懼(ju)(ju)龍(long)(long)是(shi)非常著名的(de)北美洲大(da)型暴龍(long)(long)類,是(shi)其所處時代體(ti)(ti)型最大(da)的(de)捕食(shi)者。懼(ju)(ju)龍(long)(long)屬下目前有兩個(ge)種(zhong),即模(mo)式種(zhong)強健懼(ju)(ju)龍(long)(long)和歸入種(zhong)霍氏懼(ju)(ju)龍(long)(long)。懼(ju)(ju)龍(long)(long)的(de)體(ti)(ti)長(chang)約為(wei)(wei)9米(mi),與蛇發(fa)女怪龍(long)(long)和阿爾(er)伯塔龍(long)(long)相似(si),但是(shi)卻更(geng)為(wei)(wei)健壯。一些研究認為(wei)(wei)懼(ju)(ju)龍(long)(long)的(de)體(ti)(ti)重可(ke)以(yi)達(da)到3.5噸(dun)以(yi)上。
與霸王龍(long),特暴龍(long),蛇發女(nv)怪(guai)龍(long)和阿爾(er)伯塔(ta)龍(long)一樣,懼(ju)龍(long)也有比較豐富的標(biao)本收藏(zang),因此成為被(bei)研(yan)究的最細(xi)致的大型暴龍(long)類之一。
懼(ju)龍(long)的(de)(de)屬名(ming)(ming)意(yi)為(wei)可怕(pa)的(de)(de)蜥蜴,這一(yi)(yi)(yi)屬名(ming)(ming)經(jing)常(chang)也被(bei)譯作可畏(wei)龍(long)。模式種種名(ming)(ming)的(de)(de)含義(yi)為(wei)強壯(zhuang)的(de)(de)。相比于同體長的(de)(de)阿爾伯(bo)塔龍(long)亞(ya)科,懼(ju)龍(long)確實更(geng)為(wei)健(jian)壯(zhuang),頭骨也顯得(de)更(geng)加厚實。歸入種種名(ming)(ming)是為(wei)了(le)紀(ji)念古生(sheng)(sheng)物(wu)學(xue)家杰克.霍納(na)(na)在雙麥迪遜組的(de)(de)野外工作,以(yi)及霍納(na)(na)本人對恐龍(long)古生(sheng)(sheng)物(wu)學(xue)做出(chu)(chu)的(de)(de)杰出(chu)(chu)貢獻(xian)。這里順帶說一(yi)(yi)(yi)下(xia)(xia),杰克.霍納(na)(na)曾是《侏(zhu)羅紀(ji)公園》的(de)(de)科學(xue)顧(gu)問,而在重啟的(de)(de)《侏(zhu)羅紀(ji)世(shi)界》中,劇組也在影片(pian)中致敬了(le)他,讓他客(ke)串了(le)一(yi)(yi)(yi)下(xia)(xia)(歐(ou)文第一(yi)(yi)(yi)次出(chu)(chu)場訓練伶盜龍(long)的(de)(de)時候(hou))。霍納(na)(na)在TED上還(huan)有一(yi)(yi)(yi)個(ge)著(zhu)名(ming)(ming)的(de)(de)演講叫《恐龍(long)也變形(xing)》,主(zhu)要(yao)講述(shu)的(de)(de)是過去古生(sheng)(sheng)物(wu)學(xue)研究中把同一(yi)(yi)(yi)物(wu)種幼年個(ge)體當(dang)成(cheng)新種重新命名(ming)(ming)的(de)(de)問題,以(yi)及他在解(jie)決這方面問題上所做的(de)(de)努力。
懼(ju)龍(long)(long)(long)兩側(ce)(ce)(ce)的(de)(de)(de)(de)(de)前(qian)(qian)(qian)頜(he)骨(gu)(gu)(gu)(gu)鼻骨(gu)(gu)(gu)(gu)突(tu)(tu)緊緊的(de)(de)(de)(de)(de)貼在(zai)(zai)(zai)一(yi)起,將(jiang)兩側(ce)(ce)(ce)鼻骨(gu)(gu)(gu)(gu)的(de)(de)(de)(de)(de)前(qian)(qian)(qian)緣分(fen)開。在(zai)(zai)(zai)蛇發(fa)女(nv)怪龍(long)(long)(long)中,鼻骨(gu)(gu)(gu)(gu)具(ju)有一(yi)內(nei)側(ce)(ce)(ce)突(tu)(tu),將(jiang)前(qian)(qian)(qian)頜(he)骨(gu)(gu)(gu)(gu)鼻骨(gu)(gu)(gu)(gu)突(tu)(tu)的(de)(de)(de)(de)(de)后(hou)(hou)(hou)端分(fen)開。上(shang)頜(he)骨(gu)(gu)(gu)(gu)的(de)(de)(de)(de)(de)外(wai)側(ce)(ce)(ce)緣具(ju)有兩排(pai)略(lve)呈平行排(pai)列的(de)(de)(de)(de)(de)滋(zi)養(yang)孔(kong)。懼(ju)龍(long)(long)(long)的(de)(de)(de)(de)(de)淚骨(gu)(gu)(gu)(gu)與(yu)(yu)(yu)上(shang)頜(he)骨(gu)(gu)(gu)(gu)的(de)(de)(de)(de)(de)關(guan)節(jie)與(yu)(yu)(yu)阿爾(er)伯(bo)塔龍(long)(long)(long)類似,但是在(zai)(zai)(zai)懼(ju)龍(long)(long)(long)的(de)(de)(de)(de)(de)成(cheng)年(nian)個(ge)體中,兩者的(de)(de)(de)(de)(de)關(guan)節(jie)不(bu)(bu)會(hui)被(bei)鼻骨(gu)(gu)(gu)(gu)分(fen)開。懼(ju)龍(long)(long)(long)的(de)(de)(de)(de)(de)鼻骨(gu)(gu)(gu)(gu)在(zai)(zai)(zai)鼻骨(gu)(gu)(gu)(gu)-淚骨(gu)(gu)(gu)(gu)關(guan)節(jie)點之后(hou)(hou)(hou)急劇的(de)(de)(de)(de)(de)收縮(suo),不(bu)(bu)同于蛇發(fa)女(nv)怪龍(long)(long)(long)和(he)阿爾(er)伯(bo)塔龍(long)(long)(long),它們的(de)(de)(de)(de)(de)鼻骨(gu)(gu)(gu)(gu)在(zai)(zai)(zai)這一(yi)關(guan)節(jie)點以后(hou)(hou)(hou)內(nei)外(wai)側(ce)(ce)(ce)擴展。鼻骨(gu)(gu)(gu)(gu)的(de)(de)(de)(de)(de)腹外(wai)側(ce)(ce)(ce)緣具(ju)有一(yi)條(tiao)(tiao)溝(gou)與(yu)(yu)(yu)上(shang)頜(he)骨(gu)(gu)(gu)(gu),淚骨(gu)(gu)(gu)(gu)和(he)前(qian)(qian)(qian)額骨(gu)(gu)(gu)(gu)相關(guan)節(jie),在(zai)(zai)(zai)成(cheng)年(nian)的(de)(de)(de)(de)(de)懼(ju)龍(long)(long)(long)中,這條(tiao)(tiao)溝(gou)被(bei)一(yi)道脊分(fen)開,而在(zai)(zai)(zai)蛇發(fa)女(nv)怪龍(long)(long)(long)和(he)阿爾(er)伯(bo)塔龍(long)(long)(long)中是連續的(de)(de)(de)(de)(de)。在(zai)(zai)(zai)蛇發(fa)女(nv)怪龍(long)(long)(long)的(de)(de)(de)(de)(de)鼻骨(gu)(gu)(gu)(gu)上(shang),這條(tiao)(tiao)溝(gou)的(de)(de)(de)(de)(de)后(hou)(hou)(hou)端具(ju)有一(yi)指手(shou)指狀突(tu)(tu)起與(yu)(yu)(yu)淚骨(gu)(gu)(gu)(gu)的(de)(de)(de)(de)(de)前(qian)(qian)(qian)邊緣關(guan)節(jie),而這一(yi)突(tu)(tu)起在(zai)(zai)(zai)懼(ju)龍(long)(long)(long)中不(bu)(bu)存在(zai)(zai)(zai)。
蛇(she)發女怪龍(long)(long)(long)(long)(long)和(he)阿(a)爾伯塔龍(long)(long)(long)(long)(long)的(de)淚(lei)骨(gu)(gu)的(de)背外側(ce)面具(ju)有一發達的(de)骨(gu)(gu)質角,而懼龍(long)(long)(long)(long)(long)的(de)成年個(ge)體的(de)淚(lei)骨(gu)(gu)具(ju)有一延長的(de)脊。淚(lei)骨(gu)(gu)的(de)后背側(ce)角的(de)氣孔(kong)(kong)在(zai)蛇(she)發女怪龍(long)(long)(long)(long)(long)和(he)阿(a)爾伯塔龍(long)(long)(long)(long)(long)中比(bi)較發達,而在(zai)懼龍(long)(long)(long)(long)(long)中比(bi)較小(xiao)且呈三角形。在(zai)蛇(she)發女怪龍(long)(long)(long)(long)(long)和(he)阿(a)爾伯塔龍(long)(long)(long)(long)(long)中,淚(lei)骨(gu)(gu)的(de)氣孔(kong)(kong)之間由較短的(de)骨(gu)(gu)質分隔(ge)(ge)隔(ge)(ge)開,而在(zai)懼龍(long)(long)(long)(long)(long)中,這一骨(gu)(gu)質分隔(ge)(ge)非常發達,甚至(zhi)比(bi)氣孔(kong)(kong)還要(yao)(yao)大。與蛇(she)發女怪龍(long)(long)(long)(long)(long)相比(bi),懼龍(long)(long)(long)(long)(long)的(de)前額(e)骨(gu)(gu)要(yao)(yao)更加(jia)狹長,其前端一直延伸(shen)至(zhi)額(e)骨(gu)(gu)前邊緣(yuan)的(de)前面,而蛇(she)發女怪龍(long)(long)(long)(long)(long)的(de)前額(e)骨(gu)(gu)最多(duo)延伸(shen)至(zhi)與額(e)骨(gu)(gu)前邊緣(yuan)同一位置。
