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カルノタウルス
プラハのフルパーチ博​​物館に展示された全身骨格
地質時代
約7,200万 - 約6,990万年前
（中生代後期白亜紀マーストリヒチアン）
分類
ドメイン : 真核生物 Eukaryota
界 : 動物界 Animalia
門 : 脊索動物門 Chordata
亜門 : 脊椎動物亜門 Vertebrata
綱 : 爬虫綱 Reptilia
亜綱 : 双弓亜綱 Diapsida
下綱 : 主竜形下綱 Archosauromorpha
上目 : 恐竜上目 Dinosauria
目 : 竜盤目 Saurischia
亜目 : 獣脚亜目 Theropoda
下目 : ケラトサウルス下目 Ceratosauria
科 : アベリサウルス科 Abelisauridae
階級なし : ブラキロストラ類 Brachyrostra
族 : カルノタウルス族 Carnotaurini
属 : カルノタウルス属 Carnotaurus
種

カルノタウルス（学名 Carnotaurus）は、後期白亜紀の約7,200万年前から6,900万年前の間に南アメリカに生息していた獣脚類の恐竜の属。カルノタウルスはこのカルノタウルス・サステレイ（Carnotaurus sastrei）一種からなる。カルノタウルスは、保存状態のよい1体の骨格から知られれ、南半球に生息する獣脚類のなかでも最もよく解明されている獣脚類のひとつである。1984年に発見されたカルノタウルスの化石は、アルゼンチンのチュブ州でラ・コロニア層（英語版）の岩石から発見された。カルノタウルスはアベリサウルス科の属で、後期白亜紀にゴンドワナ大陸南部で広大な捕食ニッチを占めていた大型獣脚類である。アベリサウルス科のなかでも、この属は南アメリカに限定された短吻型の分類群であるブラキロストラ類（英語版）の属とされることが多い。

カルノタウルスは、全長7.5から8m、体重1.3～2.1tの、二足歩行の捕食動物であった。獣脚類のカルノタウルスは非常に特殊で特徴的だった。眼の上には他の肉食動物には見られない太い角があり、筋肉質な首の上に非常に深い頭蓋骨が乗っていた。カルノタウルスの痕跡から、小さく退化した前肢と細長い後肢を特徴としていた。骨格は広範囲な皮膚痕とともに保存されており、直径約5mmの重なり合わない小さな鱗がモザイク状に並んでいた。鱗は側面に並んだ大きな凸凹で途切れており、羽毛のある痕跡はなかった。

特徴的な角と筋肉質な首は、同種の動物と戦うために使われた可能性がある。他の研究では、敵対関係にあった個体同士は、素早く頭で殴り合ったり、頭蓋骨の上側でゆっくり押したり、角を衝撃吸収材として使って正面からぶつかり合うなどし、戦っていた可能性がある。竜脚類のような非常に大きな獲物を狩ることができたという研究もあれば、比較的小さな動物を主に捕食していたという研究もある。脳の空洞から嗅覚が鋭敏だったことがうかがえるが、聴覚と視覚はそれほど発達していなかった。カルノタウルスは走ることによく適していたとされ、大型獣脚類のなかでも特に速く走っていたとされる。

発見

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ロサンゼルス郡自然史博物館（英語版）にあるカルノタウルスの骨格

唯一の骨格標本（ホロタイプ MACN-CH 894）は、1984年にアルゼンチンの古生物学者ホセ・ボナパルテ（英語版）率いる探検隊によって発掘された[A]。この探検隊は他に、特徴的なトゲのある竜脚類のアマルガサウルスも発見した[3]。これは1976年に始まったナショナル ジオグラフィック協会主催のプロジェクト「南アメリカのジュラ紀と白亜紀の陸生脊椎動物」の8回目の探検であった[3][B]。骨格はよく保存されており、関節があるが、尾の後3分の2、下肢の大部分、後足だけが風化により破壊されている[C][5]。頭骨の癒合した縫合線から、この骨格は成体のものだとわかった[6]。珍しいことに、広範囲に及ぶ皮膚の痕跡が保存されていた[D]。これらの痕跡の重要性を考慮し、元の発掘現場を再調査する形になり、2回目の探検が開始され、さらにいくつかの皮膚の跡が発見された[6]。頭蓋骨は化石化の過程で変形し、左側の鼻骨は右側に対し前方に変位し、また、鼻骨は上方に押し上げられ、前上顎骨は鼻骨に対し後方に押し下げられた。変形により、上顎の上方への湾曲を誇張した[E]。吻は頭蓋骨の後部よりも変形の影響を大きく受けたが、これは後者の方が剛性が高いためだったと考えられている。上または下から見ると、上顎は下顎ほどU字型ではなく、明らかに一致していなかった。この不一致は、側面から作用する変形の結果であり、この変形は上顎には影響したが、下顎には影響しなかった。これはおそらく下顎の関節の柔軟性が高いためだった[1]。

カルノタウルスの既知かれている骨格

骨格標本は、アルゼンチンチュブ州テルセン県（英語版）バハーダ・モレノ近郊の「ポチョ・サストレ」という名の農場で発見された[5]。化石は大きな赤鉄鉱のコンクリーションという非常に硬い岩の中に埋まっていたため、準備は複雑で、発掘も遅かった[8][5]。1985年、ボナパルテは Carnotaurus sastrei を新属新種として発表し、頭蓋骨と下顎について簡単に記述した論文を出版した[5]。Carnotaurusという属名は、ラテン語で「肉」を意味する "carnis" と、「雄牛」を意味する "taurus" に由来し、雄牛のような角を持つことから「肉食の雄牛」と訳される[9]。sastrei という種小名は、化石が発見された牧場のオーナーである、アンヘル・サストレに因んだもの[10]。1990年には骨格全体の包括的な説明が続いた[4]。カルノタウルスは、アベリサウルスに続いて発見されたアベリサウルス科の2番目の属である[11]。長年にわたり、この恐竜はその科の中で群を抜いて最もよく解明されていた種であり、また南半球で最もよく解明されていた獣脚類でもあった[12][13]。アウカサウルス、マジュンガサウルス、スコルピオヴェナトルなど、保存状態のよい類似のアベリサウルス類が発見されたのは21世紀に入ってからのことで、研究者たちはカルノタウルスの解剖学のある側面を再評価することができるようになった[F]。ホロタイプの骨格はアルゼンチン自然科学博物館（ベルナルディーノ・リバダビア）に展示されており[G]、レプリカは同博物館や世界中の他の博物館で見ることができる[14]。Sculptors StephenとSylvia Czerkasは、以前ロサンゼルス郡自然史博物館（英語版）に展示されていたカルノタウルスの実物大の骨格作りに手掛けた。この製作は、1980年代半ばに博物館が依頼したもので、獣脚類の皮膚の正確な状態を再現した復元骨格であった[6][15]。

