Editing Compsognathus

{{short description|Genus of dinosaurs}}
{{distinguish|Compsosaurus|Compsosuchus|Procompsognathus}}
{{pp-move-indef}}
{{Use mdy dates|date=January 2021}}
{{Automatic taxobox
| fossil_range = [[Late Jurassic]], {{fossil range|150.8|145}}
| image = Compy.jpg
| image_upright = 1.15
| image_caption = Reconstructed skeleton at the [[Museum of Ancient Life]] 
| parent_authority = [[Edward Drinker Cope|Cope]], 1875
| taxon = Compsognathus
| authority = [[Johann Andreas Wagner|Wagner]], 1859
| type_species = {{extinct}}'''''Compsognathus longipes'''''
| type_species_authority = Wagner, 1859
| synonyms =
* ''Compsognathus corallestris'' <br><small>Bidar ''et al.'', 1972</small>
}}

'''''Compsognathus''''' ({{IPAc-en|k|ɒ|m|p|ˈ|s|ɒ|ɡ|n|ə|θ|ə|s}};<ref>{{Cite OED|Compsognathus}}</ref> [[Ancient Greek|Greek]] ''kompsos''/κομψός; "elegant", "refined" or "dainty", and ''gnathos''/γνάθος; "jaw")<ref>{{cite book | last1 = Liddell | first1 = Henry George | author-link = Henry Liddell | last2 = Scott | first2 = Robert | author-link2 = Robert Scott (philologist) | year = 1980 | orig-year = 1871 | edition = abridged | title = A Greek-English Lexicon | publisher = [[Oxford University Press]] | location = Oxford, United Kingdom | isbn = 978-0-19-910207-5| title-link = A Greek-English Lexicon }}</ref> is a [[genus]] of small, [[bipedalism|bipedal]], [[carnivore|carnivorous]] [[theropoda|theropod]] [[dinosaur]]. Members of its single [[species]] '''''Compsognathus longipes''''' could grow to around the size of a [[chicken (bird)|chicken]]. They lived about 150&nbsp;[[mya (unit)|million years ago]], during the [[Tithonian]] [[Stage (stratigraphy)|age]] of the late [[Jurassic]] [[Period (geology)|period]], in what is now [[Europe]]. Paleontologists have found two well-preserved [[fossil]]s, one in [[Germany]] in the 1850s and the second in [[France]] more than a century later. Today, ''C. longipes'' is the only recognized species, although the French specimen was once thought to belong to a separate species named ''C. corallestris''.

Many presentations still describe ''Compsognathus'' as "chicken-sized" dinosaurs because of the size of the German specimen, which is now believed to be a juvenile. ''Compsognathus longipes'' is one of the few dinosaur species whose diet is known with certainty: the remains of small, agile lizards are preserved in the bellies of both specimens. Teeth discovered in Portugal may be further fossil remains of the genus.

Although not recognized as such at the time of its discovery, ''Compsognathus'' is the first theropod dinosaur known from a reasonably complete fossil skeleton. Until the 1990s, it was the smallest-known non-[[Avialae|avialan]] dinosaur, with the preceding centuries incorrectly labelling them as the closest relative of ''[[Archaeopteryx]]''.

==Discovery and species==
[[File:Compsognathus longipes cast 3.jpg|thumb|left|Joseph Oberndorfer acquired this fossil in Bavaria, Germany, in 1859. Shown here is a cast at the Bavarian State Institute for Paleontology and Historical Geology]]
''Compsognathus'' is known from two almost complete skeletons.<ref name=GSP88>{{cite book |last=Paul |first=Gregory S. |title=Predatory Dinosaurs of the World |year=1988 |publisher=Simon & Schuster |location=New York |isbn=978-0-671-61946-6 |chapter=Early Avetheropods |pages=[https://archive.org/details/predatorydinosau00paul/page/297 297–300] |chapter-url=https://archive.org/details/predatorydinosau00paul/page/297 }}</ref> The German specimen (specimen number BSP AS I 563) stems from limestone deposits in [[Bavaria]] and was part of the collection of physician and [[Fossil collecting|fossil collector]] Joseph Oberndorfer. Oberndorfer lent the specimen to paleontologist [[Johann Andreas Wagner|Johann A. Wagner]], who published a brief discussion in 1859, where he coined the name ''Compsognathus longipes''.<ref name=wagner1859>{{cite journal | last1 = Wagner | first1 = J. A. | year = 1859 | title = Über einige im lithographischen Schiefer neu aufgefundene Schildkröten und Saurier | journal = Gelehrte Anzeigen der Bayerischen Akademie der Wissenschaften | volume = 49 | page = 553}}</ref> Wagner did not recognise ''Compsognathus'' as a dinosaur, but instead described it as one of the "most curious forms among the lizards".<ref name=wagner1859/><ref name=ostrom78/> He published a more detailed description in 1861.<ref>{{cite journal |last= Wagner|first=Johann Andreas |year=1861|title= Neue Beiträge zur Kenntnis der urweltlichen Fauna des lithographischen Schiefers; V. ''Compsognathus longipes'' Wagner |journal=Abhandlungen der Bayerischen Akademie der Wissenschaften |volume=9 |pages=30–38 }}</ref> In 1866, Oberndorfer's collection, including the ''Compsognathus'' specimen, was acquired by the paleontological state collection in [[Munich]].<ref name="goerlich2006"/>

The year of discovery and the exact locality of the German specimen are unknown, possibly because Oberndorfer did not reveal details of the discovery to prevent other collectors from exploiting the locality;<ref name="goerlich2006">{{Cite journal| volume = 24| pages = 1–26| last1 = Göhlich| first1 = Ursula B.| last2 = Tischlinger| first2 = Helmut| last3 = Chiappe| first3 = Luis M.| title = ''Juravenator starki'' (reptilia, theropoda), ein neuer Raubdinosaurier aus dem Oberjura der Südlichen Frankenalb (Süddeutschland)| journal = Archaeopteryx: Jahreszeitschrift der Freunde des Jura-Museums in Eichstätt| date = 2006}}</ref> later authors have suggested that the German specimen was probably discovered during the 1850s. Weathering of the slab on which the fossil is preserved indicates that it was collected from a pile of waste rock left behind by quarrying.<ref name=reisdorf2012/> The specimen either stems from Jachenhausen or the region Riedenburg–Kehlheim.<ref name=reisdorf2012/><ref name="mauser1983">{{cite journal |last=Mäuser |first=M. |year=1983 |title=Neue Gedanken über ''Compsognathus longipes'' WAGNER und dessen Fundort |journal=Erwin Rutte-Festschrift |publisher=Weitenburger Akademie |pages=157–162}}</ref> All possible localities are part of lagoonal deposits of the [[Painten Formation]], and date to the latest part of the late [[Kimmeridgian]] or the earlier part of the early [[Tithonian]].<ref name=reisdorf2012/> In the Jurassic, the region was part of the Solnhofen archipelago. The limestone of the area, the [[Solnhofen limestone]], had been quarried for centuries, and yielded such well-preserved fossils as ''[[Archaeopteryx]]'' with feather impressions and [[pterosaur]]s with imprints of their wing membranes.<ref name=Wellnhofer2008>{{cite book |last=Wellnhofer |first=P. |title=''Archaeopteryx'' — der Urvogel von Solnhofen |year=2008 |publisher=Verlag Dr. Friedrich Pfeil |location=Munich |isbn=978-3-89937-076-8 |chapter=Dinosaurier |page=256}}</ref>

