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148-497: The term "caveman" has its taxonomic equivalent in the now-obsolete binomial classification of Homo troglodytes (Linnaeus , 1758 ). Cavemen are typically portrayed as wearing shaggy animal hides , and capable of cave painting like behaviorally modern humans of the last glacial period . They are often shown armed with rocks, cattle bone clubs, spears, or sticks with rocks tied to them, and are portrayed as unintelligent, easily frightened, and aggressive. Typically, they have

296-546: A Ceratosaurus . The film reinforced the incorrect notion that non-avian dinosaurs co-existed with prehistoric humans. The anachronistic combination of cavemen with dinosaurs eventually became a cliché , and has often been intentionally invoked for comedic effect. The comic strips B.C. , Alley Oop , the Spanish comic franchise Mortadelo y Filemón , and occasionally The Far Side and Gogs portray "cavemen" with dinosaurs. Gary Larson , in his 1989 book The Prehistory of

444-630: A carcharodontosaurid instead. In 2000 and 2006, paleontologists led by Octávio Mateus described a find from the Lourinhã Formation of central-west Portugal (ML 352) as a new specimen of Ceratosaurus , consisting of a right femur (upper thigh bone), a left tibia (shin bone), and several isolated teeth recovered from the cliffs of Valmitão beach, between the municipalities of Lourinhã and Torres Vedras . The bones were found embedded in yellow to brown, fine-grained sandstones, which were deposited by rivers as floodplain deposits and belong to

592-464: A clade of theropod dinosaurs that diverged early on from the evolutionary lineage leading to modern birds . Within Ceratosauria, some paleontologists proposed it to be most closely related to Genyodectes from Argentina, which shares the strongly elongated teeth. The geologically older genus Proceratosaurus from England , although originally described as a presumed antecedent of Ceratosaurus ,

740-504: A controlled vocabulary of contributor roles. Known as CRediT ( Contributor Roles Taxonomy ) , this is an example of a flat, non-hierarchical taxonomy; however, it does include an optional, broad classification of the degree of contribution: lead , equal or supporting . Amy Brand and co-authors summarise their intended outcome as: Identifying specific contributions to published research will lead to appropriate credit, fewer author disputes, and fewer disincentives to collaboration and

888-680: A library classification system and a search engine taxonomy . The word was coined in 1813 by the Swiss botanist A. P. de Candolle and is irregularly compounded from the Greek τάξις , taxis 'order' and νόμος , nomos 'law', connected by the French form -o- ; the regular form would be taxinomy , as used in the Greek reborrowing ταξινομία . Misplaced Pages categories form a taxonomy, which can be extracted by automatic means. As of 2009 , it has been shown that

1036-595: A 1997 article in JAMA , the Journal of the American Medical Association for a radical conceptual and systematic change, to reflect the realities of multiple authorship and to buttress accountability. We propose dropping the outmoded notion of author in favor of the more useful and realistic one of contributor. In 2012, several major academic and scientific publishing bodies mounted Project CRediT to develop

1184-400: A certain type (for example, John is a bachelor ), while universally quantified conditionals express the notion that a type is a subtype of another type (for example, " A dog is a mammal" , which means the same as " All dogs are mammals" ). The "has-a" relationship is quite different: an elephant has a trunk; a trunk is a part, not a subtype of elephant. The study of part-whole relationships

1332-673: A clade with the Argentinian genus Eoabelisaurus . Delcourt used the name Ceratosauridae to refer to this same clade, and suggested to define Ceratosauridae as containing all taxa that are more closely related to Ceratosaurus than to the abelisaurid Carnotaurus . The following cladogram showing the relationships of Ceratosaurus is based on the phylogenetic analysis conducted by Diego Pol and Oliver Rauhut in 2012: Berberosaurus Deltadromeus Spinostropheus Limusaurus Elaphrosaurus Ceratosaurus Genyodectes Noasauridae Abelisauridae A skull from

1480-594: A dry season by theropods or by a collecting bias in other localities. In 1884, Marsh considered the nasal horn of Ceratosaurus to be a "most powerful weapon" for both offensive and defensive purposes and Gilmore, in 1920, concurred with this interpretation. The use of the horn as a weapon is now generally considered unlikely. In 1985, David Norman believed that the horn was "probably not for protection against other predators," but might instead have been used for intraspecific combat among male ceratosaurs contending for breeding rights. Gregory S. Paul , in 1988, suggested

1628-491: A fixed set of ideas, sought to develop an alphabet of human thought . Leibniz intended his characteristica universalis to be an "algebra" capable of expressing all conceptual thought. The concept of creating such a " universal language " was frequently examined in the 17th century, also notably by the English philosopher John Wilkins in his work An Essay towards a Real Character and a Philosophical Language (1668), from which

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1776-552: A fragmentary, disarticulated skeleton including the skull (UMNH VP 5278) in the Cleveland-Lloyd Dinosaur Quarry of Utah. This find represents one of the largest-known Ceratosaurus specimens. A second, articulated specimen including the skull (MWC 1) was discovered in 1976 by Thor Erikson, the son of paleontologist Lance Erikson, near Fruita, Colorado . A fairly complete specimen, it lacks lower jaws, forearms, and gastralia . The skull, although reasonably complete,

1924-455: A low pitched rough voice and make vocalisations such as "ooga-booga" and grunts or speak using simple phrases. Popular culture also frequently represents cavemen as living with, or alongside of, dinosaurs , even though non-avian dinosaurs became extinct at the end of the Cretaceous period , 66 million years before the emergence of Homo sapiens . The era typically associated with the archetype

2072-540: A manually-constructed taxonomy, such as that of computational lexicons like WordNet , can be used to improve and restructure the Misplaced Pages category taxonomy. In a broader sense, taxonomy also applies to relationship schemes other than parent-child hierarchies, such as network structures . Taxonomies may then include a single child with multi-parents, for example, "Car" might appear with both parents "Vehicle" and "Steel Mechanisms"; to some however, this merely means that 'car'

2220-434: A method based on dichotomy, which was rejected by Aristotle and replaced by the method of definitions based on genus, species, and specific difference. The method of facet analysis (cf., faceted classification ) is primarily based on logical division. This approach tends to classify according to "essential" characteristics, a widely discussed and criticized concept (cf., essentialism ). These methods may overall be related to

2368-402: A morph with a shortened snout, a high and wide skull, and short, backwards-projecting teeth, and a morph characterized by a longer snout, lower skull, and long, vertical teeth. Generally speaking, the greater the similarity between sympatric species regarding their morphology, physiology, and behavior, the more intense competition between these species will be. Henderson came to the conclusion that

2516-414: A pair of horns over the eyes. The forelimbs were very short, but remained fully functional. The hand had four fingers with claws on the first three. The tail was deep from top to bottom. A row of small osteoderms (skin bones) was present down the middle of the neck, back, and tail. Additional osteoderms were present at unknown positions on the animal's body. Ceratosaurus gives its name to Ceratosauria ,

2664-658: A possible species of Labrosaurus , Labrosaurus (?) stechowi . Other authors questioned the assignment of any of the Tendaguru finds to Ceratosaurus , noting that none of these specimens displays features diagnostic for that genus. In 2011, Rauhut found both C. roechlingi and Labrosaurus (?) stechowi to be possible ceratosaurids, but found them to be undiagnostic at genus level and designated them as nomina dubia (doubtful names). In 1990, Timothy Rowe and Jacques Gauthier mentioned yet another Ceratosaurus species from Tendaguru, Ceratosaurus ingens , which purportedly

