Open Paleo

Shuangmiaosaurus

You et al., 2003 shwahng-MYOW-SAWR-us

Named after the village of Shuangmiao in Beipiao, Liaoning Province, China, the site of discovery, combined with Greek 'sauros' (lizard).

113.2–93.9 million years ago Albian–Cenomanian, Early Cretaceous–Late Cretaceous
Early Cretaceous and Late Cretaceous stages

Shuangmiaosaurus is a genus of herbivorous iguanodontian ornithopod dinosaur which lived in China during the Late Cretaceous Period, about 100 million years ago.

Diagnosis

  1. Butt-jointed maxilla-jugal suture, distinguishing it from other basal hadrosauroids
  2. Antorbital fenestra positioned on anterior dorsal margin of maxilla
  3. Expanded, laterally flattened dorsal process of the maxilla
  4. Elongate lozenge-shaped maxillary crowns with curved, mammillated denticles on mesial and distal margins
  5. Dentary with dentary ramus parallel-sided and coronoid process laterally offset with horizontal shelf separating dentition from process
  6. Tooth roots partially cemented with rugose, angular-sided roots

Species

Shuangmiaosaurus gilmorei You et al., 2003

Type species

Named for the American paleontologist Charles Whitney Gilmore.

Holotype
LPM 0165 , Liaoning Paleontological Museum
Material
Complete left maxilla with partial articulated premaxilla and lacrimal
Horizon
Sunjiawan Formation, Albian–Cenomanian, Early Cretaceous–Late Cretaceous , 113.2–93.9 million years ago
Locality
Shuangmiao Village, Beipiao, Liaoning, China The only printed position near the site is Dong's (2002) GPS fix for the Shuangmiao fossil site of the batch he identified as Crichtonsaurus; You and colleagues (2003) give the holotype only as from the Sunjiawan Formation "near Shuangmiao Village", and no source ties it to that point.

References

  1. You, H.; Ji, Q.; Li, J.; Li, Y. (2003). A new hadrosauroid dinosaur from the mid-Cretaceous of Liaoning, China. Acta Geologica Sinica (English Edition) 77(2): 148-154. Wiley. doi:10.1111/j.1755-6724.2003.tb00557.x you2003b
  2. Madzia, D.; Jagt, J. W. M.; Mulder, E. W. A. (2019). Osteology, phylogenetic affinities and taxonomic status of the enigmatic late Maastrichtian ornithopod taxon Orthomerus dolloi (Dinosauria, Ornithischia). Cretaceous Research 108: 104334. Elsevier BV. doi:10.1016/j.cretres.2019.104334

    Recovered Shuangmiaosaurus as the sister of Plesiohadros, outside Hadrosauridae, in the majority-rule trees of both runs; the strict consensus of the second run leaves it in an unresolved polytomy.

    madzia2019a
  3. Dong, Z. (2002). A new armored dinosaur (Ankylosauria) from Beipiao Basin, Liaoning Province, northeastern China. Vertebrata PalAsiatica 40(4): 276-285.

    Gives a GPS fix for the Shuangmiao locality, and places it in Xiafu Township, Beipiao City.

    dong2002a