Kaijuesaurus is a genus of therizinosaurian theropod dinosaur which lived during the Early Cretaceous in China.
Its exact classification within the therizinosaurs is still up to debate, because while it can be considered a primitive therizinosauroid much like Beipiaosaurus and Neimongosaurus, it also presents peculiar features which seem to relate him to the North-American basal genus Falcarius.
In 2010, the remains of a fossilized scapula were found by a group of peasants near the town of Liushui, in the Jilin province. A year later, paleontologist An Jingkuan along with a team from the Institute of Geological Sciences of Songyuan City began working on the site. The discovery was announced in November 2013, and the type species Kaijuesaurus sica was named and described. The generic name Kaijuesaurus can be roughly translated as “digging lizard”, and derives from the Mandarin Chinese kāi jué (開掘, to excavate / to dig out). The specific name sica (“dagger”) derives from Latin, in reference to the long, sharp forelimb claws.
Holotype LGN V88337, the type specimen of Kaijuesaurus sica, was collected in sediments that can be dated to about 123 million years ago, placing Kaijuesaurus in the Aptian stage of the Cretaceous period of what is today the Jilin Province, China. The type specimen was found scattered over an area of about 100 square meters, and consists of a rather incomplete skeleton. The recovered remnants include: a semi-complete mandible, teeth, two dorsal vertebrae, three ribs, a scapula, a rather damaged coracoid, a complete forelimb, an incomplete one (humerus and antebrachium), a complete sacrum, one ilium, one pubis, a femur, both tibiae (one incomplete), a fibula, a calcaneum, an astragalus, several tarsals, metatarsals, unguals and some damaged remains of the integument. The scattered pattern in which the bones were found suggests the specimen was probably scavenged after its death.
Kaijuesaurus measured about 2 meters in length. Although similar to other therizinosauroids like Beipiaosaurus and Neimongosaurus, some of his characteristics are more reminiscent of basal genus Falcarius. The most peculiar of these characteristics is the presence of well-developed cone-shaped frontal teeth along with the typical prosauropod-like serrated teeth, which suggest the diet of Kaijuesaurus to be omnivorous rather than purely herbivorous. However, the genus also presents the therizinosaurian traits typical of the adaptation to herbivory, including enlarged guts and the signs of loss of cursory capabilities along with the development of tetradactyl feet. The seemingly conflicting traits could be however explained by one other autapomorphy of Kaijuesaurus, i.e. the peculiar structure of its forelimbs. Kaijuesaurus had relatively short forelimbs, complete of strong, straight dagger-like claws and a broad, ridged scapula fit for powerful muscles. Jingkuan suggests that Kaijuesaurus may have thus used its strong forelimbs for digging, hunting for large burrowing insects and centipedes along with plant roots much like a modern badger. What little remains of the integument of Kaijuesaurus also shows the presence of a dense cover of down-like feathers much like the one present on Beipiaosaurus.
Very much needed PS: what the hell is this? Apart from being a prime example of trying too hard, this thingy here has a somewhat funny backstory. While browsing this page (jpdh-universe.deviantart.com/) I stumbled on the notice for a monthly art contest. The theme, inventing a paleontologically plausible archosaur complete of description, taxonomy and ecology sounded very interesting, and I eagerly set out to make what you can now see here. Of course, it was only after finishing it that I decided to ask the procedure for entering the contest, only to learn that the contest deadline was indeed the 1st of December, but of the year before!
Well, what can I say, I had fun anyway. I tried to make this as realistic as possible, but of course there are probably some (many?) inaccuracies here and there. I'm no paleontologist after all... Not that I'd complain if I were one!
EDIT: fixed some horrible mistakes in the image text.