2812-552: A presumed premaxillary tooth crown. This shows vertical striations on its inner side and lacks denticles on its front edge. These features are, in this combination, only known from Ceratosaurus . The authors, however, stressed that an assignment to Ceratosaurus is infeasible because the remains are scant and note that the assignment of the European and African material to Ceratosaurus has to be viewed with caution. In 2020, Soto and colleagues described additional Ceratosaurus teeth from

2960-431: A running animal with a horizontal posture and a tail that did not make contact with the ground. Because of the strong flattening of the fossils, Gilmore mounted the specimen, not as a free-standing skeleton, but as a bas-relief within an artificial wall. With the bones being partly embedded in a plaque, scientific access was limited. In the course of the renovation of the museum's dinosaur exhibition between 2014 and 2019,

3108-470: A shorter, taller, and stiffer body with longer legs. They would have been adapted for rapid running in open terrain and for preying upon large herbivorous dinosaurs such as sauropods and stegosaurs, but as speculated by Bakker and Bir, seasonally switched to aquatic prey items when the large herbivores were absent. However, this theory was challenged by Yun in 2019, suggesting Ceratosaurus was merely more capable of hunting aquatic prey than other theropods of

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3256-427: A similar function and illustrated two Ceratosaurus engaged in a nonlethal butting contest. In 1990, Rowe and Gauthier went further, suggesting that the nasal horn of Ceratosaurus was "probably used for display purposes alone" and played no role in physical confrontations. If used for display, the horn likely would have been brightly colored. A display function was also proposed for the row of osteoderms running down

3404-434: A subsequent 2018 study, Rafael Delcourt accepted these results, but pointed out that, as a consequence, Abelisauroidea would need to be replaced by the older synonym Ceratosauroidea, which was hitherto rarely used. For Abelisauridae, Delcourt proposed a new definition that excludes Ceratosaurus , allowing for using the name in its traditional sense. Wang and colleagues furthermore found that Ceratosaurus and Genyodectes form

3552-401: A systematic methodology to approach taxonomy building in software engineering related topics. Several taxonomies have been proposed in software testing research to classify techniques, tools, concepts and artifacts. The following are some example taxonomies: Engström et al. suggest and evaluate the use of a taxonomy to bridge the communication between researchers and practitioners engaged in

3700-408: Is mereology . Taxonomies are often represented as is-a hierarchies where each level is more specific than the level above it (in mathematical language is "a subset of" the level above). For example, a basic biology taxonomy would have concepts such as mammal , which is a subset of animal , and dogs and cats , which are subsets of mammal . This kind of taxonomy is called an is-a model because

3848-541: Is 7 cm (2.8 in) in height. It is longer and lower in the skull of MWC 1. In the living animal, the horn would likely have been more elongated due to its keratinous sheath. Behind the nasal horn, the nasal bones formed an ovalur groove. Both this groove and the nasal horn serve as features to distinguish Ceratosaurus from related genera. In addition to the large nasal horn, Ceratosaurus possessed smaller, semicircular, bony ridges in front of each eye, similar to those of Allosaurus . These ridges were formed by

3996-421: Is a tree structure of classifications for a given set of objects. It is also named containment hierarchy . At the top of this structure is a single classification, the root node, that applies to all objects. Nodes below this root are more specific classifications that apply to subsets of the total set of classified objects. The progress of reasoning proceeds from the general to the more specific. By contrast, in

4144-404: Is a part of several different taxonomies. A taxonomy might also simply be organization of kinds of things into groups, or an alphabetical list; here, however, the term vocabulary is more appropriate. In current usage within knowledge management , taxonomies are considered narrower than ontologies since ontologies apply a larger variety of relation types. Mathematically, a hierarchical taxonomy

4292-410: Is a practice and science concerned with classification or categorization. Typically, there are two parts to it: the development of an underlying scheme of classes (a taxonomy) and the allocation of things to the classes ( classification ). Originally, taxonomy referred only to the classification of organisms on the basis of shared characteristics. Today it also has a more general sense. It may refer to

4440-416: Is an approach based solely on observable, measurable similarities and differences of the things to be classified. Classification is based on overall similarity: The elements that are most alike in most attributes are classified together. But it is based on statistics, and therefore does not fulfill the criteria of logical division (e.g. to produce classes, that are mutually exclusive and jointly coextensive with

4588-400: Is evident and that the fusion is unusual, but likely not pathological. Ronald Ratkevich, in 1976, argued that this fusion had limited the running ability of the animal, but this claim was rejected by Paul in 1988, who noted that the same feature occurs in many fast-moving animals of today, including ground birds and ungulates. A 1999 analysis by Darren Tanke and Bruce Rothschild suggested that

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4736-511: Is important to notice that empiricism is not the same as empirical study, but a certain ideal of doing empirical studies. With the exception of the logical approaches they all are based on empirical studies, but are basing their studies on different philosophical principles). (3) Historical and hermeneutical approaches including Ereshefsky's "historical classification" and (4) Pragmatic, functionalist and teleological approaches (not covered by Ereshefsky). In addition there are combined approaches (e.g.,

4884-399: Is not assigned to the concept of France (whatever that might be).” Smith's alternative to concepts as units is based on a realist orientation, when scientists make successful claims about the types of entities that exist in reality, they are referring to objectively existing entities which realist philosophers call universals or natural kinds. Smith's main argument - with which many followers of

5032-455: Is now Tanzania . Although commonly considered the most important African dinosaur locality, large theropod dinosaurs are only known through few and very fragmentary remains. In 1920, German paleontologist Werner Janensch assigned several dorsal vertebrae from the quarry "TL" to Ceratosaurus , as Ceratosaurus sp. (of uncertain species). In 1925, Janensch named a new species of Ceratosaurus , C. roechlingi , based on fragmentary remains from

5180-399: Is of little use, since we seldom have anything to affirm in common of the plants which have a given number of stamens and pistils." "The ends of scientific classification are best answered, when the objects are formed into groups respecting which a greater number of general propositions can be made, and those propositions more important, than could be made respecting any other groups into which

5328-910: Is referred to is that in biological classification the anatomical traits of organisms is one kind of classification, the classification in relation to the evolution of species is another (in the section below, we expand these two fundamental sorts of classification to four). Hull adds that in biological classification, evolution supplies the theoretical orientation. Ereshefsky (2000) presented and discussed three general philosophical schools of classification: "essentialism, cluster analysis, and historical classification. Essentialism sorts entities according to causal relations rather than their intrinsic qualitative features." These three categories may, however, be considered parts of broader philosophies. Four main approaches to classification may be distinguished: (1) logical and rationalist approaches including "essentialism"; (2) empiricist approaches including cluster analysis (It

5476-717: Is the Paleolithic Era , sometimes referred to as the Stone Age , though the Paleolithic is but one part of the Stone Age. This era extends from more than 2 million years into the past until between 40,000 and 5,000 years before the present (i.e., from around 2,000 kya to between 40 and 5 kya). The image of these people living in caves arises from the fact that caves are where the preponderance of artifacts have been found from European Stone Age cultures. However, this most likely reflects