懼龍(long)(long)(long)(long)(long)額骨(gu)的(de)后(hou)四分之(zhi)一隆起(qi)參與到矢狀脊(ji)的(de)形成中,因此它的(de)矢狀脊(ji)比(bi)蛇(she)發(fa)(fa)(fa)女怪(guai)龍(long)(long)(long)(long)(long)和(he)(he)(he)阿(a)(a)爾(er)伯塔龍(long)(long)(long)(long)(long)的(de)要更高聳。懼龍(long)(long)(long)(long)(long)的(de)頂(ding)骨(gu)頸背(bei)脊(ji)較(jiao)阿(a)(a)爾(er)伯塔龍(long)(long)(long)(long)(long)和(he)(he)(he)蛇(she)發(fa)(fa)(fa)女怪(guai)龍(long)(long)(long)(long)(long)的(de)低矮,但是更寬(kuan)。懼龍(long)(long)(long)(long)(long)眶后(hou)骨(gu)上的(de)骨(gu)質結(jie)節(jie)明顯比(bi)阿(a)(a)爾(er)伯塔龍(long)(long)(long)(long)(long)和(he)(he)(he)蛇(she)發(fa)(fa)(fa)女怪(guai)龍(long)(long)(long)(long)(long)的(de)發(fa)(fa)(fa)達。位于(yu)顴骨(gu)上,眶前窩(wo)后(hou)腹側角上的(de)氣孔在蛇(she)發(fa)(fa)(fa)女怪(guai)龍(long)(long)(long)(long)(long)和(he)(he)(he)阿(a)(a)爾(er)伯塔龍(long)(long)(long)(long)(long)中較(jiao)為發(fa)(fa)(fa)達,而在懼龍(long)(long)(long)(long)(long)中比(bi)較(jiao)小(xiao)。懼龍(long)(long)(long)(long)(long)的(de)顴骨(gu)具有(you)前后(hou)向(xiang)變(bian)短但背(bei)腹向(xiang)加(jia)深(shen)的(de)角狀突,這一點與阿(a)(a)爾(er)伯塔龍(long)(long)(long)(long)(long)和(he)(he)(he)蛇(she)發(fa)(fa)(fa)女怪(guai)龍(long)(long)(long)(long)(long)不(bu)同。顴骨(gu)位于(yu)眼眶下部分的(de)背(bei)腹向(xiang)深(shen)度較(jiao)阿(a)(a)爾(er)伯塔龍(long)(long)(long)(long)(long)和(he)(he)(he)蛇(she)發(fa)(fa)(fa)女怪(guai)龍(long)(long)(long)(long)(long)有(you)所減小(xiao),但是內(nei)外側寬(kuan)度有(you)明顯的(de)加(jia)厚。方顴骨(gu)與鱗骨(gu)的(de)關節(jie)面在前后(hou)向(xiang)延長,與阿(a)(a)爾(er)伯塔龍(long)(long)(long)(long)(long)亞科的(de)成員有(you)明顯區別。基蝶骨(gu)竇較(jiao)淺較(jiao)寬(kuan),與多數(shu)暴龍(long)(long)(long)(long)(long)亞科相似,不(bu)同于(yu)阿(a)(a)爾(er)伯塔龍(long)(long)(long)(long)(long)亞科。
霍氏懼龍(long)與強(qiang)健(jian)懼龍(long)的(de)區別(bie)包括(kuo)以(yi)下特征組合:上(shang)頜骨(gu)(gu)(gu)的(de)第一(yi)個齒間板比較小。齒骨(gu)(gu)(gu)向外側(ce)拱起。前(qian)頜竇終止于(yu)(yu)第3和第4齒槽之間。內(nei)鼻孔(kong)(kong)的(de)前(qian)邊緣(yuan)(yuan)位于(yu)(yu)上(shang)頜骨(gu)(gu)(gu)第7個齒槽的(de)位置。淚(lei)骨(gu)(gu)(gu)的(de)背(bei)面(mian)膨大,但(dan)是內(nei)側(ce)面(mian)沒有(you)膨大。淚(lei)骨(gu)(gu)(gu)降支內(nei)側(ce)的(de)氣孔(kong)(kong)不(bu)如強(qiang)健(jian)懼龍(long)的(de)發(fa)達。淚(lei)骨(gu)(gu)(gu)構成眼眶邊緣(yuan)(yuan)的(de)上(shang)半部(bu)分具有(you)明(ming)顯的(de)凹陷。位于(yu)(yu)額(e)骨(gu)(gu)(gu)上(shang)的(de)上(shang)顳窩前(qian)邊緣(yuan)(yuan)為曲線,強(qiang)健(jian)懼龍(long)中是直線。頂(ding)骨(gu)(gu)(gu)的(de)后外側(ce)突(tu)的(de)基(ji)部(bu)被頂(ding)骨(gu)(gu)(gu)的(de)鱗骨(gu)(gu)(gu)關節突(tu)覆蓋(gai)。鼓(gu)室脊(ji)延(yan)伸至前(qian)耳骨(gu)(gu)(gu)上(shang)。方顴骨(gu)(gu)(gu)的(de)外側(ce)面(mian)具有(you)一(yi)明(ming)顯的(de)穿孔(kong)(kong)。
懼(ju)龍的化石標本(ben)也非常(chang)多,有(you)一些(xie)甚至沒有(you)經過正式的發(fa)表(biao)描述。以下先(xian)列出(chu)強健懼(ju)龍的一些(xie)已發(fa)表(biao)的標本(ben)。
強(qiang)健懼龍的(de)正(zheng)型(xing)標本在發(fa)現之初被當作是蛇發(fa)女怪龍的(de)的(de)標本。在戴爾.羅素1970年的(de)文章系統描述和比較(jiao)加拿(na)大地區的(de)暴龍類時才被定為(wei)新屬種。
正型(xing)標(biao)本(ben):NMC 8506保存了頭(tou)骨,肩帶骨骼,前肢,腰帶和股骨,大多數的頸椎(zhui),背椎(zhui)和薦(jian)椎(zhui),還有前11節尾(wei)椎(zhui)。
歸(gui)入標本:AMNH 5438保存了薦(jian)椎(zhui),背椎(zhui)和(he)尾(wei)椎(zhui),腰(yao)帶,右側股骨,左側脛(jing)骨和(he)第(di)二(er)跖骨。
歸入(ru)標本(ben):NMC 350保存了左側(ce)后肢。
歸入標本:AMNH 5346為一件上(shang)頜骨。
歸入標本:UA 11右側股骨和第四跖骨。
歸入標本:NMC 11594保存了不完(wan)整的,風(feng)化較嚴(yan)重的頭骨(gu)。
歸入標本:BMNH R4863保(bao)存(cun)了前頜骨(gu)(gu),上頜骨(gu)(gu)和齒(chi)骨(gu)(gu)。
歸(gui)入標本:RTMP 2001.36.1一件幾乎完整的骨架。
歸入標本(ben):FMNH PR308是(shi)一件保(bao)存(cun)質量很好的標本(ben),保(bao)存(cun)了頭骨和大多數頭后(hou)骨骼。起初被認為(wei)時(shi)阿爾伯塔(ta)龍。后(hou)在托馬斯.卡爾1999年的研究中歸入到懼龍模式種。
歸入(ru)標本:AMNH 5434曾(ceng)經被(bei)歸入(ru)到蛇發女怪(guai)龍模式種,保存了(le)幾(ji)乎(hu)(hu)完整(zheng)的(de)頭(tou)骨(gu)。頭(tou)后(hou)骨(gu)骼缺乏尾椎和后(hou)肢(zhi),其它部位幾(ji)乎(hu)(hu)完整(zheng)。在(zai)托(tuo)馬斯.卡爾1999年的(de)工作中歸入(ru)到懼龍模式種。
歸入標本:TMP 94.218.1為一個幼年個體(ti)。托馬斯.卡爾1999年的工作中列出。
歸入標本:NMC 841為一成年(nian)個體。托馬斯.卡爾1999年(nian)的工作中列出。
歸入標本:TMP 82.13.1為一個成年個體。托馬斯.卡(ka)爾1999年的工作(zuo)中(zhong)列出(chu)。
歸入標(biao)本:TMP 83.38.1為一個(ge)成年(nian)個(ge)體。托馬斯.卡爾1999年(nian)的(de)工作(zuo)中列出。
歸入標(biao)本:TMP 85.62.1為一個成年(nian)個體。托馬斯.卡爾1999年(nian)的工(gong)作中(zhong)列出。
歸入(ru)標本:TMP 1994.143.0001屬于(yu)一只約5米長的(de)年輕懼龍(long)。頭骨幾(ji)乎完整,但頭后(hou)骨骼風化嚴重。
下面列出霍(huo)氏(shi)懼龍的主(zhu)要標本(ben):
正(zheng)型(xing)標本:MOR 590保存(cun)了完(wan)整(zheng)的(de)頭骨,部分保存(cun)的(de)肩帶和前(qian)肢以及(ji)完(wan)整(zheng)的(de)后肢。
歸入(ru)標(biao)本:MOR 1130保存了(le)一個(ge)不完整的頭骨(gu),部(bu)分(fen)保存的中軸骨(gu)格序列(lie),部(bu)分(fen)保存的腰帶(dai)骨(gu)骼和(he)后(hou)肢(zhi)。
歸入標本:MOR 553S/7.19.0.97一(yi)塊齒(chi)骨,屬于一(yi)個(ge)小幼體(ti)。
歸入標本:AMNH FARB 5477包括一塊上頜骨(gu),部分(fen)保存的眶后骨(gu)和頂骨(gu)。
歸入標本:MOR 3068部(bu)分保存的下頜。
歸入標本:MOR 553D.9.19.91左側的(de)外翼骨。
歸入標(biao)本(ben):MOR 553E.7.6.91.196,右側(ce)的(de)外翼骨(gu)。
除此之外,還有(you)(you)一些被鑒定(ding)屬(shu)(shu)(shu)于懼龍(long)屬(shu)(shu)(shu),但是(shi)沒(mei)有(you)(you)明確定(ding)種(zhong)的標本。它們有(you)(you)可能屬(shu)(shu)(shu)于已知(zhi)的兩種(zhong)懼龍(long),也有(you)(you)可能是(shi)第(di)三種(zhong)。
目前主(zhu)要的(de)暴龍(long)類(lei)或虛骨龍(long)類(lei)系統發育分析都支持懼(ju)龍(long)屬于暴龍(long)亞科,且(qie)與霸王(wang)(wang)龍(long)和特暴龍(long)(有時會包(bao)括諸城暴龍(long))具(ju)有非常近的(de)親緣(yuan)關系。而排除掉(diao)亞洲的(de)暴龍(long)類(lei)以后,懼(ju)龍(long)是北美(mei)大陸上與霸王(wang)(wang)龍(long)親緣(yuan)關系最近的(de)成員。
