梁(liang)(liang)(liang)龍(long)(long)是梁(liang)(liang)(liang)龍(long)(long)科(ke)的模式屬(shu),且梁(liang)(liang)(liang)龍(long)(long)科(ke)的名(ming)稱來(lai)自于梁(liang)(liang)(liang)龍(long)(long)屬(shu)。雖然(ran)梁(liang)(liang)(liang)龍(long)(long)科(ke)的體型巨大(da),但身體較(jiao)其他的蜥腳下目修(xiu)長,例(li)如泰(tai)(tai)坦(tan)巨龍(long)(long)類及(ji)腕龍(long)(long)科(ke)。所有梁(liang)(liang)(liang)龍(long)(long)科(ke)的特征(zheng)都是長頸(jing)及(ji)長尾巴,水平的姿勢,前肢較(jiao)后(hou)肢短小。梁(liang)(liang)(liang)龍(long)(long)科(ke)繁(fan)盛于侏羅紀晚期的北(bei)美洲(zhou),及(ji)可能還(huan)有非洲(zhou),而其生態位似乎是被白堊紀的泰(tai)(tai)坦(tan)巨龍(long)(long)類所取代(dai)。
梁(liang)龍(long)(long)(long)亞(ya)科(ke)包括梁(liang)龍(long)(long)(long)及其近親,如重龍(long)(long)(long)。同時期的遠(yuan)親迷(mi)惑龍(long)(long)(long),被認(ren)為(wei)是屬于(yu)梁(liang)龍(long)(long)(long)科(ke)下的迷(mi)惑龍(long)(long)(long)亞(ya)科(ke),而不是梁(liang)龍(long)(long)(long)亞(ya)科(ke)。一些學者認(ren)為(wei),葡萄牙(ya)的丁(ding)赫羅龍(long)(long)(long)及非(fei)洲的拖尼(ni)龍(long)(long)(long)都是梁(liang)龍(long)(long)(long)的近親。
梁龍(long)(long)(long)超科包(bao)(bao)含了梁龍(long)(long)(long)科、叉龍(long)(long)(long)科、雷巴齊斯龍(long)(long)(long)科、春雷龍(long)(long)(long)及(ji)雙(shuang)腔龍(long)(long)(long),可(ke)能還有簡棘龍(long)(long)(long)及(ji)納摩蓋吐龍(long)(long)(long)科。梁龍(long)(long)(long)超科是大(da)鼻龍(long)(long)(long)類的姊妹分(fen)類單元,大(da)鼻龍(long)(long)(long)類包(bao)(bao)含圓頂龍(long)(long)(long)、腕(wan)龍(long)(long)(long)科、以及(ji)泰坦(tan)巨龍(long)(long)(long)類。這兩(liang)個演化支組合成為新蜥腳(jiao)類,是最多(duo)樣化、最成功的蜥腳(jiao)形亞(ya)目(mu)恐龍(long)(long)(long)。
馬(ma)什及(ji)(ji)海徹(che)爾根據梁龍(long)的鼻孔(kong)位置是(shi)在(zai)頭蓋頂,而假設(she)梁龍(long)是(shi)生(sheng)活(huo)于水(shui)(shui)中的。其他大(da)型蜥(xi)(xi)腳下目恐龍(long),如腕龍(long)及(ji)(ji)迷惑龍(long),也被認(ren)為有類(lei)(lei)似的水(shui)(shui)棲生(sheng)活(huo)方式(shi)。但是(shi)在(zai)1951年(nian),Kenneth A. Kermack提出研究反對這(zhe)個假設(she),因(yin)為當蜥(xi)(xi)腳類(lei)(lei)浸在(zai)水(shui)(shui)里時,胸部水(shui)(shui)壓太大(da),會令它不能呼(hu)吸(xi)。自1970年(nian)代(dai)以(yi)來,蜥(xi)(xi)腳類(lei)(lei)恐龍(long)被認(ren)為是(shi)陸地動物,以(yi)植物為食。
梁(liang)龍(long)(long)是最(zui)容易(yi)確認(ren)的恐龍(long)(long)之一(yi),有著巨大的體型,長頸及尾巴,及強(qiang)壯的四(si)肢。很多年前(qian)它都被認(ren)為是最(zui)長的恐龍(long)(long)。它的體型足以阻(zu)嚇于同(tong)一(yi)地層發現(xian)的(有可能(neng)是同(tong)時代的)異(yi)特龍(long)(long)及角鼻(bi)龍(long)(long)等獵食(shi)動物。
梁(liang)龍(long)比迷惑龍(long)、腕(wan)龍(long)要(yao)長,但(dan)是由(you)于(yu)頭尾(wei)很長,軀干很短,而且很瘦,因(yin)此(ci)體重并(bing)不重,梁(liang)龍(long)脖子(zi)雖長,但(dan)由(you)于(yu)頸骨(gu)數量少(shao)且韌(ren),因(yin)此(ci)梁(liang)龍(long)的脖子(zi)并(bing)不能(neng)像蛇頸龍(long)一般(ban)自由(you)彎曲。腕(wan)龍(long)、雷龍(long)、梁(liang)龍(long)的鼻孔都是長在頭頂(ding)上的。
