View source for Ajnabia

{{Short description|Extinct genus of reptiles}}
{{Automatic taxobox
| fossil_range = Late [[Maastrichtian]], {{fossil range|68|66}}
| taxon = Ajnabia
| authority = Longrich ''et al.'', [[2021 in paleontology|2021]]
| type_species = {{extinct}}'''''Ajnabia odysseus'''''
| type_species_authority = Longrich ''et al.'', 2021
| image = Ajnabia odysseus maxilla by Nick Longrich.jpg
| image_caption = Maxilla of ''Ajnabia odysseus'' from the late Maastrichtian of Morocco
}}

'''''Ajnabia''''' (meaning "stranger" or "foreigner") is a genus of [[lambeosaurine]] [[hadrosaur]] from the Late [[Cretaceous]] (Maastrichtian) of Morocco. It is the first definitive hadrosaur from [[Africa]], and is thought to be related to European dinosaurs like ''[[Arenysaurus]]''.<ref name="longrich2020">{{cite journal | title=The first duckbill dinosaur (Hadrosauridae: Lambeosaurinae) from Africa and the role of oceanic dispersal in dinosaur biogeography | last1=Longrich | first1=Nicholas R. | last2=Suberbiola | first2=Xabier Pereda | last3=Pyron | first3=R. Alexander | last4=Jalil | first4=Nour-Eddine | journal=Cretaceous Research | year=2021 | volume=120 | page=104678 | doi=10.1016/j.cretres.2020.104678| s2cid=228807024 | doi-access=free | bibcode=2021CrRes.12004678L }}</ref> The discovery of ''Ajnabia'' came as a surprise to the paleontologists who found it, because Africa was isolated by water from the rest of the world during the Cretaceous, such that hadrosaurs were assumed to have been unable to reach the continent.<ref>{{Cite news|url=https://www.telegraph.co.uk/news/2020/11/05/dinosaurs-swam-across-oceans-landmark-study-reveals/|title=Dinosaurs swam across oceans, landmark study reveals|first=Phoebe|last=Southworth|newspaper=The Telegraph |date=November 5, 2020|via=www.telegraph.co.uk}}</ref><ref>{{Cite web|url=https://www.msn.com/en-us/news/world/new-fossil-discovery-suggests-dinosaurs-traveled-across-oceans/ar-BB1aIUOa|title=New fossil discovery suggests dinosaurs traveled across oceans|website=www.msn.com}}</ref> ''Ajnabia'' is relatively small and similar in size to its contemporary relative ''[[Minqaria]]'', which is estimated to have reached {{convert|3.5|m|ft}} in total body length.<ref name=Minqaria>{{Cite journal|last1=Longrich |first1=N. R. |last2=Pereda-Suberbiola |first2=X. |last3=Bardet |first3=N. |last4=Jalil |first4=N.-E. |title=A new small duckbilled dinosaur (Hadrosauridae: Lambeosaurinae) from Morocco and dinosaur diversity in the late Maastrichtian of North Africa |year=2024 |journal=Scientific Reports |volume=14 |issue=1 |at=3665 |doi=10.1038/s41598-024-53447-9 |doi-access=free |pmid=38351204 |pmc=10864364 |bibcode=2024NatSR..14.3665L }}</ref> Assuming that the holotype represents an adult, ''Ajnabia'' would be one of the smallest if not the smallest known hadrosaurids.

==Discovery and naming==
[[File:Life reconstruction of Ajnabia odysseus.png|thumb|left|[[Life restoration]]]] 
''Ajnabia'' was recovered from the Late Maastrichtian strata of the phosphate mines at Sidi Chennane, in Khouribga Province, Morocco. Recovered elements include most of the left maxilla and part of the right, and a fragment of the right dentary. The name ''Ajnabia'' derives from the [[Arabic]] أجنبي (''ajnabi''), meaning "strange" or "foreign", referring to the animal as part of a dinosaur lineage that immigrated to Africa from elsewhere. The [[type species|type]] and only species is ''A. odysseus'', referring to the Greek hero and legendary sea voyager [[Odysseus]].<ref name=longrich2020/>
{{clade|style=font-size:85%; line-height:85%;
|label1=[[Arenysaurini]]
|1={{clade
 |1={{clade
  |1=''[[Arenysaurus]]''
  |2=''[[Pararhabdodon]]'' }}
 |2={{clade
  |1=''[[Koutalisaurus]]''
  |2={{clade
   |1={{clade
    |1=Basturs lambeosaurine
    |2=''[[Canardia]]'' }}
   |2={{clade
    |1=''[[Adynomosaurus]]''
    |2={{clade
     |1=Serrat del Rostiar lambeosaurine
     |2={{clade
      |1=''[[Blasisaurus]]''
      |2='''''Ajnabia''''' }} }} }} }} }} }} }}

