My old article from BDW on Huaxiagnathus

   

Huaxiagnathus orientalis - by Beri 

Illustration of a new compsognathid, Huaxiagnathus orientalis - by Beri (graphite), Copyright © 1999-2004 BERI Feb 2004 (updated) Huaxiagnathus orientalis - a large compsognathid from Early Cretaceous of China The paper was published in March, 2004 in the new Journal of Systematic Paleontology (The British National History Museum): - Sunny H. Hwang, Mark A. Norell, Ji Qiang, Gao Keqin, 2004, A LARGE COMPSOGNATHID FROM THE EARLY CRETACEOUS YIXIAN, FORMATION OF CHINA. Journal of Systematic Palaeontology Volume 2 (Issue 01), 13-30. It describes a new compsognathid, Huaxiagnathus orientalis, ( new genus and species) known from a nearly complete skeleton lacking only the distal end of the tail. At the first glance, the skull is very similar to the still unnamed new German compsognathid. Rather short forelimb has three fingers. In the paper "Huaxiasaurus" specimen is reffered to Huaxiagnathus. Supplementary information is included and has 17 new characters added to the Theropod Working Group Matrix, and several new taxa coded in it (Shenzhousaurus, Archaeornithomimus, Ornithomimus, Anserimimus, Huaxiagnathus, Sinosauropteryx, Compsognathus, IGM 100/44). The topology has compsognathids (Huaxiagnathus, Sinosauropteryx, Compsognathus) as maniraptorans more derived than Ornitholestes. Early Cretaceous, People's Republic of China, Yixian Formation, Liaoning, Yehol Group sediments. Approximate length: 130-145cm Pronounciation: hua-xia-NA-thus Holotype photograph from the paper

My original restoration of the theropod was done prior to the publication of the paper, based on the photographs available at the time on the www.

Repenomamus robustus - a large triconodont mammal from Early Cretaceous of China from BDW (2005)

   

Mesozoic Mosaic pg #4

Illustration of a fierce Masozoic triconodont mammal , Repenomamus robustus chasing juvenile Psittacosaurus - by Beri (graphite), Copyright ©2005 BERI Jan 2005