梁(liang)(liang)(liang)龍(long)(long)全(quan)長(chang)27米。由于(yu)背部(bu)(bu)(bu)骨(gu)(gu)骼(ge)較輕,使(shi)(shi)得它(ta)(ta)的(de)(de)(de)(de)(de)(de)身(shen)軀瘦小(xiao),只(zhi)有(you)(you)(you)十幾噸重(zhong)(zhong),體重(zhong)(zhong)遠(yuan)不(bu)如迷惑龍(long)(long)和(he)腕龍(long)(long)。它(ta)(ta)的(de)(de)(de)(de)(de)(de)牙(ya)齒只(zhi)長(chang)在嘴(zui)的(de)(de)(de)(de)(de)(de)前(qian)(qian)部(bu)(bu)(bu),而(er)(er)且很細(xi)(xi)小(xiao),這樣它(ta)(ta)就只(zhi)能吃(chi)些(xie)柔嫩多汁的(de)(de)(de)(de)(de)(de)植物(wu)了。鞭子似的(de)(de)(de)(de)(de)(de)長(chang)尾(wei)(wei)巴(ba)(ba)(ba)可以幫助它(ta)(ta)抵御敵害,也可以趕走所到(dao)之(zhi)處的(de)(de)(de)(de)(de)(de)其(qi)他(ta)小(xiao)動物(wu)。可以想象得出,梁(liang)(liang)(liang)龍(long)(long)在吃(chi)食(shi)(shi)的(de)(de)(de)(de)(de)(de)時(shi)候,尾(wei)(wei)巴(ba)(ba)(ba)在不(bu)斷抽打的(de)(de)(de)(de)(de)(de)情形。梁(liang)(liang)(liang)龍(long)(long)是(shi)個(ge)巨(ju)大(da)(da)(da)的(de)(de)(de)(de)(de)(de)恐龍(long)(long),它(ta)(ta)脖子長(chang)7.5米,尾(wei)(wei)巴(ba)(ba)(ba)13最長(chang)14米。盡(jin)管梁(liang)(liang)(liang)龍(long)(long)體型很大(da)(da)(da),梁(liang)(liang)(liang)龍(long)(long)的(de)(de)(de)(de)(de)(de)腦(nao)袋卻是(shi)纖(xian)細(xi)(xi)小(xiao)巧。它(ta)(ta)的(de)(de)(de)(de)(de)(de)鼻孔長(chang)在頭頂上(shang)。嘴(zui)的(de)(de)(de)(de)(de)(de)前(qian)(qian)部(bu)(bu)(bu)長(chang)著(zhu)扁平(ping)的(de)(de)(de)(de)(de)(de)牙(ya)齒,嘴(zui)的(de)(de)(de)(de)(de)(de)側(ce)(ce)面(mian)和(he)后(hou)部(bu)(bu)(bu)則(ze)沒(mei)有(you)(you)(you)牙(ya)齒。它(ta)(ta)的(de)(de)(de)(de)(de)(de)前(qian)(qian)腿(tui)比(bi)后(hou)腿(tui)短,每只(zhi)腳(jiao)上(shang)有(you)(you)(you)五個(ge)腳(jiao)趾(zhi),其(qi)中的(de)(de)(de)(de)(de)(de)一(yi)個(ge)腳(jiao)趾(zhi)長(chang)著(zhu)爪子。梁(liang)(liang)(liang)龍(long)(long)的(de)(de)(de)(de)(de)(de)腦(nao)袋非常小(xiao),所以它(ta)(ta)不(bu)聰明。梁(liang)(liang)(liang)龍(long)(long)是(shi)草食(shi)(shi)動物(wu)。吃(chi)東(dong)西時(shi),它(ta)(ta)不(bu)咀嚼(jiao),而(er)(er)是(shi)將(jiang)樹葉等食(shi)(shi)物(wu)直接吞下去。一(yi)些(xie)大(da)(da)(da)型食(shi)(shi)肉恐龍(long)(long)會(hui)(hui)捕食(shi)(shi)梁(liang)(liang)(liang)龍(long)(long).如果讓20位9歲左右的(de)(de)(de)(de)(de)(de)小(xiao)朋友頭腳(jiao)相接的(de)(de)(de)(de)(de)(de)躺在地上(shang),他(ta)們(men)組(zu)成(cheng)的(de)(de)(de)(de)(de)(de)長(chang)度基本上(shang)同梁(liang)(liang)(liang)龍(long)(long)的(de)(de)(de)(de)(de)(de)體長(chang)差不(bu)多。梁(liang)(liang)(liang)龍(long)(long)的(de)(de)(de)(de)(de)(de)脖子又(you)細(xi)(xi)又(you)長(chang),尾(wei)(wei)巴(ba)(ba)(ba)像(xiang)鞭子,四條腿(tui)像(xiang)柱子一(yi)般(ban)。梁(liang)(liang)(liang)龍(long)(long)的(de)(de)(de)(de)(de)(de)后(hou)腿(tui)比(bi)前(qian)(qian)肢稍長(chang),所以它(ta)(ta)的(de)(de)(de)(de)(de)(de)臀部(bu)(bu)(bu)高于(yu)前(qian)(qian)肩。從其(qi)纖(xian)細(xi)(xi)、小(xiao)巧的(de)(de)(de)(de)(de)(de)腦(nao)袋到(dao)其(qi)巨(ju)大(da)(da)(da)無比(bi)的(de)(de)(de)(de)(de)(de)尾(wei)(wei)巴(ba)(ba)(ba)頂稍,梁(liang)(liang)(liang)龍(long)(long)的(de)(de)(de)(de)(de)(de)身(shen)體被一(yi)串相互連接的(de)(de)(de)(de)(de)(de)中軸骨(gu)(gu)骼(ge)支(zhi)撐著(zhu),我們(men)稱其(qi)為脊(ji)椎骨(gu)(gu)。