Lambeosaurus
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2008-06-29T11:57:03Z
FunkMonk
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/* Description */
{{Taxobox
| name = ''Lambeosaurus''
| fossil_range = [[Late Cretaceous]]
| image = Lambeosaurus2-v2.jpg
| regnum = [[Animal]]ia
| phylum = [[Chordate|Chordata]]
| classis = [[Reptile|Sauropsida]]
| superordo = [[Dinosaur]]ia
| ordo = [[Ornithischia]]
| familia = [[Hadrosauridae]]
| subfamilia = [[Lambeosaurinae]]
| tribus = [[Corythosaurini]]
| genus = '''''Lambeosaurus'''''
| genus_authority = [[William Parks|Parks]], 1923
| subdivision_ranks = [[Species]]
| subdivision =
* ''L. lambei'' <small>([[type species]])</small><br/><small>Parks, 1923</small>
* ''L. laticaudus'' <br/><small>Morris, 1981</small>
* ''L. magnicristatus'' <br/><small>[[Charles Mortram Sternberg|Sternberg]], 1935</small>
* ''L. paucidens'' <br/><small>([[Othniel Charles Marsh|Marsh]], 1889) (''[[nomen dubium]]'')</small>
}}
'''''Lambeosaurus''''' ({{pronEng|ˌlæmbioʊˈsɔrəs}}, meaning "[[Lawrence Lambe|Lambe's]] lizard") is a [[genus]] of [[hadrosaurid]] [[dinosaur]] that lived about 76 to 75 million years ago, in the [[Late Cretaceous]] [[period (geology)|Period]] ([[Campanian]]) of [[North America]]. This [[bipedalism|bipedal]]/[[quadruped]]al, [[herbivore|herbivorous]] dinosaur is known for its distinctive hollow cranial crest, which in the best-known species resembled a [[hatchet]]. Several possible species have been named, from [[Alberta]] ([[Canada]]), [[Montana]] ([[USA]]), and [[Baja California]] ([[Mexico]]), but only the two Canadian species are currently well known. At about 15 [[metre|meters]] (50 [[foot (unit of length)|ft]]) long, the Mexican species ''L. laticaudus'' was one of the [[dinosaur size|longest]] [[ornithischian]]s. The other species were more modestly sized.
''Lambeosaurus'' was belatedly described in 1923 by [[William Parks]], over twenty years after the first material was studied by [[Lawrence Lambe]]. The genus has had a complicated [[taxonomy|taxonomic]] history, in part because small-bodied crested hadrosaurids now recognized as [[juvenile (organism)|juveniles]] were once thought to belong to their own genera and [[species]]. Currently, the various skulls assigned to the [[type species]] ''L. lambei'' are interpreted as showing age differences and [[sexual dimorphism]]. ''Lambeosaurus'' was closely related to the better known ''[[Corythosaurus]]'', which is found in slightly older rocks, as well as the less well-known genera ''[[Hypacrosaurus]]'' and ''[[Olorotitan]]''. All had unusual crests, which are now generally assumed to have served social functions like noisemaking and recognition.
==Description==
[[Image:Lambeosaurs scale1.png|thumb|left|200px|''Lambeosaurus'' was considerably larger than a human. ''L. laticaudus'' was one of the [[dinosaur size|largest]] [[ornithischia]]ns of all.]]