懼龍的(de)頭骨長度可以超過1米。戴爾.羅素對于懼龍的(de)體型估(gu)(gu)計(ji)是體長8-9米。而體重估(gu)(gu)計(ji)一般在2.5噸左右,但是具有較大的(de)波動范圍(1.8至(zhi)3.8噸)。2014年的(de)一項(xiang)研究估(gu)(gu)計(ji)值為3.6噸。
2017年的(de)(de)(de)(de)一項研(yan)究(jiu)參考現(xian)生(sheng)的(de)(de)(de)(de)主龍(long)(long)(long)(long)類(lei)復原了懼龍(long)(long)(long)(long)的(de)(de)(de)(de)面(mian)部(bu)軟組織。研(yan)究(jiu)人員認為(wei)懼龍(long)(long)(long)(long)的(de)(de)(de)(de)面(mian)部(bu)具(ju)有(you)(you)種類(lei)豐(feng)富的(de)(de)(de)(de)表皮組織,除了鱗(lin)片(pian)以(yi)外,在它的(de)(de)(de)(de)前(qian)頜(he)骨(gu)(gu),鼻骨(gu)(gu)和淚骨(gu)(gu)還有(you)(you)顴骨(gu)(gu),以(yi)及齒骨(gu)(gu)的(de)(de)(de)(de)吻(wen)(wen)端(duan)應(ying)該(gai)會覆(fu)蓋一些骨(gu)(gu)質(zhi)的(de)(de)(de)(de)小突(tu)起,而眶后骨(gu)(gu)角(jiao)的(de)(de)(de)(de)表面(mian)應(ying)該(gai)會覆(fu)蓋有(you)(you)非常厚(hou)的(de)(de)(de)(de)角(jiao)質(zhi)層(ceng)。除此之外,懼龍(long)(long)(long)(long)的(de)(de)(de)(de)吻(wen)(wen)端(duan)還具(ju)有(you)(you)豐(feng)富的(de)(de)(de)(de)神(shen)經陷(xian)窩。懼龍(long)(long)(long)(long)的(de)(de)(de)(de)吻(wen)(wen)端(duan)可(ke)能與現(xian)生(sheng)鱷魚的(de)(de)(de)(de)吻(wen)(wen)端(duan)具(ju)有(you)(you)相似的(de)(de)(de)(de)功能,包括捕獵,感受溫度和不同物體的(de)(de)(de)(de)材質(zhi),以(yi)及同類(lei)之間的(de)(de)(de)(de)社(she)會性行為(wei)。吻(wen)(wen)部(bu)表面(mian)覆(fu)蓋的(de)(de)(de)(de)骨(gu)(gu)質(zhi)小突(tu)起可(ke)能能夠起到對感受系統保護的(de)(de)(de)(de)作(zuo)用。
關于(yu)懼龍(long)群居(ju)性(xing)(xing)的(de)(de)(de)(de)證據(ju)(ju)在雙麥迪遜組被(bei)找(zhao)到。在一個產(chan)出懼龍(long)化石(shi)的(de)(de)(de)(de)骨(gu)(gu)床中(zhong),至少(shao)(shao)有屬于(yu)三個不(bu)同(tong)個體(ti)(ti)的(de)(de)(de)(de)懼龍(long)骨(gu)(gu)骼(ge)被(bei)發現。除(chu)此(ci)之外,這(zhe)(zhe)里還發現了5具鴨嘴(zui)龍(long)類的(de)(de)(de)(de)化石(shi)。這(zhe)(zhe)些(xie)懼龍(long)骨(gu)(gu)骼(ge)中(zhong),至少(shao)(shao)有一只大(da)型的(de)(de)(de)(de)成年個體(ti)(ti),一只中(zhong)等大(da)小(xiao)的(de)(de)(de)(de)個體(ti)(ti),還有一只小(xiao)幼體(ti)(ti)。依(yi)據(ju)(ju)對于(yu)化石(shi)點的(de)(de)(de)(de)埋藏學分析,這(zhe)(zhe)些(xie)尸體(ti)(ti)不(bu)像是(shi)被(bei)從別的(de)(de)(de)(de)地方沖下(xia)來的(de)(de)(de)(de),而像是(shi)在較短的(de)(de)(de)(de)時(shi)間(jian)內被(bei)同(tong)時(shi)埋藏的(de)(de)(de)(de)。5具鴨嘴(zui)龍(long)的(de)(de)(de)(de)骨(gu)(gu)骼(ge)上都有暴龍(long)類的(de)(de)(de)(de)齒痕,顯示這(zhe)(zhe)群懼龍(long)在死前可(ke)能進(jin)食過這(zhe)(zhe)些(xie)尸體(ti)(ti)。菲(fei)利普(pu).柯(ke)瑞(rui)認為(wei)這(zhe)(zhe)批化石(shi)是(shi)懼龍(long)群居(ju)性(xing)(xing)行為(wei)的(de)(de)(de)(de)證據(ju)(ju),并且推(tui)測它們會成群出動協(xie)同(tong)捕獵。其他古(gu)生物學家則對此(ci)持懷疑態度。
同(tong)(tong)類(lei)(lei)(lei)相殘在(zai)(zai)現生的(de)(de)(de)大(da)型(xing)(xing)(xing)食肉(rou)動(dong)物中(zhong)(zhong)(zhong)是一種常見的(de)(de)(de)現象(xiang)。化石證據(ju)顯(xian)示(shi)這種現象(xiang)在(zai)(zai)獸腳類(lei)(lei)(lei)恐(kong)龍(long)中(zhong)(zhong)(zhong)也比較常見。一件(jian)(jian)年輕的(de)(de)(de)懼龍(long)標本(ben)的(de)(de)(de)面部(bu)留(liu)有(you)(you)(you)暴龍(long)類(lei)(lei)(lei)的(de)(de)(de)咬痕(hen)(hen)。咬痕(hen)(hen)有(you)(you)(you)愈合的(de)(de)(de)痕(hen)(hen)跡,顯(xian)示(shi)這只(zhi)動(dong)物在(zai)(zai)襲擊(ji)中(zhong)(zhong)(zhong)活了下來。另外一件(jian)(jian)成(cheng)年的(de)(de)(de)懼龍(long)標本(ben)也有(you)(you)(you)大(da)型(xing)(xing)(xing)暴龍(long)類(lei)(lei)(lei)的(de)(de)(de)咬痕(hen)(hen)。這些證據(ju)顯(xian)示(shi),大(da)型(xing)(xing)(xing)暴龍(long)類(lei)(lei)(lei)的(de)(de)(de)同(tong)(tong)類(lei)(lei)(lei)相殘行(xing)為不止局(ju)限于傷害小體型(xing)(xing)(xing)的(de)(de)(de)個(ge)體,同(tong)(tong)類(lei)(lei)(lei)間(jian)的(de)(de)(de)打斗在(zai)(zai)大(da)型(xing)(xing)(xing)個(ge)體間(jian)也存在(zai)(zai)。其它的(de)(de)(de)獸腳類(lei)(lei)(lei)如大(da)型(xing)(xing)(xing)暴龍(long)類(lei)(lei)(lei)蛇發女(nv)怪龍(long)和霸王龍(long),還有(you)(you)(you)大(da)型(xing)(xing)(xing)異(yi)特龍(long)類(lei)(lei)(lei)中(zhong)(zhong)(zhong)華盜龍(long),以及小體型(xing)(xing)(xing)的(de)(de)(de)馳龍(long)類(lei)(lei)(lei)蜥鳥盜龍(long)的(de)(de)(de)頭骨上也會有(you)(you)(you)被其它動(dong)物咬過的(de)(de)(de)痕(hen)(hen)跡。菲利普.柯瑞認為,獸腳類(lei)(lei)(lei)恐(kong)龍(long)之間(jian)的(de)(de)(de)攻擊(ji)性行(xing)為主要是由于種間(jian)競(jing)爭和領域保(bao)護性行(xing)為導致的(de)(de)(de)。
大型(xing)(xing)暴龍(long)類(lei)在個體(ti)發育過程中的(de)(de)體(ti)重(zhong)增加符合“S”型(xing)(xing)曲(qu)線(xian)(xian)。懼龍(long)的(de)(de)最(zui)大生(sheng)長(chang)速(su)度為每年(nian)180千克,大于蛇發女怪龍(long)和(he)阿(a)爾伯(bo)塔(ta)龍(long),而(er)這樣(yang)的(de)(de)結果還只是使用(yong)了較低估(gu)計的(de)(de)成(cheng)體(ti)體(ti)重(zhong)(1.8噸)。使用(yong)更大的(de)(de)成(cheng)體(ti)體(ti)重(zhong)估(gu)計將會(hui)增加最(zui)大生(sheng)長(chang)速(su)率的(de)(de)估(gu)計值,但是并不會(hui)改變擬(ni)合曲(qu)線(xian)(xian)的(de)(de)整體(ti)形狀。懼龍(long)的(de)(de)最(zui)大生(sheng)長(chang)速(su)率遠(yuan)低于霸王龍(long),且“S”型(xing)(xing)曲(qu)線(xian)(xian)更早(zao)達(da)到漸進平緩。這也表明,暴龍(long)類(lei)在大型(xing)(xing)化(hua)的(de)(de)過程中可能(neng)同時(shi)使用(yong)了增加最(zui)大生(sheng)長(chang)速(su)度和(he)增加生(sheng)長(chang)時(shi)間的(de)(de)策略。