5624-412: Is the classification of items which emphasis the goals, purposes, consequences, interests, values and politics of classification. It is, for example, classifying animals into wild animals, pests, domesticated animals and pets. Also kitchenware (tools, utensils, appliances, dishes, and cookware used in food preparation, or the serving of food) is an example of a classification which is not based on any of

5772-412: Is the systematic classification involved in the design and utilization of taxonomic schemes such as the biological classification of animals and plants by genus and species. Two of the predominant types of relationships in knowledge-representation systems are predication and the universally quantified conditional . Predication relationships express the notion that an individual entity is an example of

5920-402: Is under debate. Some analyses considered Ceratosaurus as the most derived of the basal members, forming the sister taxon of Abelisauroidea. Oliver Rauhut, in 2004, proposed Genyodectes as the sister taxon of Ceratosaurus , as both genera are characterized by exceptionally long teeth in the upper jaw. Rauhut grouped Ceratosaurus and Genyodectes within the family Ceratosauridae, which

6068-514: Is usually reduced to a dewclaw that does not touch the ground, is not preserved in the holotype. Marsh, in his original 1884 description, assumed that this digit was lost in Ceratosaurus , but Charles Gilmore , in his 1920 monograph, noted an attachment area on the second metatarsal demonstrating the presence of this digit. Uniquely among theropods, Ceratosaurus possessed small, elongated, and irregularly formed osteoderms (skin bones) along

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6216-466: The Ceratosaurus specimen. In 1920, Charles Gilmore published an extensive redescription of this and the other theropod specimens received from New Haven, including the nearly complete Allosaurus specimen recovered from the same quarry. In an 1892 paper, Marsh published the first skeletal reconstruction of Ceratosaurus , which depicts the animal at 22 ft (6.7 m) in length and 12 ft (3.7 m) in height. As noted by Gilmore in 1920,

6364-463: The Middle Ages , these beings were generally depicted in art and literature as bearded and covered in hair, and often wielding clubs and dwelling in caves. While wild men were always depicted as living outside of civilization, it was not always clearly whether they were human or non-human. In Sir Arthur Conan Doyle 's The Lost World (1912), ape-men are depicted in a fight with modern humans. How

6512-745: The Middle Jurassic of England apparently displays a nasal horn similar to that of Ceratosaurus . In 1926, Friedrich von Huene described this skull as Proceratosaurus (meaning "before Ceratosaurus "), assuming that it was an antecedent of the Late Jurassic Ceratosaurus . Today, Proceratosaurus is considered a basal member of Tyrannosauroidea , a much more derived clade of theropod dinosaurs. The nasal horn would have had evolved independently in both genera. Oliver Rauhut and colleagues, in 2010, grouped Proceratosaurus within its own family, Proceratosauridae . These authors also noted that

6660-509: The tooth crowns of the upper jaws were exceptionally long. In specimen UMNH VP 5278, they measured up to 9.3 cm (3.7 in) long, which is equal to the minimum height of the lower jaw. In the holotype, they are 7 cm (2.8 in) in length, which even surpasses the minimum height of the lower jaw. In other theropods, a comparable tooth length is only known from the possibly closely related Genyodectes . In contrast, several members of Abelisauridae feature very short tooth crowns. In

6808-978: The Cleveland-Lloyd Quarry and the Dinosaur National Monument in Utah, feature, respectively, the remains of at least three large theropods: Ceratosaurus , Allosaurus , and Torvosaurus . Likewise, Como Bluff and nearby localities in Wyoming contained remains of Ceratosaurus , Allosaurus , and at least one large megalosaurid. Ceratosaurus was a rare element of the theropod fauna, as it is outnumbered by Allosaurus at an average rate of 7.5 to 1 in sites where they co-occur. Several studies attempted to explain how these sympatric species could have reduced direct competition. Donald Henderson, in 1998, argued that Ceratosaurus co-occurred with two separate potential species of Allosaurus , which he denoted as "morphs":

6956-469: The Cleveland-Lloyd Quarry, which contains the long-snouted Allosaurus morph, but appears to be more common in both Garden Park and the Dry Mesa Quarry, in which it co-occurs with the short-snouted morph. Furthermore, Henderson suggested that Ceratosaurus could have avoided competition by preferring different prey items. The evolution of its extremely elongated teeth might have been a direct result of

7104-534: The Far Side , stated he once felt that he needed to confess his cartooning sins in this regard: "O Father, I Have Portrayed Primitive Man and Dinosaurs In The Same Cartoon". The animated series The Flintstones , a spoof on family sitcoms, portrays the Flintstones even using dinosaurs, pterosaurs and prehistoric mammals as tools, household appliances, vehicles, and construction equipment. Taxonomic Taxonomy

7252-625: The Felch Quarry 1, is regarded as one of the richest fossil sites of the Morrison Formation . Numerous dinosaur fossils had been recovered from this quarry even before the discovery of Ceratosaurus , most notably a nearly complete specimen of Allosaurus (USNM 4734) in 1883 and 1884. After excavation, the specimen was shipped to the Peabody Museum of Natural History in New Haven , where it

7400-682: The First Letter Was Written and How the Alphabet was Made are two of Rudyard Kipling 's Just So Stories (1902) featuring a group of cave-people. Edgar Rice Burroughs adapted this idea for The Land That Time Forgot (1918). A genre of cavemen films emerged, typified by D. W. Griffith 's Man's Genesis (1912); they inspired Charles Chaplin 's satiric take in His Prehistoric Past (1914), as well as Brute Force (1914), The Cave Man (1912), and later, Cave Man (1934). From

7548-464: The Morrison Formation as opposed to being fully semiaquatic. In his 1986 popular book The Dinosaur Heresies , Bakker argued that the bones of the upper jaw were only loosely attached to the surrounding skull bones, allowing for some degree of movement within the skull, a condition termed cranial kinesis . Likewise, the bones of the lower jaw would have been able to move against each other and

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7696-799: The above-mentioned three methods, but clearly on pragmatic or functional criteria. Bonaccorsi, et al. (2019) is about the general theory of functional classification and applications of this approach for patent classification. Although the examples may suggest that pragmatic classifications are primitive compared to established scientific classifications, it must be considered in relation to the pragmatic and critical theory of knowledge, which consider all knowledge as influences by interests. Ridley (1986) wrote: "teleological classification. Classification of groups by their shared purposes, or functions, in life - where purpose can be identified with adaptation. An imperfectly worked-out, occasionally suggested, theoretically possible principle of classification that differs from

7844-507: The adult state of a single species. Oliver Rauhut, in 2003, and Matthew Carrano and Scott Sampson, in 2008, considered the anatomical differences cited by Madsen and Welles to support these additional species to represent ontogenetic (age-related) or individual variation. A further specimen (BYUVP 12893) was discovered in 1992 in the Agate Basin Quarry southeast of Moore, Utah , but still awaits description. The specimen, considered

7992-409: The area of software testing. They have also developed a web-based tool to facilitate and encourage the use of the taxonomy. The tool and its source code are available for public use. Uses of taxonomy in education include: Uses of taxonomy in safety include: Citing inadequacies with current practices in listing authors of papers in medical research journals, Drummond Rennie and co-authors called in