''Lambeosaurus'', best known through ''L. lambei'', was quite similar to the more famous ''[[Corythosaurus]]'' in everything but the form of the head adornment. Compared to ''Corythosaurus'', the crest of ''Lambeosaurus'' was shifted forward, and the hollow nasal passages within were at the front of the crest and stacked vertically.<ref name=PD75>{{cite journal |last=Dodson |first=Peter |authorlink=Peter Dodson |year=1975 |title=Taxonomic implications of relative growth in lambeosaurine dinosaurs |journal=Systematic Zoology |volume=24 |pages=37–54 |doi=10.2307/2412696 }}</ref> It also can be differentiated from ''Corythosaurus'' by its lack of forking [[nasal bone|nasal]] [[process (anatomy)|processes]] making up part of the sides of the crest, which is the only way to tell juveniles of the two genera apart: the crests took on their distinctive forms as the animals aged.<ref name=EFR05>{{cite book |last=Evans |first=David C. |coauthors=Forster, Catherine F.; and Reisz, Robert R. |editors=Currie, Phillip J., and Koppelhus, Eva |title=Dinosaur Provincial Park: A Spectacular Ancient Ecosystem Revealed |chapter=The type specimen of ''Tetragonosaurus erectofrons'' (Ornithischia: Hadrosauridae) and the identification of juvenile lambeosaurines |year=2005 |publisher=Indiana University Press |location=Bloomington |pages=349–366 |isbn=0-253-34595-2 }}</ref>
[[Image:Lambeosaurus.jpg|thumb|''Lambeosaurus lambei'' skeleton, Royal Tyrrell Museum.]]
In build, ''Lambeosaurus'' was like other hadrosaurids, and could move on both two legs and all fours, as shown by footprints of related animals. It had a long tail stiffened by [[ossify|ossified tendons]] that prevented it from drooping. The hands had four fingers, lacking the [[thumb|innermost finger]] of the generalized five-fingered [[tetrapod]] hand, while the second, third, and fourth fingers were bunched together and bore [[hoof|hooves]], suggesting the animal could use the hands for support. The [[little finger|fifth finger]] was free and could be used to manipulate objects. Each foot had only the three central toes.<ref name=HWF04>{{cite book |last=Horner |first=John R. |authorlink=Jack Horner (paleontologist) |coauthors=Weishampel, David B.; and Forster, Catherine A |editor=Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.)|title=The Dinosauria |edition=2nd |year= 2004|publisher=University of California Press |location=Berkeley |isbn=0-520-24209-2 |pages=438–463 |chapter=Hadrosauridae }}</ref>
The most distinctive feature, the crest, was different in the two well-known species. In ''L. lambei'', it had a hatchet-like shape when the dinosaur was full-grown, and was somewhat shorter and more rounded in specimens interpreted as females.<ref name=PD75/> The "hatchet blade" projected in front of the eyes, and the "handle" was a solid bony rod that jutted out over the back of the skull. The "hatchet blade" had two sections: the uppermost portion was a thin bony "[[cockscomb|coxcomb]]" that grew out relatively late in life, when an individual neared adulthood; and the lower portion held hollow spaces that were continuations of the nasal passages.<ref name=PD75/> In ''L. magnicristatus'', the "handle" was greatly reduced, and the "blade" expanded,<ref name=LW42>{{cite book |last=Lull |first=Richard Swann |authorlink=Richard Swann Lull |coauthors= and Wright, Nelda E. |title=Hadrosaurian Dinosaurs of North America |year=1942 |publisher=Geological Society of America |series=Geological Society of America Special Paper '''40''' |pages=193–194 }}</ref> forming a tall, exaggerated [[pompadour (hairstyle)|pompadour]]-like crest. This crest is damaged in the best overall specimen, and only the front half remains.<ref name=ER07>{{cite journal |last=Evans |first=David C. |coauthors=and Reisz, Robert R. |year=2007|title= Anatomy and relationships of ''Lambeosaurus magnicristatus'', a crested hadrosaurid dinosaur (Ornithischia) from the Dinosaur Park Formation, Alberta |journal= Journal of Vertebrate Paleontology |volume= 27 |issue= 2 |pages=373–393|doi= 10.1671/0272-4634(2007)27[373:AAROLM]2.0.CO;2}}</ref> In the lesser-known species ''L. laticaudus'' and ''L. paucidens'' the crest is not currently known. However, ''L. laticaudus'' can be recognized by its great size and the tall profile of its tail, which had elongated [[chevron (anatomy)|chevron]]s and [[spinous process|vertebral spines]] like those of ''[[Hypacrosaurus]]''.<ref name=WJM81>{{cite journal |last=Morris |first=William J. |year=1981 |title=A new species of hadrosaurian dinosaur from the Upper Cretaceous of Baja California: ?''Lambeosaurus laticaudus'' |journal=Journal of Paleontology |volume=55 |issue=2 |pages=453–462 }}</ref>