MAMMALS STRIKE BACK Repenomamus robustus - a large triconodont mammal from Early Cretaceous of China HU, Y., J. MENG, Y. WANG & C. LI. 2005. Large Mesozoic mammals fed on young dinosaurs. Nature 433: 149-152. "Mesozoic mammals are commonly portrayed as shrew- or rat-sized animals that were mainly insectivorous, probably nocturnal and lived in the shadow of dinosaurs. The largest known Mesozoic mammal represented by substantially complete remains is Repenomamus robustus, a triconodont mammal from the Lower Cretaceous of Liaoning, China. An adult individual of R. robustus was the size of a Virginia opossum. Here we report a new species of the genus, represented by a skeleton with most of the skull and postcranium preserved in articulation. The new species is 50% larger than R. robustus in skull length. In addition, stomach contents associated with a skeleton of R. robustus reveal remains of a juvenile Psittacosaurus, a ceratopsian dinosaur. Our discoveries constitute the first direct evidence that some triconodont mammals were carnivorous and fed on small vertebrates, including young dinosaurs, and also show that Mesozoic mammals had a much greater range of body sizes than previously known. We suggest that Mesozoic mammals occupied diverse niches and that some large mammals probably competed with dinosaurs for food and territory." Abstract References: 1.  Large Mesozoic mammals fed on young dinosaurs     Yaoming Hu, Jin Meng, Yuanqing Wang, Chuankui Li SUMMARY: Mesozoic mammals are commonly portrayed as shrew- or rat-sized animals that were mainly insectivorous, probably nocturnal and lived in the shadow of dinosaurs. The... CONTEXT: ...Cretaceous Jehol Biota from the Yixian Formation in Liaoning, China, has yielded several mammal species. Two of them, Repenomamus robustus and Gobiconodon zofiae, are from the basal member of the formation that has a radiometric...... Nature433, 149 - 152 (13 Jan 2005) Letters to Nature Abstract | Full Text | PDF   2.  Mammalian palaeobiology: Living large in the Cretaceous     Anne Weil SUMMARY: Discoveries of large, carnivorous mammals from the Cretaceous challenge the long-held view that primitive mammals were small and not so interesting. Have palaeontologists been asking the wrong... CONTEXT: ...of questions and speculation among palaeontologists. The dinosaur-eater belongs to a species of large mammal, Repenomamus robustus, which was described first from a skull. The new specimen is more complete — and on its left side,...... Nature433, 116 - 117 (13 Jan 2005) News and Views Full Text | PDF   3.  Mammal bites dinosaur     Description: 13 January 2005 Mammal bites dinosaur We tend...... CONTEXT: ...picture is changing. The extinct mammal Repenomamus robustus, discovered five years ago, broke the mould: it was much bigger, the size of a Virginia opossum. And now another member of the genus Repenomamus has been found that is...... http://www.nature.com/nature/links/050113/050113-8.html  *** Some comments: "Not to take anything away from the intrinsic coolness of this find, but the idea that Mesozoic mammals might have preyed on juvenile dinosaurs is hardly astonishing. Anybody familiar with the food habits of modern small mammals would have predicted it. In fact, I suggested just such a possibility way back in 1980 on pp. 70-71 of my contribution to _A Cold Look at the Warm-Blooded Dinosaurs_. What _IS_ surprising to me is just how big the bigger Mesozoic mammals seem to have gotten, at least in some faunas!" James Farlow, Ph.D. ***"...There are at least seven teeth on each jaw quadrant of the juvenile Psittacosaurus, of which most are worn. This demonstrates that the Psittacosaurus skeleton is not from an embryo (from the paper)...""Actually, late term vertebrates are notorious for grinding their teeth, whether in a womb or in an egg, Unhatched embryos of Hypacrosaurus from Canada show worn teeth." Ken Kenneth Carpenter, Ph.D. Repenomamus holotype A few notes on: Psittacosaurus sp. Age: Lower Cretaceous, Barremian Stage, Yixian Formation Place: Liaoning, China   The psittacosaurids, known only from the late Early Cretaceous of Central Asia, are considered to be close to an ancestor of the horned dinosaurs. Both the parrot-beaked and horned dinosaurs possessed jaws, being curved and tapered forward and the lateral teeth highly specialised to masticate the vegetative food. Adult psittacosaurids were relatively small, up to 2 meters in length. They were probably mostly bipedal cursors although the forelimbs in these dinosaurs were relatively long and well-developed.

My old online article from BDW (1999)

   

Mesozoic Mosaic pg #2

Illustration of Sinornithosaurus - by Beri (digital), Copyright © 1999-2004 BERI Commissioned and first published in online by: abcnews.go.com/sections/science Sep 1999