8140-411: The bite force concentrated at a smaller area due to the narrower skull. According to Henderson, the great similarities in skull shape between Ceratosaurus and the long-snouted Allosaurus morph indicate that these forms engaged in direct competition with each other. Therefore, Ceratosaurus might have been pushed out of habitats dominated by the long-snouted morph. Indeed, Ceratosaurus is very rare in

8288-425: The body cannot be inferred from this specimen. In his original description of the Ceratosaurus nasicornis holotype and subsequent publications, Marsh noted a number of characteristics that were unknown in all other theropods known at the time. Two of these features, the fused pelvis and fused metatarsus, were known from modern-day birds and, according to Marsh, clearly demonstrate the close relationship between

8436-499: The body midline. The strongly shortened metacarpals and phalanges of Ceratosaurus raise the question as to whether the hand retained the grasping function assumed for other basal theropods. Within Ceratosauria, an even more extreme hand reduction can be observed in abelisaurids, where the arm lost its original function , and in Limusaurus . In a 2016 paper on the anatomy of the Ceratosaurus hand, Carrano and Jonah Choiniere stressed

8584-507: The bone casts into their proper position, and painting to match the original color of the bones. Both the Fruita and Cleveland-Lloyd specimens were described by Madsen and Samuel Paul Welles in a 2000 monograph, with the Utah specimen being assigned to the new species C. dentisulcatus and the Colorado specimen being assigned to the new species C. magnicornis . The name dentisulcatus refers to

8732-462: The class they divide). Some people will argue that this is not classification/taxonomy at all, but such an argument must consider the definitions of classification (see above). These methods may overall be related to the empiricist theory of knowledge. Genealogical classification is classification of items according to their common heritage. This must also be done on the basis of some empirical characteristics, but these characteristics are developed by

8880-412: The classification of things or concepts, as well as to the principles underlying such work. Thus a taxonomy can be used to organize species, documents, videos or anything else. A taxonomy organizes taxonomic units known as "taxa" (singular "taxon")." Many are hierarchies . One function of a taxonomy is to help users more easily find what they are searching for. This may be effected in ways that include

9028-474: The classification scheme in Roget 's Thesaurus ultimately derives. Taxonomy in biology encompasses the description, identification, nomenclature, and classification of organisms. Uses of taxonomy include: Uses of taxonomy in business and economics include: Vegas et al. make a compelling case to advance the knowledge in the field of software engineering through the use of taxonomies. Similarly, Ore et al. provide

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9176-422: The close relationship between classification theory and concept theory. A main opponent of concepts as units is Barry Smith. Arp, Smith and Spear (2015) discuss ontologies and criticize the conceptualist understanding. The book writes (7): “The code assigned to France, for example, is ISO 3166 – 2:FR and the code is assigned to France itself — to the country that is otherwise referred to as Frankreich or Ranska. It

9324-651: The close resemblance to the condition seen in modern birds. The presence of this feature in Ceratosaurus became controversial in 1890, when Georg Baur speculated that the fusion in the holotype was the result of a healed fracture . This claim was repeated in 1892 by Cope, while arguing that C. nasicornis should be classified as a species of Megalosaurus due to insufficient anatomical differences between these genera. However, examples of fused metatarsals in dinosaurs that are not of pathological origin have been described since, including taxa more basal than Ceratosaurus . Osborn, in 1920, explained that no abnormal bone growth

9472-410: The competition with the long-snouted Allosaurus morph. Both species could also have preferred different parts of carcasses when acting as scavengers. The elongated teeth of Ceratosaurus could have served as visual signals facilitating the recognition of members of the same species or for other social functions. In addition, the large size of these theropods would have tended to decrease competition, as

9620-436: The concept theory agree - seems to be that classes cannot be determined by introspective methods, but must be based on scientific and scholarly research. Whether units are called concepts or universals, the problem is to decide when a thing (say a "blackbird") should be considered a natural class. In the case of blackbirds, for example, recent DNA analysis have reconsidered the concept (or universal) "blackbird" and found that what

9768-565: The context of legal terminology, an open-ended contextual taxonomy is employed—a taxonomy holding only with respect to a specific context. In scenarios taken from the legal domain, a formal account of the open-texture of legal terms is modeled, which suggests varying notions of the "core" and "penumbra" of the meanings of a concept. The progress of reasoning proceeds from the specific to the more general. Anthropologists have observed that taxonomies are generally embedded in local cultural and social systems, and serve various social functions. Perhaps

9916-445: The criteria for ordering these basic units into a classification". There is a widespread opinion in knowledge organization and related fields that such classes corresponds to concepts. We can, for example, classify "waterfowls" into the classes "ducks", "geese", and "swans"; we can also say, however, that the concept “waterfowl” is a generic broader term in relation to the concepts "ducks", "geese", and "swans". This example demonstrates

10064-576: The degree of preservation that caves provide over the millennia, rather than an indication of them being a typical form of shelter. Until the last glacial period, the great majority of humans did not live in caves, as nomadic hunter-gatherer tribes lived in a variety of temporary structures, such as tents and wooden huts (e.g., at Ohalo ). A few genuine cave dwellings did exist, however, such as at Mount Carmel in Israel . Stereotypical cavemen have traditionally been depicted wearing smock-like garments made from

10212-526: The descriptions, Griffith's characters cannot talk, and use sticks and stones for weapons, while the hero of Cave Man is a Tarzanesque figure who fights dinosaurs. Captain Caveman and the Teen Angels (1977-1980), is an animated comedy depicting cavemen as being hairy and carrying clubs. Griffith's Brute Force represents one of the earliest portrayals of cavemen and dinosaurs together, with its depiction of

10360-473: The designated subject as being importantly similar to other entities bearing the same designation; that is, we classify them together. Similarly the use of predicative phrases classifies actions or properties as being of a particular kind. We call this conceptual classification, since it refers to the classification involved in conceptualizing our experiences and surroundings" About systematic classification Suppe wrote: "A second, narrower sense of classification

10508-406: The dorsal (back) vertebrae, were as tall as the vertebral centra were long. The sacrum, consisting of six fused sacral vertebrae , was arched upwards, with its vertebral centra strongly reduced in height in its middle portion, as is the case in some other ceratosaurians . The tail comprised around 50 caudal vertebrae and was about half of the animal's total length. In the holotype, it

10656-425: The evolutionary line leading to modern birds and is considered basal within theropods. Ceratosauria itself contains a group of derived (nonbasal) members of the families Noasauridae and Abelisauridae , which are bracketed within the clade Abelisauroidea , as well as a number of basal members, such as Elaphrosaurus , Deltadromeus , and Ceratosaurus . The position of Ceratosaurus within basal ceratosaurians

10804-552: The first digit would have been slightly turned in when flexed . A cast of the brain cavity of the holotype was made under Marsh's supervision, probably during preparation of the skull, allowing Marsh to conclude that the brain "was of medium size, but comparatively much larger than in the herbivorous dinosaurs". The skull bones, however, had been cemented together afterwards, so the accuracy of this cast could not be verified by later studies. A second, well preserved braincase had been found with specimen MWC 1 in Fruita, Colorado, and