概要

[編集]
Size comparison of Carnotaurus
カルノタウルスとヒトの比較図

カルノタウルスは大型だが小柄な捕食動物であった[16]。唯一知られている個体の全長は約7.5から8mで[H][I][18]、カルノタウルスは最大級のアベリサウルス科でもあった[J][K][18]。非常に不完全だか、エクリクシナトサウルス（英語版）とアベリサウルスは、カルノタウルスと大きさが同程度か、あるいはもっと大型であった可能性がある[L][M][N]。2016年の研究では、全長8.9mのピクノネモサウルス（英語版）のみがカルノタウルスよりも大型だったことが判明した。また、カルノタウルスは7.8mと推定された[20]。また、体重は1.33t[O]、1.5t[P]、2t[18]、2.1t[Q]と幅広く推定されたてきたが、近年の研究では1,3tから1.7tと考えられている[23]。カルノタウルスは、特に頭蓋骨、椎骨、前肢の特徴に見られるように、高度に特殊化した獣脚類であった[R]。一方、骨盤と後肢は比較的原始的であり、より基部系統のケラトサウルスに似ていた。また、骨盤も後肢も細長かった。この個体の左大腿骨の長さは103cmだが、断面の平均直径は11cmしかない[S]。

頭蓋骨

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Side of skull
頭蓋骨の複数の角度からの画像。推定された皮膚構造の詳細と、右前頭骨

頭蓋骨の長さは59.6cmで、他のどの大型肉食恐竜よりも相対的に短く、深かった[T][U]。鼻口部先は適度に広く、ケラトサウルスのようなより原始的な獣脚類のように先細りではなく、顎は上向きに湾曲していた[24]。眼の上には一対の角が斜めに突き出ており、これらの角は前頭骨によって形成され[V]、太く円錐形状で、内部は固く、断面はやや垂直に平らになっており、長さは15cmであった[25][1]。ボナパルテは1990年、これらの角はより長いケラチン質の筒状の骨の芯を形成していたと示唆した[W]。2020年、Mauricio Cerroniらは、角がケラチン質の骨を支えていたことは納得したが、その筒は骨の芯よりもそれほど長くはなかったとした[1]。

他の恐竜と同様、頭蓋骨には左右に6つの大きな窪みの側頭窓があった。これらの側頭窓のうち最も前方にある外鼻孔は長方形の様な形で、前方の横に向いているが、ケラトサウルスなど他の恐竜のように側面から見て傾斜していなかった。この側頭窓は鼻骨と前顎骨のみによって形成されるが、一部のケラトサウルス類でも上顎骨にこの側頭窓が存在した。鼻孔と眼窩の間には前眼窩窓があった。スコルピオヴェナトルやマジュンガサウルスなどの近縁種では、高さよりも長さがあったが、カルノタウルスは対照的であり、側頭窓は長さよりも高さがあった。この窪みは、前方の上顎骨と後方の涙骨によって形成されている。これは他のアベリサウルス科と同様、カルノタウルスでもこの窪みは小さかった。前眼窩窩の下側の角には、上顎内の空洞につながるpromaxillary fenestraと呼ばれる小さな穴があった[1]。眼は鍵穴状の眼窩の上部に位置していた[X]。この上部は、比例して小さく円形に近い形状で、前方に突出した後眼窩骨（英語版）によって眼窩の下部から分離されていた[1]。It was slightly rotated forward, probably permitting some degree of binocular vision.[Y] The keyhole-like shape of the orbit was possibly related to the marked skull shortening, and is also found in related short-snouted abelisaurids.[1] As in all abelisaurids, the Template:Dinogloss (on the skull roof between the eyes) was excluded from the orbit. Behind the orbit were two openings, the Template:Dinogloss on the side and the Template:Dinogloss on the top of the skull. The infratemporal fenestra was tall, short, and kidney-shaped, while the supratemporal fenestra was short and square-shaped. Another opening, the Template:Dinogloss, was located in the lower jaw – in Carnotaurus, this opening was comparatively large.[1]

Schematic diagram of reconstructed skull

On each side of the upper jaws there were four premaxillary and twelve maxillary teeth,[Z] while the lower jaws were equipped with fifteen dentary teeth per side.[AA][1] The teeth had been described as being long and slender,[8] as opposed to the very short teeth seen in other abelisaurids.[24] However, Cerroni and colleagues, in their 2020 description of the skull, stated that all erupted teeth have been severely damaged during excavation and were later reconstructed with plaster (Bonaparte, in 1990, only noted that some lower jaw teeth had been fragmented).[1][AB] Reliable information on the shape of the teeth is therefore limited to replacement teeth and tooth roots that are still enclosed by the jaw, and can be studied using CT imaging.[1] The replacement teeth had low, flattened crowns, were closely spaced, and inclined forwards at approximately 45°.[1] In his 1990 description, Bonaparte noted that the lower jaw was shallow and weakly constructed, with the Template:Dinogloss (the foremost jaw bone) connected to the hindmost jaw bones by only two contact points; this contrasts to the robust-looking skull.[8][AC] Cerroni and colleagues instead found multiple but loose connections between the dentary and the hindmost jaw bones. This articulation, therefore, was very flexible but not necessarily weak.[1] The bottom margin of the dentary was convex, while it was straight in Majungasaurus.[1]

Illustration
Life restoration

The lower jaw was found with ossified hyoid bones, in the position they would be in if the animal was alive. These slender bones, supporting the tongue musculature and several other muscles, are rarely found in dinosaurs because they are often cartilaginous and not connected to other bones and therefore get lost easily.[AD][26][1] In Carnotaurus, three hyoid bones are preserved: a pair of curved, rod-like ceratobranchials that articulate with a single, trapezoidal element, the basihyal. Carnotaurus is the only known non-avian theropod from which a basihyal is known.[1] The back of the skull had well-developed, air-filled chambers surrounding the braincase, as in other abelisaurids. Two separate chamber systems were present, the paratympanic system, which was connected to the middle ear cavity, as well as chambers resulting from outgrowths of the air sacs of the neck.[23]

A number of autapomorphies (distinguishing features) can be found in the skull, including the pair of horns and the very short and deep skull. The maxilla had excavations above the promaxillary fenestra, which would have been excavated by the antorbital air sinus (air passages in the snout). The nasolacrimal duct, which transported eye fluid, exited on the medial (inner) surface of the lacrimal through a canal of uncertain function. Other proposed autapomorphies include a deep and long, air-filled excavation in the Template:Dinogloss and an elongated depression on the Template:Dinogloss of the Template:Dinogloss.[1]

Vertebrae

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Three views of the caudal ribs on vertebrae
Sixth tail vertebra of the holotype in A) side, B) front and C) top views, with arrows indicating the highly modified caudal ribs

The vertebral column consisted of ten cervical (neck), twelve dorsal, six fused sacral[AE] and an unknown number of caudal (tail) vertebrae.[4] The neck was nearly straight, rather than having the S-curve seen in other theropods, and also unusually wide, especially towards its base.[27] The top of the neck's spinal column featured a double row of enlarged, upwardly directed bony processes called epipophyses, creating a smooth trough on the top of the neck vertebrae. These processes were the highest points of the spine, towering above the unusually low spinous processes.[4][26] The epipophyses probably provided attachment areas for a markedly strong neck musculature.[AF] A similar double row was also present in the tail, formed there by highly modified caudal ribs, in front view protruding upwards in a V-shape, their inner sides creating a smooth, flat, top surface of the front tail vertebrae. The end of each caudal rib was furnished with a forward projecting hook-shaped expansion that connected to the caudal rib of the preceding vertebra.[26][28]