The Canadian species of ''Lambeosaurus'' appear to have been similar in size to ''Corythosaurus'', and thus around 9.4 m long (31 ft),<ref name=LW42b>Lull, Richard Swann; and Wright, Nelda E. (1942). ''Hadrosaurian Dinosaurs of North America''. 227–228.</ref> but ''L. laticaudus'' is estimated at between 15 m (50 ft) and 16.5 m (54.1 ft) long, with a weight of up to 23 [[tonne|metric tons]] (25 [[short ton|ton]]s).<ref name=WJM81/> Impressions of the [[scale (zoology)|scales]] are known for several specimens; a specimen now assigned to ''L. lambei'' had a thin [[skin]] with uniform, polygonal [[scute]]s distributed in no particular order on the neck, torso, and tail.<ref name=LW42c>Lull, Richard Swann; and Wright, Nelda E. (1942). ''Hadrosaurian Dinosaurs of North America''. 112–117.</ref> Similar scalation is known from the neck, forelimb, and foot of a specimen of ''L. magnicristatus'',<ref name=ER07/> whereas the tail of ''L. laticaudus'' had some small bony bits embedded among large hexagonal and smaller rounded scales.<ref name=WJM81/>
==Classification==
''Lambeosaurus'' is the [[biological type|type genus]] of the [[Lambeosaurinae]], the [[scientific classification|subfamily]] of hadrosaurids that had hollow skull crests. Among the lambeosaurines, it is closely related to ''Corythosaurus'' and ''[[Hypacrosaurus]]'', with little separating them but crest form.<ref name=HWF04/> The relationships among these dinosaur genera are difficult to pick out. Internet classifications sometimes include all three in the tribe Lambeosaurini, but such a tribe has not been formally defined. Instead, the equivalent [[clade]] Corythosaurini has been adopted in publications, including the most recent [[phylogenetics|phylogeny]], presented by David Evans and Robert Reisz in their redescription of ''L. magnicristatus''. This examination indicated that ''Lambeosaurus'' is the [[cladistics|sister taxon]] to a clade made up of ''Corythosaurus'', ''Hypacrosaurus'', and the [[Russia]]n genus ''[[Olorotitan]]''; these lambeosaurines, with ''[[Nipponosaurus]]'', make up Corythosaurini.<ref name=ER07/>
==Discovery and history==
[[Image:LambeosaurusDB.jpg|thumb|200px|This life restoration illustrates ''Lambeosaurus'' with the animal in a half-crouch.]]
''Lambeosaurus'' has a complicated [[taxonomy|taxonomic]] history, beginning in 1902 with [[Lawrence Lambe]]'s naming of hadrosaurid limb material and other bones (originally [[Geological Survey of Canada|GSC]] 419) from Alberta as ''[[Trachodon|Trachodon marginatus]]''.<ref name=LL02>{{cite journal |last=Lambe |first=Lawrence M. |authorlink=Lawrence Lambe |year=1902 |title=On Vertebrata of the mid-Cretaceous of the Northwest Territory. 2. New genera and species from the Belly River Series (mid-Cretaceous) |journal=Contributions to Canadian Paleontology |volume=3 |pages=25–81 }}</ref> Paleontologists began finding better remains of hadrosaurids from the same rocks in the 1910s, in what is now known as the [[Campanian|late Campanian]]-age ([[Upper Cretaceous]]) [[Dinosaur Park Formation]]. Lambe assigned two new skulls to ''T. marginatus'', and based on the new information, coined the genus ''Stephanosaurus'' for the species in 1914.<ref name=LL14>{{cite journal |last=Lambe |first=Lawrence M. |year=1914 |title=On a new genus and species of carnivorous dinosaur from the Belly River Formation of Alberta, with a description of the skull of ''Stephanosaurus marginatus'' from the same horizon |journal=Ottawa Naturalist |volume=28 |pages=13–20 }}</ref> Unfortunately, there was very little to associate the skulls with the scrappy earlier ''marginatus'' material, so in 1923 [[William Parks]] proposed a new genus and species for the skulls, with both generic and specific names honoring Lambe: ''Lambeosaurus lambei'' ([[biological type|type specimen]] [[Canadian Museum of Nature|NMC]] 2869, originally GSC 2869).<ref name=WAP23>{{cite journal |last=Parks |first=William A. |authorlink=William Parks |year=1923 |title=''Corythosaurus intermedius'', a new species of trachodont dinosaur |journal=University of Toronto Studies, Geological Series |volume=15 |pages=1–57 }}</ref>
