A new late devonian fish fauna from Northeastern Brazil

ABSTRACT

Devonian fishes from South America tend to be fragmentary and sparse, catching little attention for palaeontological sampling. However, some of these remains demonstrate a wide variety of fishes which help understanding environmental and palaeogeographic patterns across the Devonian. In the Parnaíba Basin, the occurrence of Devonian fishes was thought to be restricted to the Pimenteira Formation (Middle Devonian; Eifelian-Givetian). It is described here for the first time fish remains from the Upper Devonian (Famennian) Longá Formation. These fossils represent at least two chondrichthyan (including acanthodians) taxa based on fin spines and a jaw fragment, and osteichthyan taxa based on dermal plates. Although fragmentary, these represent the first Devonian osteichthyan occurrence for the Parnaíba Basin and add to the scares Late Devonian fish record from Brazil. Recent studies have questioned the previous interpretations regarding the relationship between Gondwana and Euramerica, instead supporting more endemic vertebrate communities. Our results reinforce the palaeontological potential of the Palaeozoic strata of the Parnaíba Basin and call for additional work on the region, which may shed light on the diversification of vertebrates across Gondwana.

KEYWORDS:

• acanthodian
• chondrichthyan
• osteichthyan
• ichthyofauna
• upper Devonian

Acknowledgments

J.M.P.R had fellowship from the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), and wishes to acknowledge the institution (Brazilian Federal Governement). V.G also acknowledges the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and the PROCIÊNCIA (Rio de Janeiro State Government) for the research fellowship grants. The authors are grateful to R.R. Machado and R.C. Silva for providing access to the material from the Longá Formation deposited in the Museu de Ciências da Terra (MCT). To Dr. Philippe Janvier and an anonymous reviewer for their kind, careful and helpful revisions, which resulted in a much improved manuscript. The authors are also grateful to Justiniano de Souza Martins for permitting access to the Fazenda Barreiras and join the UNIRIO team to collect the studied fossils in 2011. Unfortunately, he passed away in 2018, and we would like to honour his memory with this work.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) under grant [88887.484101/2020-00 to J.M.P.R.]; by the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) under grant [306605/2019-PQ-2019] and by the Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ-APQ1) under grant [E-26/010.001567/2019 to V.G];Coordenação de Aperfeiçoamento de Pessoal de Nível Superior [88887.484101/2020-00];Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro [E-26/010.001567/2019];Conselho Nacional de Desenvolvimento Científico e Tecnológico [306605/2019-PQ-2019];