This site needs JavaScript to work properly. Please enable it to take advantage of the complete set of features!
Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation

Save citation to file

Add to Collections

Name must be less than 100 characters
Unable to load your collection due to an error
Please try again

Add to My Bibliography

Unable to load your delegates due to an error
Please try again

Your saved search

Would you like email updates of new search results?
Saved Search Alert Radio Buttons
()

Create a file for external citation management software

Your RSS Feed

. 2016 Feb 1:4:e1639.
doi: 10.7717/peerj.1639. eCollection 2016.

New material and revision of Melanorosaurus thabanensis, a basal sauropodomorph from the Upper Triassic of Lesotho

Affiliations

Affiliation

  • 1 Muséum National d'Histoire Naturelle, Centre de Recherche sur la Paléobiodiversité et les Paléoenvironnements (CR2P, UMR 7207), Sorbonne Universités-MNHN, CNRS, UPMC , Paris , France.

New material and revision of Melanorosaurus thabanensis, a basal sauropodomorph from the Upper Triassic of Lesotho

Claire Peyre de Fabrègues et al. PeerJ. .
. 2016 Feb 1:4:e1639.
doi: 10.7717/peerj.1639. eCollection 2016.

Affiliation

  • 1 Muséum National d'Histoire Naturelle, Centre de Recherche sur la Paléobiodiversité et les Paléoenvironnements (CR2P, UMR 7207), Sorbonne Universités-MNHN, CNRS, UPMC , Paris , France.

Abstract

Melanorosaurus is a genus of basal sauropodomorph that currently includes two species from Southern Africa. In this paper, we redescribe the holotype femur of Melanorosaurus thabanensis from the Elliot Formation of Lesotho, as well as associated remains. The stratigraphic position of this taxon is reviewed, and it is clear that it comes from the Lower Elliot Formation being, therefore, Late Triassic in age, and not Early Jurassic as originally described. The knowledge of the anatomy of the basal sauropodomorph of Thabana Morena is enhanced by the description of six new skeletal elements from the type locality. The femur and the ilium from Thabana Morena are diagnostic and characterized by unusual proportions. The first phylogenetic analysis including both this specimen and Melanorosaurus is conducted. This analysis leads to the conclusion that the femur described in the original publication of Melanorosaurus thabanensis can no longer be referred to Melanorosaurus. For these reasons, we hereby create Meroktenos gen. nov. to encompass Meroktenos thabanensis comb. nov.

Keywords: Dinosauria; Lesotho; Lower Jurassic; Melanorosaurus; Meroktenos; Sauropodomorpha; Southern Africa; Upper Triassic.

PubMed Disclaimer

Conflict of interest statement

The authors declare there are no competing interests.

Figures

Figure 1

Figure 1. Karoo Supergroup in Lesotho (modified…

Figure 1. Karoo Supergroup in Lesotho (modified from Schlüter, 2008).

(A) Geographical location of Lesotho.…

Figure 1. Karoo Supergroup in Lesotho (modified from Schlüter, 2008).
(A) Geographical location of Lesotho. (B) Geological map of Lesotho showing the location of Thabana Morena village. The exact geographical location of the site that yielded M. thabanensis is unknown.
Figure 2

Figure 2. Anterior cervical vertebra of Meroktenos

Figure 2. Anterior cervical vertebra of Meroktenos , MNHN.F.LES351a.

(A) Right lateral and (B) dorsal views.…

Figure 2. Anterior cervical vertebra of Meroktenos, MNHN.F.LES351a.
(A) Right lateral and (B) dorsal views. ns, neural spine; pa, parapophysis; poz, postzygapophyses; prz, prezygapophyses. (Photo credit: L Cazes.)
Figure 3

Figure 3. Forelimb bones of Meroktenos .

(A)…

Figure 3. Forelimb bones of Meroktenos .

(A) Left ulna, MNHN.F.LES351b, in medial view. (B) Left?…

Figure 3. Forelimb bones of Meroktenos.
(A) Left ulna, MNHN.F.LES351b, in medial view. (B) Left? radius, MNHN.F.LES351c. ol, olecranon. (Photo credit: L Cazes.)
Figure 4

Figure 4. Right ilium of Meroktenos ,…

Figure 4. Right ilium of Meroktenos , MNHN.F.LES16a.

(A) Lateral view. (B) Interpretative drawing of a…

Figure 4. Right ilium of Meroktenos, MNHN.F.LES16a.
(A) Lateral view. (B) Interpretative drawing of a close-up of the acetabulum in ventral view, showing the neural arch of the vertebra. bcr, brevis crest; di, diapophysis; ibl, iliac blade; isp, ischial peduncle; mwa, medial wall of the acetabulum; ns, neural spine; prp, preacetabular process; pop, postacetabular process; poz, postzygapophysis; pup, pubic peduncle; sac, supracetabular crest; V, vertebra. (Photo credit: L Cazes.)
Figure 5

Figure 5. Left pubis of Meroktenos ,…

Figure 5. Left pubis of Meroktenos , MNHN.F.LES16b.

