Titanosaurs were a globally distributed clade of Cretaceous sauropods. Historically regarded as a primarily Gondwanan radiation, there is a growing number of Eurasian taxa, with several putative titanosaurs contemporaneous with, or even pre-dating, the oldest known Southern Hemisphere remains. The early Late Cretaceous Jinhua Formation, in Zhejiang Province, China, has yielded two putative titanosaurs,
Jiangshanosaurus lixianensis
and
Dongyangosaurus sinensis
. Here, we provide a detailed re-description and diagnosis of
Jiangshanosaurus
, as well as new anatomical information on
Dongyangosaurus
. Previously, a ‘derived’ titanosaurian placement for
Jiangshanosaurus
was primarily based on the presence of procoelous anterior caudal centra. We show that this taxon had amphicoelous anterior-middle caudal centra. Its only titanosaurian synapomorphy is that the dorsal margins of the scapula and coracoid are approximately level with one another.
Dongyangosaurus
can clearly be differentiated from
Jiangshanosaurus
, and displays features that indicate a closer relationship to the titanosaur radiation. Revised scores for both taxa are incorporated into an expanded phylogenetic data matrix, comprising 124 taxa scored for 548 characters. Under equal weights parsimony,
Jiangshanosaurus
is recovered as a member of the non-titanosaurian East Asian somphospondylan clade Euhelopodidae, and
Dongyangosaurus
lies just outside of Titanosauria. However, when extended implied weighting is applied, both taxa are placed within Titanosauria. Most other ‘middle’ Cretaceous East Asian sauropods are probably non-titanosaurian somphospondylans, but at least
Xianshanosaurus
appears to belong to the titanosaur radiation. Our analyses also recover the Early Cretaceous European sauropod
Normanniasaurus genceyi
as a ‘derived’ titanosaur, clustering with Gondwanan taxa. These results provide further support for a widespread diversification of titanosaurs by at least the Early Cretaceous.
Modeling East Asian climate and impacts of atmospheric CO2 concentration during the Late Cretaceous (66Ma)
