撒哈拉鯊齒(chi)龍(long)(long)(Carcharodontosaurus saharicus),是體型最大(da)的食(shi)肉(rou)恐龍(long)(long)之一(yi)。生(sheng)(sheng)存(cun)于白堊紀中期(qi)(qi)到(dao)白堊紀晚期(qi)(qi),阿(a)爾布階(jie)(Albian)到(dao)土(tu)侖階(jie)(1億—9300萬年(nian)前)。鯊齒(chi)龍(long)(long)是一(yi)種生(sheng)(sheng)存(cun)于埃及,阿(a)爾及利亞和摩洛哥等地區的巨型食(shi)肉(rou)恐龍(long)(long)。鯊齒(chi)龍(long)(long)身(shen)長(chang)11~13米,重6~9噸,高約4.5米。特點是牙冠有整齊(qi)的鋸齒(chi),適合(he)切割(ge)皮膚(fu)以及肌肉(rou)組織。它的頭(tou)比霸王龍(long)(long)略長(chang)但偏窄,腦容(rong)量(liang)比霸王龍(long)(long)小(xiao)。
撒哈拉鯊齒龍(long)(long)(long)(long)生活(huo)(huo)在非(fei)洲的(de)卡(ka)瑪(ma)卡(ka)瑪(ma)組地(di)層,當(dang)時當(dang)地(di)大片沼澤,氣候(hou)濕潤,與撒哈拉鯊齒龍(long)(long)(long)(long)共同生活(huo)(huo)著的(de)恐龍(long)(long)(long)(long)還有棘(ji)龍(long)(long)(long)(long)科棘(ji)龍(long)(long)(long)(long)(數量最多(duo))、西北阿根廷龍(long)(long)(long)(long)科的(de)三(san)角洲奔(ben)龍(long)(long)(long)(long)、蜥腳類的(de)雷巴齊斯龍(long)(long)(long)(long)等。
撒哈拉鯊(sha)齒龍(long)(long)是已知最大型的(de)(de)獸腳(jiao)類恐(kong)龍(long)(long)之一。根據不同科學(xue)家的(de)(de)估計值,撒哈拉鯊(sha)齒龍(long)(long)的(de)(de)身長約(yue)(yue)在(zai)12到13米之間,體重約(yue)(yue)在(zai)6到9公噸之間。
撒哈(ha)拉鯊齒(chi)龍(long)(long)是(shi)肉食性恐(kong)龍(long)(long),有巨大的(de)(de)嘴(zui)部,及(ji)達(da)8英寸長(chang)的(de)(de)鋸齒(chi)狀牙(ya)齒(chi)。古生物(wu)學家曾一度(du)認為鯊齒(chi)龍(long)(long)的(de)(de)頭顱骨(gu)是(shi)獸腳亞目中最長(chang)的(de)(de)。可是(shi)因為原(yuan)有的(de)(de)非(fei)洲頭顱骨(gu)中缺少(shao)了前上頜骨(gu)及(ji)方骨(gu),導致了對其實(shi)際(ji)大小的(de)(de)錯誤估(gu)計。有研究指撒哈(ha)拉鯊齒(chi)龍(long)(long)的(de)(de)頭顱骨(gu)實(shi)際(ji)是(shi)1.6米長(chang)。
撒哈拉(la)鯊齒龍(long)的顱腔(qiang)及內(nei)耳結構(gou)很像鱷魚。大(da)腦與(yu)整個(ge)腦部的相對大(da)小(xiao),類似爬行動物,但較虛骨龍(long)類及鳥類為(wei)小(xiao)。
在早期(qi)的研究中,撒哈拉鯊齒(chi)(chi)龍的頭(tou)骨被描述成較(jiao)為脆弱,并且牙(ya)(ya)齒(chi)(chi)薄得像餐刀一樣(yang)(yang)。但是一項(xiang)新的研究否認了(le)這個觀點(dian):新發現的若干牙(ya)(ya)齒(chi)(chi)比較(jiao)原先發現的牙(ya)(ya)齒(chi)(chi)更加粗壯(zhuang),而之前的頭(tou)骨和牙(ya)(ya)齒(chi)(chi)化石極有(you)可(ke)能是經過了(le)嚴重(zhong)的地層擠(ji)壓。所(suo)以鯊齒(chi)(chi)龍的頭(tou)部結構沒(mei)有(you)以往人們所(suo)想(xiang)的那樣(yang)(yang)脆弱。
