[D] Lanzhousaurus magnidens [Su] [sG] [T]
Describer
You, Ji Q., Li, 2005
Time
Cretaceous Early Barremian
Classification
Ornithischia Ornithopoda Iguanodontia Iguanodontidae
Diet
Herbivore
Fossilsite
Lanzhou Basin, Hekou Group, Zhongpu, Lintao, Gansu Province, China
Length
10 meter
Info
Genus - Typespecies - Skull
The largest-toothed herbivorous dinosaur in the world with tooth upto 14 cm in its 1 meter long lower jaw, known elements are a mandible missing the predentary, isolated maxillary and dentary teeth, cervical and dorsal verts, sternal plates, ribs, and both pubes.
Cladistic analysis recovers a close relationship between Lanzhousaurus magnidens and Lurdusaurus arenatus from the Early Cretaceous of Africa. Together, these species represent a previously unrecognized, massively-constructed quadrupedal lineage in the evolution of ornithopod dinosaurs. This discovery also implies a close connection between Eurasia and Africa during the Early Cretaceous. Lanzhousaurus magnidens is different from all other iguanodontians in possessing large individual teeth and a small tooth count per tooth row, with a mere 14, but ~4 cm-wide, tooth families preserved in a single dentary tooth row.
Etymology
Lanzhou (Chinese), name of the capital city of Gansu Province, P. R. China; magnus (Latin), big; dens (Latin), tooth.
Holotype
Partial skeleton of a single individual including mandible (missing predentary, right coronoid and right articular), isolated maxillary teeth, isolated right dentary teeth and complete, in situ left dentary teeth, a series of fourteen vertebrae (six cervicals and eight dorsals), both sternal plates, ribs, and both pubes, deposited in Fossil Research and Development Center of the Third Geology and Mineral Resources Exploration Academy of Gansu Province: GSLTZP01-001.
You, H.-L. (2006) Lanzhousaurus magnidens from the Lower Cretraceous of Gansu province, China: The largest-toothed herbivorous dinosaur in the world. JVP 26(3) Abstracts pp. 142
Lanzhousaurus magnidens is an iguanodontian dinosaur recently discovered in the Lower Cretaceous Hekou Group of Gansu Province, northwestern China, which possesses the largest teeth of any herbivorous dinosaur yet discovered. The holotype is represented by a partial skeleton of a single individual including the mandible (missing predentary, right coronoid and right articular), isolated maxillary teeth, isolated right and complete, in situ left dentary teeth, a series of fourteen vertebrae (six cervicals and eight dorsals), both sternal plates, ribs, and both pubes.
Lanzhousaurus differs from all other iguanodontians in possessing large individual teeth and a small tooth count per tooth row, with a mere 14 ~4 cm-wide tooth families preserved in a single dentary tooth row of the 1 m long lower jaw. Based on a cladistic analysis, Lanzhousaurus is firmly situated as a member of the [Styracosterna] by virtue of a suite of derived features, such as the relatively narrow, lozenge-shaped maxillary teeth with mammilliform marginal denticles, hatchet-shaped sternal plates, and pubis with expanded cranial blade and short caudal ramus. Among members of the [Styracosterna], the closest taxon to Lanzhousaurus is the Nigerian iguanodontian Lurdusaurus, and they together may represent a previously unrecognized, massively-constructed quadrupedal lineage in the evolution of ornithopod dinosaurs.
Both Lanzhousaurus and Lurdusaurus are less derived than the Iguanodontidae, which evolved derived features such as more than 20 teeth per tooth row, one or two prominent ridges on the dentary crown, and closely appressed metacarpals II-IV.
Emended diagnosis
(Paul, 2007) Adults gigantic. Overall massively constructed. Dentary pre-coronoid process length/minimum depth ratio under 5, diastema absent. Teeth extremely large, maximum tooth positions 14 in dentary, one tooth in each position. Dorsal neural spines moderately tall, modest withers present. Prepubic process of pubis deep.
Carpenter & Ishida (2010) Early and “Middle” Cretaceous Iguanodonts in Time and Space Journal of Iberian Geology 36 (2) 145-164
Lanzhousaurus magnidens You et al., 2005
Locality
Zhongpu, Lintao County, Gansu Province, People’s Republic of China.
Horizon
Lower portion of the Hekou Group (possibly equivalent to lower Fengjiashan Formation based on ostracods).
Age
Barremian (Hayashi 2006)
Comments
A fragmentary specimen lacking the ilium.
