芒果视频

基本介紹

撒(sa)哈拉鯊齒龍(long)(long)（Carcharodontosaurus saharicus），是(shi)體型(xing)(xing)最大的食(shi)肉(rou)恐龍(long)(long)之一(yi)。生存(cun)于(yu)白(bai)堊紀(ji)中期(qi)到(dao)白(bai)堊紀(ji)晚期(qi)，阿爾布階（Albian）到(dao)土侖階（1億—9300萬(wan)年前）。鯊齒龍(long)(long)是(shi)一(yi)種生存(cun)于(yu)埃及(ji)，阿爾及(ji)利(li)亞(ya)和摩(mo)洛哥等地(di)區(qu)的巨型(xing)(xing)食(shi)肉(rou)恐龍(long)(long)。鯊齒龍(long)(long)身長(chang)11～13米，重(zhong)6～9噸，高(gao)約4.5米。特點(dian)是(shi)牙冠有(you)整齊的鋸齒，適合切割皮膚以及(ji)肌(ji)肉(rou)組織。它的頭比(bi)霸王龍(long)(long)略長(chang)但偏窄，腦容量比(bi)霸王龍(long)(long)小(xiao)。

生長與分布

棲息環境

撒哈(ha)拉鯊齒(chi)龍(long)(long)(long)(long)生活在非洲的(de)卡瑪卡瑪組地(di)層(ceng)，當時當地(di)大片(pian)沼澤，氣候濕潤(run)，與撒哈(ha)拉鯊齒(chi)龍(long)(long)(long)(long)共同生活著(zhu)的(de)恐龍(long)(long)(long)(long)還有棘龍(long)(long)(long)(long)科棘龍(long)(long)(long)(long)（數量最多）、西北阿根廷(ting)龍(long)(long)(long)(long)科的(de)三(san)角洲奔龍(long)(long)(long)(long)、蜥腳類的(de)雷(lei)巴齊斯龍(long)(long)(long)(long)等。

形態及特征

基本特征

撒哈拉(la)鯊齒龍(long)(long)是已知最大型的獸腳類恐龍(long)(long)之(zhi)一。根據不同科學家的估(gu)計值，撒哈拉(la)鯊齒龍(long)(long)的身長約在(zai)12到13米之(zhi)間，體重約在(zai)6到9公噸之(zhi)間。

撒哈拉(la)(la)鯊(sha)齒(chi)(chi)龍(long)(long)是肉(rou)食性恐龍(long)(long)，有巨大的(de)(de)嘴部，及達(da)8英寸長的(de)(de)鋸齒(chi)(chi)狀牙齒(chi)(chi)。古生物學家曾一(yi)度認為鯊(sha)齒(chi)(chi)龍(long)(long)的(de)(de)頭顱(lu)骨是獸腳(jiao)亞(ya)目中(zhong)最長的(de)(de)。可是因為原有的(de)(de)非洲(zhou)頭顱(lu)骨中(zhong)缺少了前上頜(he)骨及方骨，導(dao)致了對其實際大小的(de)(de)錯誤(wu)估計。有研究指撒哈拉(la)(la)鯊(sha)齒(chi)(chi)龍(long)(long)的(de)(de)頭顱(lu)骨實際是1.6米長。

撒(sa)哈拉鯊齒(chi)龍(long)的(de)顱腔及內耳結構很像(xiang)鱷魚。大腦(nao)與整個腦(nao)部的(de)相對(dui)大小，類似爬(pa)行動物，但(dan)較(jiao)虛骨龍(long)類及鳥類為小。

頭部特征

在早期(qi)的(de)(de)研(yan)(yan)究中，撒哈拉(la)鯊齒(chi)龍(long)的(de)(de)頭骨(gu)被描述成較為脆弱(ruo)，并且牙(ya)(ya)齒(chi)薄(bo)得像(xiang)餐刀(dao)一樣。但是一項新的(de)(de)研(yan)(yan)究否認了這個觀點：新發現(xian)的(de)(de)若干牙(ya)(ya)齒(chi)比較原先發現(xian)的(de)(de)牙(ya)(ya)齒(chi)更加粗(cu)壯，而之前的(de)(de)頭骨(gu)和牙(ya)(ya)齒(chi)化(hua)石極有可(ke)能是經過了嚴重的(de)(de)地層(ceng)擠(ji)壓。所以鯊齒(chi)龍(long)的(de)(de)頭部結構沒有以往人(ren)們所想的(de)(de)那樣脆弱(ruo)。