撒哈拉鯊(sha)(sha)齒(chi)(chi)龍(long)(long)(long)(long)(long)(long)生(sheng)活在(zai)大約(yue)1億到9300萬年(nian)前的(de)(de)(de)非(fei)洲北(bei)部(bu),是當(dang)地的(de)(de)(de)頂級掠食(shi)(shi)者。當(dang)時的(de)(de)(de)北(bei)非(fei)大片(pian)是沼澤,水(shui)產(chan)豐富,另一種大型肉(rou)食(shi)(shi)恐(kong)(kong)(kong)龍(long)(long)(long)(long)(long)(long),埃(ai)及(ji)棘(ji)龍(long)(long)(long)(long)(long)(long)通常只會捕食(shi)(shi)這些水(shui)產(chan)品(例如中小型魚類)。由于埃(ai)及(ji)棘(ji)龍(long)(long)(long)(long)(long)(long)腿部(bu)較(jiao)短,移動速度較(jiao)為緩慢,而且身(shen)體(ti)結構不(bu)適合打斗,所(suo)以撒哈拉鯊(sha)(sha)齒(chi)(chi)龍(long)(long)(long)(long)(long)(long)對棘(ji)龍(long)(long)(long)(long)(long)(long)可能會構成威脅,甚至把棘(ji)龍(long)(long)(long)(long)(long)(long)作為主要獵物(wu),再是因為當(dang)地大片(pian)沼澤,不(bu)適合素食(shi)(shi)恐(kong)(kong)(kong)龍(long)(long)(long)(long)(long)(long)生(sheng)存(cun),所(suo)以當(dang)時北(bei)非(fei)的(de)(de)(de)素食(shi)(shi)恐(kong)(kong)(kong)龍(long)(long)(long)(long)(long)(long)非(fei)常稀少,而棘(ji)龍(long)(long)(long)(long)(long)(long)在(zai)當(dang)地恐(kong)(kong)(kong)龍(long)(long)(long)(long)(long)(long)的(de)(de)(de)數量占(zhan)比最大,并且紀錄片(pian)《恐(kong)(kong)(kong)龍(long)(long)(long)(long)(long)(long)星(xing)球》也展現(xian)了被鯊(sha)(sha)齒(chi)(chi)龍(long)(long)(long)(long)(long)(long)咬(yao)斷的(de)(de)(de)棘(ji)龍(long)(long)(long)(long)(long)(long)椎骨。
鯊(sha)(sha)齒龍(long)化石(shi)最先(xian)是(shi)由Charles Depéret及J. Savornin于(yu)1927年在(zai)北非所發(fa)現,發(fa)現于(yu)阿爾及利亞的(de)卡(ka)(ka)瑪卡(ka)(ka)瑪地(di)(di)層(Kem Kem Formation),地(di)(di)質年代(dai)為(wei)阿爾比(bi)階。原先(xian)被(bei)歸(gui)類(lei)為(wei)斑(ban)(ban)龍(long)的(de)一個(ge)種,撒哈拉(la)斑(ban)(ban)龍(long)(Megalosaurus saharicus)。在(zai)1931年,恩斯(si)(si)特·斯(si)(si)特莫(Ernst Stromer von Reichenbach)改(gai)建立(li)為(wei)鯊(sha)(sha)齒龍(long)屬,模式種是(shi)撒哈拉(la)鯊(sha)(sha)齒龍(long)(C. saharicus)。他(ta)斯(si)(si)特莫命名鯊(sha)(sha)齒龍(long)的(de)原因,是(shi)因為(wei)它(ta)們(men)有著類(lei)似噬人鯊(sha)(sha)屬的(de)牙(ya)齒,而這牙(ya)齒并(bing)非彎(wan)曲,幾乎(hu)是(shi)兩邊(bian)對稱而前緣凸。這個(ge)鯊(sha)(sha)齒龍(long)的(de)首個(ge)化石(shi)在(zai)第二次世界大(da)戰中被(bei)毀(hui)。在(zai)1996年,保羅·塞里諾(Paul Sereno)在(zai)摩洛哥的(de)卡(ka)(ka)瑪卡(ka)(ka)瑪群發(fa)現了鯊(sha)(sha)齒龍(long)的(de)頭蓋化石(shi)。
鯊(sha)齒龍(long)(long)屬除(chu)了模式種(zhong)撒哈(ha)拉(la)鯊(sha)齒龍(long)(long),還有一(yi)個種(zhong)。在2007年,塞利諾也發現了鯊(sha)齒龍(long)(long)屬的(de)另(ling)一(yi)個物種(zhong),在上頜骨、腦殼與(yu)撒哈(ha)拉(la)鯊(sha)齒龍(long)(long)有所差異。這一(yi)新的(de)物種(zhong)是1997年在尼日爾(er)發現,并(bing)在2007年命名為(wei)伊吉(ji)迪鯊(sha)齒龍(long)(long)(C.iguidensis)。