懼龍(long)(long)在(zai)(zai)個(ge)(ge)(ge)體(ti)(ti)(ti)發育的(de)(de)(de)過程(cheng)中會經(jing)歷(li)一系(xi)列的(de)(de)(de)形態變(bian)化。最(zui)(zui)為明(ming)顯的(de)(de)(de)一點(dian)是牙齒(chi)(chi)數(shu)量(liang)(liang)(liang)的(de)(de)(de)變(bian)化。對于(yu)霍氏(shi)懼龍(long)(long)的(de)(de)(de)研究(jiu)發現,最(zui)(zui)年輕(qing)的(de)(de)(de)個(ge)(ge)(ge)體(ti)(ti)(ti)的(de)(de)(de)上頜(he)骨齒(chi)(chi)有15個(ge)(ge)(ge)(AMNH FARB 5477),而(er)亞成(cheng)體(ti)(ti)(ti)的(de)(de)(de)增(zeng)加到了17個(ge)(ge)(ge)((MOR 590),之(zhi)后(hou)成(cheng)年個(ge)(ge)(ge)體(ti)(ti)(ti)的(de)(de)(de)數(shu)量(liang)(liang)(liang)又下(xia)降到15個(ge)(ge)(ge)(MOR 1130)。與上頜(he)相比,齒(chi)(chi)骨齒(chi)(chi)的(de)(de)(de)數(shu)量(liang)(liang)(liang)在(zai)(zai)個(ge)(ge)(ge)體(ti)(ti)(ti)發育中沒有變(bian)化。強健懼龍(long)(long)在(zai)(zai)個(ge)(ge)(ge)體(ti)(ti)(ti)發育的(de)(de)(de)過程(cheng)中也存(cun)(cun)在(zai)(zai)牙齒(chi)(chi)數(shu)量(liang)(liang)(liang)變(bian)化的(de)(de)(de)現象(xiang)。強健懼龍(long)(long)最(zui)(zui)年輕(qing)的(de)(de)(de)個(ge)(ge)(ge)體(ti)(ti)(ti)(TMP 1994.143.0001)具(ju)有13顆(ke)上頜(he)骨齒(chi)(chi),更大一點(dian)的(de)(de)(de)亞成(cheng)體(ti)(ti)(ti)(AMNH 5346)有15或(huo)16顆(ke),而(er)再(zai)老(lao)一點(dian)的(de)(de)(de)個(ge)(ge)(ge)體(ti)(ti)(ti)會減少到14顆(ke)(NMC 8506)。這(zhe)種牙齒(chi)(chi)數(shu)量(liang)(liang)(liang)的(de)(de)(de)變(bian)化在(zai)(zai)霸王龍(long)(long)中也得(de)到了證實(shi)。這(zhe)一研究(jiu)表明(ming)個(ge)(ge)(ge)體(ti)(ti)(ti)發育過程(cheng)中的(de)(de)(de)牙齒(chi)(chi)數(shu)量(liang)(liang)(liang)先增(zeng)加再(zai)減少的(de)(de)(de)現象(xiang)可(ke)能廣泛存(cun)(cun)在(zai)(zai)于(yu)暴龍(long)(long)亞科中。
對于(yu)霍氏(shi)懼龍(long)的(de)(de)研究(jiu)發(fa)(fa)(fa)現,其(qi)(qi)面部紋飾(shi)也會隨(sui)(sui)著個(ge)(ge)體發(fa)(fa)(fa)育階段的(de)(de)變化而變化,尤其(qi)(qi)是(shi)鼻骨的(de)(de)紋飾(shi)會隨(sui)(sui)著年(nian)齡增大而減(jian)弱。這種現象(xiang)也見于(yu)霸(ba)王龍(long)。對于(yu)角龍(long)類和腫頭龍(long)類的(de)(de)研究(jiu)發(fa)(fa)(fa)現,頭部的(de)(de)裝飾(shi)也會隨(sui)(sui)著個(ge)(ge)體發(fa)(fa)(fa)育而減(jian)弱。結合系統(tong)發(fa)(fa)(fa)育框架以(yi)及(ji)簡(jian)約性原則可以(yi)推測,頭部裝飾(shi)隨(sui)(sui)個(ge)(ge)體發(fa)(fa)(fa)育減(jian)弱是(shi)整個(ge)(ge)恐龍(long)單(dan)系的(de)(de)共近裔特征。
對于懼(ju)龍(long)(long)的(de)(de)(de)種群生物(wu)學研究發現,它(ta)與霸王龍(long)(long),蛇(she)發女怪龍(long)(long)和阿爾伯(bo)塔龍(long)(long)具有相似的(de)(de)(de)存(cun)活曲(qu)線,即(ji)較低的(de)(de)(de)新生個(ge)體(ti)(ti)存(cun)活率(lv),較高的(de)(de)(de)幼(you)(you)年個(ge)體(ti)(ti)存(cun)活率(lv),以及從中年期(qi)開始死亡率(lv)又再(zai)一次升高。懼(ju)龍(long)(long)以及其它(ta)大型(xing)暴龍(long)(long)類(lei)的(de)(de)(de)群居性(xing)行為可(ke)能能夠有效(xiao)降低年輕個(ge)體(ti)(ti)的(de)(de)(de)死亡率(lv)。同時(shi)大型(xing)暴龍(long)(long)類(lei)較快的(de)(de)(de)生長速(su)度也能使它(ta)們的(de)(de)(de)幼(you)(you)體(ti)(ti)快速(su)度過危(wei)險(xian)期(qi),達(da)到普通捕食(shi)者無法捕食(shi)的(de)(de)(de)體(ti)(ti)型(xing)閾值。而同類(lei)相殘行為可(ke)能是死亡率(lv)從中年時(shi)期(qi)開始再(zai)度增加的(de)(de)(de)主(zhu)要原因。
懼龍(long)的(de)(de)(de)生(sheng)活范圍(wei)與蛇發女怪龍(long)有(you)所重(zhong)疊。戴爾.羅素認為懼龍(long)身(shen)體(ti)更為龐大,適(shi)合捕食防御能力較好的(de)(de)(de)角(jiao)龍(long)類(lei),而蛇發女怪龍(long)的(de)(de)(de)體(ti)態較為輕(qing)盈,適(shi)合捕食鴨嘴龍(long)類(lei)。然(ran)而一(yi)件懼龍(long)標本的(de)(de)(de)胃容物(wu)里發現了幼年(nian)鴨嘴龍(long)類(lei)的(de)(de)(de)殘骸。另外一(yi)種可(ke)能是兩種大型暴龍(long)類(lei)雖然(ran)棲息在(zai)一(yi)片區域,但(dan)是它們生(sheng)活的(de)(de)(de)微生(sheng)境是不同的(de)(de)(de),因此兩者可(ke)能沒有(you)太多的(de)(de)(de)機會見面打架。
懼龍(long)(long)(long)登場于(yu)(yu)BBC的(de)(de)紀(ji)錄片(pian)(pian)《恐龍(long)(long)(long)星球》。在片(pian)(pian)中(zhong),懼龍(long)(long)(long)被描述為群居的(de)(de)巨型(xing)(xing)殺手,依(yi)靠團隊合作捕食落單的(de)(de)開角龍(long)(long)(long),同時也會埋伏(fu)在尖角龍(long)(long)(long)群遷徙的(de)(de)必經之路上,伺(si)機對獵物(wu)展開屠殺。懼龍(long)(long)(long)還登場于(yu)(yu)Discovery的(de)(de)同名紀(ji)錄片(pian)(pian)《恐龍(long)(long)(long)星球》中(zhong)。片(pian)(pian)中(zhong)的(de)(de)懼龍(long)(long)(long)會團隊合作捕食慈(ci)母龍(long)(long)(long),同時影(ying)片(pian)(pian)中(zhong)還將懼龍(long)(long)(long)描述為霸王(wang)龍(long)(long)(long)的(de)(de)祖先。這(zhe)種描述是不嚴謹的(de)(de),但依(yi)據現階段(duan)的(de)(de)大(da)多(duo)數系統發育分析,如果除去亞洲的(de)(de)諸城暴(bao)龍(long)(long)(long)和特(te)暴(bao)龍(long)(long)(long),懼龍(long)(long)(long)確實是北(bei)美大(da)型(xing)(xing)暴(bao)龍(long)(long)(long)類中(zhong)和霸王(wang)龍(long)(long)(long)親緣關系最近的(de)(de)成員(yuan)。
在(zai)暴(bao)龍(long)(long)科(ke)中,達(da)斯(si)布雷(lei)龍(long)(long)與特暴(bao)龍(long)(long)、暴(bao)龍(long)(long)及(ji)分支龍(long)(long)同屬于暴(bao)龍(long)(long)亞(ya)(ya)科(ke)。暴(bao)龍(long)(long)亞(ya)(ya)科(ke)的(de)物種都(dou)是(shi)較(jiao)接(jie)近(jin)暴(bao)龍(long)(long),而較(jiao)不類(lei)似(si)艾伯塔龍(long)(long),特征(zheng)都(dou)是(shi)粗壯的(de)體型、比例上較(jiao)大的(de)頭顱骨、以及(ji)較(jiao)長的(de)股骨。
達斯布(bu)雷龍(long)(long)(long)(long)通常被(bei)認為(wei)(wei)是(shi)暴(bao)(bao)龍(long)(long)(long)(long)的(de)(de)(de)近親,或(huo)是(shi)往暴(bao)(bao)龍(long)(long)(long)(long)前進演(yan)(yan)(yan)化的(de)(de)(de)直接(jie)(jie)祖(zu)先。格里(li)高利·保羅(Gregory S.Paul)曾將強(qiang)健達斯布(bu)雷龍(long)(long)(long)(long)編(bian)入暴(bao)(bao)龍(long)(long)(long)(long)屬中,但這(zhe)(zhe)個(ge)(ge)(ge)分類卻一般(ban)不被(bei)接(jie)(jie)受。很多學者(zhe)認為(wei)(wei)特(te)暴(bao)(bao)龍(long)(long)(long)(long)及暴(bao)(bao)龍(long)(long)(long)(long)是(shi)姊妹分類單元,或(huo)甚至是(shi)同屬,而達斯布(bu)雷龍(long)(long)(long)(long)是(shi)這(zhe)(zhe)個(ge)(ge)(ge)演(yan)(yan)(yan)化支的(de)(de)(de)基礎物(wu)種。菲力·柯(ke)爾(er)(Phil Currie)等人提出(chu)一個(ge)(ge)(ge)不同的(de)(de)(de)理論,分支龍(long)(long)(long)(long)與特(te)暴(bao)(bao)龍(long)(long)(long)(long)這(zhe)(zhe)兩個(ge)(ge)(ge)亞(ya)洲(zhou)屬構成一個(ge)(ge)(ge)演(yan)(yan)(yan)化支,而達斯布(bu)雷龍(long)(long)(long)(long)較接(jie)(jie)近這(zhe)(zhe)個(ge)(ge)(ge)演(yan)(yan)(yan)化支,而離北美洲(zhou)的(de)(de)(de)暴(bao)(bao)龍(long)(long)(long)(long)較遠。要待所有的(de)(de)(de)達斯布(bu)雷龍(long)(long)(long)(long)物(wu)種被(bei)研究、描述,才可以得到較清(qing)晰的(de)(de)(de)達斯布(bu)雷龍(long)(long)(long)(long)分類關系。