In two publications in 1868 and 1870, [[Thomas Huxley]], a major proponent of [[Charles Darwin]]'s theory of evolution, compared ''Compsognathus'' with ''Archaeopteryx'', which was considered the earliest known bird. Following earlier suggestions by [[Carl Gegenbaur]]<ref name="gegenbaur1863">{{cite journal | last1 = Gegenbaur | first1 = Karl | year = 1863 | title = Vergleichend-anatomische Bemerkungen über das Fußskelet der Vögel | journal = Archiv für Anatomie, Physiologie und Wissenschaftliche Medicin | volume = 1863 | pages = 450–472 }}</ref> and [[Edward Drinker Cope]],<ref name="cope1867">{{cite journal | last1 = Cope | first1 = Edward Drinker | year = 1867 | title = An account of the extinct reptiles which approached the birds | journal = Proceedings of the Academy of Natural Sciences of Philadelphia | volume = 19 | pages = 234–235 }}</ref> Huxley found that ''Archaeopteryx'' was closely similar to ''Compsognathus'', and referred to the latter as a "bird-like reptile". He concluded that [[Origin of birds|birds must have evolved from dinosaurs]], an assessment that established ''Compsognathus'' as one of the most widely known dinosaurs.<ref name="huxley1868">{{cite journal |last= Huxley|first= T.H. |year=1868|title= On the animals which are most nearly intermediate between birds and reptiles |journal=Annals and Magazine of Natural History |volume=2 |pages=66–75}}</ref><ref name="huxley1870b">{{cite wikisource | last1=Huxley | first1=Thomas H. | title=Further Evidence of the Affinity between the Dinosaurian Reptiles and Birds | wslink=Quarterly Journal of the Geological Society of London/Volume 26/Further Evidence of the Affinity between the Dinosaurian Reptiles and Birds | work=Quarterly Journal of the Geological Society of London | volume=26 | year=1870 | doi=10.1144/GSL.JGS.1870.026.01-02.08 | pages=12–31 | firsticon=yes | noicon=yes }}</ref><ref name=ostrom78/> The specimen has since been studied by many prominent paleontologists, including [[Othniel Charles Marsh]], who visited Munich in 1881. The German paleontologist J.G. Baur, who worked as an assistant of Marsh, removed the right ankle from the slab for illustration and study; this removed part got lost since.<ref name=ostrom78/><ref name="ostrom_discovery">{{Cite journal| volume = 13| issue = 1| pages = 31–37| last = Ostrom| first = John H.| title = A surprise from Solnhofen in the Peabody Museum Collections| journal = Discovery| date = 1978}}</ref> Although Baur published a detailed study of the ankle in 1882, which is now the only available source of information of this part of the skeleton, his reconstruction was later found to be inconsistent with corresponding impressions on the slab.<ref name=ostrom78/> [[John Ostrom]] thoroughly described the German specimen as well as the newly discovered French specimen in 1978, making ''Compsognathus'' one of the best-known small theropods at that time.<ref name=ostrom78/> He also concluded that the German specimen likely belongs to an immature individual.<ref name=ostrom78/>

[[File:Compsognathus corallestris = longipes.JPG|thumb|The fossil from Canjuers, France]]
The larger French specimen (Y85R M4M) was discovered in around 1971 in the [[Portland stone|Portlandian]] lithographic limestone of [[Canjuers]] near [[Nice]].<ref name=peyer06/> It dates to the lower Tithonian, as indicated by [[ammonite]] [[index fossil]]s. As Solnhofen, Canjures was famous for its limestone plates, which were quarried and sold under the name "dalles de Provence". The specimen was originally part of a large private fossil collection of Louis Ghirardi, the owner of the Canjures quarries. The collection, including the ''Compsognathus'' specimen, was sold to the [[National Museum of Natural History, France|National Museum of Natural History]] in [[Paris]] in 1983. Alain Bidar and Gérard Thomel, in a brief 1972 description, announced the new find under a separate species, ''Compsognathus corallestris''.<ref name="bidar1972a">{{Cite journal| volume = 275| pages = 2327–2329| last1 = Bidar| first1 = A.| last2 = Demay| first2 = L.| last3 = Thomel| first3 = G.| title = Sur la présence du Dinosaurien Compsognathus dans le Portlandien de Canjures (Var)| journal = Comptes Rendus de l'Académie des Sciences, Série D| date = 1972}}</ref> A more comprehensive description followed in the same year.<ref name="Bidar72">{{cite journal |last= Bidar|first= A.|author2=Demay L.|author3=Thomel G. |year=1972|title= ''Compsognathus corallestris'', une nouvelle espèce de dinosaurien théropode du Portlandien de Canjuers (Sud-Est de la France) |journal=Annales du Muséum d'Histoire Naturelle de Nice|volume=1 |pages=9–40}}</ref> According to these authors, the new species differed from the German species in its larger size and modified, flipper-like hand. Ostrom, Jean-Guy Michard and others have since relabeled it as another example of ''Compsognathus longipes''.<ref name=peyer06/><ref name="Michard91">{{cite journal|last=Michard|first=J. G.|year=1991|title=Description du Compsognathus (Saurischia, Theropoda) de Canjuers (Jurassique supérieur du Sud-est de la France), position phylogénétique, relation avec Archaeopteryx et implications sur l'origine théropodienne des oiseaux|journal= Ph.D. Dissertation, Muséum National d'Histoire Naturelle, Paris}}</ref> In 1984, George Callison and Helen Quimby identified the smaller German specimen as a juvenile of the same species.<ref name="CallisonQuimby1984">{{cite journal|last1=Callison|first1=G.|last2=Quimby|first2=H.M.|year=1984|title= Tiny dinosaurs: are they fully grown? |journal=Journal of Vertebrate Paleontology|volume=3 |pages=200–209|doi=10.1080/02724634.1984.10011975|issue=4|bibcode=1984JVPal...3..200C }}</ref><ref name="Michard91"/>

Collector Heinrich Fischer had originally labeled a partial foot consisting of three metatarsals and a phalanx, from the [[Solnhofen]] area, as belonging to ''Compsognathus longipes''. This identification was rejected by Wilhelm Dames, when he described the specimen for the first time in 1884.<ref name="dames1884">{{cite journal|last=Dames|first=W.B.|year=1884|title=Über Metatarsen eines ''Compsognathus''-ähnlichen Reptils von Solenhofen |journal=Sitzungsberichte der Gesellschaft Naturforschender Freunde zu Berlin| volume=Jahrgang 1884 | pages=179–180 |language=German}}</ref> [[Friedrich von Huene]], in 1925 and 1932, also found that the foot did probably not belong to ''Compsognathus'' itself but to a closely related genus.<ref name="huene1925">{{cite journal|last=von Huene |first=F.R. |year=1925 |title=Eine neue Rekonstruktion von ''Compsognathus longipes''| journal=Zentralblatt für Mineralogie, Geologie und Paläontologie, Abteilung B |volume=Jahrgang 1925 |number=5 |pages=157–160|language=German}}</ref><ref name="huene1932">{{Cite journal| volume = Ser. 1| issue = 4| pages = 1–361| last = Huene| first = F. von| others = Wolfgang Soergel (ed.)| title = Die fossil Reptil-Ordnung Saurischia, ihre Entwicklung und Geschichte| journal = Monographien zur Geologie und Paläontologie| date = 1932}}</ref>{{rp|336}} Ostrom, in his 1978 monography, questioned the attribution of this fossil to ''Compsognathus'' once more.<ref name=ostrom78/> Jens Zinke, in 1998, assigned forty-nine isolated teeth from the [[Camadas de Guimarota|Guimarota coal mine]] of [[Portugal]] to the genus. Zinke found that these teeth are not identical to those of ''Compsognathus longipes'', having serrations on the front edge, and thus labeled the teeth as ''Compsognathus'' sp. (of unknown species).<ref>{{cite journal|last=Zinke|first=J.|year=1998|title=Small theropod teeth from the Upper Jurassic coal mine of Guimarota (Portugal)|journal=Paläontologische Zeitschrift|volume=72|issue=1–2|pages=179–189|doi=10.1007/bf02987825|bibcode=1998PalZ...72..179Z |s2cid=128803487|url=http://www.schweizerbart.de/pubs/journals/0031-0220/paper/72/179|url-status=dead|archive-url=https://web.archive.org/web/20070927224025/http://www.schweizerbart.de/pubs/journals/0031-0220/paper/72/179|archive-date=September 27, 2007|url-access=subscription}}</ref>

