翼龍目:修订间差异
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翼龍類的翼膜由皮膚與其他軟組織構成,由不同形式的緊密纖維補強<ref name="Bennett2000">{{Cite journal |last=Bennett |first=S. Christopher |date=2000-01 |title=Pterosaur flight: The role of actinofibrils in wing function |url=http://www.tandfonline.com/doi/abs/10.1080/10292380009380572 |journal=Historical Biology |language=en |volume=14 |issue=4 |doi=10.1080/10292380009380572 |issn=0891-2963 |access-date=2022-08-07 |archive-date=2022-03-05 |archive-url=https://web.archive.org/web/20220305162350/https://www.tandfonline.com/doi/abs/10.1080/10292380009380572 |dead-url=no }}</ref>。翼膜連接至極長的第四手指與身體側面(或是後肢)之間。
過去的觀點認為,翼龍類的翼膜構造簡單,僅由皮膚構成。但現在的觀點認為,翼龍類的翼膜構造相當複雜,具有高度氣動性,適合主動飛行。翼膜是由一種排列緊密的強韌纖維所構成,名為「Actinofibrils」<ref name =Bennett2000/>。這種翼龍類專有的獨特纖維,以十字方式互相交錯、重疊。目前無法得知這種獨特纖維是由角質、肌肉、或者是具彈性物質所構成,因此也無法得知其實際功能。研究人員推測,這種纖維可能有使翼膜堅韌、或補強的作用<ref name="kellneretal2009">{{Cite journal |last=Kellner |first=Alexander W. A. |last2=Wang |first2=Xiaolin |last3=Tischlinger |first3=Helmut |last4=de Almeida Campos |first4=Diogenes |last5=Hone |first5=David W. E. |last6=Meng |first6=Xi |date=2010-01-22 |title=The soft tissue of Jeholopterus (Pterosauria, Anurognathidae, Batrachognathinae) and the structure of the pterosaur wing membrane |url=https://royalsocietypublishing.org/doi/10.1098/rspb.2009.0846 |journal=Proceedings of the Royal Society B: Biological Sciences |volume=277 |issue=1679 |doi=10.1098/rspb.2009.0846 |pmc=
某些大型標本的翼部骨頭內有中空空間,證實某些翼龍類具有類似[[鸟|鳥類]]的[[呼吸系統]]。此外,根據至少一個標本的軟組織,顯示其呼吸系統延伸到翼膜內部<ref name="claessensetal2009">{{Cite journal |last=Claessens |first=Leon P. A. M. |last2=O'Connor |first2=Patrick M. |last3=Unwin |first3=David M. |date=2009-02-18 |editor-last=Sereno |editor-first=Paul |title=Respiratory Evolution Facilitated the Origin of Pterosaur Flight and Aerial Gigantism |url=https://dx.plos.org/10.1371/journal.pone.0004497 |journal=PLoS ONE |language=en |volume=4 |issue=2 |doi=10.1371/journal.pone.0004497 |issn=1932-6203 |pmc=
翼龍類的翼膜可以分成三個部分。第一個部分是前膜(Propatagium),連接手腕部到肩膀,位於翼膜最前端,是飛行時首先遭遇到空氣的部分。某些化石證據顯示,前三根手指之間也連接者前膜<ref name="naish&martill2003"/>。翼膜的主要部分是臂膜(Brachiopatagium),從極長第四指延伸至身體兩側(或後肢)。但臂膜連接至身體兩側的哪個位置、是否連接至後肢,仍有爭議。某些翼龍類的後肢之間連接者膜,可能延伸至尾巴,稱為尾膜(Uropatagium)。根據[[索德斯龍]]的化石,其尾膜僅連接後肢,並沒有連結至尾巴。研究人員多認為,喙嘴翼龍類具有寬廣的尾膜,而翼手龍類的尾膜僅連接者後肢之間;[[無齒翼龍]]是個例外,其尾膜連接者後肢、尾巴。
從手腕延伸出的[[翅骨]](Pteroid),是一種翼龍類專有的骨頭,協助支撐手腕部到肩膀的前膜。化石證據顯示,前三根手指之間可能也連接者翼膜。因此,前膜的面積可能更大<ref name="naish&martill2003"/>。古生物學界對翅骨角度、位置的看法相當不同。[[大衛·安文]]等人認為,翅骨的角度往前,擴大前膜的面積<ref name="Wilkinson MT, Unwin DM, Ellington CP 2006 119–26">{{Cite journal |last=Wilkinson |first=Matthew T |last2=Unwin |first2=David M |last3=Ellington |first3=Charles P |date=2006-01-07 |title=High lift function of the pteroid bone and forewing of pterosaurs |url=https://royalsocietypublishing.org/doi/10.1098/rspb.2005.3278 |journal=Proceedings of the Royal Society B: Biological Sciences |language=en |volume=273 |issue=1582 |doi=10.1098/rspb.2005.3278 |issn=0962-8452 |pmc=
