Lessemsaurus is an extinct genus of sauropodiform dinosaur belonging to Lessemsauridae.

Lessemsaurus
Temporal range: Norian
~228–208.5 Ma
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Sauropodomorpha
Clade: Sauropoda
Clade: Lessemsauridae
Genus: Lessemsaurus
Bonaparte 1999
Species:
L. sauropoides
Binomial name
Lessemsaurus sauropoides

Naming and description

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The type species, L. sauropoides, was formally described by José Fernando Bonaparte in 1999 in honor of Don Lessem, a writer of popular science books. It was found in the Los Colorados Formation of the Ischigualasto-Villa Unión Basin in La Rioja Province, Argentina.[1]

It was discovered in strata dating to the Norian stage, around 210 million years ago.[2][3] It is estimated to have reached 10–12 metres (33–39 ft) long and weighed over 7 metric tons (7.7 short tons), possibly up to 8–10 metric tons (8.8–11.0 short tons), in maximum body mass.[4][5][6][7]

Classification

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Exhibit in Singapore

A cladogram after Pol, Garrido & Cerda, 2011,[8] illustrates a possible placing of Lessemsaurus and Antetonitrus in Sauropodomorpha:

Sauropodomorpha

In 2018, Apaldetti et al. recovered it as part of a clade they named Lessemsauridae, after Lessemsaurus. Their cladogram is reproduced below:[9]

The following cladogram shows the position of Lessemsaurus outside of Sauropoda, according to Oliver W. M. Rauhut and colleagues, 2020:[10]

References

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  1. ^ Weishampel, David B; et al., 2004. "Dinosaur distribution (Late Triassic, South America)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 527–528. ISBN 0-520-24209-2.
  2. ^ Bonaparte, J. F. (1999). "Evolución de las vértebras presacras en Sauropodomorpha". Ameghiniana. 36: 115–187.
  3. ^ Pol, D.; Powell, J. E. (2007). "New information on Lessemsaurus sauropoides (Dinosauria: Sauropodomorpha) from the Upper Triassic of Argentina". Special Papers in Palaeontology. 77: 223–243.
  4. ^ Diego Pol; Alberto Garrido; Ignacio A. Cerda (2011). "A New Sauropodomorph Dinosaur from the Early Jurassic of Patagonia and the Origin and Evolution of the Sauropod-type Sacrum". PLOS ONE. 6 (1): e14572. Bibcode:2011PLoSO...614572P. doi:10.1371/journal.pone.0014572. PMC 3027623. PMID 21298087.
  5. ^ Foelix, Rainer; Pabst, Ben; Kindlimann, René (2011). "Die Saurier in Frick" (PDF). Mitteilungen der aargauischen Naturforschenden Gesellschaft. 37. doi:10.5169/seals-283430.
  6. ^ Apaldetti, C.; Martínez, R.N.; Cerda, I.A.; Pol, D.; Alcober, O. (2018). "An early trend towards gigantism in Triassic sauropodomorph dinosaurs". Nature Ecology & Evolution. 2 (8): 1227–1232. Bibcode:2018NatEE...2.1227A. doi:10.1038/s41559-018-0599-y. hdl:11336/89332. PMID 29988169. S2CID 256705065.
  7. ^ McPhee, Blair W.; Benson, Roger B.J.; Botha-Brink, Jennifer; Bordy, Emese M. & Choiniere, Jonah N. (2018). "A giant dinosaur from the earliest Jurassic of South Africa and the transition to quadrupedality in early sauropodomorphs". Current Biology. 28 (19): 3143–3151.e7. Bibcode:2018CBio...28E3143M. doi:10.1016/j.cub.2018.07.063. PMID 30270189.
  8. ^ Diego Pol; Alberto Garrido; Ignacio A. Cerda (2011). "A New Sauropodomorph Dinosaur from the Early Jurassic of Patagonia and the Origin and Evolution of the Sauropod-type Sacrum". PLOS ONE. 6 (1): e14572. Bibcode:2011PLoSO...614572P. doi:10.1371/journal.pone.0014572. PMC 3027623. PMID 21298087.
  9. ^ Apaldetti; Martínez, Ricardo N.; Cerda, Ignatio A.; Pol, Diego; Alcober, Oscar (2018). "An early trend towards gigantism in Triassic sauropodomorph dinosaurs". Nature Ecology & Evolution. 2 (8): 1227–1232. Bibcode:2018NatEE...2.1227A. doi:10.1038/s41559-018-0599-y. hdl:11336/89332. PMID 29988169. S2CID 49669597.
  10. ^ Rauhut, O. W. M.; Holwerda, F. M.; Furrer, H. (2020). "A derived sauropodiform dinosaur and other sauropodomorph material from the Late Triassic of Canton Schaffhausen, Switzerland". Swiss Journal of Geosciences. 113 (1): 8. doi:10.1186/s00015-020-00360-8. S2CID 220294939.
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