==Description==
[[File:Compysizes1.png|thumb|left|Size comparison of the French (orange) and German (green) specimens, with a human]]
For decades, ''Compsognathus'' was known as the [[dinosaur size|smallest known non-avian dinosaur]],<ref name=ostrom78/> although some dinosaurs discovered later, such as ''[[Mahakala omnogovae|Mahakala]]'' and ''[[Microraptor]]'', were even smaller.<ref name="campione2014">{{Cite journal| volume = 5| issue = 9| pages = 913–923| last1 = Campione| first1 = N.E.| last2 = Evans| first2 = D.C.| last3 = Brown| first3 = C.M.| last4 = Carrano| first4 = M.T.| title = Body mass estimation in non-avian bipeds using a theoretical conversion to quadruped stylopodial proportions| journal = Methods in Ecology and Evolution| date = 2014 |doi=10.1111/2041-210X.12226| bibcode = 2014MEcEv...5..913C| s2cid = 84317234| doi-access = free}}</ref><ref name="agnolin2019">{{Cite journal| doi = 10.3389/feart.2018.00252| issn = 2296-6463| volume = 6| last1 = Agnolin| first1 = Federico L.| last2 = Motta| first2 = Matias J.| last3 = Brissón Egli| first3 = Federico| last4 = Lo Coco| first4 = Gastón| last5 = Novas| first5 = Fernando E.| title = Paravian Phylogeny and the Dinosaur-Bird Transition: An Overview| journal = Frontiers in Earth Science| date = 2019| page = 252| bibcode = 2018FrEaS...6..252A| doi-access = free| hdl = 11336/130197| hdl-access = free}}</ref> The German specimen was estimated to be {{convert|70–75|cm|abbr=on}}<ref name=ostrom78/> and {{convert|89|cm|abbr=on}}<ref name=GSP88/> in length by separate authors, while the larger French specimen was estimated at {{convert|1.25|m|abbr=on}}<ref name=GSP88/> and {{convert|1.4|m|abbr=on}}<ref name=peyer06/> in length. The height at the hip has been estimated at {{convert|20|cm|abbr=on}} for the German specimen and at {{convert|29|cm|abbr=on}} for the French specimen.<ref name=GSP88/> The German specimen was estimated to have weighed {{convert|0.32|kg|abbr=on}}<ref name=TH07>{{cite journal |last=Therrien |first=F. |author2=Henderson, D.M. |year=2007 |title=My theropod is bigger than yours...or not: estimating body size from skull length in theropods |journal=Journal of Vertebrate Paleontology |volume=27 |issue=1 |pages=108–115 |doi=10.1671/0272-4634(2007)27[108:MTIBTY]2.0.CO;2|s2cid=86025320 }}</ref> and {{convert|0.58|kg|abbr=on}},<ref name=GSP88/> and the French specimen {{convert|2.5|kg|abbr=on}}<ref name=GSP88/> and {{convert|3.5|kg|abbr=on}}.<ref name="seebacher2001">{{cite journal | doi = 10.1671/0272-4634(2001)021[0051:ANMTCA]2.0.CO;2 | last1 = Seebacher | first1 = F. | year = 2001 | title = A new method to calculate allometric length-mass relationships of dinosaurs | url = http://dinoweb.ucoz.ru/_fr/4/A_new_method_to.pdf | journal = Journal of Vertebrate Paleontology | volume = 21 | issue = 1 | pages = 51–60 | citeseerx = 10.1.1.462.255 | s2cid = 53446536 | archive-date = March 4, 2016 | access-date = August 6, 2018 | archive-url = https://web.archive.org/web/20160304002456/http://dinoweb.ucoz.ru/_fr/4/A_new_method_to.pdf | url-status = live }}</ref> Compared to other compsognathids, the larger French specimen would have been similar in size to larger ''[[Sinosauropteryx]]'' specimens, but smaller than ''[[Huaxiagnathus]]'' and ''[[Mirischia]]''.<ref name=peyer06/>

''Compsognathus'' were small, bipedal animals with long legs and longer tails, which they used for balance during locomotion. The forelimbs were smaller than the hindlimbs. The hand bore two large, clawed digits and a third, smaller digit that may have been non-functional.<ref name=peyer06/><ref name=gishlick07/> Their delicate skulls were narrow and long, with tapered snouts. The skull had five pairs of [[Fenestra (anatomy)|fenestrae]] (skull openings), the largest of which was for the [[Orbit (anatomy)|orbit]] (eye socket),<ref name="Lambert">{{cite book| last = Lambert| first = David| title = The Ultimate Dinosaur Book| publisher = Dorling Kindersley| year = 1993| location = New York| pages = [https://archive.org/details/ultimatedinosaur00lamb/page/38 38–81]| isbn = 978-1-56458-304-8| url = https://archive.org/details/ultimatedinosaur00lamb/page/38}}</ref>  with the eyes being larger in proportion to the rest of the skull. The lower jaw was slender and had no mandibular fenestra, a hole in the side of the lower jawbone commonly seen in [[archosaur]]s.

The teeth were small and pointed, suited for its diet of small vertebrates and possibly other small animals, such as insects. The German specimen had three teeth in each [[premaxilla]] (front bone of the lower jaw), 15 or 16 teeth in each maxilla, and 18 teeth in the lower jaw.<ref name="stromer1934">{{cite journal|last=Stromer| first=E. |year=1934 |title=Die Zähne des ''Compsognathus'' und Bemerkungen über das Gebiss der Theropoda |journal=Zentralblatt für Mineralogie, Geologie und Paläontologie, Abteilung B |volume=Jahrgang 1934| pages=74–85 |language=German}}</ref><ref name=ostrom78/> The French specimen had more teeth, including four in each premaxilla, 17 or 18 in the maxilla, and at least 21 teeth in the dentary.<ref name=peyer06/> Compsognathids were unique among theropods in having [[tooth crown]]s that curved backwards at two thirds of their height, while their mid-parts were straight; also, the crowns had expanded bases.<ref name=peyer06/> In ''Compsognathus'', the frontmost teeth of the upper and lower jaws were [[Serration|unserrated]], while those further back had fine serrations on their rear edges. In the German specimen, the crowns were around two times higher than wide in the front of the jaws but diminished in height further back, with the last tooth about as high as wide.<ref name="stromer1934"/> The German specimen also shows a [[diastema]] (tooth gap) behind the first three teeth of the premaxilla.<ref name=ostrom78/> As such a gap was not present in the French specimen, Peyer suggested that additional teeth were possibly present in this region the German specimen.<ref name=peyer06/>

The number of digits on the hand of ''Compsognathus'' has been a source of debate.<ref name=gishlick07/> For much of its history, ''Compsognathus'' was typically depicted with three digits, as is typical for theropods.<ref name=gishlick07/><ref name=ostrom78/> However, the type specimen only preserved phalanges from the first two digits, leading to the suggestion that ''Compsognathus'' had only two functional digits, with the third metacarpal being smaller and thinner.<ref name=ostrom78/> Study of the French specimen indicated that the third digit bore at least one or two small phalanges.<ref name=peyer06/><ref name=gishlick07/> However, there remains no evidence for an ungual phalanx on the third digit, so the digit may have been reduced and non-functional.<ref name=gishlick07/>