10952-527: The genus. In a 2016 paper, Matthew Carrano and Jonah Choiniere suggested that one or more cartilaginous (not bony) carpals were probably present, as indicated by a gap present between the forearm bones and the metacarpals, as well as by the surface texture within this gap seen in the cast. In contrast to most more- derived theropods, which showed only three digits on each hand (digits I–III), Ceratosaurus retained four digits, with digit IV being reduced in size. The first and fourth metacarpals were short, while

11100-467: The great morphological similarity of the hand with those of other basal theropods, suggesting that it still fulfilled its original grasping function, despite its shortening. Although only the first phalanges are preserved, the second phalanges would have been mobile, as indicated by the well-developed articular surfaces, and the digits would likely have allowed a similar degree of motion as in other basal theropods. As in other theropods other than abelisaurids,

11248-555: The historicist theory of knowledge. One of the main schools of historical classification is cladistics , which is today dominant in biological taxonomy, but also applied to other domains. The historical and hermeneutical approaches is not restricted to the development of the object of classification (e.g., animal species) but is also concerned with the subject of classification (the classifiers) and their embeddedness in scientific traditions and other human cultures. Pragmatic classification (and functional and teleological classification)

11396-413: The holotype, each half of the dentary , the tooth-bearing bone of the mandible , was equipped with 15 teeth, which are, however, poorly preserved. Both specimens MWC 1 and UMNH VP 5278 show only 11 teeth in each dentary, which were, as shown by the latter specimen, slightly straighter and less sturdy than those of the upper jaw. The exact number of vertebrae is unknown due to several gaps in

11544-445: The holotype. The back of the skull was more lightly built than in some other larger theropods due to extensive skull openings, yet the jaws were deep to support the proportionally large teeth. The lacrimal bone formed not only the back margin of the antorbital fenestra , a large opening between eye and bony nostril , but also part of its upper margin, unlike in members of the related Abelisauridae . The quadrate bone , which

11692-403: The holotype. The position of this plate on the body, however, is unknown. Specimen UMNH VP 5278 was also found with a number of osteoderms, which have been described as amorphous in shape. Although most of these ossicles were found at most 5 m apart from the skeleton, they were not directly associated with any vertebrae, unlike in the C. nasicornis holotype, so their original position on

11840-500: The ideal, he recognized that his own system (at least partly) represented an artificial classification. John Stuart Mill explained the artificial nature of the Linnaean classification and suggested the following definition of a natural classification: "The Linnæan arrangement answers the purpose of making us think together of all those kinds of plants, which possess the same number of stamens and pistils; but to think of them in that manner

11988-621: The influence of the cladistic paradigm - and have demanded new classifications. Smith's example of France demands an explanation. First, France is not a general concept, but an individual concept. Next, the legal definition of France is determined by the conventions that France has made with other countries. It is still a concept, however, as Leclercq (1978) demonstrates with the corresponding concept Europe . Hull (1998) continued: "Two fundamentally different sorts of classification are those that reflect structural organization and those that are systematically related to historical development." What

12136-462: The lacrimal bones. In juveniles, all three horns were smaller than in adults and the two halves of the nasal horn core were not yet fused. The premaxillary bones , which formed the tip of the snout, contained merely three teeth on each side, less than in most other theropods. The maxillary bones of the upper jaw were lined with 15 blade-like teeth on each side in the holotype. The first eight of these teeth were very long and robust, but from

12284-455: The larger and more obvious species, which means that it is not the case that folk taxonomies are based purely on utilitarian characteristics. In the seventeenth century the German mathematician and philosopher Gottfried Leibniz , following the work of the thirteenth-century Majorcan philosopher Ramon Llull on his Ars generalis ultima , a system for procedurally generating concepts by combining

12432-765: The larger. Such a hyponym, in turn, may have further subcategories for which it is a hypernym. In the simple biology example, dog is a hypernym with respect to its subcategory collie , which in turn is a hypernym with respect to Fido which is one of its hyponyms. Typically, however, hypernym is used to refer to subcategories rather than single individuals. Researchers reported that large populations consistently develop highly similar category systems. This may be relevant to lexical aspects of large communication networks and cultures such as folksonomies and language or human communication, and sense-making in general. Hull (1998) suggested "The fundamental elements of any classification are its theoretical commitments, basic units and

12580-465: The largest known from the genus, includes the front half of a skull, seven fragmentary pelvic dorsal vertebrae, and an articulated pelvis and sacrum. In 1999, Britt reported the discovery of a Ceratosaurus skeleton belonging to a juvenile individual. Discovered in Bone Cabin Quarry in Wyoming, it is 34% smaller than the C. nasicornis holotype and consists of a complete skull as well as 30% of

12728-455: The last ribs of the trunk, the humeri (upper arm bones), the distal finger bones of both hands, most of the right arm, most of the left leg, and most of the feet. The specimen was found encased in hard sandstone, leading to the skull and spine being heavily distorted during fossilization . The site of discovery, located in the Garden Park area north of Cañon City, Colorado , and known as

12876-465: The latter and dinosaurs. To set the genus apart from Allosaurus , Megalosaurus , and coelurosaurs , Marsh made Ceratosaurus the only member of both a new family , Ceratosauridae , and a new infraorder , Ceratosauria. This was questioned in 1892 by Edward Drinker Cope , Marsh's archrival in the Bone Wars , who argued that distinctive features such as the nasal horn merely showed that C. nasicornis

13024-496: The left and right nasal bones . Only the bony horn core is known from fossils. In the living animal, this core would have supported a keratinous sheath. While the base of the horn core was smooth, its upper two-thirds were wrinkled and lined with grooves that would have contained blood vessels when alive. In the holotype, the horn core is 13 cm (5.1 in) long and 2 cm (0.79 in) wide at its base, but quickly narrows to only 1.2 cm (0.47 in) further up, and

13172-420: The long, low, and flexible body of Ceratosaurus and megalosaurids. Compared to other Morrison theropods, Ceratosaurus showed taller neural spines on the foremost tail vertebrae, which were vertical rather than inclined towards the back. Together with the deep chevron bones on the underside of the tail, they indicate a deep, "crocodile-like" tail possibly adapted for swimming. On the contrary, allosaurids feature

13320-470: The lower levels of the Porto Novo Member, which is thought to be late Kimmeridgian in age. Additional bones of this individual (SHN (JJS)-65), including a left femur, a right tibia, and a partial left fibula (calf bone), were since exposed due to progressing cliff erosion . Although initially part of a private collection, these additional elements became officially curated after the private collection

13468-405: The midline of its body. Such osteoderms have been found above the neural spines of cervical vertebrae 4 and 5, as well as caudal vertebrae 4 to 10, and probably formed a continuous row that might have extended from the base of the skull to most of the tail. As suggested by Gilmore in 1920, their position in the rock matrix likely reflects their exact position in the living animal. The osteoderms above

13616-552: The most complete skeleton known from the genus and only a handful of additional specimens have been described since. Two additional species, Ceratosaurus dentisulcatus and Ceratosaurus magnicornis , were described in 2000 from two fragmentary skeletons from the Cleveland-Lloyd Quarry of Utah and from the vicinity of Fruita, Colorado . The validity of these additional species has been questioned, however, and all three skeletons possibly represent different growth stages of

