Open Paleo

Amygdalodon

Cabrera, 1947 am-ig-DAL-o-don /əmɪɡˈdælədɒn/

From Greek 'amygdale' meaning 'almond' and 'odon' meaning 'tooth', meaning 'almond tooth', referring to the almond-shaped teeth.

192.9–174.7 million years ago Pliensbachian–Toarcian, Early Jurassic
Early Jurassic stages

Amygdalodon is an extinct genus of basal sauropod from the Early Jurassic of Argentina. The type species is Amygdalodon patagonicus. Fossils of Amygdalodon have been found in the Cerro Carnerero Member of the Lonco Trapial Formation. Very little is known about it, but it is one of the few Jurassic dinosaurs from South America found thus far.

Under dispute

Amygdalodon is a fragmentary early sauropod whose position is labile. Pol and Gomez (2022) recover it near the base of Gravisauria, in a polytomy with Gongxianosaurus outside Eusauropoda, whereas Rauhut (2003) regarded it as a very basal eusauropod and earlier authors as a cetiosaurid.

Diagnosis

  1. Lateral walls of the neural canal and the centropostzygapophyseal laminae flared laterally toward the posterior
  2. Neural canal strongly flexed anteroposteriorly within the dorsal neural arches

Species

Amygdalodon patagonicus Cabrera, 1947

Type species

Named for Patagonia, the region of Argentina where the fossils were discovered in the Cerro Carnerero Member.

Lectotype
MLP 46-VIII-21-1/2 , Museo de La Plata
Material
Posterior dorsal vertebra.
Horizon
Cerro Carnerero Member, Lonco Trapial Formation, Pliensbachian–Toarcian, Early Jurassic , 192.9–174.7 million years ago
Locality
Eastern slope of the Pampa de Agnía range, Chubut, Argentina Described from the "Cerro Carnerero Formation", which Nullo and Proserpio (1975) made a member of the Lonco Trapial Formation. Pol and colleagues (2022) conclude it "was deposited at some point during the Pliensbachian or the early Toarcian".

References

  1. Cabrera, A. (1947). Un saurópodo nuevo del Jurásico de Patagonia [A New Sauropod from the Jurassic of Patagonia]. Instituto del Museo de la Universidad Nacional de La Plata, Notas del Mueso de La Plata, Paleontología 12(95): 1-17. cabrera1947a
  2. Rauhut, O. W. M. (2003). Revision of Amygdalodon patagonicus Cabrera, 1947 (Dinosauria, Sauropoda). Fossil Record 6: 173-181. Wiley. doi:10.1002/mmng.20030060110

    Revision of Amygdalodon; designated the lectotype MLP 46-VIII-21-1/2.

    rauhut2003c
  3. Pol, D.; Gomez, K.; Holwerda, F. M.; Rauhut, O. W. M.; Carballido, J. L. (2022). Sauropods from the Early Jurassic of South America and the Radiation of Eusauropoda. South American Sauropodomorph Dinosaurs: Record, Diversity and Evolution 131-163. Springer International Publishing. doi:10.1007/978-3-030-95959-3_4

    Recovered Amygdalodon near the base of Sauropoda in a polytomy with Gongxianosaurus outside Eusauropoda

    pol2022a
  4. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Sauropods. Princeton University Press.

    Places Amygdalodon near the base of Sauropoda.

    jones2026b
  5. Nullo, F.; Proserpio, C. (1975). La Formación Taquetrén en Cañadón del Zaino (Chubut) y sus relaciones estratigráficas en el ámbito de la Patagonia, de acuerdo a la flora, República Argentina [The Taquetrén Formation at Cañadón del Zaino (Chubut) and its stratigraphic relationships within Patagonia, according to the flora, Argentina]. Revista de la Asociación Geológica Argentina 30(2): 133-150.

    Reduces the Cerro Carnerero Formation to a member of the Lonco Trapial Formation.

    nullo1975a