Theropod

inlovewithgeosciences: Dilong paradoxus Geological time:...

Sat, 21 Apr 2012 20:25:12 -0400

Dilong paradoxus

Geological time: Cretaceous, 130 Ma

Found in Liaoning province, China

Size comparisons between the skulls and forearms...

Thu, 19 Apr 2012 22:19:07 -0400

Size comparisons between the skulls and forearms of Tyrannosaurus rex and Raptorex kriegsteini (now thought to be a juvenile tyrannosaurid and not its own genus)

Yutyrannus huali skull reconstruction by Scott Hartman.

Wed, 18 Apr 2012 16:07:00 -0400

Yutyrannus huali skull reconstruction by Scott Hartman.

rhamphotheca: Fossil Find: Birdlike Dinosaur Laying Beside...

Wed, 11 Apr 2012 13:01:42 -0400

rhamphotheca:

Fossil Find: Birdlike Dinosaur Laying Beside Eggs When Death Struck

by Jeanna Bryner

A mysterious birdlike dinosaur was about to lay her eggs when she perished some 70 million years ago in what is now Patagonia, researchers have found.

The scenario is based on the discovery of two dinosaur eggs lying near the partial skeletal remains of an alvarezsaurid dinosaur, which was a type of small maniraptoran, a group of theropod dinosaurs believed to be the line that eventually led to modern-day birds. Alvarezsaurids are bizarre among dinosaurs, scientists have said, due to their short, massive forelimbs tipped with a single digit sporting a gigantic claw. The dinosaurs also show highly birdlike skeletons, even though they were flightless.

The team named the dinosaur Bonapartenykus ultimus in honor of José Bonaparte, who in 1991 discovered the first alvarezsaurid in Patagonia.

The dinosaur eggs were found less than 7.9 inches (20 centimeters) from the partial skeleton and seemed to belong to that individual dinosaur. The researchers ruled out a postmortem mixing that brought the two together. The partial skeleton was also articulated, which would likely not be the case if they had been transferred there after death…

(read more: Live Science)

(illustration: Gabriel Lio; photo: Fernando Novas)

paleoillustration: “Citipati with chicks”, ”Citipati and...

Sat, 07 Apr 2012 18:32:27 -0400

Citipati with chicks

Citipati and Shuvuuia

paleoillustration:

“Citipati with chicks”, ”Citipati and Shuvuuia” and sketches, by Edyta.

Selected elements of Y. huali (ZCDM V5000, ZCDM V5001 and ELDM...

Fri, 06 Apr 2012 17:02:11 -0400

Selected elements of Y. huali (ZCDM V5000, ZCDM V5001 and ELDM V1001). a, Photograph of the skull and mandible of ELDM V1001. b, Line drawing of the skull and mandible of ELDM V1001. c–h, filamentous integumentary structures preserved in the three specimens: c, along the posterior caudal vertebrae of ZCDM V5000; d, along the cervical vertebrae of ELDM V1001; e, f, along a limb bone of ELDM V1001; g, h, near the pes of ZCDM V5001 (f and h are close-up views). Abbreviations: aop, accessory orbital process; clp, cultriform process; co, concavity; cp, cornual process; g, groove; lec, left ectopterygoid; lpa, left palatine; ls, left squamosal; mf, maxillary fenestra; np, nasal prominences; pnr, pneumatic recesses; r, ridge; sp., suborbital process; sr, surangular ridge.

From Xu et al., 2012

Concavenator corcovatus by Raúl Martín

Thu, 05 Apr 2012 22:09:45 -0400

Concavenator corcovatus by Raúl Martín

discoverynews: Shaggy T. Rex Cousin Was Heftiest Feathered...

Wed, 04 Apr 2012 18:22:02 -0400

discoverynews:

Shaggy T. Rex Cousin Was Heftiest Feathered Dino

A 3,086-pound shaggy tyrannosaur was the world’s largest known feathered animal — living or extinct — according to a paper in the latest issue of Nature.

The newly unearthed tyrannosaur, named Yutyrannus huali or “beautiful feathered tyrant,” lived about 125 million years ago in northeastern China. The over 29-foot-long non-avian dinosaur, represented by three specimens, is considerably smaller than its infamous relative T. rex, but some 40 times the weight of the largest previously known feathered dinosaur, Beipiaosaurus.

keep reading

Torvosaurus tanneri

Mon, 02 Apr 2012 19:59:34 -0400

Torvosaurus tanneri

prehistoric-birds: Scansoriopteryx (“climbing wing”) Temporal...

Fri, 30 Mar 2012 17:01:24 -0400

Life restoration of a juvenile

Holotype of synonym Epidendrosaurus

prehistoric-birds:

Scansoriopteryx (“climbing wing”)

Temporal range: Late Jurassic, 154 Ma

Fossil location: Liaoning, China

Known species: S. heilmanni

Like fellow scansoriopterygid Epidexipteryx, this tiny dinosaur was part of the clade Avialae, which is composed of the birds and their most immediate extinct relatives. The juvenile type specimen contains the fossilized impression of feathers; the most prominent of these impressions trail from the left forearm and hand, which has led to speculation that adult scansoriopterygids had reasonably well-developed wing feathers that could have aided in leaping or rudimentary gliding.

