Etymology: "Zhao Xijin's Fusui County lizard"
Time horizon: Early Cretaceous, Aptian epoch? (~120 mya)
Length: ~30m (~100 ft.)
Probable mass: 70 tons
*Now re-scaled - this animal is a bit smaller than previously predicted* Missing portions of described bones are shaded in light gray.
The mysterious, never-before-restored, and downright colossal Fusuisaurus. The first and only true brachiosaur discovery known from China (no, Qiaowanlong and Zigongosaurus are NOT brachiosaurs), this giant is unique in two critical ways: it is unusual in being so basal so late; and it is apparently more closely related to Brachiosaurus altithorax than any other species of brachiosaur. The ilium is extremely similar to Brachiosaurus, and the tail vertebrae follow a similar pattern. This species punches a hole in the notion that basal members of a clade can't grow to gigantic sizes - sometimes they can even exceed the sizes of many derived members. The charcters of all recovered elements correspond well to a late survivor of a basal progenitor lineage for Brachiosaurus. It is evidently not, as has sometimes been claimed, a basal titanosaur or a somphospondylian.
Often labeled in the Chinese press as the most basal titanosauriform known, the reputation is a bit premature. Evidently its distinctively brachiosaur features show that Fusuisaurus was considerably more advanced than the most basal titanosauriforms (Volkheimeria, "Lavocatitan" and the klamelisaurids). Pneumaticity is not very developed in the ribs, so this animal is likely more primitive than Brachiosaurus itself, despite being a far more recent species. It appears to be a living fossil that survived from the mid-Jurassic days of Brachiosaurus' direct ancestors, survivors of which seem to have long outlasted Brachiosaurus itself. How such instances of extremely long survival for such "holdover taxa" and basal bloodlines take place, particularly in a fast-evolving (and fast-turnover) warm-blooded class like Dinosauria, is still not properly understood.
Mo, J., Wang W.,Huang Z., Huang X., Xu X., 2006, "A Basal Titanosauriform from the Early Cretaceous of Guangxi, China", Acta Geologica Sinica, Vol.80 No.4 P.486-489