對于現今的(de)(de)獵食(shi)動(dong)物而言,達(da)斯布雷龍(long)體(ti)型非常巨大,相當于一(yi)(yi)頭(tou)成(cheng)年亞洲象的(de)(de)大小。成(cheng)年的(de)(de)強健懼(ju)龍(long)的(de)(de)一(yi)(yi)般身長最大可達(da)10米(mi),平均(jun)體(ti)重估(gu)計約為4噸(dun),最大個體(ti)可超過6噸(dun)。一(yi)(yi)個懼(ju)龍(long)屬的(de)(de)暫(zan)時未命(ming)名種超懼(ju)龍(long)(暫(zan)時代稱)則可以達(da)到(dao)7.5噸(dun)重。
達斯布(bu)雷(lei)龍(long)(long)(long)(long)有(you)巨大(da)(da)的(de)(de)(de)(de)頭(tou)顱(lu)(lu)骨(gu)(gu)(gu)(gu),約有(you)1.1米(mi)長。頭(tou)顱(lu)(lu)骨(gu)(gu)(gu)(gu)的(de)(de)(de)(de)構(gou)造特(te)別(bie)堅固,例如口鼻部(bu)上的(de)(de)(de)(de)鼻骨(gu)(gu)(gu)(gu)互(hu)相愈合(he),以(yi)增加強度,而頭(tou)骨(gu)(gu)(gu)(gu)的(de)(de)(de)(de)大(da)(da)型(xing)(xing)洞孔則可減(jian)低重量(liang)。成年的(de)(de)(de)(de)達斯布(bu)雷(lei)龍(long)(long)(long)(long)約有(you)60多(duo)顆牙(ya)齒,每只牙(ya)齒都非常長而厚重。牙(ya)齒的(de)(de)(de)(de)橫切面(mian)呈橢圓形(xing)而非短刃形(xing)。前上頜(he)骨(gu)(gu)(gu)(gu)的(de)(de)(de)(de)牙(ya)齒卻是呈D型(xing)(xing)的(de)(de)(de)(de),這種異齒型(xing)(xing)在暴(bao)龍(long)(long)(long)(long)科中是非常普遍的(de)(de)(de)(de)。達斯布(bu)雷(lei)龍(long)(long)(long)(long)頭(tou)顱(lu)(lu)骨(gu)(gu)(gu)(gu)的(de)(de)(de)(de)獨特(te)處在于(yu),上頜(he)骨(gu)(gu)(gu)(gu)的(de)(de)(de)(de)表面(mian)凹凸(tu)不(bu)平,以(yi)及(ji)眼睛周圍(wei)的(de)(de)(de)(de)淚骨(gu)(gu)(gu)(gu)、眶(kuang)后骨(gu)(gu)(gu)(gu)及(ji)顴骨(gu)(gu)(gu)(gu)有(you)明(ming)顯的(de)(de)(de)(de)隆(long)起。眼窩呈長橢圓形(xing),介于(yu)蛇發女怪龍(long)(long)(long)(long)的(de)(de)(de)(de)圓形(xing)及(ji)暴(bao)龍(long)(long)(long)(long)的(de)(de)(de)(de)鑰孔形(xing)之間。吻(wen)部(bu)很寬(kuan),96厘(li)米(mi)頭(tou)骨(gu)(gu)(gu)(gu)吻(wen)寬(kuan)35厘(li)米(mi),最大(da)(da)頭(tou)骨(gu)(gu)(gu)(gu)(超懼龍(long)(long)(long)(long)唯一和最大(da)(da)個體)137厘(li)米(mi)吻(wen)寬(kuan)可能達到50厘(li)米(mi),吻(wen)寬(kuan)比同體型(xing)(xing)的(de)(de)(de)(de)霸王龍(long)(long)(long)(long)都寬(kuan)不(bu)少。
與其他的(de)(de)暴龍科都有(you)著相似的(de)(de)體(ti)型,都是由呈S型的(de)(de)頸部支撐著沉重的(de)(de)頭部。它的(de)(de)前(qian)肢(zhi)(zhi)非(fei)常(chang)的(de)(de)短小,只(zhi)有(you)二指(zhi),不(bu)過(guo)在暴龍亞科中,達斯布雷(lei)龍的(de)(de)前(qian)肢(zhi)(zhi)與身體(ti)比例是目前(qian)發現最長的(de)(de)。達斯布雷(lei)龍具(ju)有(you)兩個(ge)巨大而長后肢(zhi)(zhi),上有(you)四趾,第一趾為反爪(zhua),無(wu)法接觸地面。達斯布雷(lei)龍具(ju)有(you)長及重的(de)(de)尾巴,可平衡頭部與胸部,使(shi)重心(xin)位(wei)在臀部上。
目前科(ke)學家表明,同(tong)體型(xing)的情況下,達斯布雷龍攻擊力不亞于(yu)霸王龍。
達斯布雷龍(long)(屬名:Daspletosaurus)又名懼龍(long)。是暴龍(long)科下的(de)一(yi)屬恐龍(long)。它(ta)(ta)們極少群居,大(da)多是零零散(san)散(san)的(de)分(fen)布在(zai)(zai)各處(chu)。只有(you)(you)在(zai)(zai)遷移或(huo)遠行時才有(you)(you)例外。它(ta)(ta)們有(you)(you)時住(zhu)在(zai)(zai)山(shan)林中的(de)洞(dong)穴里、有(you)(you)時住(zhu)在(zai)(zai)濃密的(de)叢林中,它(ta)(ta)們是以(yi)突襲的(de)方(fang)式獵捕食物(wu)。它(ta)(ta)用那粗(cu)大(da)有(you)(you)力的(de)尾巴橫掃(sao)獵物(wu),將其一(yi)口咬住(zhu)。
達(da)斯布雷龍的(de)棲(qi)息環境很廣,主要分(fen)布在樹林、山谷、溪邊(bian),它不喜(xi)歡在山上,因(yin)為這樣不善(shan)于(yu)奔(ben)跑(pao)。
繁殖(zhi)方式跟(gen)別的恐龍一(yi)樣(yang),也是通過產(chan)卵方式繁殖(zhi)。
強健達斯(si)(si)布雷(lei)龍(Daspletosaurus torosus)的(de)(de)(de)模式(shi)標本(ben)是(shi)(shi)一個(ge)(ge)(ge)完(wan)整(zheng)(zheng)性約(yue)75%的(de)(de)(de)骨(gu)(gu)骼(ge),包括了完(wan)整(zheng)(zheng)的(de)(de)(de)頭顱骨(gu)(gu)、幾(ji)乎完(wan)整(zheng)(zheng)的(de)(de)(de)頸(jing)椎(zhui)、完(wan)整(zheng)(zheng)的(de)(de)(de)脊椎(zhui)骨(gu)(gu)、前11節尾椎(zhui)、肩膀(bang)、一個(ge)(ge)(ge)完(wan)整(zheng)(zheng)的(de)(de)(de)前肢(zhi)、骨(gu)(gu)盆及(ji)(ji)兩根股骨(gu)(gu)。這些(xie)化石是(shi)(shi)于1921年(nian)由查爾(er)(er)斯(si)(si)·斯(si)(si)騰(teng)伯格(Charles Mortram Sternberg)所發現(xian),他最初認為這些(xie)化石屬于蛇發女怪龍的(de)(de)(de)一個(ge)(ge)(ge)新(xin)種(zhong)。但是(shi)(shi),這些(xie)標本(ben)要直到1970年(nian)才由戴爾(er)(er)·羅素(Dale Russell)完(wan)全的(de)(de)(de)描述,并(bing)建(jian)立(li)新(xin)的(de)(de)(de)達斯(si)(si)布雷(lei)龍屬。達斯(si)(si)布雷(lei)龍的(de)(de)(de)學名(ming)是(shi)(shi)由古希臘(la)文的(de)(de)(de)"δασπλητo-"(意(yi)(yi)即"懼怕")及(ji)(ji)"σαυρο?"(意(yi)(yi)即"蜥蜴")組(zu)(zu)合而來。種(zhong)名(ming)的(de)(de)(de)torosus是(shi)(shi)一拉丁文,意(yi)(yi)指"強壯"或(huo)"結實"。除了模式(shi)標本(ben),在(zai)2001年(nian)發現(xian)一個(ge)(ge)(ge)完(wan)整(zheng)(zheng)的(de)(de)(de)達斯(si)(si)布雷(lei)龍骨(gu)(gu)骼(ge)標本(ben)。這兩個(ge)(ge)(ge)標本(ben)都是(shi)(shi)來自加(jia)拿大(da)的(de)(de)(de)阿爾(er)(er)伯塔省,發現(xian)于朱迪斯(si)(si)河群中的(de)(de)(de)奧(ao)爾(er)(er)德曼組(zu)(zu)。另(ling)一個(ge)(ge)(ge)年(nian)代較(jiao)晚的(de)(de)(de)馬蹄峽(xia)谷組(zu)(zu)發現(xian)的(de)(de)(de)標本(ben),被重新(xin)歸類于艾伯塔龍。奧(ao)爾(er)(er)德曼組(zu)(zu)是(shi)(shi)在(zai)上(shang)白(bai)堊紀的(de)(de)(de)坎(kan)帕階中期形成的(de)(de)(de),距今(jin)約(yue)有7700萬(wan)-7600萬(wan)年(nian)前。