===New species and procheneosaurs===
Although the early workers in Alberta did not recognize it at the time, they were finding the remains of juvenile ''Lambeosaurus'' as well. These fossils of small-bodied crested duckbills were interpreted as adults of a distinct lineage of hadrosaurids, the subfamily Cheneosaurinae.<ref name=LW42d>Lull, Richard Swann; and Wright, Nelda E. (1942). ''Hadrosaurian Dinosaurs of North America''. 178–187.</ref> The first such animal to be named was ''Didanodon altidens'', a left [[maxilla|upper jaw]] (GSC 1092) from the Dinosaur Park Formation described by [[Henry Fairfield Osborn]] in 1902.<ref name=HFO02>{{cite journal |last=Osborn |first=Henry Fairfield |authorlink=Henry Fairfield Osborn |year=1902 |title=Distinctive characters of the mid-Cretaceous fauna. 1. New genera and species from the Belly River Series (mid-Cretaceous) |journal=Contributions to Canadian Paleontology |volume=3 |pages=1–21 }}</ref> It was referred to as ''Trachodon'' ''altidens'' by Lambe,<ref name=LL02/> and the name ''Didanodon'' seems to have rapidly fallen into obscurity, as it is not mentioned in [[Richard Swann Lull]] and Nelda Wright's influential 1942 [[monograph]] on North American hadrosaurids.
In 1920, [[William Diller Matthew]] used the name ''[[Procheneosaurus]]'' (no species name) in a caption for a photograph of a skeleton at the [[American Museum of Natural History]], from the Dinosaur Park Formation ([[American Museum of Natural History|AMNH]] 5340).<ref name=WDM20>{{cite journal |last=Matthew |first=William Diller |authorlink=William Diller Matthew |year=1920 |title=Canadian dinosaurs |journal=Natural History |volume=20 |issue=5 |pages=1–162 }}</ref> Parks believed that the procedure and description were inadequate for the name to be considered valid, and to address the situation, he coined the genus ''Tetragonosaurus''. Into this genus he placed the [[type species]] ''T. praeceps'' (based on [[Royal Ontario Museum|ROM]] 3577) and a second species ''T. erectofrons'' (based on ROM 3578) for small skulls from the Dinosaur Park Formation, and assigned Matthew's ''Procheneosaurus'' skeleton to ''T. praeceps''.<ref name=WAP31>{{cite journal |last=Parks |first=William A. |year=1931 |title=A new genus and two new species of trachodont dinosaurs from the Belly River Formation of Alberta |journal=University of Toronto Studies, Geological Series |volume=31 |pages=1–11 }}</ref> [[Charles Mortram Sternberg|Charles M. Sternberg]] followed in 1935 by adding the slightly larger ''T. cranibrevis'', based on GSC (now NMC) 8633.<ref name=CMS35>{{cite journal |last=Sternberg |first=Charles M. |authorlink=Charles Mortram Sternberg |year=1935 |title=Hooded hadrosaurs of the Belly River Series of the Upper Cretaceous |journal=Canada Department of Mines Bulletin (Geological Series) |volume=77 |issue=52 |pages=1–37 }}</ref> The use of ''Tetragonosaurus'' was rejected by Lull in favor of ''Procheneosaurus''. In 1942 he and Wright transferred the ''Tetragonosaurus'' species and, tentatively, ''Trachodon'' ''altidens'', to ''Procheneosaurus'', with ''P. praeceps'' serving as the type species.<ref name=LW42e>Lull, Richard Swann; and Wright, Nelda E. (1942). ''Hadrosaurian Dinosaurs of North America''. 1–242</ref> This usage was generally followed until 1975, when [[Peter Dodson]] showed that the "cheneosaurs" were actually [[juvenile (organism)|juveniles]] of other dinosaurs.<ref name=PD75/> ''Procheneosaurus praeceps'' and ''altidens'' are considered probable [[synonym (taxonomy)|synonyms]] of ''Lambeosaurus lambei'',<ref name=HWF04/> although both predate that name.