它(ta)(ta)的(de)(de)(de)(de)(de)(de)脖子是(shi)由15塊(kuai)脊(ji)椎骨(gu)(gu)組(zu)成(cheng),胸部(bu)(bu)(bu)和(he)背部(bu)(bu)(bu)有(you)(you)(you)10塊(kuai),而(er)(er)細(xi)(xi)長(chang)的(de)(de)(de)(de)(de)(de)尾(wei)(wei)巴(ba)(ba)(ba)內竟有(you)(you)(you)大(da)(da)(da)約70塊(kuai)!盡(jin)管梁(liang)(liang)(liang)龍(long)(long)身(shen)體龐大(da)(da)(da),但它(ta)(ta)完全(quan)可以用(yong)脖子和(he)尾(wei)(wei)巴(ba)(ba)(ba)的(de)(de)(de)(de)(de)(de)力(li)量(liang)將(jiang)自己從地面(mian)上(shang)支(zhi)撐起來(lai)(lai)。梁(liang)(liang)(liang)龍(long)(long)能用(yong)它(ta)(ta)強有(you)(you)(you)力(li)的(de)(de)(de)(de)(de)(de)尾(wei)(wei)巴(ba)(ba)(ba)來(lai)(lai)鞭打敵人,迫使(shi)(shi)進(jin)攻者后(hou)退;或者用(yong)后(hou)腿(tui)站立,用(yong)尾(wei)(wei)巴(ba)(ba)(ba)支(zhi)持(chi)部(bu)(bu)(bu)分體重(zhong)(zhong),以便能用(yong)巨(ju)大(da)(da)(da)的(de)(de)(de)(de)(de)(de)前(qian)(qian)肢來(lai)(lai)自衛(wei)。梁(liang)(liang)(liang)龍(long)(long)前(qian)(qian)肢內側(ce)(ce)腳(jiao)趾(zhi)上(shang)有(you)(you)(you)一(yi)個(ge)巨(ju)大(da)(da)(da)而(er)(er)彎曲的(de)(de)(de)(de)(de)(de)爪,那可是(shi)它(ta)(ta)鋒(feng)利的(de)(de)(de)(de)(de)(de)自衛(wei)武器。就像(xiang)人類的(de)(de)(de)(de)(de)(de)鞋后(hou)跟(gen)一(yi)樣,梁(liang)(liang)(liang)龍(long)(long)的(de)(de)(de)(de)(de)(de)腳(jiao)下大(da)(da)(da)概也生有(you)(you)(you)能將(jiang)其(qi)腳(jiao)趾(zhi)墊(dian)起來(lai)(lai)的(de)(de)(de)(de)(de)(de)腳(jiao)掌墊(dian)。有(you)(you)(you)了它(ta)(ta),梁(liang)(liang)(liang)龍(long)(long)在行走時(shi)就不(bu)會(hui)(hui)因(yin)為支(zhi)持(chi)沉重(zhong)(zhong)的(de)(de)(de)(de)(de)(de)身(shen)體而(er)(er)使(shi)(shi)肌肉感到(dao)太吃(chi)力(li)。
自從(cong)被發現(xian)以來(lai),梁龍(long)(long)步(bu)態的(de)想像(xiang)圖經(jing)歷了很大的(de)改變(bian)。例如(ru)一(yi)幅1910年(nian)的(de)早(zao)期(qi)圖繪(hui),兩頭(tou)梁龍(long)(long)的(de)四(si)肢像(xiang)蜥蜴般向兩側延(yan)展。但是這個假(jia)說卻被推翻,因(yin)梁龍(long)(long)若(ruo)能伸開四(si)肢,地上必須(xu)有一(yi)個溝(gou)來(lai)放置(zhi)它的(de)腹部(bu)。
之(zhi)后,梁龍(long)科經常被描(miao)繪成它(ta)的(de)(de)頸部(bu)高舉(ju)(ju),使它(ta)們(men)(men)可(ke)以吃高樹上(shang)的(de)(de)葉子(zi)。但是(shi),科學家們(men)(men)提(ti)出(chu)(chu)爭議,懷疑(yi)它(ta)們(men)(men)的(de)(de)心(xin)臟是(shi)否能(neng)夠維持(chi)足夠的(de)(de)血(xue)壓,供應(ying)血(xue)液至(zhi)腦部(bu)。再者,它(ta)的(de)(de)頸部(bu)結構亦(yi)被發現(xian)并不能(neng)過(guo)度(du)向上(shang)彎曲(qu)的(de)(de)。在2009年,一(yi)個研(yan)究提(ti)出(chu)(chu)所有四(si)足類都能(neng)夠將頭頸部(bu)高舉(ju)(ju),以警戒四(si)周的(de)(de)環(huan)境(jing)。研(yan)究人(ren)員也發現(xian),梁龍(long)的(de)(de)頸部(bu)可(ke)以下垂至(zhi)45度(du)。
就像重龍(long),梁龍(long)的(de)(de)長頸(jing)(jing)(jing)一(yi)(yi)直(zhi)都是科學(xue)家所爭(zheng)議的(de)(de)地方。一(yi)(yi)個(ge)(ge)1992年的(de)(de)哥倫比亞大學(xue)研究就指出梁龍(long)的(de)(de)頸(jing)(jing)(jing)結構,需要(yao)一(yi)(yi)個(ge)(ge)1.6噸重的(de)(de)心(xin)臟(zang)。這個(ge)(ge)研究繼(ji)而假設它(ta)們可能在(zai)頸(jing)(jing)(jing)部有一(yi)(yi)個(ge)(ge)輔助(zhu)的(de)(de)心(xin)臟(zang),主要(yao)是將血液輸(shu)送至另一(yi)(yi)個(ge)(ge)心(xin)臟(zang)。
