Open Paleo

Macrocollum

Müller et al., 2018 MAK-row-COLL-um

From Greek 'makros' (long) and Latin 'collum' (neck); meaning 'long neck', referring to the animal's elongated neck

227.3–205.7 million years ago Norian, Late Triassic
Late Triassic stages

Macrocollum is a genus of unaysaurid sauropodomorph dinosaur that lived during the Late Triassic period (early Norian) in what is now Brazil. It is one of the oldest dinosaurs known.

Diagnosis

  1. Antorbital fossa perforated by a promaxillary fenestra
  2. Medial margin of supratemporal fossa with simple smooth curve at frontal/parietal suture
  3. Proximal articular surface of metacarpal I transversely narrow
  4. Acetabulum not fully open
  5. Ischiadic longitudinal groove not reaching caudal half of ischium
  6. Absence of trochanteric shelf on femur
  7. Medial condyle of distal femoral articulation subrectangular in distal view
  8. Proximal end of metatarsal II with straight medial margin
  9. Cervical vertebrae remarkably elongated (centrum about six times longer than cranial height)
  10. Medial condyle of astragalus remarkably expanded cranially

Species

Macrocollum itaquii Müller et al., 2018

Type species

Named for José Jerundino Machado Itaqui, one of the principal figures behind the creation of the Centro de Apoio à Pesquisa Paleontológica da Quarta Colônia (CAPPA/UFSM).

Holotype
CAPPA/UFSM 0001a , Centro de Apoio à Pesquisa Paleontológica da Quarta Colônia, Universidade Federal de Santa Maria
Material
An almost complete and articulated skeleton.
Horizon
Caturrita Formation, Norian, Late Triassic , 227.3–205.7 million years ago
Locality
Wachholz site, Rio Grande do Sul, Brazil

References

  1. Müller, R. T.; Langer, M. C.; Dias-da-Silva, S. (2018). An exceptionally preserved association of complete dinosaur skeletons reveals the oldest long-necked sauropodomorphs. Biology Letters 14(11): 20180633. The Royal Society. doi:10.1098/rsbl.2018.0633 müller2018a
  2. Paul, G. S. (2024). The Princeton Field Guide to Dinosaurs (3rd ed.). Princeton University Press.

    Source of the body length and mass estimates.

    paul2024a
  3. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Sauropods. Princeton University Press.

    Source of the hip height estimate, and the appearance features.

    jones2026b