Sinornithosaurus - a feathery dromaeosaurid Sinornithosaurus millenii Xu, Wang & Wu, 1999 References: http://abcnews.go.com/sections/scitech (dead link) HWANG, S.H., M.A. NORELL, JI Q., and GAO K. 2002. New Specimens of Microraptor zhaoianus (Theropoda: Dromaeosauridae) from Northeastern China. American Museum Novitates 3381: 1–44. ------------- Sinornithosaurus millenii, XING XU, XIAO-LIN WANG & XIAO-CHUN WU, 1999   Holotype. IVPP (Institute of Vertebrate Paleontology and Paleoanthropology) V12811 .    Locality and horizon. Sihetun, western Liaoning, China. Layer 6, lower (Chaomidianzi) Yixian Formation, Jehol Group; probably Early Cretaceous.       Didn't paleoartists (led by McLoughlyn, Baker and Paul) predicted it would be discovered that dromaeosaurs were covered with some sort of hairy proto-feathers, a deduction based upon the close anatomical resemblance of dromaeosaurs and birds?    Well, the long awaited hard evidence was finally presented in today's issue of Nature magazine (16 Sept.,1999). Spielberg's "Jurassic Park" naked, scaly "raptors" (even this term was scientifically wrong - because it refers to the extant bird of prey genus) are doomed to be tossed in the rich archives of dinosaur misinterpretations. There is little doubt now that Deinonychus, depicted in a Hollywood manner in the movie, was too "dressed" in the feathers.   Although considered to be well known by everybody, especially after dinosaur movie planetary success, dromaeosauridae were known only form a few mainly incomplete fossils (the exceptions were some fine Mongolian specimens), so a lot of things about them were not entirely clear. Chinese paleontologists have recently found and described a fine dromaeosaurid fossil in Yixian Formation of China (Locality and horizon. Sihetun, western Liaoning, China. Layer 6, lower (Chaomidianzi) Yixian Formation, Jehol Group; probably Early Cretaceous - dated to about 125 million years ago), with a filamentous integument (a downy coat). The new feathered sensation from China was coined Sinornithosaurus millenii. The genus name is derived from Sino + Ornitho + Saurus, for " a bird-like dinosaur from China;" while the species name comes from "Millennium," in reference to the specimen's discovery near the end of the twentieth century.   The animal was rather small even for a dromaeosaurid. Its skull was about 13 cm (5,1") long, which gives the derived, approximate total length (the tail in dromaeosaurs was very long) of this dinosaur of about 110cm (43,3"). The "downy coat" was made up of filaments which were up to 4 cm (1.6") long, those filamentous structures near the cranium (skull) seem to be shorter than the postcranial fibers.  Further preparation of the specimen could reveal more fibers.  The insulation looks more like the fur than the modern birds' feathers, which look kind of furry in the picture (not like well-structured wing feathers)." The skeleton is not well articulated, but the bones are a bit jumbled and the integumentary filaments have been displaced, lacking the direct relationships to bony elements." But they are certainly close enough to enable rough determination. The skull, arms, legs, scapulae, coracoids, sacrum, a manus, a pes, and the furcula are all quite reasonably represented by the holotype, however, many vertebrae and rib elements are missing.   "Sinornithosaurus millenii gen. et sp. nov. comes from Sihetun, the famous Mesozoic fish-dinosaur-bird locality in China.. It is the oldest known dromeosaur (a basal dromaeosaurid) and its fossil "strongly supports the view that Dromaeosauridae and birds (where Aves is Avialae) are more closely related to each other than either is to Troodontidae ." Authors of the article state their analysis also indicates that Protarchaeopteryx and Caudipteryx are more remote from birds than is Troodontidae. "The currently established phylogenetic relationships among derived theropods seem to support the presence of true feathers in Dromaeosauridae, but the validity of this interpretation cannot be confirmed until more direct evidence is available."   "Sinornithosaurus not only greatly increases our knowledge of Dromaeosauridae but also provides evidence for a filamentous integument in this group. It is remarkably similar to early birds postcranially" (skeleton behind the skull). "The shoulder girdle shows that terrestrial dromaeosaurids had attained the prerequisites for powered, flapping flight, supporting the idea that bird flight originated from the ground up. The discovery of Sinornithosaurus widens the distribution of integumentary filaments among non-avian theropods."   The authors of the article XING XU, XIAO-LIN WANG & XIAO-CHUN WU claimS. millenii could apparently flap its long front limbs in a bird's mode. The evidence supposedly lies in the structure of the animal's shoulder girdle. That is, the lateral position of the glenoid (shoulder socket) would have permitted elevation, rotation and adduction of the forelimbs, providing Sinornithosaurus a wide range of arm movement similar to the capabilities of the fabled early bird Archaeopteryx.  The forelimbs were unusually long (claws well preserved, even with a horny sheath - keratin; long and curved), estimated to be 80% as long as the dromaeosaur's legs. The paired, ossified sterna possess a series of (probably five) costal facets (rib attachments), implying hinged sternocostal joints.      Sinornithosaurus is the fifth kind of theropod known to possess integumentary filaments. It is possible that these filaments indicate an insulatory layer that served to maintain body heat.    Authors suggest that the fossil provides more "evidence that the first birds took off from the ground, evolving from fast-running two-legged predatory dinosaurs called theropods". Is this almost the final answer to the famous dilemma: Did the bird's flight evolve from the ground up or from the trees down?   Well, I suggest a new solution to the problem: knowing that we've got very intelligent birds today, say African Gray parrot (Psittacus erithacus) could learn the kinds of symbolic and conceptual tasks that are generally considered as pre- or co-requisites for complex cognitive and communicative skills, why don't we ask such a smart feathery critter (who can fly), what is easier to him: To fly up from the ground or down from a branch? I am sure we'll get the straight answer.      Reference: XING XU, XIAO-LIN WANG & XIAO-CHUN WU - A dromaeosaurid dinosaur with a filamentous integument from the Yixian Formation of China , Nature 401, 262 - 266 , September 16 1999 (1999) © Macmillan Publishers Ltd.    The Nature paper discusses the specimen in considerable detail:   on-line: NATURE   Published in 1999 in now extinct online magazine: DIM Extra 4/1 (VOL 2)      Publishers interested in the above illustration (high resolution image for publishing purposes), please, contact Beri.

