Paleontology

A Guide to Recent Dinosaur Discoveries



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Several new dinosaurs have been discovered in 2009. The discovery of Australia's largest ever concentration of dinosaur bones in Queensland helped to make it a particularly good year for the southern hemisphere. The three new early Cretaceous dinosaur species identified from the Queensland find include the first new Australian sauropods to be discovered in nearly 75 years.

At 16 metres in length, Diamantinasaurus matildae is the biggest of the three, but not by much. (Genus: Diamantina River lizard, species named for Waltzing Matilda, which had been written in nearby Winton.) Its bones are distinguishable from Wintonotitan wattsi mostly because they are more robust. (Genus named for the Winton Formation where it was found, species for Keith Watts, the original finder.) Both early Cretacious period sauropods are heavy quadrupeds with long necks and tails. It is possible that Diamantinasaurus might also have had armour scales, like many other titanosaurids.

Australia's new allosaur species has been identified as Australovenator wintonensis (genus: southern hunter, species named for the Winton Formation). This biped of the early Cretaceous period was two metres tall at the hip alone: with a full height of six metres. The Australovenator Banjo represents the most complete skeleton of a carnivorous dinosaur ever found in Australia.

Aardonyx celestae, a herbivorous dinosaur of the early Jurassic period, was discovered in South Africa. (Genus: Afrikaans earth plus claw, species named for Yates' wife Celeste, who did much of the bone preparation.) When on all fours, this dinosaur was the same size as a grown man at the shoulder, but its long neck and tail made it over six metres in length. Aardonyx is particularly fascinating because it represents an intermediary stage of sauropod, one that walked bipedally but could also drop to all fours. Standing, its build is typical of bipedal dinosaurs, with powerful hind hips and legs but with front legs longer than is typical of bipedal dinosaurs. This in-between structure made Aardonyx slower than full bipeds or full quadrupeds. The earliest prosauropods are all bipeds. The discovery of Aardonix suggests that quadruped motion in sauropods and prosauropods began much earlier than previously thought.

The northern hemisphere has not been completely neglected. In the ever-rich fossil fields of Alberta, Canada, a new species of duckbill dinosaur may have been discovered by Fanti and Miyashita. What is unusual here is that the find happened nearly a thousand kilometres north of the Badlands, near a small town called Grande Prairie. Prior to this find, known Hadrosaur and other dinosaur populations had been isolated to Alaska in the north and a larger region from the Badlands south, leaving most of Alberta apparently almost entirely unpopulated. The discovery shows that at least some species of duckbilled dinosaurs nested in this area during the Cretaceous period.

The analysis is now complete on two Chinese dinosaurs originally discovered in 2006 and 2007. Xiongguanlong baimonesis (genus: Grand Pass dragon, species: white ghost, after a local landform) is an early Cretaceous period predator which may have been an ancestor of Tyrannosaurus. It has been called the missing link of the Tyrannosaurus family tree. Key differences from its much more famous late Cretaceous descendant include Xiongguanlong's long muzzle and its much smaller size, comparable to Australovenator.

The other Chinese dinosaur from the same find and period is Beishanlong grandis (great Beishan dragon), an ostrich-like ornithomimosaurian (bird-mimic lizard) which stood six metres tall from toe to beak. Although this is one of the largest ornithomimosaurians yet discovered, it was an immature specimen, so its adult height remains unknown.

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ARTICLE SOURCES AND CITATIONS
  • InfoBoxCallToAction ActionArrowhttp://dx.doi.org/10.1371/journal.pone.0006190
  • InfoBoxCallToAction ActionArrowhttp://rspb.royalsocietypublishing.org/content/early/2009/11/09/rspb.2009.1440/suppl/DC1
  • InfoBoxCallToAction ActionArrowhttp://dx.doi.org/10.1016/j.palaeo.2009.02.007
  • InfoBoxCallToAction ActionArrowhttp://rspb.royalsocietypublishing.org/content/early/2009/04/17/rspb.2009.0249.abstract
  • InfoBoxCallToAction ActionArrowhttp://rspb.royalsocietypublishing.org/content/early/2009/04/20/rspb.2009.0236.abstract