猛兽吧 关注:96,066贴子:2,842,838

回复:斗蜥鳄属(马奇莫鳄)的一些简介

只看楼主收藏回复


上图:测量尺以君王斗蜥鳄头骨162cm为标准,凯万A, B,C因为排版美观问题原论文测量尺不同意,已经根据实际尺寸对A, B, C做了修正。凯万正模的体型BCL 185.9cm。 颞孔之间宽82cm, 方骨之间宽96cm, 君王斗蜥鳄为BCL 155cm, SKL 162cm, 最大宽度61cm。
君王斗蜥鳄咬力测算, 颜色君王,虚线凯万:颞孔面积占凯万67%,颞孔侧面积是62%(**注意君王是按最末端宽度,凯万没有,因此凯万最后计算的时候加宽了虚线),此外能够附着肌肉的颅脊位置到Basioccupit的最大高度是68.5%。因此估测咬力是(((62%*68.5%))*(67%))^0.5 = 53.3%. 凯万上龙和君王斗蜥鳄在同样SKL下眼眶位置距离颌骨关节都是差不多的,因此不需要额外修正外杠杆长度。
末端咬力和其他动物比较
凯万上龙正模按照活体修正后的MPTv, 30N/cm^2计算得到咬力 41562N~48 728N。方法有限元/FBD类
君王斗蜥蜴鳄正模活体修正后的MPTv, 30N/cm^2计算得到咬力 22152N~N25972N。方法参考有限元/FBD类
霸王龙BHI 3033(小版) BCL 125cm,HW 81.7cm, 活体修正MPTv后计算得到咬力57158N。方法有限元/FBD类
宽吻鳄BCL 52cm/HL 50cm, HW 31.8cm, 活体修正MPTv后计算得到咬力5760N。方法有限元/FBD类
脆弱异常特龙SAM 005活体修正MPtv后BCL 70cm, HW 35cm, 计算得到咬力8506N, 方法有限元/FBD类
放大到TL 7.4米和君王斗蜥鳄等长的时候,BCL为106.8cm,宽吻鳄咬合力为24297.3N。
放大到HW和君王斗蜥鳄等宽的时候宽吻鳄咬力为20930N。放大到BCL等长的时候为51177.5N。


IP属地:山东39楼2018-06-03 14:03
回复
    最后一个小插曲,从线稿和比例图上显示的肋骨上看SNSM 91415的肋骨是要明显超过AMNH 7139美洲鳄的(保留的几根肋骨长度在26~34cm之间vs 一般主要在20cm~25.4cm之间),但是两者头部高度是差不多的,鳄鱼下颌骨最末端比头骨要粗, 正确摆放姿态下而斗蜥鳄下颌骨最末端的位置比头骨要细,实际粗细也就是斗蜥鳄稍微粗一点。因此看头部两者是体重差不多。肋骨就要看其肋骨是如何复原了,往后斜的幅度大不大,腹肋长度如何,类似恐龙那样的结构还是鳄鱼那样的结构。



    下图如果是类似完全类似鳄鱼那样的结构,其体重最高可能会比表格上的重175%倍左右。当然按恐龙那样的短腹肋型的能达到表上的体型就很不错了。下面会拿几个近亲来比较一下


    IP属地:山东40楼2018-06-03 15:02
    回复(7)
      2025-12-27 08:16:38
      广告
      不感兴趣
      开通SVIP免广告
      真蜥蜴鳄类的里面的一些完整骨架,有侧视图也有俯视图,用俯视图比较清晰一些,虽然有些高度摆放问题,但是可以简化估测为就是脊椎的高度来调角度。再稍作休整。此处使用骨架为下图4号



      IP属地:山东41楼2018-06-03 15:06
      回复
        斗蜥鳄和同躯干长的恒河鳄


        IP属地:浙江42楼2018-06-03 15:32
        回复
          加入同体长的棘龙
          可见头身比有多重要

          棘龙素材来自论文The riddle of Spinosaurus aegyptiacus’ dorsal sail


          IP属地:浙江43楼2018-06-03 15:36
          回复(3)
            对巴氏斗蜥鳄的体重在体围层面毛估。

            尝试修正了以后,红圈为图上肋骨,蓝圈为最长肋骨对应的位置;篮圈是一个43 X 57 cm的一个椭圆,对应周长157.5cm左右,SVL估测(179.5+6.5=186cm) 此处是最粗的位置。根据尼罗鳄68.75cmHL,BCL估测71.67cm,SVL 304cm, 去掉头后的尺寸是232.3cm;活体周长213cm,体重~820kg。
            【1】按骨架蒙皮是820*(186/232.3)*(157.5/213)^2 = 359kg
            【2】按活体增加长度5%,粗细10%之后的体重为= 456kg
            【3】按活体长度增加5%,粗细15%之后的体重为= 498kg。
            看来之前选用的472kg应该还是没有问题的,活体比骨架蒙皮重了31%左右。其体重较轻估计是因为肋骨往后衍生的幅度比较大吧,而且腹肋骨比鳄鱼短。


            IP属地:山东45楼2018-06-03 16:00
            回复

              埃及棘龙BMNH 16421, NMC 41852,体长差不多的幼年棘龙和君王斗蜥鳄正模。


              IP属地:山东46楼2018-06-03 16:36
              回复
                Gryposuchus croizati,800万年前托尔顿阶的史前长吻鳄,在南美亚马逊的。DA站上说12米

                这些细嘴、虑食鳄跟普鲁斯鳄生活在一起确定不会被当食物么


                DA站上对这个长吻鳄的描述
                8 million years ago, in the Tortonian Stage, Miocene Epoch, almost all of Northern South America was covered by a monstrously vast swampland. In these swamps were monsters.
                The Urumaco and Solimoes Formations of Brazil reveal these animals as fossils, and show that the ancient Amazon was a superb place for life. This was p\one of three 40-foot crocodilians, and is named Gryposuchus croizati. It is the biggest gavialoid, or gharial of all time. Gharials eat only fish, but the fish i nthe Amazon include arapaima, arowana, tambaqui, trahira, tambaqui, lungfish, giant catfish.,....and in the Miocene, 3-foot-long piranha, Megapiranha!!!!
                Of course, this is a male Gryposuchus. Even extinct gharials would've had the characteristic ghara on their snout. This is perhaps one of the first of it on DA!