傳統的(de)觀點(dian)認(ren)為(wei),梁(liang)龍(long)(long)的(de)長(chang)頸是為(wei)適應食性(xing)而發展出(chu)的(de)。又有研究(jiu)提出(chu)梁(liang)龍(long)(long)的(de)頸可(ke)能是用作求(qiu)偶的(de)視(shi)覺展示物,而其他的(de)因素則是其次。這個假設已遭(zao)到詳細(xi)駁斥。還(huan)有人(ren)認(ren)為(wei)它(ta)們的(de)脖子是用來擴大(da)原地進食面積的(de)。
在必要時,梁龍可以用兩條后肢站立(li),使(shi)頸部向上以吃到高處(chu)的葉子。
雖(sui)然目(mu)前沒(mei)有(you)梁(liang)龍(long)(long)(long)(long)筑巢習(xi)性的直接證(zheng)據,但已(yi)發現其他蜥腳下目(mu)的蛋巢,例如(ru)泰坦巨龍(long)(long)(long)(long)類的薩爾塔龍(long)(long)(long)(long)。泰坦巨龍(long)(long)(long)(long)類的蛋巢顯示,它們(men)可(ke)能會共同(tong)在一個地方的不(bu)同(tong)淺坑(keng)中生(sheng)蛋,而(er)每一個坑(keng)則會以植物遮蓋。而(er)梁(liang)龍(long)(long)(long)(long)亦可(ke)能會有(you)同(tong)樣的習(xi)性。電視節目(mu)《與恐龍(long)(long)(long)(long)共舞》(Walking with Dinosaurs)則出(chu)現一只(zhi)雌(ci)性梁(liang)龍(long)(long)(long)(long)用產(chan)卵管產(chan)下恐龍(long)(long)(long)(long)蛋,但這(zhe)僅止于制作單位的假(jia)設(she)。
根據一些(xie)骨頭的(de)組織學研究,梁龍的(de)生長率(lv)在(zai)蜥(xi)腳下目中(zhong)非常地快,只需約十年(nian)的(de)時間(jian)就可(ke)以(yi)達(da)至性成熟(shu),且在(zai)整個生命中(zhong)不(bu)斷的(de)生長。這反對了以(yi)往認為梁龍生長很緩慢,需要(yao)幾十年(nian)時間(jian)才到達(da)性成熟(shu)的(de)假設。
法國南部(bu)發(fa)現(xian)(xian)(xian)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)各種恐(kong)(kong)(kong)龍(long)蛋(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)可(ke)(ke)(ke)(ke)能(neng)(neng)都(dou)是(shi)(shi)蜥(xi)(xi)(xi)腳(jiao)(jiao)(jiao)類(lei)(lei)(lei)(lei)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)物(wu)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)蛋(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan),雖然(ran)里面(mian)(mian)沒(mei)(mei)有保存下(xia)胚(pei)(pei)(pei)胎(tai)。這(zhe)(zhe)些(xie)蛋(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)外表(biao)呈圓形,而(er)(er)其中(zhong)(zhong)(zhong)一(yi)(yi)處發(fa)掘(jue)現(xian)(xian)(xian)場(chang)可(ke)(ke)(ke)(ke)以(yi)(yi)清楚看出(chu),這(zhe)(zhe)些(xie)恐(kong)(kong)(kong)龍(long)蛋(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)都(dou)被(bei)生(sheng)(sheng)在(zai)(zai)(zai)(zai)(zai)(zai)溝渠里。更有趣的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)是(shi)(shi),這(zhe)(zhe)些(xie)蛋(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)在(zai)(zai)(zai)(zai)(zai)(zai)生(sheng)(sheng)下(xia)時(shi)(shi)似(si)乎(hu)就已排列成(cheng)(cheng)(cheng)弧形,由此可(ke)(ke)(ke)(ke)知,至(zhi)少(shao)這(zhe)(zhe)種蜥(xi)(xi)(xi)腳(jiao)(jiao)(jiao)類(lei)(lei)(lei)(lei)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)物(wu)是(shi)(shi)一(yi)(yi)邊繞(rao)著大(da)(da)圈(quan)子(zi),一(yi)(yi)邊生(sheng)(sheng)蛋(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(以(yi)(yi)前(qian)有一(yi)(yi)種誤傳(chuan),既是(shi)(shi)“梁(liang)龍(long)一(yi)(yi)邊走(zou)路(lu)一(yi)(yi)邊生(sheng)(sheng)蛋(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan),因此恐(kong)(kong)(kong)龍(long)蛋(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)形成(cheng)(cheng)(cheng)一(yi)(yi)條長長的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)線”,這(zhe)(zhe)是(shi)(shi)錯誤的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de))。