0002名も無き開拓者@無断転載は禁止2016/07/13(水) 23:05:21.42ID:JJ2CQhV10
鳥の恐竜っぷりは異常
0003名も無き開拓者@無断転載は禁止2016/07/13(水) 23:15:00.30ID:FRYwNoSC0
でもプテラノドンは恐竜じゃないんでしょう?
0004名も無き開拓者@無断転載は禁止2016/07/13(水) 23:19:24.28ID:JJ2CQhV10
不思議ね
0005名も無き開拓者@無断転載は禁止2016/07/13(水) 23:37:55.08ID:J9PGNh+x0
元の論文のアブストラクト読む限りでは、体の大きい動物では何度も進化してるから
口を閉じて鳴くことも進化した可能性があるんじゃないの?って程度の話で
それは鳥と同じように性的なディスプレイのときに限られていたかもしれないし
したがって口をあけて鳴く声も併用されていたかもしれない
ってことじゃない?
http://onlinelibrary.wiley.com/doi/10.1111/evo.12988/abstract
Most birds vocalize with an open beak, but vocalization with a closed beak into an inflating cavity occurs in territorial or courtship
displays in disparate species throughout birds. Closed-mouth vocalizations generate resonance conditions that favor low-frequency sounds.
By contrast, open-mouth vocalizations cover a wider frequency range. Here we describe closed-mouth vocalizations of birds
from functional and morphological perspectives and assess the distribution of closed-mouth vocalizations in birds and related outgroups.
Ancestral-state optimizations of body size and vocal behavior indicate that closed-mouth vocalizations are unlikely to be ancestral in birds
and have evolved independently at least 16 times within Aves, predominantly in large-bodied lineages. Closed-mouth vocalizations are
rare in the small-bodied passerines. In light of these results and body size trends in nonavian dinosaurs, we suggest that the capacity
for closed-mouth vocalization was present in at least some extinct nonavian dinosaurs.
As in birds, this behavior may have been limited to sexually selected vocal displays, and hence would have co-occurred with open-mouthed vocalizations. 0006名も無き開拓者@無断転載は禁止2016/07/14(木) 00:48:01.24ID:3xa9/tF90
イグアノドンやトリケラトプスの復元像に頬つけるようになって30年ぐらい経つのに形態学の観点からみた鳴き声の論文あんま出てなかったんだな