翼龍類的手腕有兩塊近側[[腕骨]]、四塊末側腕骨(不計算翅骨的狀況),顯示牠們的手腕經過明顯特化過程。在成年個體標本,這兩塊近側腕骨癒合成一塊,而其中三塊末側腕骨癒合成一塊。唯一未癒合的腕骨位於手腕中間,位於末側腕骨、翅骨之間,連接至末側腕骨的垂直突出面,另一側則是以凹處連接翅骨<ref name="wilkinsonetal2006">{{Cite journal |last=Wilkinson |first=Matthew T |last2=Unwin |first2=David M |last3=Ellington |first3=Charles P |date=2006-01-07 |title=High lift function of the pteroid bone and forewing of pterosaurs |url=https://royalsocietypublishing.org/doi/10.1098/rspb.2005.3278 |journal=Proceedings of the Royal Society B: Biological Sciences |language=en |volume=273 |issue=1582 |doi=10.1098/rspb.2005.3278 |issn=0962-8452 |pmc=
古生物學家們對於臂膜是否也連接到後肢,連接至後肢的哪個部位,目前還沒有定論。[[喙嘴翼龍類]]的[[索德斯龍]]<ref name="Unwin_Bakhurina_1994">{{Cite journal |last=Unwin |first=David M. |last2=Bakhurina |first2=Natasha N. |date=1994-09 |title=Sordes pilosus and the nature of the pterosaur flight apparatus |url=http://www.nature.com/articles/371062a0 |journal=Nature |language=en |volume=371 |issue=6492 |doi=10.1038/371062a0 |issn=0028-0836 |access-date=2022-08-07 |archive-date=2022-11-11 |archive-url=https://web.archive.org/web/20221111123101/https://www.nature.com/articles/371062a0 |dead-url=no }}</ref>、[[蛙嘴龍科]]的[[熱河翼龍]]<ref>{{Cite journal |last=Wang |first=Xiaolin |date=2002 |title=A nearly completely articulated rhamphorhynchoid pterosaur with exceptionally well-preserved wing membranes and ?hairs? from Inner Mongolia, northeast China |url=http://www.scichina.com/ky/0203/ky0226.stm |journal=Chinese Science Bulletin |language=en |volume=47 |issue=3 |doi=10.1360/02tb9054 |issn=1001-6538 |access-date=2022-08-07 |archive-date=2005-10-18 |archive-url=https://web.archive.org/web/20051018131419/http://www.scichina.com/ky/0203/ky0226.stm |dead-url=no }}</ref>、還有[[桑塔納岩層]]發現的某種翼手龍類化石,證實至少某些物種的翼膜有連接至後肢<ref>{{Cite journal |last=Frey |first=Eberhard |last2=Tischlinger |first2=Helmut |last3=Buchy |first3=Marie-Céline |last4=Martill |first4=David M. |date=2003-01 |title=New specimens of Pterosauria (Reptilia) with soft parts with implications for pterosaurian anatomy and locomotion |url=https://www.lyellcollection.org/doi/10.1144/GSL.SP.2003.217.01.14 |journal=Geological Society, London, Special Publications |language=en |volume=217 |issue=1 |doi=10.1144/GSL.SP.2003.217.01.14 |issn=0305-8719 |access-date=2022-08-07 |archive-date=2022-08-07 |archive-url=https://web.archive.org/web/20220807214729/https://www.lyellcollection.org/doi/10.1144/GSL.SP.2003.217.01.14 |dead-url=no }}</ref>。然而,現代[[蝙蝠]]與[[飛鼠]]翼膜的連接方式上有相當大的不同,而不同種類的翼龍類可能也有不同的翼膜連接方式。研究顯示翼龍類的四肢比例有相當大的不同,可能反映了不同的翼展方式<ref>{{Cite journal |last=Dyke |first=G. J. |last2=Nudds |first2=R. L. |last3=Rayner |first3=J. M. V. |date=2006-07 |title=Limb disparity and wing shape in pterosaurs |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1420-9101.2006.01096.x |journal=Journal of Evolutionary Biology |language=en |volume=19 |issue=4 |doi=10.1111/j.1420-9101.2006.01096.x |issn=1010-061X |access-date=2022-08-07 |archive-date=2022-08-07 |archive-url=https://web.archive.org/web/20220807214729/https://onlinelibrary.wiley.com/doi/10.1111/j.1420-9101.2006.01096.x |dead-url=no }}</ref>。
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