弧形的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)半(ban)徑和(he)蜥(xi)(xi)(xi)腳(jiao)(jiao)(jiao)類(lei)(lei)(lei)(lei)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)物(wu)以(yi)(yi)后腿(tui)為(wei)(wei)中(zhong)(zhong)(zhong)心旋(xuan)繞(rao)時(shi)(shi)造成(cheng)(cheng)(cheng)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)半(ban)徑相吻(wen)合,若(ruo)沿蛋(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)排列弧線畫一(yi)(yi)個圓,整個圓周(zhou)可(ke)(ke)(ke)(ke)容納大(da)(da)約一(yi)(yi)百顆蛋(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)。蛋(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)尺寸有如一(yi)(yi)顆足球,和(he)蜥(xi)(xi)(xi)腳(jiao)(jiao)(jiao)類(lei)(lei)(lei)(lei)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)物(wu)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)體(ti)型(xing)比較(jiao)起(qi)(qi)來,顯(xian)(xian)得(de)非(fei)常(chang)小,很難想象孵出(chu)來的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)幼(you)(you)(you)(you)獸(shou)(shou)(shou)(shou)將(jiang)來會(hui)長成(cheng)(cheng)(cheng)這(zhe)(zhe)么龐大(da)(da)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)成(cheng)(cheng)(cheng)獸(shou)(shou)(shou)(shou)。但(dan)(dan)(dan)是(shi)(shi)蛋(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)大(da)(da)小實際上(shang)會(hui)受到(dao)生(sheng)(sheng)理(li)限制。蛋(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)必須呼吸,當(dang)蛋(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)愈大(da)(da),表(biao)面(mian)(mian)積(ji)(ji)與(yu)體(ti)積(ji)(ji)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)比值(zhi)就愈小,因此大(da)(da)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)蛋(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)無法使(shi)胚(pei)(pei)(pei)胎(tai)透過蛋(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)殼(ke)來獲得(de)所需的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)足夠空(kong)氣。2001年科學家首次在(zai)(zai)(zai)(zai)(zai)(zai)阿(a)根(gen)廷發(fa)現(xian)(xian)(xian)了蜥(xi)(xi)(xi)腳(jiao)(jiao)(jiao)類(lei)(lei)(lei)(lei)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)物(wu)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)胚(pei)(pei)(pei)胎(tai),就連(lian)胚(pei)(pei)(pei)胎(tai)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)皮膚組(zu)織也(ye)保存得(de)很完整。還好這(zhe)(zhe)項發(fa)現(xian)(xian)(xian),證實了科學家從法國發(fa)掘(jue)現(xian)(xian)(xian)場(chang)中(zhong)(zhong)(zhong)得(de)出(chu)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)許多結(jie)論。 