13764-542: The most well-known and influential study of folk taxonomies is Émile Durkheim 's The Elementary Forms of Religious Life . A more recent treatment of folk taxonomies (including the results of several decades of empirical research) and the discussion of their relation to the scientific taxonomy can be found in Scott Atran 's Cognitive Foundations of Natural History. Folk taxonomies of organisms have been found in large part to agree with scientific classification, at least for

13912-622: The nasal horn is incompletely preserved, opening the possibility that it represented the foremost portion of a more extensive head crest, as seen in some other proceratosaurids such as Guanlong . Within the Morrison and Lourinhã Formation, Ceratosaurus fossils are frequently found in association with those of other large theropods, including the megalosaurid Torvosaurus and the allosaurid Allosaurus . The Garden Park locality in Colorado contained, besides Ceratosaurus , fossils attributed to Allosaurus . The Dry Mesa Quarry in Colorado, as well as

14060-686: The newly described genus was, at the time, the best-known theropod discovered in America. In 1898 and 1899, the specimen was transferred to the National Museum of Natural History in Washington, DC , along with many other fossils originally described by Marsh. Only part of this material was fully prepared when it arrived in Washington. Subsequent preparation lasted from 1911 to the end of 1918. Packaging and shipment from New Haven to Washington caused some damage to

14208-400: The ninth tooth onward, they gradually decrease in size. As is typical for theropods, they featured finely serrated edges, which contained some 10 denticles per 5 mm (0.20 in) in the holotype. Specimen MWC 1 merely showed 11 to 12 and specimen UMNH VP 5278 showed 12 teeth in each maxilla. The teeth were more robust and more recurved in the latter specimen. In all specimens,

14356-447: The number of possible prey items increases with size. Foster and Daniel Chure, in a 2006 study, concurred with Henderson that Ceratosaurus and Allosaurus generally shared the same habitats and preyed upon the same types of prey, meaning they likely had different feeding strategies to avoid competition. According to these researchers, this is also evidenced by different proportions of the skull, teeth, and arms. The distinction between

14504-423: The parallel grooves present on the inner sides of the premaxillary teeth and the first three teeth of the lower jaw in that specimen. Magnicornis points to the larger nasal horn. The validity of both species, however, was questioned in subsequent publications. Brooks Britt and colleagues, in 2000, claimed that the C. nasicornis holotype was in fact a juvenile individual, with the two larger species representing

14652-415: The quadrate bone could swing outwards, spreading the lower jaw at the jaw joint. Taken together, these features would have allowed the animal to widen its jaws in order to swallow larger food items. In a 2008 study, Casey Holliday and Lawrence Witmer re-evaluated similar claims made for other dinosaurs, concluding that the presence of muscle-powered cranial kinesis cannot be proven for any dinosaur species and

14800-412: The quarry "Mw" encompassing a quadrate bone, a fibula, fragmentary caudal vertebrae, and other fragments. This specimen stems from an individual substantially larger than the C. nasicornis holotype. In their 2000 monograph, Madsen and Welles confirmed the assignment of these finds to Ceratosaurus . In addition, they ascribed several teeth to the genus, which had originally been described by Janensch as

14948-426: The rationalist theory of knowledge. "Empiricism alone is not enough: a healthy advance in taxonomy depends on a sound theoretical foundation" Phenetics or numerical taxonomy is by contrast bottom-up classification, where the starting point is a set of items or individuals, which are classified by putting those with shared characteristics as members of a narrow class and proceeding upward. Numerical taxonomy

15096-421: The remainder of the skeleton including a complete pelvis. Besides these five skeletal finds, fragmentary Ceratosaurus remains have been reported from various localities from stratigraphic zones 2 and 4-6 of the Morrison Formation, including some of the major fossil sites of the formation. Dinosaur National Monument , Utah, yielded an isolated right premaxilla (DNM 972). A large shoulder blade (scapulocoracoid)

15244-455: The same formation that further support their earlier interpretation. Ceratosaurus followed the body plan typical for large theropod dinosaurs. As a biped , it moved on powerful legs, while its arms were reduced in size. Specimen USNM 4735, the first discovered skeleton and holotype of Ceratosaurus nasicornis , was an individual 5.3 m (17 ft) or 5.69 m (18.7 ft) long according to separate sources. Whether this animal

15392-465: The same species. In 1999, the discovery of the first juvenile specimen was reported. In 2000, a partial specimen was excavated and described from the Lourinhã Formation of Portugal , providing evidence for the presence of the genus outside of North America. Fragmentary remains have also been reported from Tanzania , Uruguay , and Switzerland , although their assignment to Ceratosaurus is currently not accepted by most paleontologists . Ceratosaurus

15540-482: The same things could be distributed." "A classification thus formed is properly scientific or philosophical, and is commonly called a Natural, in contradistinction to a Technical or Artificial, classification or arrangement." Ridley (1986) provided the following definitions: Ceratosaurus Ceratosaurus / ˌ s ɛr ə t oʊ ˈ s ɔːr ə s / (from Greek κέρας/κέρατος, keras/keratos meaning "horn" and σαῦρος sauros meaning "lizard")

15688-528: The second was slightly longer than the third. The metacarpus and especially the first phalanges were proportionally very short, unlike in most other basal theropods. Only the first phalanges of digits II, III, and IV are preserved in the holotype. The total number of phalanges and unguals (claw bones) is unknown. The anatomy of metacarpal I indicates that phalanges had originally been present on this digit as well. The pes (foot) consisted of three weight-bearing digits, numbered II–IV. Digit I, which in theropods

15836-408: The semicircular canals was enlarged, a feature generally found in bipedal animals. The orientation of the lateral semicircular canal indicates that the head and neck were held horizontally in neutral position. The holotype of C. nasicornis was found with its left metatarsals II to IV fused together. Marsh, in 1884, dedicated a short article to this, at the time, unknown feature in dinosaurs, noting

15984-620: The sense of smell, are well-preserved. While similar to those of Allosaurus , they were smaller than in Tyrannosaurus , which is thought to have been equipped with a very keen sense of smell. The semicircular canals , which are responsible for the sense of balance and therefore allow for inferences on habitual head orientation and locomotion, are similar to those found in other theropods. In theropods, these structures are generally conservative, suggesting that functional requirements during locomotion have been similar across species. The foremost of

16132-505: The sharing of data and code. CRediT comprises 14 specific contributor roles using the following defined terms: The taxonomy is an open standard conformiing to the OpenStand principles, and is published under a Creative Commons licence. Websites with a well designed taxonomy or hierarchy are easily understood by users, due to the possibility of users developing a mental model of the site structure. Guidelines for writing taxonomy for

16280-502: The short-snouted Allosaurus morph occupied a different ecological niche from both the long-snouted morph and Ceratosaurus . The shorter skull in this morph would have reduced bending moments occurring during biting, thus increased bite force, comparable to the condition seen in cats. Ceratosaurus and the other Allosaurus morph, though, had long-snouted skulls, which are better compared to those of dogs. The longer teeth would have been used as fangs to deliver quick, slashing bites, with

16428-437: The size of the striations. While the position of the bite marks on the herbivorous dinosaurs is consistent with predation or early access to remains, bite marks found on Allosaurus material suggest scavenging, either from the other theropods or from another Allosaurus . The unusually high concentration of theropod bite marks compared to other assemblages could be explained either by a more complete utilization of resources during