Forelimbs

[編集]
Shoulder region and arms; hands shown flexed beyond their ability to move in life
Drawing of the hand bones
Bones of the hand, as interpreted by Ruiz and colleagues (2011)[29]

The forelimbs were proportionally shorter than in any other large carnivorous dinosaurs, including tyrannosaurids.[AG] The forearm was only a quarter the size of the upper arm. There were no carpalia in the hand, so that the metacarpals articulated directly with the forearm.[29] The hand showed four basic digits,[4] though apparently only the middle two of these ended in finger bones, while the fourth consisted of a single splint-like metacarpal that may have represented an external 'spur'. The fingers themselves were fused and immobile, and may have lacked claws.[30] Carnotaurus differed from all other abelisaurids in having proportionally shorter and more robust forelimbs, and in having the fourth, splint-like metacarpal as the longest bone in the hand.[29] A 2009 study suggests that the arms were vestigial in abelisaurids, because nerve fibers responsible for stimulus transmission were reduced to an extent seen in today's emus and kiwis, which also have vestigial forelimbs.[31]

Skin

[編集]

Carnotaurus was the first theropod dinosaur discovered with a significant number of fossil skin impressions.[6] These impressions, found beneath the skeleton's right side, come from different body parts, including the lower jaw,[6] the front of the neck, the shoulder girdle, and the rib cage.[AH] The largest patch of skin corresponds to the anterior part of the tail.[AI] Originally, the right side of the skull also was covered with large patches of skin—this was not recognized when the skull was prepared, and these patches were accidentally destroyed.[6] However, the surface texture of several skull bones allows for inferences on their probable covering. A hummocky surface with grooves, pits, and small openings is found on the sides and front of the snout and indicates a scaly covering, possibly with flat scales as in today's crocodilians. The top of the snout was sculptured with numerous small holes and spikes – this texture can probably be correlated with a cornified pad (horny covering). Such a pad also occurred in Majungasaurus but was absent in Abelisaurus and Rugops. A row of large scales did probably surround the eye, as indicated by a hummocky surface with longitudinal grooves on the lacrimal and postorbital bones.[1][AJ]

Skin impressions from the tail

The skin was built up of a mosaic of polygonal, non-overlapping scales measuring approximately 5–12 mm (0.20–0.47 in) in diameter. This mosaic was divided by thin, parallel grooves.[AK] Scalation was similar across different body parts with the exception of the head, which apparently showed a different, irregular pattern of scales.[AL][14] There is no evidence of feathers.[6] Larger bump-like structures were distributed over the sides of the neck, back and tail in irregular rows. These bumps were 4 - 5 cm (1.6 - 2.0 in) in diameter and up to 5 cm (2.0 in) in height and often showed a low midline ridge. They were set 8 - 10 cm (3.1 - 3.9 in) apart from each other and became larger towards the animal's top. The bumps probably represent feature scales – clusters of condensed scutes – similar to those seen on the soft frill running along the body midline in hadrosaurid ("duck-billed") dinosaurs. These structures did not contain bone.[AM][6][32] Stephen Czerkas (1997) suggested that these structures may have protected the animal's sides while fighting members of the same species (conspecifics) and other theropods, arguing that similar structures can be found on the neck of the modern iguana where they provide limited protection in combat.[6]

More recent studies of the skin of Carnotaurus published in 2021 suggest that previous depictions of the scales on the body are inaccurate, and the larger feature scales were randomly distributed along the body, not distributed in discrete rows like in older artistic depictions and illustrations. There is also no sign of progressive size variation in feature scales along different areas along the body. The basement scales of Carnotaurus were by comparison highly variable, ranging in size from small and elongated, to large and polygonal, and from circular-to-lenticular in the thoracic, scapular, and tail regions, respectively. This scale differentiation may have been related to regulating body heat and shedding excess heat via thermoregulation due to its large body size and active lifestyle.[33]

Classification

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Restored skeleton
Restored cast of the holotype, Museu de Ciências Naturais da PUC Minas
Forelimb bones

Carnotaurus is one of the best-understood genera of the Abelisauridae, a family of large theropods restricted to the ancient southern supercontinent Gondwana. Abelisaurids were the dominant predators in the Late Cretaceous of Gondwana, replacing the carcharodontosaurids and occupying the ecological niche filled by the tyrannosaurids in the northern continents.[16] Several notable traits that evolved within this family, including shortening of the skull and arms as well as peculiarities in the cervical and caudal vertebrae, were more pronounced in Carnotaurus than in any other abelisaurid.[AN][AO][28]

Though relationships within the Abelisauridae are debated, Carnotaurus is consistently shown to be one of the most derived members of the family by cladistical analyses.[AP] Its nearest relative might have been Aucasaurus[34][35][36][37] or Majungasaurus.[38][39][40] A 2008 review, in contrast, suggested that Carnotaurus was not closely related to either genus, and instead proposed Ilokelesia as its sister taxon.[AQ] Juan Canale and colleagues, in 2009, erected the new clade Brachyrostra to include Carnotaurus but not Majungasaurus; this classification has been followed by a number of studies since.[34][37][41]

Carnotaurus is eponymous for two subgroups of the Abelisauridae: the Carnotaurinae and the Carnotaurini. Paleontologists do not universally accept these groups. The Carnotaurinae was defined to include all derived abelisaurids with the exclusion of Abelisaurus, which is considered a basal member in most studies.[42] However, a 2008 review suggested that Abelisaurus was a derived abelisaurid instead.[AR] Carnotaurini was proposed to name the clade formed by Carnotaurus and Aucasaurus;[35] only those paleontologists who consider Aucasaurus as the nearest relative of Carnotaurus use this group.[43] A 2024 study recovered Carnotaurini as a valid clade consisting of Carnotaurus, Aucasaurus, Niebla and Koleken.[44]

Below is a cladogram published by Canale and colleagues in 2009.[34]

Carnotaurinae
 

Majungasaurus

 
Brachyrostra
Carnotaurini
 

Aucasaurus

 
 

Carnotaurus

 
 
 
 

Ilokelesia

 
 
 

Skorpiovenator

 
 

Ekrixinatosaurus

 
 
 
 
 

Paleobiology

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Function of the horns

[編集]
Drawing of a Carnotaurus head
Restoration of the head showing the soft tissues inferred from osteological morphology of the skull

Carnotaurus is the only known carnivorous bipedal animal with a pair of horns on the frontal bone.[45] The use of these horns is not entirely clear. Several interpretations have revolved around use in fighting conspecifics or in killing prey, though a use in display for courtship or recognition of members of the same species is possible as well.[1]