===Integument===
[[File:Compsognathus BW.jpg|thumb|Evidence from related species suggests that the body might have been covered with feather-like structures.]]
Some relatives of ''Compsognathus'', namely ''[[Sinosauropteryx]]'' and ''[[Sinocalliopteryx]]'', have been preserved with the remains of simple feathers covering the body like fur,<ref name="Currie2001"/> prompting some scientists to suggest that ''Compsognathus'' might have been feathered in a similar way.<ref name="jietal2007">{{cite journal | last1 = Ji | first1 = S. | last2 = Ji | first2 = Q. | last3 = Lu | first3 = J. | last4 = Yuan | first4 = C. | year = 2007 | title = A new giant compsognathid dinosaur with long filamentous integuments from Lower Cretaceous of Northeastern China | journal = Acta Geologica Sinica | volume = 81 | issue = 1| pages = 8–15 }}</ref> Consequently, many depictions of ''Compsognathus'' show them with coverings of downy proto-feathers. However, no feathers or feather-like covering have been preserved with ''Compsognathus'' fossils, in contrast to ''Archaeopteryx'', which are found in the same sediments. Karin Peyer, in 2006, reported skin impressions preserved on the side of the tail starting at the 13th tail vertebra. The impressions showed small bumpy tubercles, similar to the scales found on the tail and hind legs of ''[[Juravenator]]''.<ref name=peyer2006>{{cite journal | doi = 10.1671/0272-4634(2006)26[879:AROCFT]2.0.CO;2 | last1 = Peyer | first1 = K. | year = 2006 | title = A reconsideration of ''Compsognathus'' from the Upper Tithonian of Canjuers, southeastern France | journal = Journal of Vertebrate Paleontology | volume = 26 | issue = 4| pages = 879–896 | s2cid = 86338296 }}</ref> Additional scales had in 1901 been reported by Von Huene, in the abdominal region of the German ''Compsognathus'', but Ostrom subsequently disproved this interpretation;<ref name=ostrom78/><ref name="Huene01">{{cite journal |last= von Huene|first= F.|year=1901|title= Der vermuthliche Hautpanzer des "Compsognathus longipes" Wagner |journal=Neues Jahrbuch für Mineralogie, Geologie und Paläontologie |volume= 1|pages=157–160}}</ref> in 2012, Achim Reisdorf postulated that they are plaques of [[adipocere]], corpse wax.<ref name=reisdorf2012>{{cite journal | last1 = Reisdorf | first1 = A.G. | last2 = Wuttke | first2 = M. | year = 2012 | title = Re-evaluating Moodie's Opisthotonic-Posture Hypothesis in fossil vertebrates. Part I: Reptiles – The taphonomy of the bipedal dinosaurs ''Compsognathus longipes'' and ''Juravenator starki'' from the Solnhofen Archipelago (Jurassic, Germany) | journal = Palaeobiodiversity and Palaeoenvironments | volume = 92 | issue = 1| pages = 119–168 | doi = 10.1007/s12549-011-0068-y | s2cid = 129785393 }}</ref>

Like ''Compsognathus'', and unlike ''Sinosauropteryx'', a patch of fossilized skin from the tail and hindlimb of the possible relative ''[[Juravenator starki]]'' shows mainly scales, though there is some indication that simple feathers were also present in the preserved areas.<ref name=Goehlich2006>{{cite journal | last1 = Goehlich | first1 = U.B. | last2 = Tischlinger | first2 = H. | last3 = Chiappe | first3 = L.M. | year = 2006 | title = ''Juraventaor starki'' (Reptilia, Theropoda) ein nuer Raubdinosaurier aus dem Oberjura der Suedlichen Frankenalb (Sueddeutschland): Skelettanatomie und Wiechteilbefunde | journal = Archaeopteryx | volume = 24 | pages = 1–26 }}</ref> This may mean that a feather covering was not ubiquitous in this group of dinosaurs, or maybe that some species had fewer feathers than others.<ref>{{cite journal |last= Xu|first= Xing |year=2006|title= Palaeontology: Scales, feathers and dinosaurs |journal=Nature |volume= 440|issue=7082|pages=287–8 |doi=10.1038/440287a |pmid= 16541058 |bibcode = 2006Natur.440..287X |s2cid= 28376204 |doi-access= free }}</ref>

==Classification==

[[File:Archaeopteryx, Compsognathus and Rhamphorhynchus by Knight.jpg|left|thumb|Outdated restoration of ''Compsognathus'' and ''[[Archaeopteryx]]'' by [[Charles R. Knight]]]]
Originally classified as a lizard, the dinosaurian affinities of ''Compsognathus'' were first noted by Gegenbaur, Cope, and Huxley between 1863 and 1868.<ref name="gegenbaur1863"/><ref name="cope1867"/><ref name="huxley1868"/> Cope, in 1870, classified ''Compsognathus'' within a new clade of dinosaurs, the Symphypoda, which also contained ''Ornithotarsus'' (today classified as ''[[Hadrosaurus]]'').<ref name="cope1870">{{Cite journal| volume = 14| issue = 1| pages = 1–252| last = Cope| first = E. D.| title = Synopsis of the extinct Batrachia, Reptilia, and Aves of North America| journal = Transactions of the American Philosophical Society| series = New Series| date = 1870| doi = 10.2307/1005355| jstor = 1005355| url = https://www.biodiversitylibrary.org/bibliography/60482| archive-date = May 31, 2022| access-date = June 21, 2021| archive-url = https://web.archive.org/web/20220531232346/https://www.biodiversitylibrary.org/bibliography/60482| url-status = live}}</ref><ref name="baur1891">{{Cite journal| volume = 25| issue = 293| pages = 434–454| last = Baur| first = Georg| title = Remarks on the reptiles generally called Dinosauria| journal = The American Naturalist| date = 1891| doi = 10.1086/275329| s2cid = 84575190}}</ref> Later, both genera were found to belong to other groups of Cope's classification of dinosaurs: ''Compsognathus'' to the Gonipoda (equivalent to [[Theropoda]], in which it is now classified), and ''Ornithotarsus'' to the Orthopoda (equivalent to [[Ornithischia]]).<ref name="baur1891"/> Huxley, in 1870, rejected Cope's dinosaur classification scheme, and instead proposed the new clade [[Ornithoscelida]], in which he included the Dinosauria (comprising several forms now considered as ornithischians) and another new clade, the Compsognatha, which contained ''Compsognathus'' as the only member.<ref name="huxley1870">{{cite wikisource | last1=Huxley | first1=Thomas H. | title=On the Classification of the Dinosauria, with observations on the Dinosauria of the Trias | wslink=Quarterly Journal of the Geological Society of London/Volume 26/On the Classification of the Dinosauria, with observations on the Dinosauria of the Trias | work=Quarterly Journal of the Geological Society of London | volume=26 | year=1870 | doi=10.1144/gsl.jgs.1870.026.01-02.09 | pages=32–51 | firsticon=yes | noicon=yes }}</ref><ref name="seeley1888">{{Cite journal| volume = 43| issue = 258–265| pages = 165–171| last = Seeley| first = Harry Govier| title = On the classification of the fossil animals commonly named Dinosauria| journal = Proceedings of the Royal Society of London| date = 1888}}</ref> Later, these groups fell into disuse, although a resurrection of the Ornithoscelida was proposed in 2017.<ref name="baron2017">{{Cite journal| doi = 10.1038/nature21700| issn = 1476-4687| volume = 543| issue = 7646| pages = 501–506| last1 = Baron| first1 = Matthew G.| last2 = Norman| first2 = David B.| last3 = Barrett| first3 = Paul M.| title = A new hypothesis of dinosaur relationships and early dinosaur evolution| journal = Nature| access-date = December 27, 2020| date = 2017| pmid = 28332513| bibcode = 2017Natur.543..501B| s2cid = 205254710| url = https://www.nature.com/articles/nature21700| archive-date = March 23, 2017| archive-url = https://web.archive.org/web/20170323013818/https://www.nature.com/articles/nature21700| url-status = live| url-access = subscription}}</ref> The group Compsognatha was used for the last time by Marsh in a 1896 publication, where it was treated as a suborder of Theropoda.<ref name="marsh1996">{{Cite journal| volume = 3| issue = 9| pages = 388–400| last = Marsh| first = O. C.| title = Classification of Dinosaurs| journal = Geological Magazine| date = 1896| doi = 10.1017/S0016756800131826| bibcode = 1896GeoM....3..388M| s2cid = 131106051| url = https://zenodo.org/record/2210524| archive-date = July 28, 2020| access-date = July 1, 2019| archive-url = https://web.archive.org/web/20200728200916/https://zenodo.org/record/2210524| url-status = live}}</ref><ref name=peyer06/> In the same publication, Marsh erected the new family [[Compsognathidae]].<ref name="marsh1996"/><ref name=peyer06/> Friedrich von Huene, in 1914, erected the new [[infraorder]] [[Coelurosauria]], which includes the Compsognathidae amongst other families of small theropods; this classification remained in use since.<ref name="huene1914">{{Cite journal| volume = 1914| pages = 154–158| last = Huene| first = F. von| title = Das natürliche system der Saurischia| journal = Zentralblatt für Mineralogie, Geologie und Paläontologie, Abteilung B| date = 1914}}</ref><ref name=peyer06/>