                IP属地:浙江48楼2018-06-03 19:41
                收起回复
                  2025-12-27 08:10:38
                  广告
                  不感兴趣
                  开通SVIP免广告

                  恒河食鱼鳄的
                  Finally, let us note that the Gharialitself, Gavialis gangeticus,is not necessarily a small animal [adjacent image, from wikipedia, shows acaptive False gharial]. A Gharial skull at Munich is 77.3 cm long (making itthe third longest modern crocodilian skull), but again its total length was notrecorded. Of course, there are tales of giants that were measured whole: analleged 7 m specimen was shot on the Kosi River in 1924, a 6.6 m longindividual on the Gogra River in 1920, and a 6.4 m animal was killed in theCheko River in 1934. I have no idea whether these lengths were ever verified.It is well known that gharials have occasionally been found with jewellery intheir stomachs, but this has been attributed to their possibly feeding on theremains of funerals, or even on picking up such objects for use as gastroliths.However, big gharials are not limited to a diet of small prey as they arealleged to sometimes take goats and feral dogs. There are a couple ofauthenticated attacks on humans: 55 year old Sankara Behera was attacked by onein 1979 at the Satkoshia Gorge Sanctuary (Bustard & Singh 1981). It grabbedhis arm and he fell into the river; his son rescued him and he later recovered.A few other people have been bitten (Steel 1989), but these attacks mostly seemto have been motivated by territoriality or nest-defence.
                  Note how I cleverly avoided even mentioningthe phylogenetic affinities of Tomistoma andGavialis,easily the most controversial areas in crocodilian evolutionary biology.
                  Refs– –
                  Alderton, D. 1991. Crocodiles& Alligators of the World. Blandford, London.
                  Bustard, H. R. & Singh, L. A. K. 1981.Gharial attacks on man. Journal of Bombay NaturalHistory Society 78,610-611.
                  Guggisberg, C. A. W. 1972. Crocodiles:Their Natural History, Folklore and Conservation. David &Charles, Newton Abbot.
                  Head, J. J. 2001. Systematics and body sizeof the gigantic, enigmatic crocodyloidRhamphosuchuscrassidens, and the faunal history of Siwalik group (Miocene)crocodilians.Journal of VertebratePaleontology 21(Supp. to No. 3), 59.
                  McAliley, L. R., Willis, R. E., Ray, D. A.,White, P. S., Brochu, C. A. & Densmore, L. D. 2006. Are crocodiles reallymonophyletic? – Evidence for subdivisions from sequence and morphological data. MolecularPhylogenetics and Evolution 39,16-32.
                  Steel, R. 1989. Crocodiles.Christopher Helm, London.
                  慕尼黑博物馆的恒河鳄头骨长77.3厘米(使它第三长的现代鳄鱼头骨),但又总长度没有记录。当然,有一些巨大生物的传言:一个所谓的7米的样本在1924年戈西河的镜头,哥格拉河1920年一个长6.6米的个体,和一个6.4米的动物在1934年契科河身亡。我不知道这些长度是否曾经被验证过。众所周知,恒河鳄偶尔被发现在它们胃里的珠宝,但这已被归因于它们可能对葬礼后遗体的啃食,甚至拿来作为胃石等对象。然而,大型恒河鳄不限于捕食小猎物,宣称它们有时捕食山羊和野狗。有几个真实可靠的对人类的攻击事例,55岁的SankaraBehera 被袭击,恒河鳄抓住了他的胳膊,他掉进了河里,他的儿子救了他,他后来康复了。其他几人被咬伤,但这些攻击大部分似乎是出于保护领地或护巢。



                  IP属地:浙江49楼2018-06-03 19:43
                  回复(4)


                    IP属地:浙江51楼2018-06-04 15:50
                    回复

                      Elosuchus,最大的确认的个体BCL 107cm。这里下颌骨用了帝王鳄的.....下颌孔极小,那些带有下颌骨孔的或许是另外一种Kem Kem和Niger的大型鳄鱼。(126~150cm的下颌骨,一个155cm的头骨, 此外皇者发了一个更大Kem Kem的下颌残片,这个明显比上一个所谓的2米巨鳄更大....)。


                      IP属地:山东52楼2018-06-05 17:21
                      回复


                        皇者新发的这个比原先的那个后端大一些,大概是150cm的ML,当然这个尺寸也还是没有Sereno贴牌的那个大(155cm的SKL或者ML). 这个对应SKL 133cm, 比核实最大的Elosuchus(SKL 117cm. BCL 107.7cm)要大一些。当然吻部和头骨强度可能会稍弱(加入和2015 JVP摘要的那个是一个类型的,那个听参会的人说和摘要都是比Elosuchus更像细吻食鱼鳄)


                        IP属地:山东53楼2018-06-05 17:41
                        回复
                          马奇莫鳄有没有办法猎杀美扭椎龙和中棘龙,就像bbc卫星滑齿龙拖扭椎龙下水一样?


                          IP属地:福建来自iPhone客户端54楼2020-05-26 00:42
                          回复