Open Paleo

Melanorosaurus

Haughton, 1924 me-LAN-or-o-SAWR-us

From Greek 'melas' meaning 'black', 'oros' meaning 'mountain', and 'sauros' meaning 'lizard'; translates as 'Black Mountain Lizard', named for the Black Mountains (Thaba Nyama) near the South African discovery site.

227.3–201.4 million years ago Norian–Rhaetian, Late Triassic
Late Triassic stages

Melanorosaurus is a genus of basal sauropodomorph dinosaur that lived during the Late Triassic period. An omnivore from South Africa, it had a large body and sturdy limbs, suggesting it moved quadrupedally. Its limb bones were massive and heavy like the limb bones of true sauropods.

Diagnosis

  1. Posterior margin of the ulna with a pronounced sigmoidal outline.
  2. Sigmoidal dorsal margin of the iliac pubic peduncle.
  3. Ratio of ilium height at the level of the ischiac peduncle to total ilium length greater than 0.67.
  4. Ilium with a straight posterior margin continuous with the ischial peduncle, steeply angled at 65° to the horizontal.
  5. Proximal caudal vertebrae with dorsoventrally elongate, mediolaterally narrow, heart-shaped centra at least 1.42 times taller than wide.
  6. Proximal caudal centra with a deeply incised ventral midline groove.
  7. Proximal caudal centra with foramina on their lateral surfaces.

Species

Melanorosaurus readi Haughton, 1924

Type species

Named for Mr. B. Read, former Principal of the Bensonvale Training School, in recognition of kindness, interest, and hospitality.

Lectotype
SAM-PK-3449 , Iziko South African Museum
Material
Partial skeleton of one individual: a mid-cervical neural arch and centrum, a cervicodorsal centrum, two dorsal centra and two dorsal neural arches, two partial sacral and three caudal vertebrae, the right ulna and partial left radius, the right ilium and partial left pubis, complete left and partial right tibiae, the left fibula, and metatarsals I-IV.
Notes
Barrett and Choiniere (2024) designated SAM-PK-3449 as the lectotype and excluded SAM-PK-3450 (a different individual found ~18 m away); the femur and humerus that Haughton (1924) only doubtfully associated with the type are not part of the lectotype.
Horizon
lower Elliot Formation, Norian–Rhaetian, Late Triassic , 227.3–201.4 million years ago
Locality
Thaba 'Nyama, Herschel, Eastern Cape, South Africa

Synonyms of the genus

Name Type Reason
Roccosaurus junior subjective Treated as a synonym of Melanorosaurus; remains a nomen nudum.

References

  1. Haughton, S. H. (1924). The fauna and stratigraphy of the Stormberg Series. Annals of the South African Museum 12: 323-497. haughton1924a
  2. Barrett, P. M.; Choiniere, J. N. (2024). Melanorosaurus readi Haughton, 1924 (Dinosauria, Sauropodomorpha) from the Late Triassic of South Africa: osteology and designation of a lectotype. Journal of Vertebrate Paleontology 44(1): e2337802. Informa UK Limited. doi:10.1080/02724634.2024.2337802

    Revised osteology based on the syntype series; designates SAM-PK-3449 as the lectotype, excludes SAM-PK-3450, and restricts the hypodigm to the lectotype.

    barrett2024b
  3. 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). Pensoft Publishers. doi:10.1186/s00015-020-00360-8

    Follows the node-based Vulcanodon definition of Sauropoda and recovers Melanorosaurus in the pectinate sauropodiform grade outside it.

    rauhut2020a
  4. McPhee, B. W.; Choiniere, J. N. (2017). The osteology of Pulanesaura eocollum: implications for the inclusivity of Sauropoda (Dinosauria). Zoological Journal of the Linnean Society. Oxford University Press (OUP). doi:10.1093/zoolinnean/zlx074

    Reviews the competing definitions of Sauropoda, including Yates's stem definition with Melanorosaurus as external specifier, and questions the validity of Melanorosaurus.

    mcphee2017a