16576-482: The skins of animals and held up by a shoulder strap on one side, or loincloths made from leopard or tiger skins. Stereotypical cavewomen are similarly depicted, but sometimes with slimmer proportions and bones tied up in their hair. They are also depicted carrying large clubs approximately conical in shape. They often have grunt-like names, such as "Ugg" and "Zog". Caveman-like heraldic " wild men " were found in European and African iconography for hundreds of years. During

16724-427: The snout to the occipital condyle , which connects to the first cervical vertebra. The width of this skull is difficult to reconstruct, as it is heavily distorted, and Gilmore's 1920 reconstruction was later found to be too wide. The fairly complete skull of specimen MWC 1 was estimated to have been 60 cm (24 in) long and 16 cm (6.3 in) wide. This skull was somewhat more elongated than that of

16872-427: The so-called evolutionary taxonomy ", which mixes historical and empiricist principles). Logical division (top-down classification or downward classification) is an approach that divides a class into subclasses and then divide subclasses into their subclasses, and so on, which finally forms a tree of classes. The root of the tree is the original class, and the leaves of the tree are the final classes. Plato advocated

17020-413: The specific objects are considered as instances of a concept. For example, Fido is-an instance of the concept dog and Fluffy is-a cat . In linguistics , is-a relations are called hyponymy . When one word describes a category, but another describe some subset of that category, the larger term is called a hypernym with respect to the smaller, and the smaller is called a "hyponym" with respect to

17168-470: The specimen was dismantled and freed from the encasing plaque. In the new exhibition, which was set to open in 2019, the mount was planned to be replaced by a free-standing cast and the original bones were to be stored in the museum collection to allow full access for scientists. After the discovery of the holotype of C. nasicornis , a significant Ceratosaurus find was not made until the early 1960s, when paleontologist James Madsen and his team unearthed

17316-408: The spine of the Ceratosaurus nasicornis holotype. At least 20 vertebrae formed the neck and back in front of the sacrum . In the middle portion of the neck, the centra (bodies) of the vertebrae were as long as they were tall, while in the front and rear portions of the neck, the centra were shorter than their height. The upwards projecting neural spines were comparatively large and, in

17464-430: The tail were found separated from the neural spines by 25 mm (0.98 in) to 38 mm (1.5 in), possibly accounting for skin and muscles present in between, while those of the neck were much closer to the neural spines. Apart from the body midline, the skin contained additional osteoderms, as indicated by a 58 mm (2.3 in) by 70 mm (2.8 in) large, roughly quadrangular plate found together with

17612-448: The theory of evolution. Charles Darwin's main contribution to classification theory of not just his claim "... all true classification is genealogical ..." but that he provided operational guidance for classification. Genealogical classification is not restricted to biology, but is also much used in, for example, classification of languages, and may be considered a general approach to classification." These methods may overall be related to

17760-466: The trunk was depicted much too long in this reconstruction, incorporating at least six dorsal vertebrae too many. This error was repeated in several subsequent publications, including the first life reconstruction, which was drawn in 1899 by Frank Bond under the guidance of Charles R. Knight , but not published until 1920. A more accurate life reconstruction, published in 1901, was produced by Joseph M. Gleeson , again under Knight's supervision. The holotype

17908-474: The two Allosaurus morphs, however, was questioned by some later studies. Kenneth Carpenter , in a 2010 study, found that short-snouted individuals of Allosaurus from the Cleveland-Lloyd Quarry represent cases of extreme individual variation rather than a separate taxon. Furthermore, the skull of USNM 4734 from the Garden Park locality, which formed the basis for Henderson's analysis of the short-snouted morph,

18056-443: The two main such principles, phenetic and phylogenetic classification ". Natural classification is a concept closely related to the concept natural kind . Carl Linnaeus is often recognized as the first scholar to clearly have differentiated "artificial" and "natural" classifications A natural classification is one, using Plato's metaphor, that is “carving nature at its joints” Although Linnaeus considered natural classification

18204-608: The validity of C. dentisulcatus , assigned the specimen to Ceratosaurus aff. Ceratosaurus nasicornis . Other reports include a single tooth found in Moutier , Switzerland . Originally named by Janensch in 1920 as Labrosaurus meriani , the tooth was later assigned Ceratosaurus sp. (of unknown species) by Madsen and Welles. In 2008, Matías Soto and Daniel Perea described teeth from the Tacuarembó Formation in Uruguay , including

18352-405: The web include: Frederick Suppe distinguished two senses of classification: a broad meaning, which he called "conceptual classification" and a narrow meaning, which he called "systematic classification". About conceptual classification Suppe wrote: "Classification is intrinsic to the use of language, hence to most if not all communication. Whenever we use nominative phrases we are classifying

18500-509: The years, separate authors classified Ceratosaurus within Deinodontidae , Megalosauridae , Coelurosauria , Carnosauria , and Deinodontoidea . In his 1920 revision, Gilmore argued that the genus was the most basal theropod known from after the Triassic , being not that closely related to any other contemporary theropod known at that time. It thus warrants its own family: Ceratosauridae. It

18648-404: Was CT-scanned by paleontologists Kent Sanders and David Smith, allowing for reconstructions of the inner ear , gross regions of the brain, and cranial sinuses transporting blood away from the brain. In 2005, the researchers concluded that Ceratosaurus possessed a brain cavity typical for basal theropods and similar to that of Allosaurus . The impressions for the olfactory bulbs , which house

18796-475: Was a carnivorous theropod dinosaur that lived in the Late Jurassic period ( Kimmeridgian to Tithonian ages ). The genus was first described in 1884 by American paleontologist Othniel Charles Marsh based on a nearly complete skeleton discovered in Garden Park, Colorado , in rocks belonging to the Morrison Formation . The type species is Ceratosaurus nasicornis . The Garden Park specimen remains

18944-492: Was a distinct species, but were insufficient to justify a distinct genus. Consequently, he assigned C. nasicornis to the genus Megalosaurus , creating the new combination Megalosaurus nasicornis . Although Ceratosaurus was retained as a distinct genus in all subsequent analyses, its relationships remained controversial during the following century. Both Ceratosauridae and Ceratosauria were not widely accepted, with only few and poorly known additional members identified. Over

19092-399: Was a medium-sized theropod. The original specimen is estimated to be 5.3 m (17 ft) or 5.69 m (18.7 ft) long, while the specimen described as C. dentisulcatus was larger, at around 7 m (23 ft) long. Ceratosaurus was characterized by deep jaws that supported proportionally very long, blade-like teeth, a prominent, ridge-like horn on the midline of the snout, and

19240-457: Was claimed to be the largest yet discovered, although estimates have not been published. Another specimen, ML 352, discovered in Portugal in 2000, was estimated at 6 m (20 ft) in length and 600 kg (1,320 lb). The skull was quite large in proportion to the rest of its body. It measures 55 cm (22 in) in length in the C. nasicornis holotype, measured from the tip of

19388-434: Was connected to the lower jaw at its bottom end to form the jaw joint, was inclined so that the jaw joint was displaced backwards in relation to the occipital condyle. This also led to a broadening of the base of the lateral temporal fenestra , a large opening behind the eyes. The most distinctive feature was a prominent horn situated on the skull midline behind the bony nostrils, which was formed from fused protuberances of