UPDATE (Feb.2014)

In the paper published 10 years later, authors claim this dromaeosaur from China's Jehol formation had grooved fangs as a venomous delivery system. In other words, Sinraptor's killing technique was something between a venomous snake and a Heloderma lizard.

The birdlike raptor Sinornithosaurus was venomous

 Enpu Gonga, Larry D. Martinb, David A. Burnhamb and Amanda R. Falkc

 
Reference: PNAS doi:10.1073/pnas.0912360107

 Edited by David B. Wake, University of California, Berkeley, Berkeley, CA, and approved November 16, 2009 (received for review October 26, 2009) 

Abstract

We suggest that some of the most avian dromaeosaurs, such as Sinornithosaurus, were venomous, and propose an ecological model for that taxon based on its unusual dentition and other cranial features including grooved teeth, a possible pocket for venom glands, and a groove leading from that pocket to the exposed bases of the teeth. These features are all analogous to the venomous morphology of lizards. Sinornithosaurus and related dromaeosaurs probably fed on the abundant birds of the Jehol forests during the Early Cretaceous in northeastern China.

A new titanosaur from the Early Cretaceous of China

(Image credit: University of Pennsylvania)

 A fossil of a new sauropod titanosaur, Yongjinglong datangi, has been discovered in northwestern China by University of Pennsylvania paleontologists. The dinosaur lived some 100 million years ago during the Early Cretaceous period. The estimated length of this juvenile sauropod was about 20 meters. Adult animal of this species were probably larger.
The research was led by doctoral student Liguo Li and professor Peter Dodson.

Liguo Li: "The shoulder blade was very long, nearly 2 meters, with sides that were nearly parallel, unlike many other Titanosaurs whose scapulae bow outward." 

The dinosaur's vertebrae had large cavities in the interior. The research team believes the large cavities in dinosaur's vertebrae contained  air sacs.

Peter Dodson:
 "These spaces are unusually large in this species. It's believed that dinosaurs, like birds, had air sacs in their trunk, abdominal cavity and neck as a way of lightening the body." Image: University of Pennsylvania

 My restoration of  Yongjinglong datangi

Peter Dodson :
  "...Not only does the discovery point to the fact that Titanosaurs encompass a diverse group of dinosaurs, but it also supports the growing consensus that sauropods were a dominant group in the Early Cretaceous — a view that U.S. specimens alone could not confirm.
Based on U.S. fossils, it was once thought that sauropods dominated herbivorous dinosaur fauna during the Jurassic but became almost extinct during the Cretaceous," Dodson said. "We now realise that, in other parts of the world, particularly in South America and Asia, sauropod dinosaurs continued to flourish in the Cretaceous, so the thought that they were minor components is no longer a tenable view."
 (citation from;  http://www.science20.com/)

 BDW:
 Indeed, while researching the late Albian ichnofauna near Pula, Istria, which is roughly the same age as this Chinese titanosaur, I came to the similar conclusion. Sauropods were large and their tracks abundant in the coastal intertidal environment. They were apparently, competing for food with giant iguanodontoids and ankylosaurs.

Paper:   Li L-G, Li D-Q, You H-L, Dodson P (2014) A New Titanosaurian Sauropod from the Hekou Group (Lower Cretaceous) of the Lanzhou-Minhe Basin, Gansu Province, China. PLoS ONE 9(1): e85979.
 The whole paper is here free for download.