在(zai)建(jian)立強(qiang)健達斯(si)布(bu)(bu)雷龍的(de)(de)(de)正(zheng)模(mo)標(biao)本時,羅素將由巴納姆·布(bu)(bu)郎(Barnum Brown)于(yu)(yu)1913年所挖(wa)掘的(de)(de)(de)標(biao)本,建(jian)立為(wei)強(qiang)健達斯(si)布(bu)(bu)雷龍的(de)(de)(de)副(fu)模(mo)標(biao)本。這個(ge)標(biao)本包含了一個(ge)骨(gu)盆(pen)、部(bu)份(fen)后(hou)肢、及(ji)(ji)一些(xie)相連(lian)的(de)(de)(de)脊椎,是發(fa)(fa)現(xian)于(yu)(yu)阿爾(er)(er)伯塔(ta)省的(de)(de)(de)奧(ao)爾(er)(er)德曼組的(de)(de)(de)較(jiao)上層(ceng)。這個(ge)較(jiao)上層(ceng)后(hou)被更名(ming)為(wei)恐龍公(gong)園(yuan)(yuan)組,屬于(yu)(yu)坎帕階晚(wan)期,距今7600萬-7400萬年前(qian)(qian)。于(yu)(yu)1914年,布(bu)(bu)郎從同一地層(ceng)發(fa)(fa)現(xian)接(jie)近完整的(de)(de)(de)骨(gu)骼及(ji)(ji)頭(tou)顱(lu)(lu)(lu)骨(gu),并于(yu)(yu)40年后(hou)由美國自(zi)(zi)然(ran)歷(li)史博物(wu)館(guan)售予(yu)芝加哥(ge)的(de)(de)(de)菲(fei)爾(er)(er)德自(zi)(zi)然(ran)歷(li)史博物(wu)館(guan)。這顱(lu)(lu)(lu)骨(gu)目前(qian)(qian)在(zai)芝加哥(ge)菲(fei)爾(er)(er)德博物(wu)館(guan)展出(chu)中,并多(duo)年以來都(dou)被歸類為(wei)是"Albertosaurus libratus"。但在(zai)發(fa)(fa)現(xian)幾個(ge)頭(tou)顱(lu)(lu)(lu)骨(gu)特征(包括(kuo)大部(bu)份(fen)的(de)(de)(de)牙齒(chi))被石膏隱藏多(duo)年后(hou),這個(ge)標(biao)本才被重置在(zai)達斯(si)布(bu)(bu)雷龍屬中。在(zai)恐龍公(gong)園(yuan)(yuan)組一共(gong)發(fa)(fa)現(xian)了八具標(biao)本,大部(bu)份(fen)都(dou)是在(zai)恐龍省立公(gong)園(yuan)(yuan)的(de)(de)(de)范圍內。菲(fei)力·柯爾(er)(er)(Phil Currie)發(fa)(fa)現(xian)恐龍公(gong)園(yuan)(yuan)標(biao)本的(de)(de)(de)頭(tou)顱(lu)(lu)(lu)骨(gu)上有一些(xie)不同的(de)(de)(de)特征,認為(wei)這代表一個(ge)新的(de)(de)(de)達斯(si)布(bu)(bu)雷龍物(wu)種。這個(ge)新物(wu)種的(de)(de)(de)圖畫經已(yi)被出(chu)版,但仍有待正(zheng)式的(de)(de)(de)命名(ming)及(ji)(ji)描述。
在(zai)(zai)1990年(nian)(nian),新墨西哥(ge)州的(de)嘉(jia)德蘭組發現(xian)了一(yi)(yi)(yi)個(ge)新的(de)暴(bao)(bao)龍(long)(long)(long)科(ke)(ke)標(biao)本,包括頭顱骨碎片、肋骨及部份后(hou)肢(zhi),被編入后(hou)彎齒龍(long)(long)(long),后(hou)彎齒龍(long)(long)(long)的(de)狀態(tai)是個(ge)疑名(ming)。后(hou)來很(hen)多學者(zhe)都將這(zhe)(zhe)個(ge)標(biao)本,連(lian)同一(yi)(yi)(yi)些其(qi)他新墨西哥(ge)州發現(xian)的(de)化石(shi),重新歸(gui)類于達斯布雷龍(long)(long)(long)屬(shu)中的(de)未(wei)命(ming)名(ming)種。在(zai)(zai)2010年(nian)(nian)的(de)一(yi)(yi)(yi)個(ge)研(yan)究,認(ren)為(wei)這(zhe)(zhe)個(ge)新墨西哥(ge)物種,其(qi)實是早(zao)期(qi)的(de)暴(bao)(bao)龍(long)(long)(long)科(ke)(ke),并建立(li)為(wei)新屬(shu),Bistahieversor。目前對(dui)嘉(jia)德蘭組的(de)年(nian)(nian)代有所爭議,一(yi)(yi)(yi)些研(yan)究指出其(qi)年(nian)(nian)代屬(shu)于坎(kan)帕階(jie)晚期(qi),而其(qi)他研(yan)究則認(ren)為(wei)是麥斯特(te)(te)里希特(te)(te)階(jie)早(zao)期(qi)。
于(yu)1992年(nian),杰(jie)克·霍納(Jack Horner)及他的(de)(de)同僚發表一份有(you)(you)關(guan)美(mei)國蒙大拿州雙麥(mai)(mai)迪(di)(di)遜(xun)組較上(shang)層的(de)(de)新發現(xian)暴(bao)(bao)龍科恐龍的(de)(de)初步報告,認為這(zhe)些新化(hua)(hua)石(shi)(shi)是(shi)(shi)達斯布雷(lei)龍及后期暴(bao)(bao)龍的(de)(de)過(guo)渡物種,其年(nian)代(dai)為坎潘階(jie)。在(zai)(zai)2001年(nian),雙麥(mai)(mai)迪(di)(di)遜(xun)組的(de)(de)上(shang)層發現(xian)另一個部份骨(gu)骼,在(zai)(zai)其下(xia)腹(fu)內保存了一頭鴨嘴龍科的(de)(de)幼年(nian)個體化(hua)(hua)石(shi)(shi)。這(zhe)個標本被歸類于(yu)達斯布雷(lei)龍的(de)(de)一種,但(dan)(dan)卻沒有(you)(you)明定是(shi)(shi)哪一個種。在(zai)(zai)雙麥(mai)(mai)迪(di)(di)遜(xun)的(de)(de)骨(gu)床(chuang)中(zhong),曾發現(xian)最少(shao)三個以(yi)上(shang)的(de)(de)達斯布雷(lei)龍化(hua)(hua)石(shi)(shi)。這(zhe)些標本都(dou)沒有(you)(you)被詳細描述,但(dan)(dan)柯爾認為所有(you)(you)的(de)(de)雙麥(mai)(mai)迪(di)(di)遜(xun)化(hua)(hua)石(shi)(shi)都(dou)是(shi)(shi)達斯布雷(lei)龍屬中(zhong)的(de)(de)第三個未(wei)被命(ming)名種。
雖然達斯布雷龍的(de)(de)化(hua)石并(bing)不像著名的(de)(de)近親霸(ba)王龍那樣(yang)地驚人(ren)地常見和普遍被發(fa)現,但都足以讓古生物(wu)(wu)學家來(lai)研(yan)究(jiu)其生物(wu)(wu)學的(de)(de)某些范(fan)疇。目(mu)前至(zhi)少發(fa)現了14個標本(ben),不算上零碎的(de)(de)骨骼(ge)碎片和私人(ren)收藏(zang)家的(de)(de)化(hua)石。
于坎帕階晚期的(de)(de)北美洲,達斯布雷龍(long)(long)(long)與蛇(she)發女(nv)怪(guai)龍(long)(long)(long)生存于相同(tong)時代的(de)(de)相同(tong)地(di)區。這是少數兩(liang)個(ge)暴(bao)龍(long)(long)(long)科的(de)(de)屬共存的(de)(de)例(li)子。在現今(jin)的(de)(de)獵食動物中(zhong),體型相似的(de)(de)獵食動物因為解剖(pou)學、行為或地(di)理的(de)(de)原因,會區分成不同(tong)的(de)(de)生態位,以限(xian)制(zhi)競爭(zheng)。有幾個(ge)研(yan)究嘗試解釋達斯布雷龍(long)(long)(long)及(ji)蛇(she)發女(nv)怪(guai)龍(long)(long)(long)的(de)(de)生態位差(cha)異。
戴(dai)爾·羅素假設(she)較輕盈、常見的(de)(de)(de)(de)蛇(she)(she)發(fa)女怪(guai)龍(long)(long)(long)可(ke)能獵(lie)食(shi)(shi)(shi)當時(shi)繁盛的(de)(de)(de)(de)鴨(ya)嘴龍(long)(long)(long)科,而(er)較強(qiang)壯(zhuang)、稀少(shao)的(de)(de)(de)(de)達斯(si)布雷龍(long)(long)(long)則專門獵(lie)食(shi)(shi)(shi)數量較小、防御較好的(de)(de)(de)(de)角龍(long)(long)(long)科。但是(shi),在(zai)雙麥迪遜(xun)組發(fa)現的(de)(de)(de)(de)達斯(si)布雷龍(long)(long)(long)標本(ben),在(zai)其胃部保存了(le)鴨(ya)嘴龍(long)(long)(long)科幼年體的(de)(de)(de)(de)已(yi)消化化石。暴龍(long)(long)(long)亞科(例如達斯(si)布雷龍(long)(long)(long))有(you)著(zhu)較高及較寬的(de)(de)(de)(de)口鼻(bi)部,比有(you)較低口鼻(bi)部的(de)(de)(de)(de)艾伯塔龍(long)(long)(long)亞科(例如蛇(she)(she)發(fa)女怪(guai)龍(long)(long)(long))更為強(qiang)壯(zhuang),不過牙齒的(de)(de)(de)(de)強(qiang)度則差異(yi)不大。這顯示兩者在(zai)攝食(shi)(shi)(shi)的(de)(de)(de)(de)技巧(qiao)或食(shi)(shi)(shi)性都有(you)所不同。