19536-545: Was donated to the Sociedade de História Natural in Torres Vedras and were described in detail in 2015. The specimen was ascribed to the species Ceratosaurus dentisulcatus by Mateus and colleagues in 2006. A 2008 review by Carrano and Sampson confirmed the assignment to Ceratosaurus , but concluded that the assignment to any specific species is not possible at present. In 2015, Elisabete Malafaia and colleagues, who questioned

19684-406: Was erected by Janensch in 1920 and was based on 25 isolated, very large teeth up to 15 cm (5.9 in) in length. However, Janensch assigned this species to Megalosaurus , not to Ceratosaurus . Therefore, this name might be a simple copying error. Rauhut, in 2011, showed that Megalosaurus ingens was not closely related to either Megalosaurus or Ceratosaurus , but possibly represents

19832-432: Was estimated at 2.84 m (9.33 ft). The tail was deep from top to bottom due to its high neural spines and elongated chevrons , bones located below the vertebral centra. As in other dinosaurs, it counterbalanced the body and contained the massive caudofemoralis muscle, which was responsible for forward thrust during locomotion, pulling the upper thigh backwards when contracted . The scapula (shoulder blade)

19980-444: Was estimated by James Madsen to have been around 8.8 m (29 ft) long, but was later estimated at 7 m (23 ft) long. Its weight was calculated at 980 kg (2,160 lb), 452 kg (996 lb), and 700 kg (1,540 lb) in separate works. The second skeleton, MWC 1, was somewhat smaller than UMNH VP 5278 and might have weighed 275 kg (606 lb). The third, yet undescribed, specimen BYUVP 12893

20128-481: Was followed by several later accounts. Shuo Wang and colleagues, in 2017, concluded that Noasauridae were not nested within Abelisauroidea as was previously assumed, but instead were more basal than Ceratosaurus . Because noasaurids had been used as a fix point to define the clades Abelisauroidea and Abelisauridae, these clades would consequently include many more taxa per definition, including Ceratosaurus . In

20276-495: Was formerly considered one species (with subspecies) are in reality many different species, which just have chosen similar characteristics to adopt to their ecological niches. An important argument for considering concepts the basis of classification is that concepts are subject to change and that they changes when scientific revolutions occur. Our concepts of many birds, for example, have changed with recent development in DNA analysis and

20424-466: Was found disarticulated and is strongly flattened sideways. Although it was a large individual, it had not yet reached adult size, as indicated by unfused sutures between the skull bones. Scientifically accurate three-dimensional reconstructions of the skull for use in museum exhibits were produced using a complicated process including molding and casting of the individual original bones, correction of deformities, reconstruction of missing parts, assembly of

20572-430: Was fully grown is unclear. Othniel Charles Marsh , in 1884, suggested that this specimen weighed about half as much as the contemporary Allosaurus . In more recent accounts, this was revised to 418 kilograms (922 lb), 524 kg (1,155 lb), or 670 kg (1,480 lb). Three additional skeletons discovered in the latter half of the 20th century were substantially larger. The first of these, UMNH VP 5278,

20720-479: Was fused with the coracoid , forming a single bone without any visible demarcation between the two original elements. The C. nasicornis holotype was found with an articulated left arm including an incomplete hand. Although disarticulated during preparation, a cast had been made of the fossil beforehand to document the original relative positions of the bones. Carpal bones were not known from any specimen, leading some authors to suggest that they were lost in

20868-426: Was later found to be an early tyrannosauroid. Ceratosaurus shared its habitat with other large theropod genera, including Torvosaurus and Allosaurus , and it has been suggested that these theropods occupied different ecological niches to reduce competition. Ceratosaurus may have preyed upon plant-eating dinosaurs, although some paleontologists suggested that it hunted aquatic prey such as fish. The nasal horn

21016-888: Was later found to have been reconstructed too short. In a 2004 study, Robert Bakker and Gary Bir suggested that Ceratosaurus was primarily specialized in aquatic prey such as lungfish , crocodiles, and turtles. As indicated by a statistical analysis of shed teeth from 50 separate localities in and around Como Bluff, teeth of both Ceratosaurus and megalosaurids were most common in habitats in and around water sources such as wet floodplains , lake margins, and swamps. Ceratosaurus also occasionally occurred in terrestrial localities. Allosaurids, however, were equally common in terrestrial and aquatic habitats. From these results, Bakker and Bir concluded that Ceratosaurus and megalosaurids must have predominantly hunted near and within water bodies, with Ceratosaurus also feeding on carcasses of larger dinosaurs on occasion. The researchers furthermore noted

21164-769: Was likely absent in most. An Allosaurus pubic foot shows marks by the teeth of another theropod, probably Ceratosaurus or Torvosaurus . The location of the bone in the body (along the bottom margin of the torso and partially shielded by the legs) and the fact that it was among the most massive in the skeleton indicates that the Allosaurus was being scavenged. A bone assemblage in the Upper Jurassic Mygatt-Moore Quarry preserves an unusually high occurrence of theropod bite marks, most of which can be attributed to Allosaurus and Ceratosaurus , while others could have been made by Saurophaganax or Torvosaurus given

21312-463: Was mounted by Gilmore in 1910 and 1911. Since then, it was exhibited at the National Museum of Natural History. Most early reconstructions show Ceratosaurus in an upright posture, with the tail dragging on the ground. Gilmore's mount of the holotype, in contrast, was very ahead of its time. Inspired by the upper thigh bones, which were found angled against the lower leg, he depicted the mount as

21460-571: Was not until the establishment of cladistic analysis in the 1980s, however, that Marsh's original claim of Ceratosauria as a distinct group gained ground. In 1985, the newly discovered South American genera Abelisaurus and Carnotaurus were found to be closely related to Ceratosaurus . Gauthier, in 1986, recognized Coelophysoidea to be closely related to Ceratosaurus , although this clade falls outside of Ceratosauria in most recent analyses. Many additional members of Ceratosauria have been recognized since then. Ceratosauria split off early from

21608-426: Was probably not used as a weapon as was originally suggested by Marsh, but more likely was used solely for display. The first specimen, holotype USNM 4735, was discovered and excavated by farmer Marshall Parker Felch in 1883 and 1884. Found in articulation, with the bones still connected to each other, it was nearly complete, including the skull. Significant missing parts include an unknown number of vertebrae, all but

21756-721: Was reported from Como Bluff in Wyoming . Another specimen stems from the Dry Mesa Quarry of Colorado and includes a left scapulocoracoid, as well as fragments of vertebrae and limb bones. In Mygatt Moore Quarry, Colorado, the genus is known from teeth. From 1909 to 1913, German expeditions of the Berlin Museum für Naturkunde uncovered a diverse dinosaur fauna from the Tendaguru Formation in German East Africa , in what

21904-456: Was studied by Marsh, who described it as the new genus and species Ceratosaurus nasicornis in 1884. The name Ceratosaurus may be translated as "horn lizard" (from the Greek words κερας/κερατος , keras/keratos —"horn" and σαυρος / sauros —"lizard") and nasicornis with "nose horn" (from the Latin words nasus —"nose" and cornu —"horn"). Given the completeness of the specimen,

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