Jiangxititan

Jiangxititan; Temporal range: Late Cretaceous, Maastrichtian PreꞒ Ꞓ O S D C P T J K Pg N
	Life restoration as a titanosaur
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Clade:	Saurischia
Clade:	†Sauropodomorpha
Clade:	†Sauropoda
Clade:	†Macronaria
Clade:	†Somphospondyli
Genus:	†Jiangxititan; Mo et al., 2023
Species:	†J. ganzhouensis
Binomial name
	†Jiangxititan ganzhouensis; Mo et al., 2023

Jiangxititan is an extinct genus of somphospondylan titanosauriform dinosaur from the Late Cretaceous Nanxiong Formation of China. The genus contains a single species, J. ganzhouensis, known from several articulated vertebrae with ribs. Originally described as a titanosaur, Jiangxititan was later suggested to be a non-titanosaurian somphospondylan.

Discovery and naming

The Jiangxititan holotype specimen, NHMG 034062, was discovered in sediments of the Nanxiong Formation near Tankou Town in Ganzhou City of Jiangxi Province, southern China. The specimen consists of the three posteriormost cervical vertebrae with two cervical ribs, articulated with the first four dorsal vertebrae with three dorsal ribs.^[1]

In 2023, Mo et al. described Jiangxititan ganzhouensis as a new genus and species of macronarian sauropod based on these fossil remains. The generic name, "Jiangxititan", combines a reference to the type locality in Jiangxi Province with the word "titan", a common suffix for giant sauropod names, referencing the pre-Olympian gods of Greek mythology. The specific name, "ganzhouensis", references the discovery of the fossil in Ganzhou City.^[1]

Classification

Mo et al. (2023) recovered Jiangxititan as a derived member of the titanosaurian clade Lognkosauria, as the sister taxon to Mongolosaurus. The results of their phylogenetic analyses are shown in the cladogram below:^[1]

Titanosauria

Diamantinasauria

	Xianshanosaurus

	Daxiatitan

	Australodocus

Lithostrotia

Malawisaurus

	Aeolosaurus

	Rapetosaurus

Isisaurus

Saltasaurus

	Opisthocoelicaudia

	Alamosaurus

	Vahiny

	Jainosaurus

	Jiangxititan

	Mongolosaurus

A subsequent analysis by Han and colleagues in 2024 recovered Jiangxititan as a non-titanosaurian somphospondylan, in a polytomy with several other basal somphospondylans. Removing Jiangxititan as an unstable operational taxonomic unit in their analyses allowed for increased resolution, with more taxa recovered in the Euhelopodidae. The reduced consensus tree from their phylogenetic analyses is shown in the cladogram below:^[2]

	Brontomerus

	Malarguesaurus

	Paluxysaurus

Angolatitan

Chubutisaurus

Cloverly titanosauriform

Fukuititan

Gobititan

Jiangxititan

	Ruixinia

	Jiangshanosaurus

	Europatitan

	Tastavinsaurus

	Ligabuesaurus

	Dongbeititan

	Tangvayosaurus

	Phuwiangosaurus

Qiaowanlong

	Yongjinglong

	Euhelopus

Huanghetitan spp.

	Diamantinasauria

	Titanosauria

References

^ ^a ^b ^c Mo, Jin-You; Fu, Qiong-Yao; Yu, Yi-Lun; Xu, Xing (2023-09-21). "A New Titanosaurian Sauropod from the Upper Cretaceous of Jiangxi Province, Southern China". Historical Biology: 1–15. doi:10.1080/08912963.2023.2259413. ISSN 0891-2963.
^ Han, Fenglu; Yang, Ling; Lou, Fasheng; Sullivan, Corwin; Xu, Xing; Qiu, Wenjiang; Liu, Hanfeng; Yu, Juan; Wu, Rui; Ke, Yuzheng; Xu, Mengyuan; Hu, Jinfeng (2024-01-17). "A new titanosaurian sauropod, Gandititan cavocaudatus gen. et sp. nov., from the Late Cretaceous of southern China". Journal of Systematic Palaeontology. 22 (1). Bibcode:2024JSPal..2293038H. doi:10.1080/14772019.2023.2293038.