其他學者認(ren)為它(ta)們(men)之間的(de)(de)競(jing)爭受到(dao)地理(li)區(qu)分(fen)(fen)(fen)的(de)(de)限制。不像其他的(de)(de)恐龍(long)(long)(long)(long)(long)類,它(ta)們(men)的(de)(de)區(qu)分(fen)(fen)(fen)似(si)(si)乎(hu)與(yu)離海(hai)岸的(de)(de)距離沒有關聯,而也與(yu)海(hai)拔高或(huo)低無關。但是,雖然生活區(qu)域有部(bu)分(fen)(fen)(fen)的(de)(de)重疊,蛇(she)發女怪(guai)龍(long)(long)(long)(long)(long)似(si)(si)乎(hu)在北方較(jiao)為普遍,而達斯(si)布雷龍(long)(long)(long)(long)(long)則(ze)傾向(xiang)于南方。其他的(de)(de)恐龍(long)(long)(long)(long)(long)亦(yi)有類似(si)(si)的(de)(de)地理(li)分(fen)(fen)(fen)布。在坎潘(pan)階,鴨(ya)嘴(zui)龍(long)(long)(long)(long)(long)亞(ya)(ya)科(ke)(ke)與(yu)開角龍(long)(long)(long)(long)(long)亞(ya)(ya)科(ke)(ke)繁盛于雙麥迪遜組(zu)與(yu)北美(mei)洲西南部(bu)。湯(tang)瑪(ma)斯(si)·荷茲(Thomas Holtz)指出這個地理(li)分(fen)(fen)(fen)布型(xing)式,顯示暴(bao)龍(long)(long)(long)(long)(long)亞(ya)(ya)科(ke)(ke)、開角龍(long)(long)(long)(long)(long)亞(ya)(ya)科(ke)(ke)及(ji)鴨(ya)嘴(zui)龍(long)(long)(long)(long)(long)亞(ya)(ya)科(ke)(ke)都有著同樣的(de)(de)生態位傾向(xiang)。他認(ren)為于麥斯(si)特里希特階末期,暴(bao)龍(long)(long)(long)(long)(long)亞(ya)(ya)科(ke)(ke)(如(ru)暴(bao)龍(long)(long)(long)(long)(long))、鴨(ya)嘴(zui)龍(long)(long)(long)(long)(long)亞(ya)(ya)科(ke)(ke)及(ji)開角龍(long)(long)(long)(long)(long)亞(ya)(ya)科(ke)(ke)(如(ru)三角龍(long)(long)(long)(long)(long))廣泛分(fen)(fen)(fen)布在北美(mei)洲西部(bu),而艾伯(bo)塔龍(long)(long)(long)(long)(long)亞(ya)(ya)科(ke)(ke)及(ji)尖角龍(long)(long)(long)(long)(long)亞(ya)(ya)科(ke)(ke)已滅(mie)絕,賴(lai)氏龍(long)(long)(long)(long)(long)亞(ya)(ya)科(ke)(ke)則(ze)已很(hen)稀少。
在恐(kong)龍(long)(long)(long)公(gong)園地(di)層(ceng)發(fa)現(xian)的(de)一個年輕(qing)達(da)斯(si)(si)布(bu)雷龍(long)(long)(long)標本,面部(bu)上有(you)被(bei)其他暴龍(long)(long)(long)科咬(yao)(yao)傷的(de)痕(hen)(hen)跡。這個咬(yao)(yao)痕(hen)(hen)已(yi)經痊愈,顯示它在這次事(shi)件后(hou)存活過來。在同一地(di)層(ceng)發(fa)現(xian)的(de)一個成年達(da)斯(si)(si)布(bu)雷龍(long)(long)(long)標本也(ye)有(you)相似咬(yao)(yao)痕(hen)(hen),可見(jian)這類攻擊并不(bu)限于年輕(qing)的(de)動物。雖然這些攻擊可能是來自其他物種(zhong),但獵(lie)食動物常發(fa)生物種(zhong)內的(de)打斗、攻擊行(xing)為。目(mu)前已(yi)在其他的(de)暴龍(long)(long)(long)科(如(ru)蛇發(fa)女怪龍(long)(long)(long)及暴龍(long)(long)(long))以及其他的(de)獸腳亞(ya)目(mu)(如(ru)中華盜龍(long)(long)(long)及蜥鳥盜龍(long)(long)(long))發(fa)現(xian)這種(zhong)面部(bu)的(de)攻擊痕(hen)(hen)跡。Darren Tanke與(yu)菲力·柯爾(Phil Currie)提(ti)出(chu)(chu)假說,指出(chu)(chu)這些攻擊是因(yin)為競(jing)爭疆域、食物資源、或支配群族而出(chu)(chu)現(xian)的(de)種(zhong)內競(jing)爭。
達(da)(da)斯(si)(si)(si)(si)布雷(lei)龍(long)(long)(long)群(qun)體(ti)(ti)生活的(de)證(zheng)據(ju)(ju)是發(fa)現于蒙大拿州雙(shuang)麥迪遜組骨床(chuang)的(de)化(hua)石。骨床(chuang)內(nei)有三頭(tou)達(da)(da)斯(si)(si)(si)(si)布雷(lei)龍(long)(long)(long)的(de)遺骸,包括一頭(tou)大的(de)成(cheng)年(nian)個體(ti)(ti)、一頭(tou)小(xiao)的(de)幼龍(long)(long)(long)、及(ji)另一頭(tou)中型大小(xiao)的(de)達(da)(da)斯(si)(si)(si)(si)布雷(lei)龍(long)(long)(long)。同(tong)一地點還發(fa)現最少五頭(tou)鴨嘴龍(long)(long)(long)科化(hua)石。地質(zhi)學證(zheng)據(ju)(ju)顯(xian)示,這(zhe)些(xie)遺骸并非被河流沖積(ji)在一起,而是在短暫時間遭(zao)到集體(ti)(ti)掩葬。鴨嘴龍(long)(long)(long)科的(de)遺骸是分(fen)散的(de),并且有很(hen)多暴龍(long)(long)(long)科牙齒的(de)咬痕(hen),可見達(da)(da)斯(si)(si)(si)(si)布雷(lei)龍(long)(long)(long)在死(si)前曾吃過(guo)這(zhe)些(xie)鴨嘴龍(long)(long)(long)科動物(wu)。這(zhe)些(xie)動物(wu)的(de)死(si)亡原因(yin)并不清楚。菲力·柯爾猜測達(da)(da)斯(si)(si)(si)(si)布雷(lei)龍(long)(long)(long)是群(qun)體(ti)(ti)狩獵的(de),但無法確(que)定(ding)。其他科學家則對(dui)達(da)(da)斯(si)(si)(si)(si)布雷(lei)龍(long)(long)(long)及(ji)其他大型獸腳(jiao)亞目(mu)的(de)群(qun)體(ti)(ti)活動證(zheng)據(ju)(ju)抱(bao)有懷疑(yi)。
古生(sheng)(sheng)物(wu)學(xue)家格里高利(li)(li)·艾利(li)(li)克森(Gregory Erickson)及(ji)其(qi)同僚(liao)研究了(le)(le)暴龍(long)(long)科(ke)的(de)生(sheng)(sheng)長(chang)(chang)(chang)及(ji)壽(shou)命(ming)。透過骨頭(tou)組織(zhi)學(xue)的(de)分析,可(ke)以確定標本死亡時的(de)年齡。將不同個體的(de)年齡與體型繪制(zhi)為(wei)(wei)圖表(biao),就可(ke)得到(dao)生(sheng)(sheng)長(chang)(chang)(chang)曲(qu)線。艾利(li)(li)克森指出暴龍(long)(long)科(ke)經歷長(chang)(chang)(chang)時間(jian)的(de)幼(you)龍(long)(long)狀態,會(hui)在(zai)4年內急(ji)速(su)(su)成長(chang)(chang)(chang)。這個急(ji)速(su)(su)成長(chang)(chang)(chang)的(de)階段會(hui)在(zai)達到(dao)性(xing)成熟時完結,成年后的(de)生(sheng)(sheng)長(chang)(chang)(chang)率(lv)會(hui)減慢。艾利(li)(li)克森只(zhi)研究了(le)(le)從雙麥迪(di)遜組發現的(de)達斯(si)(si)布(bu)雷(lei)龍(long)(long)標本,但(dan)這些標本都有相(xiang)同的(de)生(sheng)(sheng)長(chang)(chang)(chang)模式。與艾伯塔龍(long)(long)相(xiang)比,因達斯(si)(si)布(bu)雷(lei)龍(long)(long)的(de)體重(zhong)(zhong)較高,在(zai)急(ji)速(su)(su)成長(chang)(chang)(chang)期有著較快的(de)生(sheng)(sheng)長(chang)(chang)(chang)率(lv)。達斯(si)(si)布(bu)雷(lei)龍(long)(long)的(de)最大生(sheng)(sheng)長(chang)(chang)(chang)率(lv)為(wei)(wei)每年180公斤(假設成年的(de)達斯(si)(si)布(bu)雷(lei)龍(long)(long)體重(zhong)(zhong)是(shi)3500公斤)。其(qi)他學(xue)者指出達斯(si)(si)布(bu)雷(lei)龍(long)(long)應(ying)為(wei)(wei)更重(zhong)(zhong),不過這只(zhi)會(hui)影響達斯(si)(si)布(bu)雷(lei)龍(long)(long)生(sheng)(sheng)長(chang)(chang)(chang)率(lv)的(de)量,而(er)非(fei)整體模式。
艾(ai)利(li)克(ke)(ke)森等人將(jiang)每一個(ge)(ge)年(nian)齡層的(de)(de)(de)標本作成(cheng)(cheng)表格,整理出(chu)艾(ai)伯塔龍(long)(long)(long)群族(zu)的(de)(de)(de)生(sheng)長模式。艾(ai)利(li)克(ke)(ke)森指(zhi)出(chu)艾(ai)伯塔龍(long)(long)(long)的(de)(de)(de)幼年(nian)個(ge)(ge)體(ti)化(hua)石(shi)紀錄(lu)較為(wei)稀少,處在急速成(cheng)(cheng)長期的(de)(de)(de)接近成(cheng)(cheng)年(nian)個(ge)(ge)體(ti)及成(cheng)(cheng)年(nian)個(ge)(ge)體(ti)則(ze)更為(wei)常見(jian)。這可能是因(yin)為(wei)化(hua)石(shi)化(hua)過程與(yu)挖掘化(hua)石(shi)的(de)(de)(de)偏差。艾(ai)利(li)克(ke)(ke)森假設這些(xie)差異是來自幼龍(long)(long)(long)在某(mou)一體(ti)型(xing)的(de)(de)(de)低(di)死亡(wang)(wang)率,就(jiu)像現(xian)今的(de)(de)(de)某(mou)些(xie)大型(xing)哺乳(ru)類(lei)(例(li)如象)一樣(yang)。因(yin)為(wei)暴龍(long)(long)(long)科(ke)在兩歲時(shi)體(ti)型(xing)就(jiu)超(chao)越了(le)所有(you)同期的(de)(de)(de)獵食動物,所以(yi)在缺(que)乏被(bei)獵食的(de)(de)(de)情(qing)況下(xia),出(chu)現(xian)低(di)死亡(wang)(wang)率。古生(sheng)物學(xue)家并沒(mei)有(you)足夠(gou)的(de)(de)(de)達(da)斯布雷龍(long)(long)(long)化(hua)石(shi)來進(jin)行類(lei)似(si)的(de)(de)(de)分析(xi),但艾(ai)利(li)克(ke)(ke)森則(ze)認(ren)為(wei)達(da)斯布雷龍(long)(long)(long)也有(you)類(lei)似(si)的(de)(de)(de)生(sheng)長趨勢。