但(dan)(dan)(dan)是(shi)(shi)從這(zhe)(zhe)些(xie)發(fa)現(xian)(xian)(xian)中(zhong)(zhong)(zhong),我(wo)(wo)(wo)們(men)(men)(men)(men)無法推(tui)敲雌恐(kong)(kong)(kong)龍(long)是(shi)(shi)如 [3] ?何(he)把(ba)蛋(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)生(sheng)(sheng)到(dao)地(di)面(mian)(mian)上(shang)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)。由于(yu)蜥(xi)(xi)(xi)腳(jiao)(jiao)(jiao)類(lei)(lei)(lei)(lei)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)物(wu)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)身(shen)體(ti)離(li)(li)地(di)面(mian)(mian)有一(yi)(yi)大(da)(da)段距(ju)離(li)(li),而(er)(er)且從詳細的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)化石蛋(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)研究(jiu)中(zhong)(zhong)(zhong)得(de)知,蛋(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)殼(ke)硬(ying)且易碎,因此生(sheng)(sheng)蛋(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)對(dui)蜥(xi)(xi)(xi)腳(jiao)(jiao)(jiao)類(lei)(lei)(lei)(lei)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)物(wu)來說確實是(shi)(shi)個大(da)(da)問題(ti)。它(ta)也(ye)許用(yong)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)是(shi)(shi)蹲姿(zi),但(dan)(dan)(dan)即(ji)使(shi)如此,仍然(ran)距(ju)溝渠底部(bu)至(zhi)少(shao)還有八英尺的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)距(ju)離(li)(li)。我(wo)(wo)(wo)們(men)(men)(men)(men)提出(chu)了一(yi)(yi)個可(ke)(ke)(ke)(ke)能(neng)(neng)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)方法,但(dan)(dan)(dan)沒(mei)(mei)有人能(neng)(neng)確定(ding)這(zhe)(zhe)就是(shi)(shi)雌恐(kong)(kong)(kong)龍(long)真正的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)生(sheng)(sheng)蛋(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)方法。我(wo)(wo)(wo)們(men)(men)(men)(men)認(ren)為(wei)(wei)雌恐(kong)(kong)(kong)龍(long)身(shen)上(shang)有一(yi)(yi)根(gen)管(guan)子(zi),可(ke)(ke)(ke)(ke)以(yi)(yi)輕輕將(jiang)蛋(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)放到(dao)地(di)面(mian)(mian)。現(xian)(xian)(xian)代(dai)(dai)烏龜就是(shi)(shi)利用(yong)管(guan)子(zi)生(sheng)(sheng)蛋(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan),雖然(ran)它(ta)們(men)(men)(men)(men)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)管(guan)子(zi)較(jiao)短。 發(fa)現(xian)(xian)(xian)到(dao)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)蜥(xi)(xi)(xi)腳(jiao)(jiao)(jiao)類(lei)(lei)(lei)(lei)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)物(wu)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)蛋(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)還透露出(chu)更具(ju)意義的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)訊息。蛋(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)數目(mu)對(dui)蜥(xi)(xi)(xi)腳(jiao)(jiao)(jiao)類(lei)(lei)(lei)(lei)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)物(wu)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)行為(wei)(wei)有何(he)意義?