Editing Rapetosaurus

{{Short description|Extinct genus of dinosaurs}}
{{speciesbox
| fossil_range = [[Late Cretaceous]] ([[Maastrichtian]]), {{Geological range|70|66}}
| image = FMNH Rapetosaurus.jpg 
| image_caption = Juvenile skeleton, [[Field Museum of Natural History]]
| image2 = Rapetosaurus BW.jpg
| image2_caption = ''Rapetosaurus'' restoration
| display_parents = 2
| genus = Rapetosaurus
| parent_authority = [[Kristina Curry Rogers|Curry Rogers]] & [[Catherine Forster|Forster]], 2001
| species = krausei
| authority = Curry Rogers & Forster, 2001
}}
'''''Rapetosaurus''''' ({{IPAc-en|r|ə|ˌ|p|eɪ|t|uː|ˈ|s|ɔːr|ə|s}} {{respell|rə|PAY|too|SOR|əs}}<ref name=CurryRogers2001/>) is a [[genus]] of [[titanosaurian]] [[sauropod]] [[dinosaur]] that lived in [[Madagascar]] from 70 to 66 [[million years ago]], at the end of the [[Cretaceous]] [[Period (geology)|Period]]. Only one [[species]], '''''Rapetosaurus krausei''''', has been identified.

Like other sauropods, ''Rapetosaurus'' was a quadrupedal [[herbivore]]; it is calculated to have reached lengths of 15&nbsp;metres (49&nbsp;ft).

==Description==
''Rapetosaurus'' was a fairly typical sauropod, with a short and slender [[tail]], a very long [[neck]] and a huge, [[elephant]]-like body. Its head resembles the head of a [[diplodocid]], with a long, narrow snout and nostrils on the top of its [[skull]]. It was a herbivore and its small, pencil-like teeth were good for ripping the leaves off trees but not for chewing.
 [[File:Rapetosaurus Scale.svg|thumb|Size comparison between the juvenile ''Rapetosaurus'' and a human|250x250px]]
It was fairly modest in size for a [[titanosaur]]. The juvenile specimen measured {{convert|8|m}} from head to tail and "probably weighed about as much as an elephant". An adult would have been about twice as long ({{convert|15|m}} in length),<ref name=Montague2006/><ref name="Giant2016">{{Cite web |url=https://www.sciencedaily.com/releases/2016/04/160421145814.htm |title=Giant dinosaurs hatched with adult-like proportions |date=April 21, 2016 |website=ScienceDaily |language=en |access-date=May 3, 2025 }}</ref> which is still less than half the length of its gigantic kin, like ''[[Argentinosaurus]]'' and ''[[Paralititan]]''. In 2020, Molina-Perez and Larramendi estimated the size of the probable adult specimen (MAD 93-18), which is known from a femur, at 16.5 meters (54&nbsp;ft) and 10.3 tonnes (11.35 short tons).<ref>{{Cite book|last=Molina-Perez & Larramendi|title=Dinosaur Facts and Figures: The Sauropods and Other Sauropodomorphs|publisher=Princeton University Press|year=2020|location=New Jersey|pages=265|bibcode=2020dffs.book.....M }}</ref>

==Discovery and naming==
[[File:Rapetosaurus krausei, cast skull, ROM.jpg|thumb|Skull cast, [[Royal Ontario Museum]], Canada.]] 
The discovery of ''Rapetosaurus'', known by the single species ''Rapetosaurus krausei'', marked the first time a [[titanosaur]] had been recovered with an almost perfectly intact [[skeleton]], complete with [[skull]]. It has helped to clarify some difficult, century-old [[scientific classification|classification]] issues among this large group of [[sauropod]] [[dinosaur]]s and provides a good baseline for the reconstruction of other [[titanosaur]]s that are known only from partial [[fossil]]ized remains.

The discovery was published in 2001 by [[Kristina Curry Rogers]] and [[Catherine Forster|Catherine A. Forster]] in the scientific journal ''[[Nature (journal)|Nature]]''. The nearly-complete skeleton is that of a juvenile and partial remains from three other individuals were also recovered.
[[File:Rapetosaurus krausei Skeletal.png|left|thumb|Skeletal reconstruction of ''R. krausei'', scaled as juvenile specimen FMNH PR 2209.]]
The dig uncovered a partial skull (UA 8698, the [[holotype]] specimen), another partial skull, a juvenile skeleton missing only a few tail [[vertebra]]e, and an unrelated vertebra. The juvenile skeleton, in particular, is the most complete titanosaur skeleton ever recovered and the only one with a head still attached to the body.

