae, photograph (a) and linedrawing (b). c, d, Close-up of the integumentary structures showing the simple branching pattern, photograph (c) and linedrawing (d). Not to scale.

^ Xu, X., Norell, M. A., Kuang, X., Wang, X., Zhao, Q., Jia, C. (2004). "Basal tyrannosauroids from China and evidence for protofeathers in tyrannosauroids". Nature. 431 (7009): 680–684. doi:10.1038/nature02855.  

http://s4.zetaboards.com/The_Paleo_Handbook/topic/8329803/1/

China Dinosaur Fossils Article, Liaoning Province : http://science.nationalgeographic.com/science/prehistoric-world/china-fossils/