| Full text | |
| Author(s): Show less - |
Prado, Gustavo
;
Salvato, Rafael C. J. P. S.
;
Becker-Kerber, Bruno
;
Silva, Evandro P.
;
Pinheiro, Felipe L.
;
Oses, Gabriel L.
;
Galante, Douglas
;
Rodrigues, Jaime J.
;
Dias, Ismar De Souza
;
Carvalho, Evan T.
;
Saitta, Lucas M.
;
Lino, Luiz E.
Total Authors: 12
|
| Document type: | Journal article |
| Source: | LETHAIA; v. 58, n. 3, p. 17-pg., 2025-06-01. |
| Abstract | |
Eumelanin is a ubiquitous type of pigment, standing present in all major life branches. Chemically, it consists of 5,6-dihydroxyindole (DHI) and 5,6-dihydroxyindole-2-carboxylic acid (DHICA) units bonded with varied functional groups. This biochrome is involved in many different roles, such as free radical scavenging, microbial inhibition, etc. Eumelanin is produced by organelles called melanosomes, which are found throughout the animals' body. In the fish's eyes, this pigment mainly plays a protective role against UV radiation damage and waterborne insults. The previous detection of melanosomes in the eyes of fossil teleosts already provided evidence for the palaeobiology and palaeoecology of extinct fish lineages. Nonetheless, the presence of these organelles remains to be detected in exceptionally preserved fossils from Brazil. Here, we report the microscopic and chemical investigation of fossil melanin from the eyes of the Cretaceous fish Dastilbe crandalli. Results show that the eye has a circular shape with non-recalcitrant dark brown tissues at its rims, exhibiting densely packed, solid, subspherical micrometric granules rich in carbon and with vibrational spectra of eumelanin. Geothermic calculations of the Raman spectra indicate that melanin is not much thermally altered. This result is consistent with other proposals for the maximum temperature for this unit, raising the possibility of its use to estimate the thermal alteration of geomelanins. Besides that, these results also indicate that Dastilbe fish possibly had a limited visual capability or lived in the shallow but shadowed (by aquatic plants) portions of the palaeolake. square Melanin, Raman Spectroscopy, Cretaceous, Crato Formation. (AU) | |
| FAPESP's process: | 21/05083-8 - Nanoscale multitechnical synchrotron characterization applied to the problem of biogenicity of minerals |
| Grantee: | Douglas Galante |
| Support Opportunities: | Regular Research Grants |
| FAPESP's process: | 12/18936-0 - Applications of Raman Spectroscopy in paleobiology and astrobiology |
| Grantee: | Setembrino Petri |
| Support Opportunities: | Regular Research Grants |
| FAPESP's process: | 23/14250-0 - Expanding the frontiers of research in biomineralization and fossil preservation |
| Grantee: | Gabriel Ladeira Oses |
| Support Opportunities: | Scholarships in Brazil - Generation Project |
| FAPESP's process: | 20/11320-0 - Unveiling the hidden: investigating the first animals of South America through phase-contrast SR-microCT and deep learning image processing |
| Grantee: | Bruno Becker Kerber |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |
| FAPESP's process: | 22/06133-1 - X-ray diffraction tomography (XRD-CT) and pair distribution function tomography (PDF-CT): novel tools for paleontological investigations |
| Grantee: | Bruno Becker Kerber |
| Support Opportunities: | Scholarships abroad - Research Internship - Post-doctor |
| FAPESP's process: | 23/10680-0 - CHEMICAL AND TAPHONOMIC ASPECTS OF THE RECONSTRUCTION OF COLOUR PATTERNS OF DINOSAURS FROM THE CRATO FORMATION (CRETACEOUS, ARARIPE BASIN, NE BRAZIL) |
| Grantee: | Gustavo Marcondes Evangelista Martins Prado |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |
| FAPESP's process: | 21/07007-7 - Palaeometry applied to the investigation of biomineralization, environments and fossil preservation |
| Grantee: | Gabriel Ladeira Oses |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |
| FAPESP's process: | 22/06485-5 - Expanding the frontiers of research in biomineralization and fossil preservation |
| Grantee: | Gabriel Ladeira Oses |
| Support Opportunities: | Generation Project Research Grant |