Greg Paul (1988) proposed that the horns were butting weapons and that the small orbita would have minimized the possibility of hurting the eyes while fighting.[8] Gerardo Mazzetta and colleagues (1998) suggested that Carnotaurus used its horns in a way similar to rams. They calculated that the neck musculature was strong enough to absorb the force of two individuals colliding with their heads frontally at a speed of 5.7 m/s each.[21] Fernando Novas (2009) interpreted several skeletal features as adaptations for delivering blows with the head.[AS] He suggested that the shortness of the skull might have made head movements quicker by reducing the moment of inertia, while the muscular neck would have allowed strong head blows. He also noted an enhanced rigidity and strength of the spinal column that may have evolved to withstand shocks conducted by the head and neck.[AT]

Other studies suggest that rivaling Carnotaurus did not deliver rapid head blows, but pushed slowly against each other with the upper sides of their skulls.[45][46] Mazzetta and colleagues, in 2009, argued that the horns may have been a device for the distribution of compression forces without damage to the brain. This is supported by the flattened upper sides of the horns, the strongly fused bones of the top of the skull, and the inability of the skull to survive rapid head blows.[45] Rafael Delcourt, in 2018, suggested that the horns could have been used either in slow headbutting and shoving, as seen in the modern marine iguana, or in blows to the opponent's neck and flanks, as seen in the modern giraffe.[37] The latter possibility had been previously proposed for the related Majungasaurus in a 2011 conference paper.[47]

Gerardo Mazzetta and colleagues (1998) propose that the horns might also have been used to injure or kill small prey. Though horn cores are blunt, they may have had a similar form to modern bovid horns if there was a keratinous covering. However, this would be the only reported example of horns being used as hunting weapons in animals.[21]

Jaw function and diet

[編集]
Cast of skull
Skull cast, Dinosaur Discovery Museum, Kenosha, Wisconsin

Analyses of the jaw structure of Carnotaurus by Mazzetta and colleagues, in 1998, 2004, and 2009, suggest that the animal was capable of quick bites, but not strong ones.[21][22][45] Quick bites are more important than strong bites when capturing small prey, as shown by studies of modern-day crocodiles.[45] These researchers also noted a high degree of flexibility (kinesis) within the skull and especially the lower jaw, somewhat similar to modern snakes. Elasticity of the jaw would have allowed Carnotaurus to swallow small prey items whole. In addition, the front part of the lower jaw was hinged, and thus able to move up and down. When pressed downwards, the teeth would have projected forward, allowing Carnotaurus to spike small prey items; when the teeth were curved upwards, the now backward projecting teeth would have hindered the caught prey from escaping.[21] Mazzetta and colleagues also found that the skull was able to withstand forces that appear when tugging on large prey items.[45] Carnotaurus may therefore have fed mainly on relatively small prey, but also was able to hunt large dinosaurs.[45] In 2009, Mazzetta and colleagues estimated a bite force of around 3,341 newtons.[45] A 2022 study estimating bite force for 33 different dinosaurs suggests that the bite force in Carnotaurus was around 3,392 newtons at the anterior portion of the jaws; slightly higher than the previous estimate. The posterior bite force at the back of the jaws meanwhile, was estimated at 7,172 newtons.[48]

This interpretation was questioned by François Therrien and colleagues (2005), who found that the biting force of Carnotaurus was twice that of the American alligator, which may have the strongest bite of any living tetrapod. These researchers also noted analogies with modern Komodo dragons: the flexural strength of the lower jaw decreases towards the tip linearly, indicating that the jaws were not suited for high precision catching of small prey but for delivering slashing wounds to weaken big prey. As a consequence, according to this study, Carnotaurus must have mainly preyed upon large animals, possibly by ambush.[49] Cerroni and colleagues, in 2020, argued that flexibility was restricted to the lower jaw, while the thickened skull roof and the ossification of several cranial joints suggest that the skull had no or only little kinesis.[1]

Robert Bakker (1998) found that Carnotaurus mainly fed upon very large prey, especially sauropods. As he noted, several adaptations of the skull—the short snout, the relatively small teeth and the strong back of the skull (occiput)—had independently evolved in Allosaurus. These features suggest that the upper jaw was used like a serrated club to inflict wounds; big sauropods would have been weakened by repeated attacks.[50]

Locomotion

[編集]
Cross-section of the tail muscles
Cross section through the tail of Carnotaurus, showing the enlarged caudofemoralis muscle and the V-shaped caudal ribs
3D reconstructions of the tail muscles, tail, and pelvic bones seen from the side and above

Mazzetta and colleagues (1998, 1999) presumed that Carnotaurus was a swift runner, arguing that the thigh bone was adapted to withstand high bending moments while running; The ability of an animal's leg to withstand those forces limits its top speed. The running adaptations of Carnotaurus would have been better than those of a human, although not nearly as good as those of an ostrich.[AU][51] Scientists calculate that Carnotaurus had a top speed of up to 48–56 km (30–35 mi) per hour.[52]

In dinosaurs, the most important locomotor muscle was located in the tail. This muscle, called the caudofemoralis, attaches to the fourth trochanter, a prominent ridge on the thigh bone, and pulls the thigh bone backwards when contracted. Scott Persons and Phil Currie (2011) argued that in the tail vertebrae of Carnotaurus, the caudal ribs did not protrude horizontally ("T-shaped"), but were angled against the vertical axis of the vertebrae, forming a "V". This would have provided additional space for a caudofemoralis muscle larger than in any other theropod—the muscle mass was calculated at 111 - 137キログラム (245 - 302 lb) per leg. Therefore, Carnotaurus could have been one of the fastest large theropods.[28] While the caudofemoralis muscle was enlarged, the epaxial muscles situated above the caudal ribs would have been proportionally smaller. These muscles, called the longissimus and spinalis muscle, were responsible for tail movement and stability. To maintain tail stability in spite of reduction of these muscles, the caudal ribs bear forward projecting processes interlocking the vertebrae with each other and with the pelvis, stiffening the tail. As a consequence, the ability to make tight turns would have been diminished, because the hip and tail had to be turned simultaneously, unlike in other theropods.[28]

Brain and senses

[編集]

Cerroni and Paulina-Carabajal, in 2019, used a CT scan to study the endocranial cavity that contained the brain. The volume of the endocranial cavity was 168.8 cm3, although the brain would only have filled a fraction of this space. The authors used two different brain size estimates, assuming a brain size of 50% and 37% of the endocranial cavity, respectively. This results in a reptile encephalization quotient (a measure of intelligence) larger than that of the related Majungasaurus but smaller than in tyrannosaurids. The pineal gland, which produces hormones, might have been smaller than in other abelisaurids, as indicated by a low dural expansion – a space on top of the forebrain in which the pineal gland is thought to have been located.[23]

The olfactory bulbs, which housed the sense of smell, were large, while the optic lobes, which were responsible for sight, were relatively small. This indicates that the sense of smell might have been better developed than the sense of sight, while the opposite is the case in modern birds. The front end of the olfactory tracts and bulbs were curved downwards, a feature only shared by Indosaurus; in other abelisaurids, these structures were oriented horizontally. As hypothesized by Cerroni and Paulina-Carabajal, this downward-curvature, together with the large size of the bulbs, might indicate that Carnotaurus relied more on the sense of smell than other abelisaurids. The flocculus, a brain lobe thought to be correlated with gaze stabilization (coordination between eyes and body), was large in Carnotaurus and other South American abelisaurids. This could indicate that these forms frequently used quick movements of the head and body. Hearing might have been poorly developed in Carnotaurus and other abelisaurids, as indicated by the short lagena of the inner ear. The hearing range was estimated to be below 3 kHz.[23]