The fossilized remains were found in the Mahajanga basin in northwest [[Madagascar]], not far from the port city of [[Mahajanga]]. They were recovered from a layer of sandstone known as the Anembalemba Member, which is part of the [[Maevarano Formation]]. The rock formation has been dated to the [[Maastrichtian]] [[faunal stage|stage]] of the late Cretaceous, which means the fossilized bones are about 70 million years old. They were found by a field team from [[Stony Brook University]] with the assistance of the local [[Universite d'Antananarivo]]. The team leader, David Krause, had been excavating fossils from the site since 1993.

The generic name ''Rapetosaurus'' is derived from Rapeto (a [[giant (mythology)|giant]] [[deity]] in [[Malagasy culture|Malagasy]] [[folklore]] credited for the geographical features of the land<ref>Zoë Crossland, Ancestral Encounters in Highland Madagascar: Material Signs and Traces of the Dead, Cambridge University Press, 17/02/2014</ref>) and ''sauros'', which is [[Ancient Greek|Greek]] for [[lizard]]. The species epithet, ''krausei'', is named after the team leader of the expedition, [[David W. Krause]].

==Paleobiology==
===Growth===
[[File:Rapetosaurus-mount-at-field-museum.jpg|thumb|left|Field Museum mount in side view]] 
A rare specimen of a juvenile ''Rapetosaurus'' was uncovered in a museum collection by Kristina Curry Rogers and colleagues. The specimen was estimated to weigh about 40 kilograms (88 pounds) and was likely between 39 and 77 days old by the time of its death. At the time of its hatching, the juvenile ''Rapetosaurus'' was estimated to be 3.4 kilograms (7.8 pounds) in weight. Based on bone remodeling, the juvenile sauropod was also believed to have been capable of surviving with little to no parental care. Analysis of the bones further revealed the young ''Rapetosaurus'' likely starved to death due to Cretaceous Madagascar's harsh droughts.<ref>{{cite web| url = https://www.latimes.com/science/sciencenow/la-sci-sn-baby-dinosaur-titanosaur-20160421-story.html| title = Rapetosaurus krausei: Tiny titanosaurus was just a few weeks old, scientists say - Los Angeles Times| website = [[Los Angeles Times]]| date = 21 April 2016}} </ref><ref>{{cite web |url=https://www.livescience.com/54496-baby-dinosaur-died-of-starvation.html |title = Lap Dinos? Gigantic Sauropods Started Out Chihuahua-Size {{!}} Live Science|website = [[Live Science]]| date=21 April 2016 }}</ref><ref name=Giant2016/>

==Paleoecology==
[[File:MajungasaurusROM.JPG|thumb|Mounted ''[[Majungasaurus]]'' and ''Rapetosaurus'' ]] 
During the Maastrichtian, like it is now, Madagascar was an island, having [[plate tectonics|separated]] from the [[Indian subcontinent]] less than 20 million years earlier. It was drifting northwards but still 10–15[[Degree (angle)|°]] more southerly in [[latitude]] than it is today. The prevailing [[climate]] of the time was semi-arid, with pronounced [[season]]ality in temperature and rainfall. Many prehistoric animals inhabited a coastal [[flood plain]] cut by many sandy [[river]] [[Channel (geography)|channels]].<ref name=rogersetal2007>{{cite book |last=Rogers |first=Raymond R. |author2=Krause, David W.|author3-link=Kristina Curry Rogers |author3=Curry Rogers, Kristina|author4=Rasoamiaramanana, Armand H.|author5=Rahantarisoa, Lydia |year=2007 |chapter=Paleoenvironment and Paleoecology of ''Majungasaurus crenatissimus'' (Theropoda: Abelisauridae) from the Late Cretaceous of Madagascar |editor=Sampson, Scott D. |editor2=Krause, David W. |title=''Majungasaurus crenatissimus'' (Theropoda: Abelisauridae) from the Late Cretaceous of Madagascar |journal=Journal of Vertebrate Paleontology |volume=27 |series=Society of Vertebrate Paleontology Memoir '''8''' |pages=21–31 |doi=10.1671/0272-4634(2007)27[21:PAPOMC]2.0.CO;2|s2cid=130262308 }}</ref> Strong geological evidence suggests the occurrence of periodic [[debris flow]]s through these channels at the beginning of the wet season, burying the carcasses of organisms killed during the preceding dry season and providing for their exceptional preservation as fossils.<ref name=rogers2005>{{cite journal |last=Rogers |first=Raymond R. |year=2005 |title=Fine-grained debris flows and extraordinary vertebrate burials in the Late Cretaceous of Madagascar |journal=Geology |volume=33 |issue=4 |pages=297–300 |doi=10.1130/G21036.1|bibcode=2005Geo....33..297R }}</ref> Sea levels in the area were rising throughout the Maastrichtian, and would continue to do so into the [[Paleocene Epoch]], so ''Rapetosaurus'' may have roamed coastal environments like [[tidal flats]] as well. The neighboring [[Berivotra Formation]] represents the contemporaneous [[Marine (ocean)|marine]] environment.<ref name=rogersetal2007 />

