[dinosaur] Pterosaur and extant bird vertebral pneumatization (free pdf)

Ben Creisler
[email protected]

A new paper  in open access:


Richard Buchmann, Leonardo dos Santos Avilla &Taissa Rodrigues (2019)
Comparative analysis of the vertebral pneumatization in pterosaurs
(Reptilia: Pterosauria) and extant birds (Avialae: Neornithes).
PLoS ONE 14(10): e0224165.
doi: https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.1371_journal.pone.0224165&d=DwIBaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=0SbqruqdBdKr5iPTTtrzEf6VNKBtKHxc5-DO6nbuXSY&s=vmIs6euXnORlPpkTGGxWJ5iAnsy3C4PW50Lf8GW36X0&e= 
https://urldefense.proofpoint.com/v2/url?u=https-3A__journals.plos.org_plosone_article-3Fid-3D10.1371_journal.pone.0224165&d=DwIBaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=0SbqruqdBdKr5iPTTtrzEf6VNKBtKHxc5-DO6nbuXSY&s=QJDKdYTRff7TWjs_zVJY2bKNeC2YKuTNxDlKE9aMi_M&e= 

Free pdf:
https://urldefense.proofpoint.com/v2/url?u=https-3A__journals.plos.org_plosone_article_file-3Fid-3D10.1371_journal.pone.0224165-26type-3Dprintable&d=DwIBaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=0SbqruqdBdKr5iPTTtrzEf6VNKBtKHxc5-DO6nbuXSY&s=O81W-erUGekTRuVRMnVNaEsQcGg7xvBV-9F0k6SAxbU&e= 


Birds and pterosaurs have pneumatic bones, a feature likely related to
their flight capabilities but whose evolution and origin is still poorly
understood. Pneumatic foramina are present on the external surface of the
bone and are reliable indicators of post-cranial skeletal pneumatization
present in Pterosauria, Eusauropoda, and Neotheropoda. Here, we carried out
a qualitative analysis of the position, size and number of pneumatic
foramina of the cervical and thoracic/dorsal vertebrae of pterosaurs and
birds, as they have the potential to challenge hypotheses about the
emergence and evolution of the respiratory trait in these groups. We also
discussed differences between pneumatic and vascular foramina for
identification purposes. Besides phylogenetic representativeness, the
pterosaur taxonomic sampling considered the preservation of specimens and,
for birds, their life habit, as this relates to the level of
pneumatization. Pneumatic foramina on the lateral faces of the centrum of
the mid-cervical vertebrae of pterosaurs and birds differ in position and
size, and those adjacent to the neural canal additionally differ in number.
The avian posterior cervical vertebrae show a higher number of pneumatic
foramina in comparison to their mid-cervicals, while the opposite is true
for pterosaurs, suggesting differences in the cervical air sac of these
clades. Pneumatic foramina were found at the base of the transverse
processes of the notarial vertebrae of birds, while they were absent from
some of the pterosaurs analyzed here, revealing the presence of a pneumatic
hiatus in the vertebral column that might be explained due to the distance
of this structure to the cervical air sac. These findings indicate that,
although the overall skeletal pneumatization of pterosaurs and birds
present deep homologies, some pneumatic features occurred convergently
because variation in the number of pneumatic foramina along the vertebral
column is related to the position of the air sacs in pterosaurs and birds
and/or the habit of each species. There is an evident reduction of the
pneumatic foramina in birds that have aquatic foraging and an increase in
the ones which perform static soaring. Although we did not find any
external anatomical difference between pneumatic and vascular foramina, we
observed that vascular foramina occur at specific sites and thus
identification on the basis of location is reliable.


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