The "procheneosaurs" weren't the only crested duckbills being studied and named in the early 1900s. It was then the accepted practice to name genera and species for what is now seen as more likely individual variation, variation due to age or sex, or distortion from fossilization. Three more species were named during this period that relate to ''Lambeosaurus'', all in 1935. Sternberg, in the same paper as ''T. cranibrevis'', named a skull and partial skeleton (GSC—now NMC—8705) ''L. magnicristatum'' (corrected to ''magnicristatus''), and a smaller skull (GSC—now NMC—8703) ''L. clavinitialis'', with a less prominent crest and reduced spine pointing from the back.<ref name=CMS35/> Parks contributed ''Corythosaurus frontalis'', based on skull GSC 5853 (now ROM 869), which differed from the well-known tall, straight, rounded crest of other specimens of ''Corythosaurus'' by having a low crest cocked forward.<ref name=WAP35>{{cite journal |last=Parks |first=William A. |year=1931 |title=New species of trachodont dinosaurs from the Cretaceous formations of Alberta |journal=University of Toronto Studies, Geological Series |volume=37 |pages=1–45 }}</ref>
===Reconsideration and consolidation===
New specimens were not described for many years following the activity of the early 1900s. In 1964 [[John Ostrom]] noted that an old species named by [[Othniel Charles Marsh]], ''[[Hadrosaurus]] paucidens'', based on [[National Museum of Natural History|USNM]] 5457, a partial [[maxilla]] and [[squamosal]] from the [[Judith River Formation]] of [[Fergus County, Montana|Fergus County]], [[Montana]], was probably a specimen of ''Lambeosaurus''.<ref name=JHO64>{{cite journal |last=Ostrom |first=John H. |authorlink=John Ostrom |year=1964 |title=The systematic position of ''Hadrosaurus'' (''Ceratops'') ''paucidens'' Marsh |journal=Journal of Paleontology |volume=38 |issue=1 |pages=130–134 }}</ref>
In 1975, Peter Dodson, examining why there should be so many species and genera of lambeosaurine duckbills within such a short geological time frame and small area, published the results of a [[morphometrics|morphometric]] study in which he measured dozens of skulls. He found that many of the species had been based on remains that were better interpreted as juveniles or different sexes. For ''Lambeosaurus'', he found that ''L. clavinitialis'' was probably the female of ''L. lambei'', and ''Corythosaurus frontalis'' and ''Procheneosaurus praeceps'' were probably its juveniles. ''L. magnicristatus'' was different enough to warrant its own species. He interpreted ''Procheneosaurus cranibrevis'' and ''P. erectofrons'' as juvenile corythosaurs.<ref name=PD75/> However, restudy of the ''Procheneosaurus''/''Tetragonosaurus'' remains indicates that within species, assignments had become confused, and the type specimen of ''P. cranibrevis'' was a ''Lambeosaurus'' juvenile, whereas others were ''Corythosaurus'', based on the distinctive form of the contact of the [[nasal bone]] with the [[premaxilla]].<ref name=EFR05/>
Also during the 1970s, [[William J. Morris|Bill Morris]] was studying giant lambeosaurine remains from Baja California. He named them ?''L. laticaudus'' in 1981 (type specimen [[Natural History Museum of Los Angeles County|LACM]] 17715). Morris used a question mark in his work because no complete crest had been found for his species, and without it a definitive assignment could not be made. From what was known of the skull, he considered it to be most like ''Lambeosaurus''. He interpreted this species as water-bound, due to features like its size, its tall and narrow tail (interpreted as a [[ability to swim|swimming]] adaptation), and weak [[pelvis|hip]] articulations, as well as a healed broken [[femur|thigh bone]] that he thought would have been too much of a handicap for a terrestrial animal to have survived long enough to heal.<ref name=WJM81/>
==Species==
[[Image:Lambeosaurus lambei BW.jpg|thumb|225px|right|Profiles of various ''Lambeosaurus'' specimens, once assigned to their own species, now interpreted as different growth stages and sexes of ''L. lambei''.]]
