Abstract

Phylogenetic relationships among the diverse Cretaceous sauropods of East Asia have
long been controversial. Debate has centered on whether there is any evidence for an endemic
clade of Asian species (“Euhelopodidae”) and on the placement of these taxa within the context
of higher sauropod phylogeny. While most Cretaceous sauropod taxa from Asia are recognized
as part of Somphospondyli, recent discoveries have suggested Brachiosauridae may
have dispersed into Asia as well. We present new fossils and analyses bearing on these issues.
Additional material of the holotype individual of Erketu ellisoni recovered on a subsequent
visit to the type locality expands the character data available for this unique sauropod. Associated
sauropod dorsal and caudal vertebrae were collected from the same horizon, at a location
approximately 2 km from the holotype excavation. !e dorsal vertebra exhibits synapomorphies
suggesting a representative of Titanosauria co-occurred with Erketu ellisoni. !ese new
specimens, as well as recent discoveries of contemporary Asian sauropod taxa, allow a basis
for phylogenetic reappraisal of Erketu and related taxa. Phylogenetic results support a sister
group relationship between the Asian Cretaceous sauropods Erketu and Qiaowanlong. Although
Qiaowanlong was described as a brachiosaurid, it joins Erketu on the somphospondylian side
of the Brachiosauridae-Somphospondyli divergence, erasing the evidence for the dispersal of
Brachiosauridae into Asia.