(A) Anterior, (B) medial, (C) posterior, (D) lateral,…

Figure 5. Left pubis of Meroktenos, MNHN.F.LES16b.
(A) Anterior, (B) medial, (C) posterior, (D) lateral, (E) proximal, and (F) distal views. ac, acetabulum; ilp, iliac peduncle; isp, ischial peduncle; of, obturator foramen; pa, pubic apron; pp, pubic plate. (Photo credit: L Cazes.)
Figure 6

Figure 6. Right femur of Meroktenos ,…

Figure 6. Right femur of Meroktenos , MNHN.F.LES16c.

(A) Anterior, (B) medial, (C) posterior, (D) lateral,…

Figure 6. Right femur of Meroktenos, MNHN.F.LES16c.
(A) Anterior, (B) medial, (C) posterior, (D) lateral, (E) proximal, and (F) distal views. ef, extensor fossa; fc, fibular condyle; fh, femoral head; lc, lateral condyle; lt, lesser trochanter; mc, medial condyle; pf, popliteal fossa; tfc, tibiofibular crest; 4t, fourth trochanter. (Photo credit: L Cazes.)
Figure 7

Figure 7. Right metatarsal II of Meroktenos

Figure 7. Right metatarsal II of Meroktenos , MNHN.F.LES16d.

(A) Dorsal, (B) ventral, (C) medial, (D)…

Figure 7. Right metatarsal II of Meroktenos, MNHN.F.LES16d.
(A) Dorsal, (B) ventral, (C) medial, (D) lateral, (E) proximal, and (F) distal views. asI, articular surface for metatarsal I; clf, collateral ligament fossa. Arrows indicate the proximal end of the bone. In (E) and (F), the lateral side of the bone is at the right side of the picture. (Photo credit: L Cazes.)
Figure 8

Figure 8. Comparative figure showing the posterior…

Figure 8. Comparative figure showing the posterior view of the femora of Late Triassic basal…

Figure 8. Comparative figure showing the posterior view of the femora of Late Triassic basal sauropodomorphs from Southwestern Gondwana.
(A) Right femur of Meroktenos thabanensis MNHN.F.LES16c (photo credit: L Cazes). (B) Right femur of Eucnemesaurus entaxonis BP/1/6234 (modified from McPhee et al., 2015). (C) Left femur of Melanorosaurus readi SAM-PK-3450 (photo credit: C. Peyre de Fabrègues). (D) Right femur of ‘The Maphutseng dinosaur’ MNHN.F.LES394 (photo credit: L Cazes). (E) Right femur of Coloradisaurus brevis PVL 5904 (photo credit: C Peyre de Fabrègues). (F) Right femur of Lessemsaurus sauropoides PVL 4822/65 (photo credit: C Peyre de Fabrègues). (G) Left femur of Mussaurus patagonicus MLP 68-II-27-1 specimen A (photo credit: A Otero). (H) Left femur of Riojasaurus incertus PVL 3808 (photo credit: C Peyre de Fabrègues). All specimens are presented at the same scale to emphasize the disparity of proportions.
Figure 9

Figure 9. Phylogenetic position of Meroktenos based…

Figure 9. Phylogenetic position of Meroktenos based on the data set available from Apaldetti et…

Figure 9. Phylogenetic position of Meroktenos based on the data set available from Apaldetti et al. (2014).
(A) Strict consensus of the 440 most parsimonious trees (L = 1,308 steps). (B) Majority-rule consensus of the 440 most parsimonious trees. Sauropoda sensu Salgado, Coria & Calvo, (1997) (Peyre de Fabrègues, Allain & Barriel, 2015).

References

    1. Allain R, Aquesbi N. Anatomy and phylogenetic relationships of Tazoudasaurus naimi (Dinosauria, Sauropoda) from the late Early Jurassic of Morocco. Geodiversitas. 2008;30:345–424.
    1. Apaldetti C, Martinez RN, Pol D, Souter T. Redescription of the skull of Coloradisaurus brevis (Dinosauria, Sauropodomorpha) from the Late Triassic Los Colorados Formation of the Ischigualasto-Villa Union Basin, northwestern Argentina. Journal of Vertebrate Paleontology. 2014;34:1113–1132. doi: 10.1080/02724634.2014.859147. - DOI
    1. Apaldetti C, Pol D, Yates AM. The postcranial anatomy of Coloradisaurus brevis (Dinosauria: Sauropodomorpha) from the Late Triassic of Argentina and its phylogenetic implications. Palaeontology. 2013;56:277–301. doi: 10.1111/j.1475-4983.2012.01198.x. - DOI
    1. Barrett PM. A new basal sauropodomorph dinosaur from the upper Elliot Formation (Lower Jurassic) of South Africa. Journal of Vertebrate Paleontology. 2009;29:1032–1045. doi: 10.1671/039.029.0401. - DOI
    1. Barrett PM, Yates AM. New information on the palate and lower jaw of Massospondylus (Dinosauria: Sauropodomorpha) Palaeontologia Africana. 2005;41:123–130.

LinkOut - more resources

Cite
Morty Proxy This is a proxified and sanitized view of the page, visit original site.