Even if it got some use out of its wing feathers while airborne, Scansoriopteryx was most likely incapable of powered flight. Instead, the dinosaur’s elongated hands and specialized foot anatomy imply that it was adapted to a scansorial (climbing) lifestyle—hence its genus name. The unusually long third finger may have served two major purposes: as an additional climbing adaptation and as a tool for digging insects out of crevices in trees.

(Info sources: x x) (Photo sources: x x) {Art credit: [Image: John Conway (http://jconway.co.uk)]}

fuckyeahdinoart: Carcharodontosaurus by ~PaleoPastori

Mon, 26 Mar 2012 16:00:06 -0400

fuckyeahdinoart:

Carcharodontosaurus by ~PaleoPastori

artforartists: Mr. Iridescent by ~WanderingAlbatross

Sun, 25 Mar 2012 17:45:19 -0400

artforartists:

Mr. Iridescent by ~WanderingAlbatross

Cryolophosaurus by David Krentz

Tue, 20 Mar 2012 16:09:08 -0400

Cryolophosaurus by David Krentz

lazyosaurus: Carcharodontosaurus

Mon, 19 Mar 2012 21:27:54 -0400

lazyosaurus:

Carcharodontosaurus

paleoillustration: Carnotaurus sastrei by Karel...

Sun, 18 Mar 2012 18:59:00 -0400

paleoillustration:

Carnotaurus sastrei by Karel Cettl / DeviantArt gallery

Mick Ellison’s Microraptor reconstruction, based on new...

Fri, 09 Mar 2012 20:14:32 -0500

Mick Ellison’s Microraptor reconstruction, based on new evidence that it sported iridescent black plumage.

paleoillustration: GMC91 aka Dave aka Juvenile Sinornithosaurus...

Thu, 08 Mar 2012 21:53:00 -0500

paleoillustration:

GMC91 aka Dave aka Juvenile Sinornithosaurus millenii, by Dinomaniac.

Cryolophosaurus (by Jeff Kubina)

Thu, 01 Mar 2012 12:04:05 -0500

Cryolophosaurus (by Jeff Kubina)

T. Rex Has Most Powerful Bite of Any Terrestrial Animal Ever

Wed, 29 Feb 2012 20:28:05 -0500

T. Rex Has Most Powerful Bite of Any Terrestrial Animal Ever:

(Photograph by Ira Block; model by Brian Cooley)

Research at the University of Liverpool, using computer models to reconstruct the jaw muscle of Tyrannosaurus rex, has suggested that the dinosaur had the most powerful bite of any living or extinct terrestrial animal.

The team artificially scaled up the skulls of a human, alligator, a juvenile T. rex, and Allosaurus to the size of an adult T. rex. In each case the bite forces increased as expected, but they did not increase to the level of the adult T. rex, suggesting that it had the most powerful bite of any terrestrial animal.

Previous studies have estimated that T. rex’s bite had a force of 8,000 to 13,400 Newtons, but given the size of the animal, thought to weigh more than 6,000kg, researchers suspected that its bite may have been more powerful than this. Liverpool scientists developed a computer model to reverse engineer the animal’s bite, a method that has previously been used to predict dinosaur running speeds.

An animal’s bite force is largely determined by the size of the jaw muscles. Using their computer models, researchers tested a range of alternative muscle values, as it is not precisely known what the muscles of dinosaurs were like. Even with error margins factored in, the computer model still showed that theT. rex had a more powerful bite than previously suggested.

The smallest values predicted were around 20,000 Newtons, while the largest values were as high as 57,000 Newtons, which would be equivalent to the force of a medium sized elephant sitting down on the ground.

Researchers also found that the results for the juvenile T. rex had a relatively the weaker bite than the adult T. rex, even when size differences and uncertainties about muscle size were taken into account. The large difference between the two measurements, despite the error margins factored in, may suggest that T. rex underwent a change in feeding behaviour as it grew.

Dr Karl Bates, from the University’s Department of Musculoskeletal Biology, said: “The power of the T. rex jaw has been a much debated topic over the years. Scientists only have the skeleton to work with, as muscle does not survive with the fossil, so we often have to rely on statistical analysis or qualitative comparisons to living animals, which differ greatly in size and shape from the giant enigmatic dinosaurs like T. rex. As these methods are somewhat indirect, it can be difficult to get an objective insight into how dinosaurs might have functioned and what they may or may not have been capable of in life.

“To build on previous methods of analysis, we took what we knew about T. rex from its skeleton and built a computer model that incorporated the major anatomical and physiological factors that determine bite performance. We then asked the computer model to produce a bite so that we could measure the speed and force of it directly. We compared this to other animals of smaller body mass and also scaled up smaller animals to the size of T. rex to compare how powerful it was in relative terms.

“Our results show that the T. rex had an extremely powerful bite, making it one of the most dangerous predators to have roamed our planet. Its unique musculoskeletal system will continue to fascinate scientists for years to come.”

Variation in the skulls of theropod dinosaurs: the Late...

Wed, 29 Feb 2012 16:50:45 -0500

Variation in the skulls of theropod dinosaurs: the Late Triassic coelophysoid Coelophysis; the Early Jurassic ceratosaur Ceratosaurus; the Late Jurassic allosaur Allosaurus; the middle Cretaceous spinosaur Suchomimus; the Late Cretaceous dromaeosaur Velociraptor; the Late Cretaceous tyrannosaur Tyrannosaurus.

From Scott Sampson’s Dinosaur Odyssey