價值及其他

生態地位

撒(sa)哈(ha)拉(la)鯊齒龍(long)(long)(long)(long)(long)生活在大(da)約1億到9300萬年前的(de)(de)(de)(de)非(fei)(fei)(fei)洲(zhou)北(bei)(bei)部，是(shi)(shi)當(dang)地的(de)(de)(de)(de)頂級(ji)掠食者。當(dang)時的(de)(de)(de)(de)北(bei)(bei)非(fei)(fei)(fei)大(da)片(pian)是(shi)(shi)沼(zhao)澤，水(shui)產豐富，另一種(zhong)大(da)型肉食恐(kong)(kong)(kong)龍(long)(long)(long)(long)(long)，埃及(ji)棘(ji)龍(long)(long)(long)(long)(long)通常只會捕食這些水(shui)產品（例如中小型魚類(lei)）。由于埃及(ji)棘(ji)龍(long)(long)(long)(long)(long)腿部較短(duan)，移動速度(du)較為緩慢，而(er)且(qie)身體(ti)結構不適合打(da)斗(dou)，所以撒(sa)哈(ha)拉(la)鯊齒龍(long)(long)(long)(long)(long)對棘(ji)龍(long)(long)(long)(long)(long)可能會構成威脅，甚至把棘(ji)龍(long)(long)(long)(long)(long)作為主要獵(lie)物，再是(shi)(shi)因為當(dang)地大(da)片(pian)沼(zhao)澤，不適合素食恐(kong)(kong)(kong)龍(long)(long)(long)(long)(long)生存，所以當(dang)時北(bei)(bei)非(fei)(fei)(fei)的(de)(de)(de)(de)素食恐(kong)(kong)(kong)龍(long)(long)(long)(long)(long)非(fei)(fei)(fei)常稀少，而(er)棘(ji)龍(long)(long)(long)(long)(long)在當(dang)地恐(kong)(kong)(kong)龍(long)(long)(long)(long)(long)的(de)(de)(de)(de)數量占比最大(da)，并且(qie)紀錄片(pian)《恐(kong)(kong)(kong)龍(long)(long)(long)(long)(long)星球》也(ye)展現了(le)被鯊齒龍(long)(long)(long)(long)(long)咬斷的(de)(de)(de)(de)棘(ji)龍(long)(long)(long)(long)(long)椎骨(gu)。

發現歷史

鯊齒(chi)龍(long)(long)(long)化石最先(xian)是由Charles Depéret及(ji)J. Savornin于(yu)1927年(nian)在(zai)(zai)北非所(suo)發(fa)(fa)現(xian)，發(fa)(fa)現(xian)于(yu)阿爾及(ji)利亞的(de)(de)卡(ka)瑪卡(ka)瑪地層（Kem Kem Formation），地質(zhi)年(nian)代(dai)為(wei)阿爾比階。原先(xian)被(bei)歸類(lei)為(wei)斑龍(long)(long)(long)的(de)(de)一個種，撒(sa)哈(ha)拉斑龍(long)(long)(long)（Megalosaurus saharicus）。在(zai)(zai)1931年(nian)，恩斯特·斯特莫（Ernst Stromer von Reichenbach）改建立為(wei)鯊齒(chi)龍(long)(long)(long)屬，模式種是撒(sa)哈(ha)拉鯊齒(chi)龍(long)(long)(long)（C. saharicus）。他斯特莫命名鯊齒(chi)龍(long)(long)(long)的(de)(de)原因，是因為(wei)它(ta)們有著類(lei)似噬人鯊屬的(de)(de)牙(ya)(ya)齒(chi)，而(er)這牙(ya)(ya)齒(chi)并非彎曲，幾乎是兩邊對稱而(er)前(qian)緣凸。這個鯊齒(chi)龍(long)(long)(long)的(de)(de)首個化石在(zai)(zai)第(di)二(er)次世(shi)界大戰(zhan)中被(bei)毀。在(zai)(zai)1996年(nian)，保羅·塞里諾（Paul Sereno）在(zai)(zai)摩洛(luo)哥的(de)(de)卡(ka)瑪卡(ka)瑪群(qun)發(fa)(fa)現(xian)了鯊齒(chi)龍(long)(long)(long)的(de)(de)頭蓋化石。

同屬物種

鯊齒(chi)龍(long)(long)屬(shu)除了模式種(zhong)撒哈拉鯊齒(chi)龍(long)(long)，還有一個種(zhong)。在2007年(nian)，塞利諾也發現(xian)了鯊齒(chi)龍(long)(long)屬(shu)的(de)另(ling)一個物種(zhong)，在上(shang)頜骨、腦殼與(yu)撒哈拉鯊齒(chi)龍(long)(long)有所差(cha)異。這(zhe)一新的(de)物種(zhong)是1997年(nian)在尼日爾發現(xian)，并在2007年(nian)命名為伊(yi)吉迪(di)鯊齒(chi)龍(long)(long)（C.iguidensis）。