Lanzhousaurus

Lanzhousaurus (meaning "Lanzhou lizard") is a genus of ornithopod dinosaur. Lanzhousaurus lived in the Gansu region of what is now China during the Early Cretaceous (Barremian). A partial skeleton has been recovered from the Hekou Group. It was described by You, Ji and Li in 2005 and the type and only species is Lanzhousaurus magnidens.^[1] It has been estimated to be about 10 meters (33 feet) in length and 6 tonnes (6.6 short tons) in weight.^[2]

Lanzhousaurus Temporal range: Lower Cretaceous, 130 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Skeletal mount of Lanzhousaurus
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Clade:	†Ornithischia
Clade:	†Ornithopoda
Clade:	†Styracosterna
Genus:	†Lanzhousaurus You, Ji & Li, 2005
Type species
†Lanzhousaurus magnidens You, Ji & Li, 2005

Dentition

Jaw and teeth of Lanzhousaurus

The genus has been described as having "astonishingly huge teeth", among the largest for any herbivorous creature ever, which indicate it was a styracosternan iguanodont. The mandible, longer than one meter, suggests a very large size for the animal. Tooth enamel of this dinosaur was growing very rapidly.^[3]

Classification

Life restoration

In their 2020 reassessment of the hadrosauromorph Orthomerus, Madzia, Jagt & Mulder ran phylogenetic analyses of Iguanodontia. In their analyses, Lanzhousaurus was recovered as a non-hadrosauriform styracosternan member of the Ankylopollexia, similar to the 2005 description by You, Ji & Li. The results of their phylogenetic analyses are shown in the cladogram below:^[4][1]

Ankylopollexia	Camptosaurus Styracosterna Cumnoria Uteodon Draconyx Planicoxa Theiophytalia Hippodraco Owenodon Muttaburrasaurus Dakotadon Osmakasaurus Cedrorestes Iguanacolossus Lanzhousaurus Yunganglong Fukuisaurus Hadrosauriformes Siamodon Hypselospinus Barilium Lurdusaurus Iguanodontidae Hadrosauroidea