The Compsognathidae are a group of mostly small dinosaurs from the late Jurassic and early [[Cretaceous]] periods of China, Europe and South America.<ref name=peyer06/> For many years, ''Compsognathus'' was the only member known, but in recent decades paleontologists have discovered several related genera. The [[clade]] includes ''[[Aristosuchus]]'',<ref>{{cite journal |last= Seeley|first= H.G.|year=1887|title= On ''Aristosuchus pusillus'' (Owen), being further notes on the fossils described by Sir. R. Owen as ''Poikilopleuron pusillus'', Owen|journal=Quarterly Journal of the Geological Society of London|volume= 43|issue=1–4|pages=221–228|doi=10.1144/GSL.JGS.1887.043.01-04.22|s2cid= 131237500}}</ref> ''[[Huaxiagnathus]]'',<ref>{{cite journal |last= Hwang |first= S.H. |author2= Norell, M. A. |author3= Qiang, J. |author4= Keqin, G. |s2cid= 86321886 |year= 2004 |title= A large compsognathid from the Early Cretaceous Yixian Formation of China |journal= Journal of Systematic Palaeontology |volume= 2 |issue= 1 |pages= 13–39 |doi= 10.1017/S1477201903001081 |bibcode= 2004JSPal...2...13H |url= http://doc.rero.ch/record/14846/files/PAL_E1983.pdf |archive-date= April 9, 2023 |access-date= January 3, 2023 |archive-url= https://web.archive.org/web/20230409033109/https://doc.rero.ch/record/14846/files/PAL_E1983.pdf |url-status= live }}</ref> ''[[Mirischia]]'',<ref>{{cite journal|last=Naish|first=D.|author2=Martill, D. M.|author3=Frey, E.|year=2004|title=Ecology, systematics and biogeographical relationships of dinosaurs, including a new theropod, from the Santana Formation (?Albian, Early Cretaceous) of Brazil|journal=Historical Biology|volume=16|issue=2–4|pages=1–14|doi=10.1080/08912960410001674200|bibcode=2004HBio...16...57N|url=http://darrennaish.files.wordpress.com/2013/01/naish-et-al-2004-new-theropod-mirischia-from-brazil.pdf|citeseerx=10.1.1.394.9219|s2cid=18592288|archive-date=August 9, 2017|access-date=August 6, 2018|archive-url=https://web.archive.org/web/20170809123620/https://darrennaish.files.wordpress.com/2013/01/naish-et-al-2004-new-theropod-mirischia-from-brazil.pdf|url-status=live}}</ref> ''[[Sinosauropteryx]]'',<ref name="Currie2001">{{cite journal|last= Currie|first= P.J.|author2= P. Chen|year= 2001|title= Anatomy of Sinosauropteryx prima from Liaoning, northeastern China|journal= Canadian Journal of Earth Sciences|volume= 38|issue= 12|pages= 1705–1727|doi= 10.1139/cjes-38-12-1705|bibcode= 2001CaJES..38.1705C|url= http://doc.rero.ch/record/14314/files/PAL_E1480.pdf|archive-date= January 22, 2023|access-date= January 3, 2023|archive-url= https://web.archive.org/web/20230122224657/https://doc.rero.ch/record/14314/files/PAL_E1480.pdf|url-status= live}}</ref><ref name="Ji1996">{{cite journal |last= Ji|first= Q. |author2=Ji S.A. |year=1996|title= On discovery of the earliest bird fossil in China and the origin of birds (in Chinese)|journal=Chinese Geology |volume= 233|pages=30–33}}</ref> and perhaps ''[[Juravenator]]'' and ''[[Scipionyx]]''.<ref>{{cite journal |last=Göhlich |first=U. |author2=L. M Chiappe |year=2006 |title=A new carnivorous dinosaur from the Late Jurassic Solnhofen archipelago |url=http://doc.rero.ch/record/232914/files/PAL_E4515.pdf |url-status=live |journal=Nature |volume=440 |issue=7082 |pages=329–332 |bibcode=2006Natur.440..329G |doi=10.1038/nature04579 |pmid=16541071 |s2cid=4427002 |archive-url=https://web.archive.org/web/20230123105644/http://doc.rero.ch/record/232914/files/PAL_E4515.pdf |archive-date=January 23, 2023 |access-date=August 6, 2018}}</ref><ref>{{cite journal|last=Dal Sasso|first=C.|author2=M. Signore|year=1998|title=Exceptional soft-tissue preservation in a theropod dinosaur from Italy|journal=Nature|volume=392|issue=6674|pages=383–387|doi=10.1038/32884|bibcode=1998Natur.392..383D|s2cid=4325093|url=http://doc.rero.ch/record/14901/files/PAL_E2043.pdf|archive-date=September 20, 2016|access-date=December 3, 2022|archive-url=https://web.archive.org/web/20160920170653/https://doc.rero.ch/record/14901/files/PAL_E2043.pdf|url-status=live}}</ref> At one time, ''[[Mononykus]]'' was proposed as a member of the family, but this was rejected by Chen and coauthors in a 1998 paper; they considered the similarities between ''Mononykus'' and the compsognathids to be an example of [[convergent evolution]].<ref name="Chen">{{cite journal| last = Chen| first = P.| author2 = Dong, Z. |author3 = Zhen, S.| title = An exceptionally well-preserved theropod dinosaur from the Yixian Formation of China| journal = Nature| volume = 391| issue =6663| pages = 147–152| year = 1998| doi = 10.1038/34356| bibcode=1998Natur.391..147C| s2cid = 4430927| url = http://doc.rero.ch/record/14898/files/PAL_E2040.pdf}}</ref> The position of ''Compsognathus'' and its relatives within the [[Coelurosauria|coelurosaur]] group is uncertain. Some, such as theropod expert [[Thomas R. Holtz Jr.|Thomas Holtz Jr.]] and co-authors [[Ralph Molnar]] and [[Phil Currie]] in the landmark 2004 text ''Dinosauria'', hold the family as the most [[Basal (phylogenetics)|basal]] of the coelurosaurs,<ref name="dinosauria04">{{cite book|title=The Dinosauria|url=https://archive.org/details/dinosauriandedit00weis|url-access=limited|year=2004|chapter=Basal Tetanurae|veditors=Weishampel DB, Osmólska H, Dodson P |vauthors=Holtz TR, Molnar RE, Currie PJ |page=[https://archive.org/details/dinosauriandedit00weis/page/n123 105]|publisher=University of California Press|isbn=978-0-520-24209-8|edition=2nd}}</ref> while others as part of the [[Maniraptora]].<ref>{{cite journal |last= Gauthier|first= J.A.|year=1986|title= Saurischian monophyly and the origin of birds|journal=In Padian, K. (Ed.) the Origin of Birds and the Evolution of Flight, Memoirs of the California Academy of Sciences |volume=8|pages=1–55}}</ref><ref>{{cite journal |last= Forster|first= C.A.|author2 = Sampson, S.D.|author3=Chiappe, L.M. |author4=Krause, D.W. |year=1998|title= The theropod ancestry of birds: new evidence from the Late Cretaceous of Madagascar|journal=Science|volume=279|issue=5358|pages=1915–1919 |doi=10.1126/science.279.5358.1915|pmid= 9506938 |bibcode = 1998Sci...279.1915F }}</ref>