Two species of ''Lambeosaurus'' are currently confirmed valid, with a third widely accepted and a fourth sometimes accepted. ''L. lambei'' Parks, 1923 is known from at least 17 individuals, with seven skulls and partial skeletons and around ten isolated skulls. ''L. clavinitialis'' C.M. Sternberg, 1935, ''Corythosaurus frontalis'' Parks, 1935, and ''Procheneosaurus praeceps'' Parks, 1931 are all regarded as synonyms of ''L. lambei'' in the most recent review.<ref name=HWF04/> It is possible that ''L. clavinitialis'' skulls without the backward spine may represent ''L. magnicristatus'' individuals instead,<ref name=JAH75>{{cite journal |last=Hopson |first=James A. |year=1975 |title=The evolution of cranial display structures in hadrosaurian dinosaurs |journal=Paleobiology |volume=1 |issue=1 |pages=21–43 |url=http://links.jstor.org/sici?sici=0094-8373(197524)1%3A1%3C21%3ATEOCDS%3E2.0.CO%3B2-I| accessdate=2007-07-28}}</ref> although this was rejected in the 2007 redescription of ''L. magnicristatus''.<ref name=ER07/> ''L. magnicristatus'' C.M. Sternberg, 1935 is only known from two specimens, both with skulls. Unfortunately, the majority of the articulated skeleton of the type specimen has been lost. Many of the bones were extensively damaged by water while in storage and were discarded before description; other portions of this skeleton have also been lost. Its remains come from slightly younger rocks than ''L. lambei''.<ref name=ER07/> The specific name is derived from the [[Latin]] ''magnus'' "large" and ''cristatus'' "crested", referring to its bony crest.<ref name ="Cassell79">{{cite book | last = Simpson | first = D.P. | title = Cassell's Latin Dictionary | publisher = Cassell Ltd. | date = 1979 | edition = 5 | location = London | pages = 883 | id = ISBN 0-304-52257-0}}</ref> The large ''L. laticaudus'' Morris, 1981, known from disassociated remains from several individuals, is accepted as a potential species as well,<ref name=HWF04/> although it could instead be a species of ''Hypacrosaurus''.<ref name=ER07/><ref name=TAGetal07>{{cite journal |last=Gates |first=Terry A. |coauthors=Sampson, Scott D.; Delgado de Jesús, Carlos R.; Zanno, Lindsay E.; Eberth, David; Hernandez-Rivera, René; Aguillón Martínez, Martha C.; and Kirkland, James I. |year=2007 |title=''Velafrons coahuilensis'', a new lambeosaurine hadrosaurid (Dinosauria: Ornithopoda) from the Late Campanian Cerro del Pueblo Formation, Coahuila, Mexico |journal=Journal of Vertebrate Paleontology |volume=27 |issue=4 |pages=917–930 |doi=10.1671/0272-4634(2007)27[917:VCANLH]2.0.CO;2}}</ref> Its validity has been questioned by the describers of ''[[Velafrons]]'', who find its remains to be nondiagnostic but distinct from their genus.<ref name=TAGetal07/> The specific name here is derived from the Latin ''latus'' "broad" and ''cauda'' "tail".<ref name ="Cassell79"/>
''L. paucidens'' (Marsh, 1889) is regarded as a [[nomen dubium|dubious name]] and is listed as ''Hadrosaurus paucidens'' in the latest review,<ref name=HWF04/> although at least one author, [[Donald F. Glut]], accepts it as a species of ''Lambeosaurus''.<ref name=DFG97>{{cite book|chapter=Lambeosaurus |last=Glut |first=Donald F. |authorlink=Donald F. Glut |title=Dinosaurs: The Encyclopedia |year=1997 |publisher=McFarland & Co |location=Jefferson, North Carolina |pages=525–533 |isbn=0-89950-917-7}}</ref> In this case, the specific epithet is derived from the Latin ''pauci-'' "few" and ''dens'' "tooth".<ref name ="Cassell79"/> The irregularities of ''Procheneosaurus cranibrevis'', and the identity of the type as a juvenile lambeosaur, were recognized in 2005,<ref name=EFR05/> and thus have not yet entered wide circulation. Finally, ''Didanodon'' and ''Trachodon altidens'' have received confusing treatment in the most recent review: ''Didanodon'' was assigned without comment to ''Lambeosaurus'', yet the species ''Trachodon altidens'' was listed separately in a table of dubious names.<ref name=HWF04/>
==Paleoecology==
[[Image:Dinosaur Park Fm.jpg|thumb|left|Rocks of the [[Dinosaur Park Formation]] exposed along the [[Red Deer River]], [[Dinosaur Provincial Park]], in southern [[Alberta]].]]
