Geological time: Cretaceous, 130 Ma
Found in Liaoning province, China
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.
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)
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
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.
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.