For almost a century, ''Compsognathus longipes'' was the only well-known small theropod species. This led to comparisons with ''[[Archaeopteryx]]'' and to suggestions of an especially close relationship with birds. In fact, ''Compsognathus'', rather than ''Archaeopteryx'', piqued Huxley's interest in the origin of birds.<ref name = "FasWeis04">{{cite book|title=The Evolution and Extinction of the Dinosaurs|year=2005|chapter=Theropoda I:Nature red in tooth and claw|veditors=Fastovsky DE, Weishampel DB |vauthors=Fastovsky DE, Weishampel DB |pages=265–299|publisher=Cambridge University Press|isbn=978-0-521-81172-9|edition=2nd}}</ref> The two animals share similarities in shape and proportions, so many in fact that two specimens of ''Archaeopteryx'', the "Eichstätt" and the "Solnhofen", were for a time misidentified as those of ''Compsognathus''.<ref name="Lambert"/> Many other types of theropod dinosaurs, such as [[maniraptora]]ns, are now known to have been more closely related to birds.<ref name=weishampel04/>

[[File:Compsognathus longipes.jpg|thumb|Skeletal reconstruction by Marsh, 1896]]
[[File:Compsognathidae.jpg|thumb|Diagrams showing known elements of the two specimens (middle) and other [[compsognathids]]]]
Below is a simplified cladogram placing ''Compsognathus'' in Compsognathidae by Senter ''et al.'' in 2012.<ref name=senter10>{{Cite journal | last1 = Senter | first1 = P. | last2 = Kirkland | first2 = J. I. | last3 = Deblieux | first3 = D. D. | last4 = Madsen | first4 = S. | last5 = Toth | first5 = N. | editor1-last = Dodson | editor1-first = Peter | title = New Dromaeosaurids (Dinosauria: Theropoda) from the Lower Cretaceous of Utah, and the Evolution of the Dromaeosaurid Tail | doi = 10.1371/journal.pone.0036790 | journal = PLOS ONE | volume = 7 | issue = 5 | pages = e36790 | year = 2012 | pmid = 22615813| pmc = 3352940|bibcode = 2012PLoSO...736790S | doi-access = free }}</ref>

{{clade| style=font-size:100%; line-height:100%
      |label1=[[Compsognathidae]]
      |1={{clade
         |1={{clade
            |1=''[[Sinocalliopteryx]]''
            |2=''[[Huaxiagnathus]]'' }}
         |2={{clade
            |1=''[[Sinosauropteryx]]''
            |2={{clade
               |1='''''Compsognathus'''''
               |2={{clade
                  |1=''[[Juravenator]]''
                  |2=''[[Scipionyx]]'' }} }} }} }} }}

Here is an alternative phylogeny, published by ''Cau'' in 2024, with both specimens in bold.
{{clade|style=font-size:85%;line-height:80%
|label1=[[Tetanurae]]
|1={{clade
|1={{clade
 |1=''[[Siamraptor]]''
 |2=''[[Siamotyrannus]]'' }}
|label2=[[Orionides]]
|2={{clade
|1={{clade
|1=''[[Streptospondylus]]''
|2=''[[Xuanhanosaurus]]''
|3=''[[Poekilopleuron]]''
|4=''[[Piveteausaurus]]''
|5=''[[Piatnitzkysaurus]]''
|6=''[[Marshosaurus]]''
|7=''[[Leshansaurus]]''
|8=''[[Eustreptospondylus]]''
|9=''[[Condorraptor]]''
|10=''[[Asfaltovenator]]''
|11={{clade
|1=''[[Sciurumimus]]''
|2=''[[Nedcolbertia]]''
|3=''[[Magnosaurus]]''
|4=''[[Duriavenator]]''
|5=''[[Afrovenator]]''
|6={{clade
|1='''''Compsognathus longipes'''''
|2='''''Compsognathus corallestris'''''
|3=''[[Torvosaurus|Torvosaurus tanneri]]''
|4=''[[Torvosaurus|Torvosaurus gurneyi]]''
|5=''[[Megalosaurus]]''
|6={{clade
|1=''[[Scipionyx]]''
|2=''[[Wiehenvenator]]''
|3=''[[Iberospinus]]''
|4={{clade
|1=[[Baryonychinae]]
|2=[[Spinosaurinae]] }} }} }} }} }}
|label2=[[Avetheropoda]]
|2={{clade
|1=[[Allosauroidea]] (Incl. ''[[Juravenator]]'' at an indeterminate position)
|label2=[[Coelurosauria]]
|2={{clade
|1=''[[Sinosauropteryx]]''
|2=''[[Sinocalliopteryx]]''
|3=''[[Mirischia]]''
|4=''[[Huaxiagnathus]]''
|5=''[[Zuolong]]''
|label6=[[Tyrannoraptora]]
|6={{clade
|1=[[Maniraptoromorpha]]
|2={{clade
|1=NGMC 2124
|2=''[[Tanycolagreus]]''
|3=''[[Stokesosaurus]]''
|4=''[[Juratyrant]]''
|5=[[Eutyrannosauria]] }} }} }} }} }} }} }}

==Paleobiology==

[[File:Compsognathus_UDL.png|thumb|Life restoration]]
In a 2001 study conducted by Bruce Rothschild and other paleontologists, nine foot bones referred to ''Compsognathus'' were examined for signs of [[stress fracture]], but none were found.<ref name="rothschild-dino">{{cite journal |last1=Rothschild |first1=B. |last2=Tanke |first2=D. H. |last3=Ford |first3=T. L. |year=2001 |title=Theropod stress fractures and tendon avulsions as a clue to activity |journal=Mesozoic Vertebrate Life |editor-last1=Tanke |editor-first1=D. H. |editor-last2=Carpenter |editor-first2=K. |publisher=Indiana University Press |pages=331–336}}</ref>

===Habitat===
Bidar and colleagues, in their 1972 description of the French specimen, argued that this specimen had webbed hands which would look like flippers in life. This interpretation was based on a supposed impression of the flipper that consists of several undulating wrinkles running parallel to the forelimb on the surface of the slab.<ref name="Bidar72"/> In a 1975 popular book, L. Beverly Halstead depicts the animal as an amphibious dinosaur capable of feeding on aquatic prey and swimming out of reach of larger predators.<ref>{{cite book|last=Halstead |first= L.B.|year=1975|title=The evolution and ecology of the dinosaurs|publisher=Eurobook|isbn =978-0-85654-018-9}}</ref> Ostrom debunked this hypothesis, noting that the forelimb of the French specimen is poorly preserved, and that the wrinkles extend well beyond the skeleton and thus are likely sedimentary structures unrelated to the fossil.<ref name=ostrom78/><ref name=peyer06/>