Age and paleoenvironment

[編集]
Carnotaurus in environment

Originally, the rocks in which Carnotaurus was found were assigned to the upper part of the Gorro Frigio Formation, which was considered to be approximately 100 million years old (Albian or Cenomanian stage).[5][AV] Later, they were realized to pertain to the much younger La Colonia Formation,[12] dating to the Campanian and Maastrichtian stages (83.6 to 66 million years ago).[1] Novas, in a 2009 book, gave a narrower time span of 72 to 69.9 million years ago (lower Maastrichtian stage).[AW] Carnotaurus therefore was the latest South American abelisaurid known.[28] By the Late Cretaceous, South America was already isolated from both Africa and North America.[53]

The La Colonia Formation is exposed over the southern slope of the North Patagonian Massif.[54] Most vertebrate fossils, including Carnotaurus, come from the formation's middle section (called the middle facies association).[54] This part likely represents the deposits of an environment of estuaries, tidal flats or coastal plains.[54] The climate would have been seasonal with both dry and humid periods.[54] The most common vertebrates collected include ceratodontid lungfish, turtles, plesiosaurs, crocodiles, dinosaurs, lizards, snakes and mammals.[55] Other dinosaurs include Koleken inakayali, which is closely related to Carnotaurus;[44] the saltasauroid titanosaur Titanomachya gimenezi;[56] an unnamed ankylosaur; and an unnamed hadrosauroid, among others. Some of the snakes that have been found belong to the families Boidae and Madtsoidae, such as Alamitophis argentinus.[57] Turtles are represented by at least five taxa, four from Chelidae (Pleurodira) and one from Meiolaniidae (Cryptodira).[58] Plesiosaurs include two elasmosaurs (Kawanectes and Chubutinectes) and a polycotylid (Sulcusuchus).[59][60] Mammals are represented by Reigitherium bunodontum and Coloniatherium cilinskii, the former of which was considered the first record of a South American docodont,[54][61] and the possible gondwanatherians or multituberculates Argentodites coloniensis and Ferugliotherium windhauseni.[62][63] Remains of an enantiornithine and, possibly, of a neornithine bird have been discovered.[64][65]

脚注

[編集]

注釈

[編集]
  1. ^ p. 276 in Novas (2009)[2]
  2. ^ p. 2 in Bonaparte (1990)[4]
  3. ^ p. 2 in Bonaparte (1990)[4]
  4. ^ p. 2 in Bonaparte (1990)[4]
  5. ^ p. 191 in Carrano and Sampson (2008)[7]
  6. ^ p. 191 in Carrano and Sampson (2008)[7]
  7. ^ p. 3 in Bonaparte (1990)[4]
  8. ^ p. 38 in Bonaparte (1990)[4]
  9. ^ p. 162 in Juárez Valieri et al. (2010)[17]
  10. ^ p. 191 in Carrano and Sampson (2008)[7]
  11. ^ p. 162 in Juárez Valieri et al. (2010)[17]
  12. ^ p. 163 in Juárez Valieri et al. (2010)[17]
  13. ^ p. 556 in Calvo et al. (2004)[19]
  14. ^ p. 191 in Carrano and Sampson (2008)[7]
  15. ^ p. 30 in Bonaparte (1990)[4]
  16. ^ p. 187 in Mazzetta et al. (1998)[21]
  17. ^ p. 79 in Mazzetta et al. (2004)[22]
  18. ^ p. 276 in Novas (2009)[2]
  19. ^ p. 28–32 in Bonaparte (1990)[4]
  20. ^ p. 8 in Bonaparte (1990)[4]
  21. ^ p. 191 in Carrano and Sampson (2008)[7]
  22. ^ p. 4–5 in Bonaparte (1990)[4]
  23. ^ p. 5 in Bonaparte (1990)[4]
  24. ^ p. 3 in Bonaparte (1990)[4]
  25. ^ p. 191 in Mazzetta et al. (1998)[21]
  26. ^ p. 255 in Novas (2009)[2]
  27. ^ p. 6 in Bonaparte (1990)[4]
  28. ^ p. 6 in Bonaparte (1990)[4]
  29. ^ p. 6 in Bonaparte (1990)[4]
  30. ^ p. 6 in Bonaparte (1990)[4]
  31. ^ p. 191 in Carrano and Sampson (2008)[7]
  32. ^ pp. 257 in Novas (2009)[2]
  33. ^ p. 1276 in Ruiz et al. (2011)[29]
  34. ^ p. 32 in Bonaparte (1990)[4]
  35. ^ p. 32 in Bonaparte (1990)[4]
  36. ^ p. 3 in Bonaparte (1990)[4]
  37. ^ pp. 264–299 in Novas (2009)[2]
  38. ^ pp. 264–299 in Novas (2009)[2]
  39. ^ p. 32 in Bonaparte (1990)[4]
  40. ^ p. 276–277 in Novas (2009)[2]
  41. ^ pp. 256–261 in Novas (2009)[2]
  42. ^ pp. 188–189 and 202 in Carrano and Sampson (2008)[7]
  43. ^ p. 202 in Carrano and Sampson (2008)[7]
  44. ^ p. 202 in Carrano and Sampson (2008)[7]
  45. ^ pp. 259–261 in Novas (2009)[2]
  46. ^ pp. 260–261 in Novas (2009)[2]
  47. ^ p. 186 and 190 in Mazzetta et al. (1998)[21]
  48. ^ p. 3 in Bonaparte (1990)[4]
  49. ^ p. 276 in Novas (2009)[2]