You, Ji Q., Li, 2005
Time
Cretaceous Early Barremian
Classification
Ornithischia Ornithopoda Iguanodontia Iguanodontidae
Diet
Herbivore
Fossilsite
Lanzhou Basin, Hekou Group, Zhongpu, Lintao, Gansu Province, China
Length
10 meter
Info
Genus - Typespecies - Skull
The largest-toothed herbivorous dinosaur in the world with tooth upto 14 cm in its 1 meter long lower jaw, known elements are a mandible missing the predentary, isolated maxillary and dentary teeth, cervical and dorsal verts, sternal plates, ribs, and both pubes.
Cladistic analysis recovers a close relationship between Lanzhousaurus magnidens and Lurdusaurus arenatus from the Early Cretaceous of Africa. Together, these species represent a previously unrecognized, massively-constructed quadrupedal lineage in the evolution of ornithopod dinosaurs. This discovery also implies a close connection between Eurasia and Africa during the Early Cretaceous. Lanzhousaurus magnidens is different from all other iguanodontians in possessing large individual teeth and a small tooth count per tooth row, with a mere 14, but ~4 cm-wide, tooth families preserved in a single dentary tooth row.
Etymology
Lanzhou (Chinese), name of the capital city of Gansu Province, P. R. China; magnus (Latin), big; dens (Latin), tooth.
Holotype
Partial skeleton of a single individual including mandible (missing predentary, right coronoid and right articular), isolated maxillary teeth, isolated right dentary teeth and complete, in situ left dentary teeth, a series of fourteen vertebrae (six cervicals and eight dorsals), both sternal plates, ribs, and both pubes, deposited in Fossil Research and Development Center of the Third Geology and Mineral Resources Exploration Academy of Gansu Province: GSLTZP01-001.
You, H.-L. (2006) Lanzhousaurus magnidens from the Lower Cretraceous of Gansu province, China: The largest-toothed herbivorous dinosaur in the world. JVP 26(3) Abstracts pp. 142
Lanzhousaurus magnidens is an iguanodontian dinosaur recently discovered in the Lower Cretaceous Hekou Group of Gansu Province, northwestern China, which possesses the largest teeth of any herbivorous dinosaur yet discovered. The holotype is represented by a partial skeleton of a single individual including the mandible (missing predentary, right coronoid and right articular), isolated maxillary teeth, isolated right and complete, in situ left dentary teeth, a series of fourteen vertebrae (six cervicals and eight dorsals), both sternal plates, ribs, and both pubes.
Lanzhousaurus differs from all other iguanodontians in possessing large individual teeth and a small tooth count per tooth row, with a mere 14 ~4 cm-wide tooth families preserved in a single dentary tooth row of the 1 m long lower jaw. Based on a cladistic analysis, Lanzhousaurus is firmly situated as a member of the [Styracosterna] by virtue of a suite of derived features, such as the relatively narrow, lozenge-shaped maxillary teeth with mammilliform marginal denticles, hatchet-shaped sternal plates, and pubis with expanded cranial blade and short caudal ramus. Among members of the [Styracosterna], the closest taxon to Lanzhousaurus is the Nigerian iguanodontian Lurdusaurus, and they together may represent a previously unrecognized, massively-constructed quadrupedal lineage in the evolution of ornithopod dinosaurs.
Both Lanzhousaurus and Lurdusaurus are less derived than the Iguanodontidae, which evolved derived features such as more than 20 teeth per tooth row, one or two prominent ridges on the dentary crown, and closely appressed metacarpals II-IV.
Emended diagnosis
(Paul, 2007) Adults gigantic. Overall massively constructed. Dentary pre-coronoid process length/minimum depth ratio under 5, diastema absent. Teeth extremely large, maximum tooth positions 14 in dentary, one tooth in each position. Dorsal neural spines moderately tall, modest withers present. Prepubic process of pubis deep.
Carpenter & Ishida (2010) Early and “Middle” Cretaceous Iguanodonts in Time and Space Journal of Iberian Geology 36 (2) 145-164
Lanzhousaurus magnidens You et al., 2005
Locality
Zhongpu, Lintao County, Gansu Province, People’s Republic of China.
Horizon
Lower portion of the Hekou Group (possibly equivalent to lower Fengjiashan Formation based on ostracods).
Age
Barremian (Hayashi 2006)
Comments
A fragmentary specimen lacking the ilium.