===Diet===
[[File:Compsognathus by Nopcsa, 1903.jpg|thumb|This 1903 illustration by [[Franz Nopcsa von Felső-Szilvás]] shows the gastric content of the German specimen]]
The remains of a lizard in the German specimen's thoracic cavity show that ''Compsognathus'' preyed on small vertebrates.<ref name="Chen"/> Marsh, who examined the specimen in 1881, thought that this small skeleton in the ''Compsognathus'' belly was an embryo, but in 1903, [[Franz Nopcsa von Felső-Szilvás|Franz Nopcsa]] concluded that it was a lizard.<ref name="nopcsa1903">{{cite journal |last= Nopcsa|first= Baron F.|year=1903|title= Neues ueber ''Compsognathus'' |journal=Neues Jahrbuch für Mineralogie, Geologie und Paläontologie |volume=16 |pages=476–494}}</ref> Ostrom identified the remains as belonging to a lizard of the genus ''[[Bavarisaurus]]'',<ref>{{cite journal |last= Evans|first= S.E.|year=1994|title= The Solnhofen (Jurassic: Tithonian) lizard genus Bavarisaurus: new skull material and a reinterpretation |journal=Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen |volume=192 |pages=37–52}}</ref> which he concluded was a fast and agile runner owing to its long tail and limb proportions. This in turn led to the conclusion that its predators, ''Compsognathus'', must have had sharp vision and the ability to rapidly accelerate and outrun the lizard.<ref name=ostrom78/> Conrad made the lizard found in the thoracic cavity of the German specimen of ''Compsognathus'' the [[holotype]] of a new species ''[[Schoenesmahl|Schoenesmahl dyspepsia]]''.<ref name=":0">{{Cite journal|author=Jack L. Conrad |year=2017 |title=A new lizard (Squamata) was the last meal of ''Compsognathus'' (Theropoda: Dinosauria) and is a holotype in a holotype |journal=Zoological Journal of the Linnean Society |volume=183 |issue= 3|pages= 584–634|doi=10.1093/zoolinnean/zlx055 }}</ref> The lizard is in several pieces, indicating that the ''Compsognathus'' must have dismembered it while restraining it with its hands and teeth, and then swallowed the remains whole; a similar strategy is used by modern predatory birds.<ref name=":0" /> The French specimen's gastric contents consist of unidentified lizards or [[Rhynchocephalia|sphenodontids]].<ref name=peyer06/>

===Possible eggs===
The plate of the German ''Compsognathus'' shows several circular irregularities {{convert|10|mm|abbr=on}} in diameter near the skeletal remains. Peter Griffiths interpreted them as immature eggs in 1993.<ref>{{cite journal |last= Griffiths|first= P.|year=1993|title= The question of ''Compsognathus'' eggs |journal=Revue de Paleobiologie Spec. |volume= 7|pages=85–94}}</ref> However, later researchers have doubted their connection to the genus because they were found outside the body cavity of the animal. A well-preserved fossil of a ''[[Sinosauropteryx]]'', a genus related to ''Compsognathus'', shows two [[oviduct]]s bearing two unlaid eggs. These proportionally larger and less numerous eggs of ''Sinosauropteryx'' cast further doubt on the original identification of the purported ''Compsognathus'' eggs.<ref name="Chen"/> In 1964 German geologist [[Karl Werner Barthel]] had explained the discs as gas bubbles formed in the sediment because of the putrefaction of the carcass.<ref>{{cite journal | last1 = Barthel | first1 = K.W. | year = 1964 | title = Zur Entstehung der Solnhofener Plattenkalke (unteres Untertithon) | journal = Mitteilungen der Bayerischen Staatssammlung für Paläontologie und historische Geologie | volume = 4 | pages = 7–69 }}</ref>

===Speed===
In 2007, William Sellers and Phillip Manning estimated a maximum speed of {{convert|17.8|m/s|mph}} based on a computer model of the skeleton and muscles.<ref>{{cite journal |last1=Sellers |first1=William |last2=Manning |first2=Phillip |year=2007 |url=https://www.researchgate.net/publication/6127793 |title=Estimating maximum running speeds using evolutionary robotics |journal=Proceedings. Biological Sciences |publisher=The Royal Society |volume=274 |issue=1626 |pages=2711–6 |doi=10.1098/rspb.2007.0846|pmid=17711833 |pmc=2279215 }}</ref> This estimate has been criticized by other scholars.<ref>{{cite web|url=https://www.newscientist.com/article/dn12524-t-rex-could-catch-a-human-simulations-show/|title=T. rex could catch a human, simulations show|website=New Scientist|date=August 22, 2007|last1=Inman|first1=Mason|access-date=September 29, 2019|archive-date=September 29, 2019|archive-url=https://web.archive.org/web/20190929195722/https://www.newscientist.com/article/dn12524-t-rex-could-catch-a-human-simulations-show/|url-status=live}}</ref>

==Paleoenvironment==
[[File:Archaeopteryx lithographica by durbed.jpg|thumb|Restoration of an ''Archaeopteryx'' chasing a juvenile ''Compsognathus'']]
During the late Jurassic, Europe was a dry, tropical [[archipelago]] at the edge of the [[Tethys Ocean|Tethys Sea]]. The fine limestone in which the skeletons of ''Compsognathus'' have been found originated in [[calcite]] from the shells of marine organisms. Both the German and French areas where ''Compsognathus'' specimens have been preserved were lagoons situated between the beaches and coral reefs of the Jurassic European islands in the Tethys Sea.<ref>{{cite book |last= Viohl|first= G.|year=1985|chapter= Geology of the Solnhofen lithographic limestone and the habitat of ''Archaeopteryx'' |veditors= Hecht MK, Ostrom JH, Viohl G, Wellnhofer P |title=The Beginnings of Birds: Proceedings of the International ''Archaeopteryx'' Conference. |location=Eichstätt| publisher=Freunde des Jura-Museums |pages=31–44 |oclc= 13213820}}</ref> Contemporaries of ''Compsognathus longipes'' include the early avialan ''[[Archaeopteryx]] lithographica'' and the pterosaurs ''[[Rhamphorhynchus]] muensteri'' and ''[[Pterodactylus]] antiquus''. The same sediments in which ''Compsognathus'' have been preserved also contain fossils of a number of marine animals such as fish, crustaceans, echinoderms and marine mollusks, confirming the coastal habitat of this theropod. No other dinosaur has been found in association with ''Compsognathus'', indicating that these little dinosaurs might in fact have been the top land predator in these islands.<ref name=weishampel04>{{cite book |last1=Weishampel |first1=D.B. |last2=Dodson |first2=P. |last3=Oslmolska |first3=H. |year=2004 |title=The Dinosauria |edition=Second |publisher=University of California Press}}</ref>

===Taphonomy===
Much discussion revolved around the [[taphonomy]] of the German specimen, i.e. how the individual died and became fossilized. Reisdorf and Wuttke, in 2012, speculated about the events that lead to the death and transportation of the specimen to its place of burial. First, the individual must have been brought into the lagoon from its habitat, which probably was on the surrounding islands. It is possible that a flash flood swept the animal into the sea, in which case it likely died by drowning. It is also possible that the animal swam or drifted onto the sea, or that it rafted on plants, and was then transported by surface currents to its place of burial. In any case, the specimen would have arrived on the sea floor within a few hours after its death, as otherwise gases forming in its body cavity would have prevented it from sinking in one piece. Water depth at the burial site would have been large enough to prevent refloating of the carcass after such gases were produced. Rounded structures on the slab might have been formed by the release of these gases.<ref name=reisdorf2012/>

Taphonomic reconstructions are complicated as the exact locality and the position and orientation of the fossil within the sediments is no longer known.<ref name=reisdorf2012/> As a [[compression fossil]], the specimen would originally have been preserved on both the upper surface of a layer and the lower surface of the subsequent layer (i.e., on a slab and its counter-slab); the counter-slab is now lost. Reisdorf and Wuttke, in 2012, argued that the front and hind limbs of the left side of the body were better {{Dinogloss|articulated}} (still connected together) than those of the right side. This suggests that the specimen is located on the bottom side of the upper slab, and was lying on its left side.<ref name=reisdorf2012/> The German specimen was preserved with a high degree of articulation – only the skull, hands, cervical ribs and gastralia show disarticulation. The braincase was displaced behind the skull, the first tail vertebra was rotated by 90°, and the tail shows a break between the seventh and eighth tail vertebra.<ref name=reisdorf2012/>

