Cranial evolution in the extinct Rodrigues Island owl Otus murivorus (Strigidae), associated with unexpected ecological adaptations
Abstract Island birds that were victims of anthropic extinctions were often more specialist species, having evolved their most distinctive features in isolation, making the study of fossil insular birds most interesting. Here we studied a fossil cranium of the ‘giant’ extinct scops owl Otus murivoru...
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Nature Portfolio
2020-08-01
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| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-020-69868-1 |
| _version_ | 1819194858032594944 |
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| author | Anaïs Duhamel Julian P. Hume Pauline Guenser Céline Salaviale Antoine Louchart |
| author_facet | Anaïs Duhamel Julian P. Hume Pauline Guenser Céline Salaviale Antoine Louchart |
| author_sort | Anaïs Duhamel |
| collection | DOAJ |
| description | Abstract Island birds that were victims of anthropic extinctions were often more specialist species, having evolved their most distinctive features in isolation, making the study of fossil insular birds most interesting. Here we studied a fossil cranium of the ‘giant’ extinct scops owl Otus murivorus from Rodrigues Island (Mascarene Islands, southwestern Indian Ocean), to determine any potential unique characters. The fossil and extant strigids were imaged through X-ray microtomography, providing 3D views of external and internal (endocast, inner ear) cranial structures. Geometric morphometrics and analyses of traditional measurements yielded new information about the Rodrigues owl’s evolution and ecology. Otus murivorus exhibits a 2-tier “lag behind” phenomenon for cranium and brain evolution, both being proportionately small relative to increased body size. It also had a much more developed olfactory bulb than congeners, indicating an unexpectedly developed olfactory sense, suggesting a partial food scavenging habit. In addition, O. murivorus had the eyes placed more laterally than O. sunia, the species from which it was derived, probably a side effect of a small brain; rather terrestrial habits; probably relatively fearless behavior; and a less vertical posture (head less upright) than other owls (this in part an allometric effect of size increase). These evolutionary features, added to gigantism and wing reduction, make the extinct Rodrigues owl’s evolution remarkable, and with multiple causes. |
| first_indexed | 2024-12-23T02:03:32Z |
| format | Article |
| id | doaj.art-ca9c8fbe915e44ecad47c991fcfbefc5 |
| institution | Directory Open Access Journal |
| issn | 2045-2322 |
| language | English |
| last_indexed | 2024-12-23T02:03:32Z |
| publishDate | 2020-08-01 |
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| spelling | doaj.art-ca9c8fbe915e44ecad47c991fcfbefc52022-12-21T18:03:56ZengNature PortfolioScientific Reports2045-23222020-08-0110111210.1038/s41598-020-69868-1Cranial evolution in the extinct Rodrigues Island owl Otus murivorus (Strigidae), associated with unexpected ecological adaptationsAnaïs Duhamel0Julian P. Hume1Pauline Guenser2Céline Salaviale3Antoine Louchart4Univ Lyon, Univ Lyon 1, ENSL, CNRS, LGL-TPEBird Group, Department of Life Sciences, Natural History MuseumUniv Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR 5023 LEHNAUniv Lyon, Univ Lyon 1, ENSL, CNRS, LGL-TPEUniv Lyon, Univ Lyon 1, ENSL, CNRS, LGL-TPEAbstract Island birds that were victims of anthropic extinctions were often more specialist species, having evolved their most distinctive features in isolation, making the study of fossil insular birds most interesting. Here we studied a fossil cranium of the ‘giant’ extinct scops owl Otus murivorus from Rodrigues Island (Mascarene Islands, southwestern Indian Ocean), to determine any potential unique characters. The fossil and extant strigids were imaged through X-ray microtomography, providing 3D views of external and internal (endocast, inner ear) cranial structures. Geometric morphometrics and analyses of traditional measurements yielded new information about the Rodrigues owl’s evolution and ecology. Otus murivorus exhibits a 2-tier “lag behind” phenomenon for cranium and brain evolution, both being proportionately small relative to increased body size. It also had a much more developed olfactory bulb than congeners, indicating an unexpectedly developed olfactory sense, suggesting a partial food scavenging habit. In addition, O. murivorus had the eyes placed more laterally than O. sunia, the species from which it was derived, probably a side effect of a small brain; rather terrestrial habits; probably relatively fearless behavior; and a less vertical posture (head less upright) than other owls (this in part an allometric effect of size increase). These evolutionary features, added to gigantism and wing reduction, make the extinct Rodrigues owl’s evolution remarkable, and with multiple causes.https://doi.org/10.1038/s41598-020-69868-1 |
| spellingShingle | Anaïs Duhamel Julian P. Hume Pauline Guenser Céline Salaviale Antoine Louchart Cranial evolution in the extinct Rodrigues Island owl Otus murivorus (Strigidae), associated with unexpected ecological adaptations Scientific Reports |
| title | Cranial evolution in the extinct Rodrigues Island owl Otus murivorus (Strigidae), associated with unexpected ecological adaptations |
| title_full | Cranial evolution in the extinct Rodrigues Island owl Otus murivorus (Strigidae), associated with unexpected ecological adaptations |
| title_fullStr | Cranial evolution in the extinct Rodrigues Island owl Otus murivorus (Strigidae), associated with unexpected ecological adaptations |
| title_full_unstemmed | Cranial evolution in the extinct Rodrigues Island owl Otus murivorus (Strigidae), associated with unexpected ecological adaptations |
| title_short | Cranial evolution in the extinct Rodrigues Island owl Otus murivorus (Strigidae), associated with unexpected ecological adaptations |
| title_sort | cranial evolution in the extinct rodrigues island owl otus murivorus strigidae associated with unexpected ecological adaptations |
| url | https://doi.org/10.1038/s41598-020-69868-1 |
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