出典

[編集]
  1. ^ a b c d e f g h i j k l m n o p q r s t u Cerroni, M. A.; Canale, J. I.; Novas, F. E. (2020). “The skull of Carnotaurus sastrei Bonaparte 1985 revisited: insights from craniofacial bones, palate and lower jaw”. Historical Biology 33 (10): 2444–2485. doi:10.1080/08912963.2020.1802445. https://figshare.com/articles/dataset/The_skull_of_i_Carnotaurus_sastrei_i_Bonaparte_1985_revisited_insights_from_craniofacial_bones_palate_and_lower_jaw/12848981. 
  2. ^ a b c d e f g h i j k Novas, Fernando E. (2009). The age of dinosaurs in South America. Bloomington: Indiana University Press. ISBN 978-0-253-35289-7 
  3. ^ a b Salgado, Leonardo; Bonaparte, José F. (1991). “Un nuevo sauropodo Dicraeosauridae, Amargasaurus cazaui gen. et sp. nov., de la Formacion La Amarga, Neocomiano de la Provincia del Neuquén, Argentina” (スペイン語). Ameghiniana 28 (3–4): 334. 
  4. ^ a b c d e f g h i j k l m n o p q r s t u v w x Bonaparte, José F.; Novas, Fernando E.; Coria, Rodolfo A. (1990). “Carnotaurus sastrei Bonaparte, the horned, lightly built carnosaur from the Middle Cretaceous of Patagonia”. Contributions in Science 416: 1–41. doi:10.5962/p.226819. オリジナルのJuly 21, 2010時点におけるアーカイブ。. https://web.archive.org/web/20100721002530/https://nhm.org/site/sites/default/files/pdf/contrib_science/CS416.pdf. 
  5. ^ a b c d e Bonaparte, José F. (1985). “A horned Cretaceous carnosaur from Patagonia”. National Geographic Research 1 (1): 149–151. 
  6. ^ a b c d e f g h i Czerkas, Stephen A.; Czerkas, Sylvia J. (1997). “The Integument and Life Restoration of Carnotaurus”. In Wolberg, D. I.; Stump, E.; Rosenberg, G. D.. Dinofest International. Academy of Natural Sciences, Philadelphia. pp. 155–158 
  7. ^ a b c d e f g h i Carrano, Matthew T.; Sampson, Scott D. (January 2008). “The Phylogeny of Ceratosauria (Dinosauria: Theropoda)”. Journal of Systematic Palaeontology 6 (2): 183–236. Bibcode: 2008JSPal...6..183C. doi:10.1017/S1477201907002246. 
  8. ^ a b c d Paul, Gregory S. (1988). Predatory Dinosaurs of the World. Simon and Schuster. pp. 284–285. ISBN 978-0-671-61946-6. https://archive.org/details/predatorydinosau00paul/page/284 
  9. ^ Yong, Ed (October 18, 2011). “Butch tail made Carnotaurus a champion dinosaur sprinter”. National Geographic. オリジナルのOctober 29, 2018時点におけるアーカイブ。. https://web.archive.org/web/20181029045945/https://www.nationalgeographic.com/science/phenomena/2011/10/18/butch-tail-made-carnotaurus-a-champion-dinosaur-sprinter/ July 31, 2019閲覧。. 
  10. ^ “Re: Carnotaurus sastrei etymology”. Dinosaur Mailing List (September 19, 2006). February 22, 2012時点のオリジナルよりアーカイブ。December 27, 2012閲覧。
  11. ^ Bonaparte, José F. (1991). “The gondwanian theropod families Abelisauridae and Noasauridae”. Historical Biology 5 (1): 1. Bibcode: 1991HBio....5....1B. doi:10.1080/10292389109380385. 
  12. ^ a b Bonaparte, José F. (1996). “Cretaceous tetrapods of Argentina”. Münchener Geowissenschaftliche Abhandlung A (30): 89. 
  13. ^ Glut, Donald F. (1997). “Carnotaurus”. Dinosaurs, the encyclopedia. Jefferson, North Carolina: McFarland & Company, Inc. Publishers. pp. 256–259. ISBN 978-0-375-82419-7. https://archive.org/details/dinosaursmostcom00holt/page/256 
  14. ^ a b Glut, Donald F. (2003). “Carnotaurus”. Dinosaurs: The Encyclopedia. 3rd Supplement. Jefferson, North Carolina: McFarland & Company, Inc.. pp. 274–276. ISBN 978-0-7864-1166-5. https://archive.org/details/dinosaursencyclo00glut_2/page/274 
  15. ^ Glut, Donald F. (2000). “Carnotaurus”. Dinosaurs: The Encyclopedia. 1st Supplement. Jefferson, North Carolina: McFarland & Company, Inc.. pp. 165–167. ISBN 978-0-7864-0591-6 
  16. ^ a b Candeiro, Carlos Roberto dos Anjos; Martinelli, Agustín Guillermo. “Abelisauroidea and carchardontosauridae (theropoda, dinosauria) in the cretaceous of south america. Paleogeographical and geocronological implications”. Uberlândia 17 (33): 5–19. 
  17. ^ a b c Juárez Valieri, Rubén D.; Porfiri, Juan D.; Calvo, Jorge O. (2010). “New information on Ekrixinatosaurus novasi Calvo et al. 2004, a giant and massively-constructed Abelisauroid from the 'Middle Cretaceous' of Patagonia”. Paleontologıa y Dinosaurios en América Latina: 161–169. 
  18. ^ a b c Paul, Gregory S. (2010). The Princeton Field Guide to Dinosaurs (1st ed.). Princeton University Press. ISBN 9780691137209 
  19. ^ Calvo, Jorge O.; Rubilar-Rogers, David; Moreno, Karen (2004). “A new Abelisauridae (Dinosauria: Theropoda) from northwest Patagonia”. Ameghiniana 41 (4): 555–563. https://ameghiniana.org.ar/index.php/ameghiniana/article/view/852. 
  20. ^ Grillo, O.N.; Delcourt, R. (2016). “Allometry and body length of abelisauroid theropods: Pycnonemosaurus nevesi is the new king”. Cretaceous Research 69: 71–89. Bibcode: 2017CrRes..69...71G. doi:10.1016/j.cretres.2016.09.001. 
  21. ^ a b c d e f g Mazzetta, Gerardo V.; Fariña, Richard A.; Vizcaíno, Sergio F. (1998). “On the palaeobiology of the South American horned theropod Carnotaurus sastrei Bonaparte”. Gaia 15: 185–192. http://www.arca.museus.ul.pt/ArcaSite/obj/gaia/MNHNL-0000782-MG-DOC-web.PDF. 
  22. ^ a b Mazzetta, Gerardo V.; Christiansen, Per; Fariña, Richard A. (June 2004). “Giants and Bizarres: Body Size of Some Southern South American Cretaceous Dinosaurs”. Historical Biology 16 (2–4): 71–83. Bibcode: 2004HBio...16...71M. doi:10.1080/08912960410001715132. 
  23. ^ a b c d Cerroni, Mauricio A.; Paulina-Carabajal, Ariana (2019). “Novel information on the endocranial morphology of the abelisaurid theropod Carnotaurus sastrei”. Comptes Rendus Palevol 18 (8): 985–995. Bibcode: 2019CRPal..18..985C. doi:10.1016/j.crpv.2019.09.005. 
