Genus
Valid Extinct

Nanosaurus

Marsh 1877

Nanosaurus is an extinct genus of neornithischian dinosaur that lived about 155 to 148 million years ago, during the Late Jurassic in North America. Its fossils are known from the Morrison Formation of the south-western United States. The type and only species, Nanosaurus agilis, was described and named by Othniel Charles Marsh in 1877. The taxon has a complicated taxonomic history, largely the work of Marsh and Peter M. Galton, involving the genera Laosaurus, Hallopus, Drinker, Othnielia, and Othnielosaurus, the latter three now being considered to be synonyms of Nanosaurus. It had historically been classified as a hypsilophodont or fabrosaur, types of generalized small bipedal herbivore, but more recent research has abandoned these groupings as paraphyletic and Nanosaurus is today considered a basal member of Neornithischia.

Temporal range
Triassic
Jurassic
Cretaceous
Paleogene
Neogene
252 201 145 66 0 Ma
PBDB occurrences
32
Group
Dinosaures
Herbivore Ground dwelling, gregarious Terrestrial
Nanosaurus
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Wikimedia
PBDB ↗ Wikipedia ↗
Classification
Dinosauria Unranked clade
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Ornithischia Unranked clade
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Neornithischia Unranked clade
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Nanosaurus Genus
Fossil sites 32 geolocated sites
Distribution
Top countries
🇺🇸 United States
32
Geological formations
Morrison
32
Temporal distribution
Tithonian (149.2–143.1 Ma)
28
Kimmeridgian (154.8–149.2 Ma)
3
Oxfordian (161.5–154.8 Ma)
1
Species (5)
Drinker nisti subjective synonym of Nanosaurus agilis 158 Ma
Laosaurus gracilis subjective synonym of Nanosaurus agilis 158 Ma
Nanosaurus agilis 158 Ma
Nanosaurus rex subjective synonym of Nanosaurus agilis 158 Ma
Othnielosaurus consors subjective synonym of Nanosaurus agilis 158 Ma
Synonyms (2)
Drinker subjective synonym of Nanosaurus
Othnielosaurus subjective synonym of Nanosaurus
Images 1
Bibliography
Original description
O. C. Marsh. 1877. Notice of some new vertebrate fossils. American Journal of Arts and Sciences 14:249-256 DOI ↗
Bibliography (23)
J. R. Foster, D. C. Pagnac, and R. K. Hunt-Foster. 2020. An unusually diverse northern biota from the Morrison Formation (Upper Jurassic), Black Hills, Wyoming. Geology of the Intermountain West 7:29-67 DOI ↗
K. Carpenter and P. M. Galton. 2018. A photo documentation of bipedal ornithischian dinosaurs from the Upper Jurassic Morrison Formation, USA. Geology of the Intermountain West 5:167-207 DOI ↗
E. Tschopp and O. Mateus. 2017. Osteology of Galeamopus pabsti sp. nov. (Sauropoda: Diplodocidae), with implications for neurocentral closure timing, and the cervico-dorsal transition in diplodocids. PeerJ 5:e3179:1-126 DOI ↗
J. R. Foster, J. B. McHugh, and J. E. Peterson, M. F. Leschin. 2016. Major bonebeds in mudrocks of the Morrison Formation (Upper Jurassic), northern Colorado Plateau of Utah and Colorado. Geology of the Intermountain West 3:33-66 DOI ↗
P. M. Galton, K. Carpenter, and S. G. Dalman. 2015. The holotype pes of the Morrison dinosaur Camptonotus amplus MARSH, 1879 (Upper Jurassic, western USA) – is it Camptosaurus, Sauropoda or Allosaurus?. Neues Jahrbuch für Geologie und Paläontologie Abhandlungen 275(3):317-335 DOI ↗