Besides ''Rapetosaurus'', fossil taxa recovered from the Maevarano include [[fish]], [[frog]]s, lizards, snakes,<ref name=rogersetal2007 /> seven distinct species of [[crocodylomorph]]s,<ref name=krauseetal2006>{{cite journal |last=Krause |first=David W. |author2=O'Connor, Patrick M.|author3-link=Kristina Curry Rogers |author3=Curry Rogers, Kristina|author4=Sampson, Scott D.|author5=Buckley, Gregory A.|author6=Rogers, Raymond R. |year=2006 |title=Late Cretaceous terrestrial vertebrates from Madagascar: implications for Latin American biogeography |journal=Annals of the Missouri Botanical Garden |volume=93 |issue=2 |pages=178–208 |url=http://www.mbgpress.info/index.php?task=id&id=11002 |doi=10.3417/0026-6493(2006)93[178:LCTVFM]2.0.CO;2|s2cid=9166607 }}</ref> [[Mesozoic mammals of Madagascar#Cretaceous|five or six species of mammals]],<ref name=krauseetal2006 /> ''[[Vorona]]''<ref name=forsteretal1996>{{cite journal |last=Forster |first=Catherine A. |author2=Chiappe, Luis M. |author3=Krause, David W. |author4= Sampson, Scott D.  |title=The first Cretaceous bird from Madagascar |journal=Nature |volume=382 |issue=6591 |pages=532–534 |doi=10.1038/382532a0 |year=1996|bibcode=1996Natur.382..532F |s2cid=4364184 }}</ref> and several other birds,<ref name=rogersetal2007 /> the possibly flighted [[dromaeosaurid]] ''[[Rahonavis]]'',<ref name=forsteretal1998>{{cite journal |last=Forster |first=Catherine |author2=Sampson, Scott D. |author3=Chiappe, Luis M. |author4= Krause, David 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><ref name=makovickyetal2005>{{cite journal |last=Makovicky |first=Peter J. |author2=Apesteguía, Sebastian |author3= Agnolín, Federico L.  |year=2005 |title=The earliest dromaeosaurid theropod from South America |journal=Nature |volume=437 |issue=7061 |pages=1007–1011 |doi=10.1038/nature03996 |pmid=16222297 |bibcode=2005Natur.437.1007M|s2cid=27078534 }}</ref> the [[Noasauridae|noasaurid]] ''[[Masiakasaurus]]'',<ref name=sampsonetal2001>{{cite journal |last=Sampson |first=Scott D. |author2=Carrano, Matthew T. |author3= Forster, Catherine A.  |year=2001 |title=A bizarre predatory dinosaur from the Late Cretaceous of Madagascar |journal=Nature |volume=409 |issue=6819 |pages=504–506 |doi=10.1038/35054046 |pmid=11206544|bibcode=2001Natur.409..504S |s2cid=205013285 }}</ref> and the [[Abelisauridae|abelisaurid]] ''[[Majungasaurus]]''.<ref name=krauseetal2007>{{cite book |last=Krause |first=David W. |author2=Sampson, Scott D. |author3=Carrano, Matthew T. |author4= O'Connor, Patrick M.  |year=2007 |chapter=Overview of the history of discovery, taxonomy, phylogeny, and biogeography of ''Majungasaurus crenatissimus'' (Theropoda: Abelisauridae) from the Late Cretaceous of Madagascar |editor=Sampson, Scott D. |editor2=Krause, David W. |title=''Majungasaurus crenatissimus'' (Theropoda: Abelisauridae) from the Late Cretaceous of Madagascar |journal=Journal of Vertebrate Paleontology |volume=27 |series=Society of Vertebrate Paleontology Memoir '''8''' |pages=1–20 |doi=10.1671/0272-4634(2007)27[1:OOTHOD]2.0.CO;2|s2cid=13274054 }}</ref> A variety of extinct mammals have also been discovered, such as [[gondwanatheres]] and non-[[placental]] [[eutherians]], the former reaching large sizes such as ''[[Vintana]]''.