==Palaeoecology==
[[File:Maastrichtian Dinosaur Fauna of Morocco by Nick Longrich.jpg|thumb|Late Maastrichtian dinosaurs of Morocco, including ''Ajnabia odysseus'', ''Chenanisaurus barbaricus'']]
The holotype specimen, MHNM KHG 222, was recovered from the phosphates of the [[Ouled Abdoun Basin]] of north-central [[Morocco]]. The phosphates are a nearshore marine environment, dominated by sharks, fish, [[Mosasauridae|mosasaurs]], and other marine reptiles. Dinosaurs are rare, however, including the large [[abelisaurid]] ''[[Chenanisaurus barbaricus]]'', two other potentially distinct abelisaurids of smaller size, and an unnamed [[titanosaurian]].<ref name=longrich2017>{{cite journal | last1 = Longrich | first1 = N.R. | last2 = Pereda-Suberbiola | first2 = X. | last3 = Jalil | first3 = N.-E. | last4 = Khaldoune | first4 = F. | last5 = Jourani | first5 = E. | title = An abelisaurid from the latest Cretaceous (late Maastrichtian) of Morocco, North Africa | journal = Cretaceous Research | volume = 76 | pages = 40–52 | date = 2017 | doi = 10.1016/j.cretres.2017.03.021 | doi-access = free | bibcode = 2017CrRes..76...40L }}</ref><ref name=longrich2023>{{cite journal | url=https://www.sciencedirect.com/science/article/pii/S0195667123002057 | title=New fossils of Abelisauridae (Dinosauria: Theropoda) from the upper Maastrichtian of Morocco, North Africa | last1=Longrich | first1=Nicholas R. | last2=Isasmendi | first2=Erik | last3=Perada-Suberbiola | first3=Xabier | last4=Jalil | first4=Nour-Eddine | journal=Cretaceous Research | year=2023 | volume=152 | pages=105677 | doi=10.1016/j.cretres.2023.105677| bibcode=2023CrRes.15205677L }}</ref><ref name=perada-suberbiola2004>{{cite journal | url=https://www.sciencedirect.com/science/article/pii/S0899536204000776 | title=The first record of a sauropod dinosaur from the Late Cretaceous phosphates of Morocco | journal=Journal of African Earth Sciences | last1=Perada-Suberbiola | first1=Xabier | last2=Bardet | first2=Nathalie | last3=Iarochène | first3=Mohamed | last4=Bouya | first4=Baâdi | last5=Amaghzaz | first5=Mbarek | year=2004 | volume=40 | issue=1–2 | pages=81–88 | doi=10.1016/j.jafrearsci.2004.07.002| bibcode=2004JAfES..40...81P }}</ref> Moroccan lambeosaurine fossils belonging to individuals of various sizes, including the holotype of ''[[Minqaria]]'', indicate that hadrosaurs were diverse and abundant within the ecosystem.<ref name=Minqaria/> These dinosaurs would have lived in the very latest Cretaceous (Late Maastrichtian) approximately 1 million years before the K-Pg boundary and the [[Chicxulub impact|Chicxulub asteroid impact]] that wiped out the dinosaurs.<ref name=longrich2020/>