''Lambeosaurus lambei'' and ''L. magnicristatus'', from the [[Dinosaur Park Formation]], were members of a diverse and well-documented [[fauna]] of prehistoric animals that included such well-known dinosaurs as the [[ceratopsidae|horned]] ''[[Centrosaurus]]'', ''[[Styracosaurus]]'', and ''[[Chasmosaurus]]'', fellow duckbills ''[[Prosaurolophus]]'', ''[[Gryposaurus]]'', ''Corythosaurus'', and ''[[Parasaurolophus]]'', [[tyrannosaurid]] ''[[Gorgosaurus]]'', and [[ankylosauria|armored]] ''[[Edmontonia]]'' and ''[[Euoplocephalus]]''.<ref name=WETAL04>Weishampel, David B.; Barrett, Paul M.; Coria, Rodolfo A.; Le Loeuff, Jean; Xu Xing; Zhao Xijin; Sahni, Ashok; Gomani, Elizabeth, M.P.; and Noto, Christopher R. (2004). "Dinosaur Distribution", in ''The Dinosauria'' (2nd), pp. 517–606.</ref> The Dinosaur Park Formation is interpreted as a low-relief setting of [[river]]s and [[floodplain]]s that became more [[swamp]]y and influenced by [[ocean|marine]] conditions over time as the [[Western Interior Seaway]] [[transgression (geology)|transgressed]] westward.<ref name=DAE05>Eberth, David A. 2005. "The geology", in ''Dinosaur Provincial Park'', pp. 54–82.</ref> The [[climate]] was warmer than present-day Alberta, without [[frost]], but with wetter and drier seasons. [[Conifer]]s were apparently the dominant [[forest canopy|canopy]] plants, with an [[understory]] of [[fern]]s, [[tree fern]]s, and [[angiosperm]]s.<ref name=BK05>Braman, Dennis R., and Koppelhus, Eva B. 2005. "Campanian palynomorphs", in ''Dinosaur Provincial Park'', pp. 101–130.</ref> The anatomically similar ''L. lambei'', ''L. magnicristatus'', and ''Corythosaurus'' were separated by time within the formation, based on [[stratigraphy]]. ''Corythosaurus'' fossils are known from the lower two-thirds of the Formation, ''L. lambei'' fossils are present in the upper third, and ''L. magnicristatus'' remains are rare and present only at the very top, where the marine influence was greater.<ref name=RE05>{{cite book |last=Ryan |first=Michael J. |coauthors=and Evans, David C. |editors=Currie, Phillip J., and Koppelhus, Eva |title=Dinosaur Provincial Park: A Spectacular Ancient Ecosystem Revealed |chapter=Ornithischian Dinosaurs |year=2005 |publisher=Indiana University Press |location=Bloomington |pages=312–348 |isbn=0-253-34595-2 }}</ref>
==Paleobiology==
===Feeding===
As a hadrosaurid, ''Lambeosaurus'' was a large bipedal/quadrupedal herbivore, eating [[plant]]s with a sophisticated skull that permitted a grinding motion analogous to [[mammal]]ian [[mastication|chewing]]. Its [[tooth|teeth]] were continually replaced and were packed into dental batteries that each contained over 100 teeth, only a relative handful of which were in use at any time. It used its beak to crop plant material, which was held in the jaws by a [[cheek]]-like organ. Feeding would have been from the ground up to around 4 meters (13 ft) above.<ref name=HWF04/> As noted by [[Robert T. Bakker|Bob Bakker]], lambeosaurines have narrower beaks than hadrosaurines, implying that ''Lambeosaurus'' and its relatives could feed more selectively than their broad-beaked, crestless counterparts.<ref name=RTB86>{{cite book |last=Bakker |first=Robert T. |authorlink=Robert T. Bakker |year=1986 |title=[[The Dinosaur Heresies: New Theories Unlocking the Mystery of the Dinosaurs and their Extinction]] |publisher=William Morrow |location=New York |pages=p. 194 |isbn=0-8217-2859-8}}</ref>
===Cranial crest===
[[Image:Lambeosaurus magnicristatus DB.jpg|thumb|right|A life restoration of tall-crested ''Lambeosaurus magnicristatus''.]]