自然(ran)界有一(yi)(yi)個很明(ming)顯(xian)(xian)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)行為(wei)(wei)模式(shi),即(ji)生(sheng)(sheng)產數目(mu)愈多,父(fu)母照顧(gu)程度就愈低。在(zai)(zai)(zai)(zai)(zai)(zai)生(sheng)(sheng)產數目(mu)對(dui)父(fu)母照顧(gu)比例的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)一(yi)(yi)端,魚和(he)兩棲類(lei)(lei)(lei)(lei)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)物(wu)一(yi)(yi)次產下(xia)數千顆蛋(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan),但(dan)(dan)(dan)卻(que)不關心它(ta)們(men)(men)(men)(men)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)死活。人類(lei)(lei)(lei)(lei)為(wei)(wei)此比例另一(yi)(yi)端的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)代(dai)(dai)表(biao),一(yi)(yi)次通常(chang)只生(sheng)(sheng)產一(yi)(yi)名嬰兒,但(dan)(dan)(dan)卻(que)付出(chu)長期的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)關愛。蜥(xi)(xi)(xi)腳(jiao)(jiao)(jiao)類(lei)(lei)(lei)(lei)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)物(wu)似(si)乎(hu)會(hui)產下(xia)為(wei)(wei)數可(ke)(ke)(ke)(ke)觀的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)蛋(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan),因此即(ji)使(shi)它(ta)們(men)(men)(men)(men)讓(rang)這(zhe)(zhe)些(xie)蛋(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)(dan)自生(sheng)(sheng)自滅,也(ye)不會(hui)影響蜥(xi)(xi)(xi)腳(jiao)(jiao)(jiao)類(lei)(lei)(lei)(lei)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)物(wu)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)平衡。但(dan)(dan)(dan)我(wo)(wo)(wo)們(men)(men)(men)(men)想以(yi)(yi)比這(zhe)(zhe)項敘述更明(ming)確的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)解(jie)釋,來說明(ming)蜥(xi)(xi)(xi)腳(jiao)(jiao)(jiao)類(lei)(lei)(lei)(lei)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)物(wu)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)行為(wei)(wei)。梁(liang)龍(long)可(ke)(ke)(ke)(ke)能(neng)(neng)采用(yong)一(yi)(yi)種托(tuo)兒所的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)模式(shi),也(ye)就是(shi)(shi)同年齡的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)幼(you)(you)(you)(you)獸(shou)(shou)(shou)(shou)在(zai)(zai)(zai)(zai)(zai)(zai)孵化后會(hui)聚集(ji)在(zai)(zai)(zai)(zai)(zai)(zai)一(yi)(yi)起(qi)(qi)。現(xian)(xian)(xian)代(dai)(dai)駝鳥即(ji)采用(yong)此一(yi)(yi)模式(shi);然(ran)而(er)(er)在(zai)(zai)(zai)(zai)(zai)(zai)此模式(shi)中(zhong)(zhong)(zhong),一(yi)(yi)只成(cheng)(cheng)(cheng)鳥會(hui)留下(xia)來照顧(gu)幼(you)(you)(you)(you)鳥。但(dan)(dan)(dan)為(wei)(wei)何(he)我(wo)(wo)(wo)們(men)(men)(men)(men)會(hui)認(ren)為(wei)(wei)蜥(xi)(xi)(xi)腳(jiao)(jiao)(jiao)類(lei)(lei)(lei)(lei)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)物(wu)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)幼(you)(you)(you)(you)獸(shou)(shou)(shou)(shou)會(hui)聚集(ji)在(zai)(zai)(zai)(zai)(zai)(zai)一(yi)(yi)起(qi)(qi)?