TY - JOUR
T1 - Deep reptilian evolutionary roots of a major avian respiratory adaptation
AU - Wang, Yan-yin
AU - Claessens, Leon P. A. M.
AU - Sullivan, Corwin
N1 - Funding Information:
This research was funded by the Natural Sciences and Engineering Research Council of Canada (Discovery Grant RGPIN-2017-06246) and start-up funding awarded by the University of Alberta to C.S., National Foundation Science Grant (DBI 0743327) awarded to L.P.A.M.C., and a Student Research Project from the Dinosaur Research Institute awarded to Y.Y.W. We are grateful to Carl Mehling (AMNH), Binghe Di (IVPP), Eva Biedron (MCZ), Nicole Ridgwell (NMMNH), Braden Barr (UAMZ), Brandon Strilisky (TMP), Clive Coy, Howard Gibbons, and Robin Sissons (UALVP), and Daniel Brinkman (YPM) for access to archosaur specimens. We thank Oksana V. Vernygora and Nicolàs E. Campione for technical advice on performing the ancestral state reconstruction using R. We thank members of the Sullivan, Currie, and Caldwell labs at the University of Alberta for discussion. We thank Sydney Mohr and Khoi Nguyen for the permissions to adapt their artworks into silhouettes. We thank Brad McFeeters, Craig Dylke, FunkMonk, Jagged Fang Design, Mariana Ruiz, Michael Keesey, Raven Amos, Steven Traver, and Tasman Dixon for uploading their artwork to the public domain section of the platform PhyloPic.
Funding Information:
This research was funded by the Natural Sciences and Engineering Research Council of Canada (Discovery Grant RGPIN-2017-06246) and start-up funding awarded by the University of Alberta to C.S., National Foundation Science Grant (DBI 0743327) awarded to L.P.A.M.C., and a Student Research Project from the Dinosaur Research Institute awarded to Y.Y.W. We are grateful to Carl Mehling (AMNH), Binghe Di (IVPP), Eva Biedron (MCZ), Nicole Ridgwell (NMMNH), Braden Barr (UAMZ), Brandon Strilisky (TMP), Clive Coy, Howard Gibbons, and Robin Sissons (UALVP), and Daniel Brinkman (YPM) for access to archosaur specimens. We thank Oksana V. Vernygora and Nicolàs E. Campione for technical advice on performing the ancestral state reconstruction using R. We thank members of the Sullivan, Currie, and Caldwell labs at the University of Alberta for discussion. We thank Sydney Mohr and Khoi Nguyen for the permissions to adapt their artworks into silhouettes. We thank Brad McFeeters, Craig Dylke, FunkMonk, Jagged Fang Design, Mariana Ruiz, Michael Keesey, Raven Amos, Steven Traver, and Tasman Dixon for uploading their artwork to the public domain section of the platform PhyloPic.
Publisher Copyright:
© 2023, The Author(s).
PY - 2023/1/17
Y1 - 2023/1/17
N2 - Vertebral ribs of the anterior thorax in extant birds bear bony prongs called uncinate processes, which improve the mechanical advantage of mm. appendicocostales to move air through the immobile lung and pneumatic air sacs. Among non-avian archosaurs, broad, cartilaginous uncinate processes are present in extant crocodylians, and likely have a ventilatory function. Preserved ossified or calcified uncinate processes are known in several non-avian dinosaurs. However, whether other fossil archosaurs possessed cartilaginous uncinate processes has been unclear. Here, we establish osteological correlates for uncinate attachment to vertebral ribs in extant archosaurs, with which we inferred the presence of uncinate processes in at least 19 fossil archosaur taxa. An ancestral state reconstruction based on the infer distribution suggests that cartilaginous uncinate processes were plesiomorphically present in Dinosauria and arguably in Archosauria, indicating that uncinate processes, and presumably their ventilatory function, have a deep evolutionary history extending back well beyond the origin of birds.A newly discovered osteological correlate for structures associated with ventilatory muscle attachment indicates a deep evolutionary history of respiratory innovation within Archosauria.
AB - Vertebral ribs of the anterior thorax in extant birds bear bony prongs called uncinate processes, which improve the mechanical advantage of mm. appendicocostales to move air through the immobile lung and pneumatic air sacs. Among non-avian archosaurs, broad, cartilaginous uncinate processes are present in extant crocodylians, and likely have a ventilatory function. Preserved ossified or calcified uncinate processes are known in several non-avian dinosaurs. However, whether other fossil archosaurs possessed cartilaginous uncinate processes has been unclear. Here, we establish osteological correlates for uncinate attachment to vertebral ribs in extant archosaurs, with which we inferred the presence of uncinate processes in at least 19 fossil archosaur taxa. An ancestral state reconstruction based on the infer distribution suggests that cartilaginous uncinate processes were plesiomorphically present in Dinosauria and arguably in Archosauria, indicating that uncinate processes, and presumably their ventilatory function, have a deep evolutionary history extending back well beyond the origin of birds.A newly discovered osteological correlate for structures associated with ventilatory muscle attachment indicates a deep evolutionary history of respiratory innovation within Archosauria.
U2 - 10.1038/s42003-022-04301-z
DO - 10.1038/s42003-022-04301-z
M3 - Article
C2 - 36650231
SN - 2399-3642
VL - 6
JO - Communications Biology
JF - Communications Biology
IS - 1
M1 - 3
ER -