===Palaeobiogeography===
[[File:Chase on the beach.jpg|thumb|left|Restoration of ''[[Chenanisaurus]]'' hunting ''Ajnabia'']]
Hadrosaurs, the taxonomic group ''Ajnabia'' is assigned to, had not been documented from Africa until its discovery; specifically, its close relatives within [[Lambeosaurinae]] are all known from Europe. Given this taxonomic position and reconstructions of Late Cretaceous continents and seas, [[oceanic dispersal]] between Europe and North Africa is considered the only viable explanation for the presence of ''Ajnabia'' in Africa. While oceanic dispersal had previously been considered for the distribution of European hadrosaurs, intermittent land connections as means of dispersal could not be ruled out. The much more prominent oceanic barrier between Europe and Africa, characterized by deep waters, makes ''Ajnabia'' far stronger evidence of this phenomenon, as the gap could be narrowed by varying conditions but not conceivably bridge entirely. The possibility ''Ajnabia'' was a carcassed or fossil that had floated from Europe was also considered highly unlikely due to the fossil's [[taphonomy]] and the inability to assign it to any known European species. Further evidence for the oceanic dispersal as the model for lambeosaur dispersal also exists from the lack of more complete interchange of fauna between locations, expected from land bridge dispersal.<ref name=longrich2020/> In turn, ''Ajnabia'' has been used as an important datapoint to support the possibility of oceanic dispersal between European islands.<ref name=nikolov2024>{{cite journal | url=https://www.sciencedirect.com/science/article/pii/S0195667123003476 | title=The ontogenetic status of a small hadrosauroid dinosaur from the uppermost Cretaceous of Bulgaria, and implications for the paleobiogeography and assembly of European island faunas | journal=Cretaceous Research | last1=Nikolov | first1=Vladimir | last2=Dochev | first2=Docho | last3=Brusatte | first3=Stephen L. | year=2024 | volume=157 | doi=10.1016/j.cretres.2023.105819| bibcode=2024CrRes.15705819N }}</ref> Possible means of dispersal include swimming, drifting, or rafting (wherein animals are transported on top of floating debris or vegetation). Rafting is considered unlikely for a large animal, but it's considered possible young hadrosaurs could be transported in this way.<ref name=longrich2020 />
[[File:LateCretaceousMap.jpg|thumb|Map of the continents in the Late Cretaceous, the southern "Gondwanan" continents were diverging and Northern Africa was an island]]
More broadly speaking, the Maastrichtian fauna of the Northe African ecosystem ''Ajnabia'' inhabited seems biogeographically linked more to [[Gondwana]]n faunas - that is, those of the southern continents - then that of Europe and the other [[Laurasia]]n continents of the [[Northern Hemisphere]]. Whilst Laurasia is characterized by [[tyrannosaurid]]s, [[ornithischia]]ns and herbivorous [[coelurosaur]]s, Gondwana is dominated by titanosaurs and abelisaurs, as seen in Morocco. Despite this, a degree of [[endemism]] is noted, similar to that of other Gondwanan continents. A small abelisaur from the Sidi Daoui region is unlike those from [[South America]] or [[India]], but may be related to North African forms from earlier in the Cretaceous or similarly sized abelisaurs in Europe;<ref name=longrich2023/> likewise, ''Chenanisaurus'' may represent a distinct lineage from other known abelisaurs.<ref name=longrich2017/><ref name=longrich2023/> Inversely, other Gondwanan animals from South America such as [[ankylosaur]]s, [[unenlagiine|unenlagiinae]]s, [[elasmaria]]ns, and [[megaraptorid]]s aren't documented in Africa. This endemism is explained by the fragmentation of the former Gondwanan supercontinent into increasingly distant landmasses, leading to the ancestrally linked faunas of different southern continents becoming distinct. Even within the African continent, the presence of a Trans-Saharan seaway connecting the [[Tethys Ocean]] of Europe to the [[Gulf of Guinea]] may have isolated the fauna of Northern Africa from more southern portions of the continent, such as fossil bearing sites in [[Kenya]], and Morocco itself may have been an isolated island.<ref name=longrich2023/>

==References==
{{Reflist|2}}

==External links==
* [https://www.nicklongrich.com/blog/ajnabia-odysseus-the-first-duckbill-dinosaur-from-africa Ajnabia odysseus- the first duckbill dinosaur from Africa- by Nick Longrich]
* [https://www.oxfordmail.co.uk/news/national/18848966.duckbilled-dinosaurs-crossed-oceans-reach-africa-fossil-reveals/ Duckbilled dinosaurs crossed oceans to reach Africa, fossil reveals]

{{Ornithopoda|H.}}
{{Portalbar|Dinosaurs|Morocco}}
{{Taxonbar|from=Q101096375}}

[[Category:Cretaceous Morocco]]
[[Category:Fossil taxa described in 2020]]
[[Category:Late Cretaceous dinosaurs of Africa]]
[[Category:Lambeosaurines]]
[[Category:Maastrichtian genus first appearances]]
[[Category:Maastrichtian genus extinctions]]
[[Category:Ornithischian genera]]
[[Category:Taxa named by Nicholas R. Longrich]]