First record of rhynchosaurs (<scp>Archosauromorpha</scp>: <scp>Rhynchosauria</scp>: <scp>Hyperodapedontinae</scp>) from the early <scp>Late Triassic</scp><i>Santacruzodon</i><scp>Assemblage Zone</scp> of the <scp>Santa Maria Supersequence, Brazil</s
Rhynchosauria is a group of extinct, exclusively Triassic, terrestrial, and herbivorous archosauromorphs, characterized by a peculiar maxillary-mandibular apparatus. They reached global distribution during the Carnian, with the Hyperodapedontinae clade. The rhynchosaurian record from South America is included in the Ladinian-?earliest Carnian Dinodontosaurus Assemblage Zone (Pinheiros-Chiniquá Sequence, Brazil) and Tarjadia Assemblage Zone (Chañares Formation, Argentina), and for strictly Carnian Hyperodapedon Assemblage Zone (Lower Candelária Sequence, Brazil) and Ischigualasto Formation (Argentina). Here, we present the first record of Hyperodapedontinae from the Brazilian Early Carnian Santacruzodon Assemblage Zone (Santa Cruz Sequence). The most diagnostic elements belong to a nearly complete left pes, which presents a combination of hyperodapedontine traits. The presence of a second individual of cf. Hyperodapedontinae is based on a fragmentary, isolated left metatarsal IV. An isolated fragment of premaxilla could belong to the second specimen (based on preservation mode) or to a third individual. This new report fills a gap within the South American rhynchosaurian distribution, strengthening biostratigraphic correlation with other regions from Gondwana (i.e., Madagascar), where similar and coeval faunas are known. The inclusion of these specimens in a phylogenetic dataset resulted in low resolution results, due to missing data because postcranial characters for rhynchosaurs are still poorly explored.
Authors
- César Leandro Schultz (ORCID: https://orcid.org/0000-0001-7121-0409)
- Ana María Ribeiro (ORCID: https://orcid.org/0000-0003-4167-8558)
- Agustín G. Martinelli (ORCID: https://orcid.org/0000-0003-4489-0888)
- Marco B D Andrade (ORCID: https://orcid.org/0000-0002-3452-801X)
- Francesco Battista (ORCID: https://orcid.org/0000-0002-6154-1906)
Institutions
- Universidade Federal do Rio Grande do Sul (BR)
- Consejo Nacional de Investigaciones Científicas y Técnicas (AR)
- Bernardino Rivadavia Natural Sciences Museum (AR)
- Natura (Brazil) (BR)
- Secretaria do Meio Ambiente (BR)
- Pontifícia Universidade Católica do Rio Grande do Sul (BR)
Publication Details
- Journal
- The Anatomical Record
- Published
- 2024-10-11
- DOI
- https://doi.org/10.1002/ar.25589
- Citations
- 1
- Primary Topic
- Paleontology and Evolutionary Biology
- Type
- article
- Field-Weighted Citation Impact
- 1.59
Funders
- Consejo Nacional de Investigaciones Científicas y Técnicas
- Conselho Nacional de Desenvolvimento Científico e Tecnológico