Like other [[Lambeosaurinae|lambeosaurines]] such as ''Parasaurolophus'' and ''Corythosaurus'', ''Lambeosaurus'' had a distinctive crest on the top of its head. Its nasal cavity ran back through this crest, making it mostly hollow. Many suggestions have been made for the function or functions of the crest, including housing [[salt gland]]s, improving the [[olfaction|sense of smell]], use as a snorkel or air trap, acting as a resonating chamber for making sounds, or being a method for different species or different sexes of the same species to recognize each other.<ref name=JAH75/><ref name=DBN85>{{cite book |last=Norman |first=David B. |authorlink=David B. Norman |title=The Illustrated Encyclopedia of Dinosaurs: An Original and Compelling Insight into Life in the Dinosaur Kingdom|chapter=Hadrosaurids II |year=1985 |publisher=Crescent Books |location=New York|pages=122–127 |isbn=0-517-468905 }}</ref> Social functions such as noisemaking and recognition have become the most widely accepted of the various hypotheses.<ref name=HWF04/>
The large size of hadrosaurid [[orbit (anatomy)|eye sockets]] and the presence of [[sclerotic ring]]s in the eyes imply acute vision and [[diurnal animal|diurnal]] habits, evidence that sight was important to these animals. The hadrosaurid sense of [[hearing (sense)|hearing]] also appears to be strong. There is at least one example, in the related ''Corythosaurus'', of a slender [[stapes]] (reptilian ear bone) in place, which combined with a large space for an [[eardrum]] implies a sensitive [[middle ear]], and the hadrosaurid [[lagena]] is elongate like a [[crocodilia]]n's. This indicates that the auditory portion of the [[inner ear]] was well-developed.<ref name=JAH75/> If used as a noisemaker, the crest could also have provided recognizable differences for different species or sexes, because the differing layouts of the nasal passages corresponding to the different crest shapes would have produced intrinsically different sounds.<ref name=DBW81>{{cite journal |last=Weishampel |first=David B. |authorlink=David B. Weishampel |year=1981 |title=Acoustic analyses of potential vocalization in lambeosaurine dinosaurs (Reptilia: Ornithischia) |journal=Paleobiology |volume=7 |issue=2 |pages=252–261 }}</ref>
==See also==
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|commons = Lambeosaurus
|hightaxon = Lambeosaurini
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==References==
{{reflist|2}}
==External links==
* [http://paleodb.org/cgi-bin/bridge.pl?action=checkTaxonInfo&taxon_name=Lambeosaurus ''Lambeosaurus''] Paleobiology Database (technical)
* [http://www.dinoruss.com/de_4/5a7af53.htm ''Lambeosaurus''] DinoRuss' Lair
* [http://internt.nhm.ac.uk/jdsml/nature-online/dino-directory/detail.dsml?Genus=Lambeosaurus ''Lambeosaurus''] Natural History Museum
* [http://www.users.qwest.net/~jstweet1/lambeosaurinae.htm Lambeosaurinae] at ''Thescelosaurus''!
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[[Category:Cretaceous dinosaurs]]
[[Category:Dinosaurs of North America]]
[[Category:Hadrosaurs]]
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