The role of Brazil in the golden age of dinosaur origins discoveries

Whereas early dinosaurs from Brazil are known for a long time, this record was poorly preserved and/or underrated. Nevertheless, intense fieldwork efforts yielded several new specimens during the last decade. These discoveries reshaped our understanding regarding the early evolution of dinosaurs. The new fossils from Brazil are exquisitely preserved, illuminating obscure details of the skeleton. For instance, the internal regions of the skulls hold data on the behavior of these creatures, which was crucial to access information on balance, olfaction, diet and “cognitive capabilities”. These were pioneer studies on the neurobiology of the oldest dinosaurs (Bronzati et al. 2017, Müller et al. 2021). An unusual association of a small creature related to pterosaurs (Ezcurra et al. 2020) and an early dinosaur brings to us the first unambiguous carnivorous member of lineage that encompasses the giant long necked sauropods (Figure 1e; Cabreira et al. 2016). Regarding the lineage that originated the colossal sauropods, another specimen preserved the first adaptations related to the acquisition of an herbivorous diet (Pretto et al. 2019), whereas an impressive association with complete and articulated skeletons provided evidences on the oldest long necked sauropodomorphs worldwide (Figure 1c–d; Müller et al. 2018). Advanced geochronology investigations constrained the age of these discoveries (Langer et al. 2018), ordering the sequence of evolutionary innovations and faunistic shifts during the rise of dinosaurs. Finally, the first complete skeleton of an early predatory dinosaur from the lineage of herrerasaurids was unearthed from these Brazilian beds (Figure 1a–b; Pacheco et al. 2019), depicting the whole skeletal anatomy of these beasts.

Figure 1
Representative early dinosaurs from the Late Triassic of Southern Brazil. a) Fossilized skull of Gnathovorax cabreirai. b) Life reconstruction of Gnathovorax cabreirai by Márcio L. Castro. c) Life reconstruction of Macrocollum itaquii by Márcio L. Castro. d) Fossilized skull of Macrocollum itaquii. e) Detail of the skull cast of Buriolestes schultzi.

The impact of Brazilian discoveries on the knowledge regarding the origin of the “Terrible Lizards” is undeniable. Despite the phylogenetic disputes, the frontiers of gross anatomy have been crossed, leading us to another level of investigations. Our challenges are the alpha taxonomy of early dinosaurs, the limits of intraspecific variation, the biology of these creatures, and precise age of dinosaur-bearing sites. Fortunately, there are several new specimens recently unearthed from Brazil and other countries being prepared and studied. During the next few years, we will witness far more discoveries on this exciting topic of natural history.

REFERENCES

• BRONZATI M, RAUHUT OW, BITTENCOURT JS & LANGER MC. 2017. Endocast of the Late Triassic (Carnian) dinosaur Saturnalia tupiniquim: implications for the evolution of brain tissue in Sauropodomorpha. Sci Rep 7: 1-7.
• CABREIRA SF ET AL. 2016. A unique Late Triassic dinosauromorph assemblage reveals dinosaur ancestral anatomy and diet. Curr Biol 26: 3090-3095.
• EZCURRA MD ET AL. 2020. Enigmatic dinosaur precursors bridge the gap to the origin of Pterosauria. Nature 588: 445-449.
• LANGER MC, RAMENZANI J & DA-ROSA AAS. 2018. U-Pb age constraints on dinosaur rise from south Brazil. Gondwana Res 57: 133-140.
• MÜLLER RT, FERREIRA JD, PRETTO FA, BRONZATI M & KERBER L. 2021. The endocranial anatomy of Buriolestes schultzi (Dinosauria: Saurischia) and the early evolution of brain tissues in sauropodomorph dinosaurs. J Anat 238: 809-827.
• MÜLLER RT, LANGER MC & DIAS-DA-SILVA S. 2018. An exceptionally preserved association of complete dinosaur skeletons reveals the oldest long-necked sauropodomorphs. Biol Lett 14: 20180633.
• PACHECO C, MÜLLER RT, LANGER MC, PRETTO FA, KERBER L & DIAS-DA-SILVA S. 2019. Gnathovorax cabreirai: a new early dinosaur and the origin and initial radiation of predatory dinosaurs. PeerJ 7: e7963.
• PRETTO FA, LANGER MC & SCHULTZ CL. 2019. A new dinosaur (Saurischia: Sauropodomorpha) from the Late Triassic of Brazil provides insights on the evolution of sauropodomorph body plan. Zool J Linn Soc 185: 388-416.
• SERENO PC, FORSTER CA, ROGERS RR & MONETTA AM. 1993. Primitive dinosaur skeleton from Argentina and the early evolution of Dinosauria. Nature 361: 64-66.
• SERENO PC & NOVAS FE. 1992. The complete skull and skeleton of an early dinosaur. Science 258: 1137-1140.

Publication Dates

• Publication in this collection
  20 Mar 2023
• Date of issue
  2023

History

• Received
  14 Apr 2022
• Accepted
  9 June 2022