這(zhe)(zhe)是(shi)(shi)從它(ta)們(men)(men)(men)(men)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)足印推(tui)測(ce)而(er)(er)來。幾處發(fa)掘(jue)現(xian)(xian)(xian)場(chang)顯(xian)(xian)示蜥(xi)(xi)(xi)腳(jiao)(jiao)(jiao)類(lei)(lei)(lei)(lei)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)物(wu)喜歡成(cheng)(cheng)(cheng)群(qun)移動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong),但(dan)(dan)(dan)在(zai)(zai)(zai)(zai)(zai)(zai)這(zhe)(zhe)些(xie)足印中(zhong)(zhong)(zhong)卻(que)沒(mei)(mei)有任何(he)幼(you)(you)(you)(you)獸(shou)(shou)(shou)(shou)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)小足跡(ji)。相反的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de),韓國金東巖層(Jindng F·rmatin)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)一(yi)(yi)處足印遺址,顯(xian)(xian)示有一(yi)(yi)群(qun)非(fei)常(chang)小的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)蜥(xi)(xi)(xi)腳(jiao)(jiao)(jiao)類(lei)(lei)(lei)(lei)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)物(wu)集(ji)體(ti)行動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)。這(zhe)(zhe)和(he)我(wo)(wo)(wo)們(men)(men)(men)(men)對(dui)現(xian)(xian)(xian)代(dai)(dai)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)物(wu)行為(wei)(wei)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)理(li)解(jie)比較(jiao)起(qi)(qi)來,這(zhe)(zhe)種假設似(si)乎(hu)有些(xie)奇怪。但(dan)(dan)(dan)由于(yu)蜥(xi)(xi)(xi)腳(jiao)(jiao)(jiao)類(lei)(lei)(lei)(lei)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)物(wu)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)幼(you)(you)(you)(you)獸(shou)(shou)(shou)(shou)和(he)成(cheng)(cheng)(cheng)獸(shou)(shou)(shou)(shou)之(zhi)間的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)體(ti)型(xing)差異非(fei)常(chang)大(da)(da),如果幼(you)(you)(you)(you)獸(shou)(shou)(shou)(shou)和(he)成(cheng)(cheng)(cheng)獸(shou)(shou)(shou)(shou)走(zou)在(zai)(zai)(zai)(zai)(zai)(zai)一(yi)(yi)起(qi)(qi)時(shi)(shi),可(ke)(ke)(ke)(ke)能(neng)(neng)會(hui)被(bei)壓死。此外,在(zai)(zai)(zai)(zai)(zai)(zai)群(qun)體(ti)移動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)時(shi)(shi),幼(you)(you)(you)(you)獸(shou)(shou)(shou)(shou)可(ke)(ke)(ke)(ke)能(neng)(neng)跟不上(shang)成(cheng)(cheng)(cheng)獸(shou)(shou)(shou)(shou)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)腳(jiao)(jiao)(jiao)步。但(dan)(dan)(dan)這(zhe)(zhe)又衍生(sheng)(sheng)出(chu)另一(yi)(yi)個重要(yao)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)問題(ti):幼(you)(you)(you)(you)獸(shou)(shou)(shou)(shou)何(he)時(shi)(shi)而(er)(er)且如何(he)加入成(cheng)(cheng)(cheng)獸(shou)(shou)(shou)(shou)群(qun)體(ti)?