目前(qian)(qian)已發(fa)現的(de)達斯布雷龍化石都(dou)發(fa)現于上白(bai)堊(e)紀坎帕階中(zhong)至(zhi)晚(wan)期的(de)地(di)層,距今約7700萬(wan)-7400萬(wan)年前(qian)(qian)。在(zai)白(bai)堊(e)紀中(zhong)期,北美洲被西部(bu)(bu)內陸海(hai)(hai)(hai)(hai)道一分為(wei)(wei)二,蒙大拿州及(ji)阿爾伯(bo)塔省大部(bu)(bu)份都(dou)在(zai)海(hai)(hai)(hai)(hai)平(ping)面之下。在(zai)這段達斯布雷龍存活的(de)時期,西部(bu)(bu)拉拉米造山(shan)(shan)運(yun)動使得落(luo)基山(shan)(shan)脈(mo)隆起,使海(hai)(hai)(hai)(hai)道向東方(fang)(fang)及(ji)南方(fang)(fang)后退。大型河(he)流從西側(ce)的(de)山(shan)(shan)脈(mo)流至(zhi)東側(ce)的(de)海(hai)(hai)(hai)(hai)道,當中(zhong)的(de)沉(chen)積物(wu)形成(cheng)廣大的(de)海(hai)(hai)(hai)(hai)岸平(ping)原,成(cheng)為(wei)(wei)朱迪斯河(he)群的(de)雙(shuang)麥迪遜組(zu)與(yu)其(qi)他(ta)的(de)地(di)層。約7300萬(wan)年前(qian)(qian),海(hai)(hai)(hai)(hai)道再次(ci)向西方(fang)(fang)與(yu)北方(fang)(fang)海(hai)(hai)(hai)(hai)侵,逐漸(jian)淹沒恐龍公園組(zu),涵蓋(gai)美國西部(bu)(bu)及(ji)加(jia)拿大西部(bu)(bu)。
達斯(si)布雷龍生(sheng)(sheng)(sheng)活在西(xi)部(bu)內陸(lu)海道西(xi)岸的(de)廣大(da)沖積平原(yuan)。大(da)型的(de)河(he)流流經(jing)土地,有(you)(you)時(shi)會出(chu)現泛(fan)濫,形成(cheng)新的(de)沉積層(ceng)。當水源充足時(shi),可以(yi)維持(chi)大(da)量(liang)的(de)植(zhi)物(wu)及(ji)動物(wu)生(sheng)(sheng)(sheng)活,但這(zhe)個區(qu)域(yu)會發生(sheng)(sheng)(sheng)周期性的(de)干(gan)旱,造(zao)成(cheng)大(da)量(liang)生(sheng)(sheng)(sheng)物(wu)的(de)死亡,形成(cheng)朱(zhu)迪(di)斯(si)河(he)群(qun)與雙麥(mai)迪(di)遜組(zu)的(de)眾多(duo)骨床。在現今的(de)東非(fei)也有(you)(you)相似的(de)情況(kuang)。平原(yuan)西(xi)方(fang)的(de)周期性火(huo)山(shan)噴發,產生(sheng)(sheng)(sheng)的(de)火(huo)山(shan)灰會影響整個地區(qu),這(zhe)成(cheng)大(da)量(liang)的(de)死亡,而同時(shi)豐富了土壤(rang),有(you)(you)助于(yu)日后的(de)植(zhi)物(wu)生(sheng)(sheng)(sheng)長。科學家也借由這(zhe)些火(huo)山(shan)灰得出(chu)準確(que)的(de)放射性測(ce)年。海平面的(de)改變(bian),在不(bu)同時(shi)期對朱(zhu)迪(di)斯(si)河(he)群(qun)的(de)不(bu)同地區(qu),造(zao)成(cheng)許多(duo)環境變(bian)動,包括離岸及(ji)近(jin)岸的(de)海洋生(sheng)(sheng)(sheng)態、海岸濕地、三角洲及(ji)礁湖、內陸(lu)的(de)泛(fan)濫平原(yuan)等。與朱(zhu)迪(di)斯(si)河(he)群(qun)的(de)其(qi)他地層(ceng)相比,雙麥(mai)迪(di)遜組(zu)是在更內陸(lu)的(de)高海拔地區(qu)。
在(zai)雙麥(mai)迪遜組及(ji)(ji)(ji)(ji)朱迪斯河群(qun)(qun)有(you)良(liang)好的(de)脊(ji)椎動(dong)(dong)物(wu)化(hua)(hua)石(shi)紀錄,這是因為豐富的(de)動(dong)(dong)物(wu)群(qun)(qun)、周期性(xing)的(de)自然災害及(ji)(ji)(ji)(ji)大量的(de)沉積巖所(suo)造成(cheng)的(de)。這些地區(qu)有(you)多樣性(xing)的(de)淡水及(ji)(ji)(ji)(ji)入海口魚(yu)(yu)類(lei)化(hua)(hua)石(shi),包括鯊魚(yu)(yu)、鰩目(mu)、鱘魚(yu)(yu)、雀鱔目(mu)及(ji)(ji)(ji)(ji)其(qi)他魚(yu)(yu)類(lei)。朱迪斯河群(qun)(qun)也保存很多水生爬行(xing)(xing)動(dong)(dong)物(wu)及(ji)(ji)(ji)(ji)兩棲動(dong)(dong)物(wu)化(hua)(hua)石(shi),包括有(you)青蛙、鯢、龜、鱷(e)龍及(ji)(ji)(ji)(ji)鱷(e)魚(yu)(yu)。陸(lu)地上的(de)爬行(xing)(xing)動(dong)(dong)物(wu),則(ze)有(you)叉舌蜥科(ke)、石(shi)龍子科(ke)、巨蜥科(ke)及(ji)(ji)(ji)(ji)蛇蜥科(ke)。天空的(de)飛(fei)行(xing)(xing)動(dong)(dong)物(wu)則(ze)包含(han):神龍翼(yi)龍科(ke)及(ji)(ji)(ji)(ji)新鳥亞綱(如虛椎鳥等)。哺乳動(dong)(dong)物(wu)則(ze)包含(han):多瘤齒目(mu)、有(you)袋目(mu)及(ji)(ji)(ji)(ji)真(zhen)獸(shou)類(lei)哺乳動(dong)(dong)物(wu)。除此上述(shu)物(wu)種之(zhi)外(wai),還有(you)達斯布雷(lei)龍及(ji)(ji)(ji)(ji)其(qi)他恐(kong)龍。
在奧爾(er)德曼(man)組(zu)(zu),強健達(da)斯布雷(lei)龍(long)(long)(long)(long)(long)可(ke)能獵(lie)食鴨嘴龍(long)(long)(long)(long)(long)科(ke)(ke)(如短冠龍(long)(long)(long)(long)(long)及(ji)亞冠龍(long)(long)(long)(long)(long))、小型的(de)(de)鳥腳(jiao)下目(mu)(如奔山龍(long)(long)(long)(long)(long))、角龍(long)(long)(long)(long)(long)科(ke)(ke)(如尖角龍(long)(long)(long)(long)(long))、腫頭(tou)龍(long)(long)(long)(long)(long)下目(mu)、似(si)鳥龍(long)(long)(long)(long)(long)下目(mu)、鐮(lian)刀龍(long)(long)(long)(long)(long)超科(ke)(ke)及(ji)甲(jia)龍(long)(long)(long)(long)(long)下目(mu)。其他獵(lie)食恐(kong)龍(long)(long)(long)(long)(long)包括:傷(shang)齒龍(long)(long)(long)(long)(long)科(ke)(ke)、竊蛋(dan)龍(long)(long)(long)(long)(long)下目(mu)、馳龍(long)(long)(long)(long)(long)科(ke)(ke)的(de)(de)蜥鳥盜龍(long)(long)(long)(long)(long)、及(ji)艾伯塔龍(long)(long)(long)(long)(long)亞科(ke)(ke)。恐(kong)龍(long)(long)(long)(long)(long)公園(yuan)(yuan)組(zu)(zu)及(ji)雙麥(mai)迪遜(xun)組(zu)(zu)有(you)著類(lei)似(si)奧爾(er)德曼(man)組(zu)(zu)的(de)(de)動物群組(zu)(zu)成,而(er)恐(kong)龍(long)(long)(long)(long)(long)公園(yuan)(yuan)組(zu)(zu)則沒有(you)互(hu)相競爭的(de)(de)多種大型獵(lie)食恐(kong)龍(long)(long)(long)(long)(long)。蛇(she)發女怪龍(long)(long)(long)(long)(long)與達(da)斯布雷(lei)龍(long)(long)(long)(long)(long)同(tong)時(shi)生活于恐(kong)龍(long)(long)(long)(long)(long)公園(yuan)(yuan)組(zu)(zu)與雙麥(mai)迪遜(xun)組(zu)(zu)上(shang)層。幼年暴龍(long)(long)(long)(long)(long)科(ke)(ke)的(de)(de)生態位,介乎成年暴龍(long)(long)(long)(long)(long)科(ke)(ke)及(ji)小型的(de)(de)獸腳(jiao)亞目(mu)之間(jian),它(ta)們之間(jian)的(de)(de)體重有(you)數倍(bei)的(de)(de)差距(ju)。