  24. ^ a b Sampson, Scott D.; Witmer, Lawrence M. (2007). “Craniofacial Anatomy of Majungasaurus crenatissimus (Theropoda: Abelisauridae) From the Late Cretaceous of Madagascar”. Journal of Vertebrate Paleontology 27 (sp8): 95–96. doi:10.1671/0272-4634(2007)27[32:CAOMCT]2.0.CO;2. 
  25. ^ Paulina Carabajal, Ariana (2011). “The braincase anatomy of Carnotaurus sastrei (Theropoda: Abelisauridae) from the Upper Cretaceous of Patagonia”. Journal of Vertebrate Paleontology 31 (2): 378–386. Bibcode: 2011JVPal..31..378P. doi:10.1080/02724634.2011.550354. 
  26. ^ a b c “Carnotaurus – delving into self-parody?” (2012年). December 7, 2012閲覧。
  27. ^ Méndez, Ariel (2014). “The cervical vertebrae of the Late Cretaceous abelisaurid dinosaur Carnotaurus sastrei”. Acta Palaeontologica Polonica 59 (1): 99–107. doi:10.4202/app.2011.0129. hdl:11336/32909. 
  28. ^ a b c d e Persons, W.S.; Currie, P.J. (2011). Farke, Andrew Allen. ed. “Dinosaur Speed Demon: The caudal musculature of Carnotaurus sastrei and implications for the evolution of South American abelisaurids”. PLOS ONE 6 (10): e25763. Bibcode: 2011PLoSO...625763P. doi:10.1371/journal.pone.0025763. PMC 3197156. PMID 22043292. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3197156/. 
  29. ^ a b c d Ruiz, Javier; Torices, Angélica; Serrano, Humberto; López, Valle (2011). “The hand structure of Carnotaurus sastrei (Theropoda, Abelisauridae): implications for hand diversity and evolution in abelisaurids”. Palaeontology 54 (6): 1271–1277. Bibcode: 2011Palgy..54.1271R. doi:10.1111/j.1475-4983.2011.01091.x. オリジナルのSeptember 22, 2017時点におけるアーカイブ。. https://web.archive.org/web/20170922051617/http://eprints.ucm.es/16940/1/38-Carnotauro_1.pdf December 18, 2018閲覧。. 
  30. ^ Agnolin, Federico L.; Chiarelli, Pablo (June 2010). “The position of the claws in Noasauridae (Dinosauria: Abelisauroidea) and its implications for abelisauroid manus evolution”. Paläontologische Zeitschrift 84 (2): 293–300. Bibcode: 2010PalZ...84..293A. doi:10.1007/s12542-009-0044-2. 
  31. ^ Senter, P. (2010). “Vestigial skeletal structures in dinosaurs”. Journal of Zoology 280 (4): 60–71. doi:10.1111/j.1469-7998.2009.00640.x. 
  32. ^ Campione, Nicolás E.; Barrett, Paul M.; Evans, David C. (2020). “On the ancestry of feathers in Mesozoic dinosaurs”. In Christian Foth; Oliver W.M. Rauhut. The Evolution of Feathers. Springer. pp. 213–243. ISBN 978-3-030-27222-7 
  33. ^ Hendrickx, Christophe; Bell, Phil R. (August 2021). “The scaly skin of the abelisaurid Carnotaurus sastrei (Theropoda: Ceratosauria) from the Upper Cretaceous of Patagonia”. Cretaceous Research 128: 104994. Bibcode: 2021CrRes.12804994H. doi:10.1016/j.cretres.2021.104994. 
  34. ^ a b c Canale, Juan I.; Scanferla, Carlos A.; Agnolin, Federico; Novas, Fernando E. (2009). “New carnivorous dinosaur from the Late Cretaceous of NW Patagonia and the evolution of abelisaurid theropods”. Naturwissenschaften 96 (3): 409–14. Bibcode: 2009NW.....96..409C. doi:10.1007/s00114-008-0487-4. hdl:11336/52024. PMID 19057888. 
  35. ^ a b Coria, Rodolfo A.; Chiappe, Luis M.; Dingus, Lowell (2002). “A new close relative of Carnotaurus sastrei Bonaparte 1985 (Theropoda: Abelisauridae) from the Late Cretaceous of Patagonia”. Journal of Vertebrate Paleontology 22 (2): 460. doi:10.1671/0272-4634(2002)022[0460:ANCROC]2.0.CO;2. 
  36. ^ Ezcurra, Martín D.; Agnolin, Federico L.; Novas, Fernando E. (May 10, 2010). “An abelisauroid dinosaur with a non-atrophied manus from the Late Cretaceous Pari Aike Formation of southern Patagonia”. Zootaxa 2450 (1): 1. doi:10.11646/zootaxa.2450.1.1. 
  37. ^ a b c Delcourt, Rafael (2018). “Ceratosaur palaeobiology: new insights on evolution and ecology of the southern rulers”. Scientific Reports 8 (1): 9730. Bibcode: 2018NatSR...8.9730D. doi:10.1038/s41598-018-28154-x. PMC 6021374. PMID 29950661. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6021374/. 
  38. ^ Sereno, Paul C.; Wilson, Jeffrey A.; Conrad, Jack L. (July 7, 2004). “New dinosaurs link southern landmasses in the Mid-Cretaceous”. Proceedings of the Royal Society B: Biological Sciences 271 (1546): 1325–1330. doi:10.1098/rspb.2004.2692. PMC 1691741. PMID 15306329. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1691741/. 
  39. ^ Tykoski, Ronald B.; Rowe, Timothy (2004). “Ceratosauria”. In Weishampel, David B.; Dodson, Peter; Osmólska, Halszka. The Dinosauria (Second ed.). Berkeley: University of California Press. p. 65. ISBN 978-0-520-24209-8. https://archive.org/details/dinosauriandedit00weis 
  40. ^ Wilson, Jeffrey A.; Sereno, Paul C.; Srivastava, Suresh; Bhatt, Devendra K.; Khosla, Ashu; Sahni, Ashok (2003). “A new abelisaurid (Dinosauria, Theropoda) from the Lameta Formation (Cretaceous, Maastrichtian) of India”. Contributions from the Museum of Paleontology 31 (1): 25. hdl:2027.42/48667. 
  41. ^ Wang, Shuo; Stiegler, Josef; Amiot, Romain; Wang, Xu; Du, Guo-hao; Clark, James M.; Xu, Xing (January 2017). “Extreme Ontogenetic Changes in a Ceratosaurian Theropod”. Current Biology 27 (1): 144–148. Bibcode: 2017CBio...27..144W. doi:10.1016/j.cub.2016.10.043. PMID 28017609. 
  42. ^ “Carnotaurinae”. Taxon Search (2005年). May 16, 2012時点のオリジナルよりアーカイブ。December 29, 2012閲覧。
  43. ^ “Carnotaurini”. Taxon Search (2005年). May 16, 2012時点のオリジナルよりアーカイブ。December 29, 2012閲覧。
  44. ^ a b Pol, Diego; Baiano, Mattia Antonio; Černý, David; Novas, Fernando; Cerda, Ignacio A. (21 May 2024). “A new abelisaurid dinosaur from the end Cretaceous of Patagonia and evolutionary rates among the Ceratosauria”. Cladistics 40 (3): 307–356. doi:10.1111/cla.12583. PMID 38771085. 
  45. ^ a b c d e f g h Mazzetta, Gerardo V.; Cisilino, Adrián P.; Blanco, R. Ernesto; Calvo, Néstor (2009). “Cranial mechanics and functional interpretation of the horned carnivorous dinosaur Carnotaurus sastrei”. Journal of Vertebrate Paleontology 29 (3): 822–830. Bibcode: 2009JVPal..29..822M. doi:10.1671/039.029.0313. hdl:11336/34937. 