[[File:Majungasaurus, Masiakasaurus, Rapetosaurus.jpg|thumb|left|Restoration of two ''[[Majungasaurus]]'' chasing ''Rapetosaurus'']] 
The skull of ''[[Majungasaurus]]'', a large [[abelisauridae|abelisaurid]] [[theropod]], was discovered in 1996. It is similar to species found in [[India]] and [[Argentina]], indicating that land bridges between the fragments of the former supercontinent of Gondwana still existed in the late Cretaceous, far later than was previously believed. The most likely occurrence was a land bridge allowing animals to cross from [[South America]] to [[Antarctica]], and then up to India and Madagascar. ''Majungasaurus'' was the largest predator in its environment, while the only known contemporaneous large herbivores were sauropods like ''Rapetosaurus''. Scientists have suggested that ''Majungasaurus'' specialized in hunting sauropods. ''Majungasaurus'' tooth marks on ''Rapetosaurus'' bones indicate that it at least fed on these sauropods, whether or not it actually killed them.<ref name=rogersetal2003>{{cite journal |last=Rogers |first=Raymond R. |author2=Krause, David W.|author3-link=Kristina Curry Rogers |author3=Curry Rogers, Kristina |year=2007 |title=Cannibalism in the Madagascan dinosaur ''Majungatholus atopus'' |journal=Nature |volume=422 |issue=6931 |pages=515–518 |doi=10.1038/nature01532 |pmid=12673249|bibcode=2003Natur.422..515R |s2cid=4389583 }}</ref>

Typically, titanosaurs were unusual among sauropods in that they coexisted with large [[ornithischia]]n dinosaurs such as [[ceratopsid]]s, [[hadrosaur]]s, and [[ankylosaur]]s. However, ''Rapetosaurus'' was atypical among titanosaurs in that it shared the Mahajanga basin with only one other large herbivore, another titanosaur. Smaller herbivores were rare, with only one, ''[[Simosuchus]]'', being discovered during over 100 years of collection in that area. Due to the absence of ornithischian dinosaurs, it is suggested that prehistoric Madagascar saw a different herbivore community dynamic than was seen elsewhere in the Cretaceous.<ref name=CurryRogers2001/>
{{clearboth}}

==References==
{{Reflist|refs=
<ref name=CurryRogers2001>{{cite journal | first1 = K. | last1 = Curry Rogers | first2 = C.A. | last2 = Forster | title = The last of the dinosaur titans: a new sauropod from Madagascar | journal = Nature | volume = 412 | issue = 6846 | pages = 530–534 | year = 2001 | doi = 10.1038/35087566 | pmid = 11484051 | bibcode = 2001Natur.412..530C | s2cid = 4347583 }}</ref>
<ref name=Montague2006>{{cite journal| last = Montague | first= J.R. | title = Estimates of body size and geological time of origin for 612 dinosaur genera (Saurischia, Ornithischia) | journal = Florida Scientist | volume = 69 | issue = 4| pages = 243–257| year = 2006 | jstor = 24321451 }}</ref>
}}

==Sources==
*Kristina Curry Rogers, and Catherine A. Forster. 2004. "The skull of ''Rapetosaurus krausei'' (Sauropoda: Titanosauria) from the Late Cretaceous of Madagascar". ''[[Journal of Vertebrate Paleontology]]'', 24(1), pages 121–144. ''Abstract at [http://www.bioone.org/bioone/?request=get-abstract&issn=0272-4634&volume=024&issue=01&page=0121 BioOne]

==External links==
*''[https://web.archive.org/web/20041212044018/http://www.smm.org/research/Paleontology/Rapeto.php Paleontology News &mdash; Rapetosaurus]'' from the Science Museum of Minnesota.
*''[https://web.archive.org/web/20051109121531/http://naples.cc.sunysb.edu/UAff/press.nsf/0/27c07f8d01443df985256a9b00651b11?OpenDocument Stony Brook Paleontologists Discover New Dinosaur and Name It in Honor of One of Their Own]'' from [[Stony Brook University]].
*''[https://web.archive.org/web/20070927212709/http://www.timeforkids.com/TFK/news/story/0,6260,169874,00.html New Dinosaur Species Found]'' from Time for Kids Online.
*''[https://web.archive.org/web/20010927213522/http://news.nationalgeographic.com/news/2001/08/0801_madagascardino.html Skeleton of New Dinosaur "Titan" Found in Madagascar]'' from National Geographic.
*''[http://news.bbc.co.uk/hi/english/sci/tech/newsid_1469000/1469608.stm Dino skull fills knowledge gap]'' from the BBC.
*''[http://www.trexmuseum.org/newsalert.html New Madagascar Dinosaur Discoveries]'' from the ''T. Rex'' Museum.
*A [https://www.nsf.gov/od/lpa/news/press/01/pr0161.htm press release], from the National Science Foundation, including a reconstruction (illustration).

{{Sauropodomorpha|T.}}
{{Taxonbar|from=Q135300}}
{{Portal bar|Dinosaurs|Madagascar}}

[[Category:Lithostrotia]]
[[Category:Dinosaur genera]]
[[Category:Maastrichtian dinosaurs]]
[[Category:Maevarano Formation]]
[[Category:Taxa named by Kristina Curry Rogers]]
[[Category:Taxa named by Catherine Forster]]
[[Category:Fossil taxa described in 2001]]
[[Category:Dinosaurs of Madagascar]]