[[File:German Compsognathus.jpg|thumb|left|Illustration of the German specimen]] 
In both ''Compsognathus'' specimens, the neck is strongly curved, with the head coming to rest above the pelvis; the spine of the tail was likewise curved.<ref name="faux2007"/> This posture, known as the [[death pose]], is found in many vertebrate fossils, and the German ''Compsognathus'' specimen was central in several studies that sought to explain this phenomenon. The physician Moodie, in 1918, suggested that the death pose in ''Compsognathus'' and similar fossils was the result of an [[opisthotonus]] – death throes causing spastic stiffening of the back musculature – while the animal was dying. This hypothesis was soon challenged by paleontologist Friedrich von Huene, who argued that the death pose was the result of desiccation and therefore occurred only after the death. Peter Wellnhofer, in 1991, argued that death poses resulted from the elastic pull of the ligaments, which are released after death.<ref name=reisdorf2012/> The veterinarian Cynthia Faux and the paleontologist Kevin Padian, in a 2007 study that gained much attention, supported the original opisthotonus hypothesis of Moodie. These authors furthermore argued that upon death, muscles are relaxed and body parts can be easily moved relative to each other. Since opisthotonic postures are already established during death, they may only be preserved if the animal dies in place and becomes buried rapidly. This contradicts previous interpretations on the environment and taphonomy of ''Compsognathus'' and other fossils from the Solnhofen limestones, which assumed very slow burial at the bottom of lagoons into which the carcasses were transported from nearby islands.<ref name="faux2007">{{Cite journal| doi = 10.1666/06015.1| issn = 0094-8373| volume = 33| issue = 2| pages = 201–226| last1 = Faux| first1 = Cynthia Marshall| last2 = Padian| first2 = Kevin| title = The opisthotonic posture of vertebrate skeletons: postmortem contraction or death throes?| journal = Paleobiology| date = 2007| bibcode = 2007Pbio...33..201F| s2cid = 86181173| url = https://pubs.geoscienceworld.org/paleobiol/article/33/2/201/140456/The-opisthotonic-posture-of-vertebrate-skeletons| archive-date = September 1, 2023| access-date = December 13, 2020| archive-url = https://web.archive.org/web/20230901094344/https://pubs.geoscienceworld.org/paleobiol/article/33/2/201/140456/The-opisthotonic-posture-of-vertebrate-skeletons| url-status = live}}</ref><ref name=reisdorf2012/> Reisdorf and Wuttke concluded that the death posture indeed resulted from the release of ligaments, more specifically the {{Dinogloss|Ligamentum elasticum interlaminare}}, which spans the spine from the neck to tail in modern birds. The release of this ligament would have occurred gradually while the surrounding muscle tissue decayed, and only after the carcass was transported to its final site of deposition.<ref name=reisdorf2012/>

The bottom water of the lagoon was likely anaerobic (devoid in oxygen), resulting in a sea floor devoid of life except for microbial mats, and therefore preventing scavenging of the carcass.<ref name=reisdorf2012/> In the trunk region of the German specimen, the surface of the slab is markedly different in texture to the surrounding areas of the slab, showing irregular, nodular surfaces within depressions. Ostrom, in 1978, interpreted these structures as traces of weathering that took place just before the fossil was collected.<ref name=ostrom78/><ref name=reisdorf2012/> Nopcsa, in 1903, instead suggested that these structures resulted from decomposing tissue of the carcass.<ref name="nopcsa1903"/><ref name=reisdorf2012/> Reisdorf and Wuttke, in their 2012 study, suggested that the structures are the remains of [[adipocere]] (corpse wax formed by bacteria) that formed around the carcass before burial. Such adipocere would have helped in conserving the state of articulation of the fossil for years when burial was very slow. The presence of adipocere would possibly rule out hypersalinity (very high salt contents) of the bottom water, because such conditions appear to be unfavorable for the adipocere producing bacteria.<ref name=reisdorf2012/>

==In popular culture==
''Compsognathus'' is one of the more popular dinosaurs.<ref name=ostrom78/> For a long time, it was considered unique in its small size, which is commonly compared to that of a chicken.<ref name=ostrom78/><ref name=RW86>{{cite book |last=Wilson |first=Ron |title=100 Dinosaurs from A to Z |url=https://archive.org/details/100dinosaursfrom0000wils |url-access=registration |year=1986 |publisher=Grosset & Dunlap |location=New York |isbn=978-0-448-18992-5 |page=[https://archive.org/details/100dinosaursfrom0000wils/page/18 18]}}</ref><ref name=SA88>{{cite book |last=Attmore |first=Stephen |title=Dinosaurs |year=1988 |publisher=Brimax Books |location=Newmarket, England |isbn=978-0-86112-460-2 |page=[https://archive.org/details/dinosaurs0000attm/page/18 18] |url=https://archive.org/details/dinosaurs0000attm/page/18 }}</ref> The animals have appeared in the ''[[Jurassic Park]]'' franchise: in the films ''[[The Lost World: Jurassic Park]]'', ''[[Jurassic Park III]]'', ''[[Jurassic World: Fallen Kingdom]]'' and ''[[Jurassic World Dominion]]'', and the television series ''[[Jurassic World Camp Cretaceous|Camp Cretaceous]]''. In ''The Lost World: Jurassic Park'', the species is incorrectly identified as ''Compsognathus triassicus'', combining the genus name of ''Compsognathus longipes'' with the [[specific name (zoology)|specific name]] of ''[[Procompsognathus triassicus]]'', a distantly related small carnivore that also appears in the ''Jurassic Park'' series.<ref>{{cite book|last=Berry|first=Mark F.|title=The dinosaur filmography|publisher=McFarland|location=Jefferson, North Carolina|year=2002 |page=273|isbn=978-0-7864-1028-6}}</ref>

==References==
{{Reflist|30em|refs=
<ref name=gishlick07>{{cite journal | first1 = Alan D. | last1 = Gishlick | first2 = Jacques A. | last2 = Gauthier | year = 2007 | title = On the manual morphology of Compsognathus longipes and its bearing on the diagnosis of Compsognathidae | journal = Zoological Journal of the Linnean Society | volume = 149 | issue = 4 | pages = 569–581 | doi = 10.1111/j.1096-3642.2007.00269.x | doi-access = free }}</ref>
<ref name=ostrom78>{{cite journal |last=Ostrom |first=J.H. |year=1978 |title=The osteology of ''Compsognathus longipes'' |journal=Zitteliana |volume=4 |pages=73–118 |url=https://www.zobodat.at/pdf/Zitteliana_4_0073-0118.pdf |archive-date=November 1, 2022 |access-date=June 17, 2024 |archive-url=https://web.archive.org/web/20221101024154/https://www.zobodat.at/pdf/Zitteliana_4_0073-0118.pdf |url-status=live }}</ref>
<ref name=peyer06>{{cite journal | last = Peyer | first= Karin | year = 2006 | title = A reconsideration of Compsognathus from the upper Tithonian of Canjuers, southeastern France | journal = Journal of Vertebrate Paleontology | volume = 26 | issue = 4 | pages = 879–896 | doi = 10.1671/0272-4634(2006)26[879:AROCFT]2.0.CO;2 | s2cid= 86338296 }}</ref>
}}

== External links ==
* {{Wikispecies-inline|Compsognathidae}}
* {{Commons-inline}}

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[[Category:Compsognathidae]]
[[Category:Dinosaur genera]]
[[Category:Tithonian dinosaurs]]
[[Category:Fossil taxa described in 1859]]
[[Category:Taxa named by Johann Andreas Wagner]]
[[Category:Dinosaurs of Germany]]
[[Category:Dinosaurs of France]]