J. R. Foster and A. B. Heckert. 2011. Ichthyoliths and other microvertebrate remains from the Morrison Formation (Upper Jurassic) of northeastern Wyoming: A screen-washed sample indicates a significant aquatic component to the fauna. Palaeogeography, Palaeoclimatology, Palaeoecology 305:264-279 DOI ↗
N. A. Christiansen and E. Tschopp. 2010. Exceptional stegosaur integument impressions from the Upper Jurassic Morrison Formation of Wyoming. Swiss Journal of Geosciences 103(2):163-171 DOI ↗
H. Galiano and R. Albersdörfer. 2010. A New Basal Diplodocoid Species, Amphicoelias brontodiplodocus from the Morrison Formation, Big Horn Basin, Wyoming, with Taxonomic Reevaluation of Diplodocus, Apatosaurus, Barosaurus and Other Genera. Dinosauria International (Ten Sleep, WY) Report for September 2010
P. M. Galton. 2007. Teeth of ornithischian dinosaurs (mostly Ornithopoda) from the Morrison Formation (Upper Jurassic) of the western United States. Horns and Beaks: Ceratopsian and Ornithopod Dinosaurs
M. T. Carrano and J. Velez-Juarbe. 2006. Paleoecology of the Quarry 9 vertebrate assemblage from Como Bluff, Wyoming (Morrison Formation, Late Jurassic). Palaeogeography, Palaeoclimatology, Palaeoecology 234(2-4):147-159 DOI ↗
J. R. Foster. 2003. Paleoecological analysis of the vertebrate fauna of the Morrison Formation (Upper Jurassic), Rocky Mountain region, U.S.A. New Mexico Museum of Natural History and Science Bulletin 23:1-95
M. V. Connely. 2002. Stratigraphy and Paleoecology of the Morrison Formation, Como Bluff, Wyoming
C. E. Turner and F. Peterson. 1999. Biostratigraphy of dinosaurs in the Upper Jurassic Morrison Formation of the Western Interior, U.S.A. Vertebrate Paleontology in Utah, Utah Geological Survey Miscellaneous Publication 99-1:77-114
K. Carpenter. 1998. Vertebrate biostratigraphy of the Morrison Formation near Cañon City, Colorado. Modern Geology 23:407-426
R. T. Bakker. 1996. The real Jurassic park: dinosaurs and habitats at Como Bluff, Wyoming. The Continental Jurassic. Museum of Northern Arizona Bulletin 60:35-49
R. T. Bakker, P. M. Galton, and J. Siegwarth, J. Filla. 1990. A new latest Jurassic vertebrate fauna, from the highest levels of the Morrison Formation at Como Bluff, Wyoming, with comments on Morrison biochronology. Part IV. The dinosaurs: a new Othnielia-like hypsilophodontoid. Hunteria 2(6):8-19
T Kobayashi. 1933. Faunal study of the Wanwanian (basal Ordovician) series with special notes on the Ribeiridae and the Ellesmereoceroids. Journal of the Faculty of Science Imperial University of Tokyo Section II Geology, Mineralogy, Geography, Seismology 3(7):249-328
G. G. Simpson. 1926. The fauna of Quarry Nine. American Journal of Science 12(67):1-11 DOI ↗
C. W. Gilmore. 1914. Osteology of the armored Dinosauria in the United States National Museum, with special reference to the genus Stegosaurus. United States National Museum Bulletin 89:1-136 DOI ↗
C. W. Gilmore. 1909. A new rhynchocephalian reptile from the Jurassic of Wyoming, with notes on the fauna of "Quarry 9". Proceedings of the United States National Museum 37(1698):35-42 DOI ↗
O. C. Marsh. 1894. The typical Ornithopoda of the American Jurassic. American Journal of Science, series 3 48:85-90 DOI ↗
O. C. Marsh. 1877. Notice of some new vertebrate fossils. American Journal of Arts and Sciences 14:249-256 DOI ↗
O. C. Marsh. 1877. Notice of new dinosaurian reptiles from the Jurassic formation. American Journal of Science and Arts 14:514-516 DOI ↗