  46. ^ Chure, Daniel J. (1998). “On the orbit of theropod dinosaurs”. Gaia 15: 233–240. 
  47. ^ Snively, Eric; Cotton, John R.; Witmer, Lawrence; Ridgely, Ryan; Theodor, Jessica (2011). "Finite element comparison of cranial sinus function in the dinosaur Majungasaurus and head-clubbing giraffes". Summer Bioengineering Conference. Vol. 54587. American Society of Mechanical Engineers. pp. 1075–1076.
  48. ^ Sakamoto, Manabu (2022). “Estimating bite force in extinct dinosaurs using phylogenetically predicted physiological cross-sectional areas of jaw adductor muscles”. PeerJ 10: e13731. doi:10.7717/peerj.13731. PMC 9285543. PMID 35846881. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9285543/. 
  49. ^ Therrien, François; Henderson, Donald; Ruff, Christopher (2005). “Bite Me – Biomechanical Models of Theropod Mandibles and Implications for Feeding Behavior”. In Carpenter, Kenneth. The carnivorous dinosaurs. Indiana University Press. pp. 179–198, 228. ISBN 978-0-253-34539-4. https://archive.org/details/carnivorousdinos00carp 
  50. ^ Bakker, Robert T. (1998). “Brontosaur killers: Late Jurassic allosaurids as sabre-tooth cat analogues”. Gaia 15: 145–158. http://www.arca.museus.ul.pt/ArcaSite/obj/gaia/MNHNL-0000779-MG-DOC-web.PDF. 
  51. ^ Mazzetta, Gerardo V.; Farina, Richard A. (1999). “Estimacion de la capacidad atlética de Amargasaurus cazaui Salgado y Bonaparte, 1991, y Carnotaurus sastrei Bonaparte, 1985 (Saurischia, Sauropoda-Theropoda)” (スペイン語). XIV Jornadas Argentinas de Paleontologia de Vertebrados, Ameghiniana 36 (1): 105–106. 
  52. ^ “Predatory dinosaur was fearsomely fast”. CBC News. (October 21, 2011). http://www.cbc.ca/news/technology/predatory-dinosaur-was-fearsomely-fast-1.1064092 April 22, 2017閲覧。 
  53. ^ Le Loeuff, Jean (1997). “Biogeography”. In Padian, Kevin; Currie, Philip J.. Encyclopedia of dinosaurs. San Diego: Academic Press. pp. 51–56. ISBN 978-0-12-226810-6. https://archive.org/details/encyclopediadino00curr_075 
  54. ^ a b c d e Pascual, Rosendo; Goin, Francisco J.; González, Pablo; Ardolino, Alberto; Puerta, Pablo F. (2000). “A highly derived docodont from the Patagonian Late Cretaceous: evolutionary implications for Gondwanan mammals”. Geodiversitas 22 (3): 395–414. http://sciencepress.mnhn.fr/en/periodiques/geodiversitas/22/3/un-docodonte-tres-derive-du-cretace-superieur-de-la-patagonie-implications-evolutives-pour-des-mammiferes-gondwaniens. 
  55. ^ Sterli, Juliana; De la Fuente, Marcelo S. (2011). “A new turtle from the La Colonia Formation (Campanian–Maastrichtian), Patagonia, Argentina, with remarks on the evolution of the vertebral column in turtles”. Palaeontology 54 (1): 65. Bibcode: 2011Palgy..54...63S. doi:10.1111/j.1475-4983.2010.01002.x. 
  56. ^ Pérez-Moreno, A.; Salgado, L.; Carballido, J. L.; Otero, A.; Pol, D. (2024). “A new titanosaur from the La Colonia Formation (Campanian-Maastrichtian), Chubut Province, Argentina”. Historical Biology: An International Journal of Paleobiology: 1–20. doi:10.1080/08912963.2024.2332997. 
  57. ^ Albino, Adriana M. (2000). “New record of snakes from the Cretaceous of Patagonia (Argentina)”. Geodiversitas 22 (2): 247–253. http://sciencepress.mnhn.fr/en/periodiques/geodiversitas/22/2/de-nouveaux-restes-de-serpents-du-cretace-superieur-de-patagonie-argentine. 
  58. ^ Gasparini, Zulma; De la Fuente, Marcelo (2000). “Tortugas y Plesiosaurios de la Formación La Colonia (Cretácico Superior) de Patagonia, Argentina” (スペイン語). Revista Española de Paleontología 15 (1): 23. 
  59. ^ O’Gorman, José P.; Carignano, Ana Paula; Calvo-Marcilese, Lydia; Pérez Panera, Juan Pablo (2023-08-10). “A new elasmosaurid (Sauropterygia, Plesiosauria) from the upper levels of the La Colonia Formation (upper Maastrichtian), Chubut Province, Argentina” (英語). Cretaceous Research 152: 105674. Bibcode: 2023CrRes.15205674O. doi:10.1016/j.cretres.2023.105674. ISSN 0195-6671. 
  60. ^ O'Gorman, J.P.; Gasparini, Z. (2013). “Revision of Sulcusuchus erraini (Sauropterygia, Polycotylidae) from the Upper Cretaceous of Patagonia, Argentina”. Alcheringa: An Australasian Journal of Palaeontology 37 (2): 163–176. Bibcode: 2013Alch...37..163O. doi:10.1080/03115518.2013.736788. hdl:11336/2489. 
  61. ^ Rougier, G. W.; Turazzinni, G. F.; Cardozo, M. S.; Harper, T.; Lires, A. I.; Canessa, L. A. (2021). “New Specimens of Reigitherium bunodontum from the Late Cretaceous La Colonia Formation, Patagonia, Argentina and Meridiolestidan Diversity in South America”. Journal of Mammalian Evolution 28 (4): 1051–1081. doi:10.1007/s10914-021-09585-2. 
  62. ^ Kielan−Jaworowska, Zofia; Ortiz−Jaureguizar, Edgardo; Vieytes, Carolina; Pascual, Rosendo; Goin, Francisco J. (2007). “First ?cimolodontan multi−tuberculate mammal from South America”. Acta Palaeontologica Polonica 52 (2): 257–262. http://www.app.pan.pl/archive/published/app52/app52-257.pdf. 
  63. ^ Gurovich, Y.; Beck, R. (2009). “The phylogenetic affinities of the enigmatic mammalian clade Gondwanatheria”. Journal of Mammalian Evolution 16 (1): 25–49. doi:10.1007/s10914-008-9097-3. 
  64. ^ Lawver, Daniel R.; Debee, Aj M.; Clarke, Julia A.; Rougier, Guillermo W. (January 1, 2011). “A New Enantiornithine Bird from the Upper Cretaceous La Colonia Formation of Patagonia, Argentina”. Annals of Carnegie Museum 80 (1): 35–42. doi:10.2992/007.080.0104. 
  65. ^ Acosta Hospitaleche, C.; O'Gorman, J. P.; Panzeri, K. M. (2023). “A new Cretaceous bird from the Maastrichtian La Colonia Formation (Patagonia, Argentina)”. Cretaceous Research 150: 105595. Bibcode: 2023CrRes.15005595A. doi:10.1016/j.cretres.2023.105595. 
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